COLORECTAL CANCER SCREENING

[nicholson]

[Note: this was a discussion that Rodney started in response to a post on another thread. After talking about it with Rodney, we thought it worthwhile on this new "General Health and Longevity" forum to start a new thread on colon cancer screening. So I've moved the discussion to its own thread here. While our good diets make colon cancer less of an issue for CR practitioners than the general population, it is a serious enough health risk (3rd leading cause of cancer deaths) that it is worth serious consideration, and screening for. -Dean]

 

Despite having no known family history of colon problems of any kind in previous generations, my brother and I both seem to acquire a new polyp about every two years.  So, of course, we need to have occasional colonoscopies.   My last colonoscopy was two weeks ago, and prior to that the previous one had been in 2009.  

 

You can guess how many new polyps they found this time:  three of course:  One of moderate size, one smaller, and one tiny one  ......   likely to have appeared, respectively, in 2010, 2012 and 2014.   All of them were quickly and painlessly removed and sent to pathology.

 

Polyps of course, start off benign, but if left long enough, are likely to turn into cancer.

 

Now the relevence of this to Dean's post is that none of the nine polyps I have had removed over the years have shown even the very earliest suggestions of turning cancerous - even the one just removed, for example, that probably had been sitting there for five years since 2010.  (But what would the current status of the one found in 1998 be, had it not been found and removed?)

 

It seems likely the explanation of the benign nature of my polyps might be that I have gone a long way out of my way to avoid eating stuff that, while no doubt devastatingly tasty, might also be devastatingly carcinogenic (incinerated fat, for example, in particular). 

 

Anyway, SFSG.  I have noted to have another colonoscopy in 2019 and expect them to find another two then.  Six years is a bit too long to go between checks for someone who regularly seems to sprout new ones.  Anyone approaching the age of 60, who is aiming to live to be 100, and has never had one, probably ought to get a baseline colonoscopy and then follow the gastroenterologist's advice.  Having them reduces the chance of getting colon cancer - a rather common form of the disease - by not far short of 100%.  Not only that, the health systems have finally figured out that doing colonoscopies at appropriate intervals - which will vary from patient to patient - is less expensive than the cost of treating the cancer when it appears if colonoscopies are not done.

 

Incidentally,  all my polyps have been found in the ASCENDING colon or at the very start of the transverse colon.  They would never have been found by any other investigative technique until far too late.

 

It may also be worth mentioning that it is surprising to me how often, even when cancer is found in a polyp, if it is found early, the cancer can be surgically cured.  And I do mean *genuinely* cured - not the five-year supposed cure so often talked about in cancer treatments.   But changes in diet are of course necessary if cancerous polyps are not to recur.

 

Rodney.

 

"The unverified conventional wisdom is almost invariably mistaken."

[Dean Pomerleau]

Thanks for the warning about polyps Rodney. 

 

Sadly, my 75 year-old father-in-law, who is obese,diabetic and hypercholesterolemic, finally went to the doctor a few weeks ago after noticing blood in his stool starting several months ago, and more recently, experiencing acute symptoms of anemia (weakness, dizziness). They immediately did a colonoscopy, his first ever, and found a pretty big tumor in his colon. Not surprisingly, the biopsy showed it to be cancerous. He'll be going in for surgery in a few weeks, after they determine the status of a second polyp they detected via CT scan, but were unable to biopsy the first time around because they couldn't get the scope past the big, first tumor. He's always eaten a very crappy diet, and doesn't exercise.

 

Everyone should get regular colonoscopies, starting at 50 according to the American Cancer Society Guidelines. 

 

--Dean

[nicholson]

Yes.  But to be clear, "regular" means a different number of years for different people.  If no polyps are found, the next colonoscopy might be suggested for ten years later.  If just a single polyp is found perhaps five years later for the next one.  In my case it is suggested to be two to three years before the next procedure.  But I will probably make it four years and expect them to find two more polyps.  In three years they might find only one with another ready to pop up momentarily. 

 

Bear in mind also that they are reluctant to do colonoscopies after age 70.  So in my case they refused to make an appointment for the actual procedure before I had a consultation first.  I assume they wanted to check whether my apparent future life expectancy justified the cost of the procedure, and to ascertain whether there might be risks to doing the procedure associated with advancing age.

 

Rodney.

 

"The unverified conventional wisdom is almost invariably mistaken."

[Dean Pomerleau]

For anyone who is understandably reluctant to get a colonoscopy due to its unpleasantness (esp. the prep), it is important to know that unlike unpleasant mammograms for breast cancer screening, where the harm vs. benefits are controversial [3] despite pretty good evidence that mortality is reduced by regular mammographies, at least in the 50-69 age range [4], colon cancer screening via sigmoidoscopy or colonoscopy, does indeed appear to save lives and do more good than harm [1-3]. For example, [1] found deaths from colon cancer were reduced by around 50% in those who were routinely screened via sigmoidoscopy. From the meta-analysis [3]:

 

[M]eta-analysis revealed that, compared with no intervention,

colonoscopy reduced CRC-related mortality by 57% (relative risk [RR] 0.43; 95%

confidence interval [CI], 0.33-0.58), whereas FS [Flexible Sigmoidoscopy] reduced

CRC-related mortality by 40% (RR 0.60; 95% CI, 0.45-0.78), and gFOBT [Faecal

Occult Blood Testing] reduced CRC-related mortality by 18% (RR 0.82; 95% CI,

0.76-0.88).

 

So there is good evidence that despite how much of a pain it is to prep for, and undergo a colonoscopy, it is a screening procedure that, when done at appropriate, risk-adjusted intervals as Rodney points out, prevents death from our nations 3rd most deadly form of cancer.

 

--Dean

 

------------

[1] N Engl J Med. 2012 Jun 21;366(25):2345-57. doi: 10.1056/NEJMoa1114635. Epub 2012

May 21.

Colorectal-cancer incidence and mortality with screening flexible sigmoidoscopy.

Schoen RE(1), Pinsky PF, Weissfeld JL, Yokochi LA, Church T, Laiyemo AO,
Bresalier R, Andriole GL, Buys SS, Crawford ED, Fouad MN, Isaacs C, Johnson CC,
Reding DJ, O'Brien B, Carrick DM, Wright P, Riley TL, Purdue MP, Izmirlian G,
Kramer BS, Miller AB, Gohagan JK, Prorok PC, Berg CD; PLCO Project Team.

BACKGROUND: The benefits of endoscopic testing for colorectal-cancer screening
are uncertain. We evaluated the effect of screening with flexible sigmoidoscopy
on colorectal-cancer incidence and mortality.
METHODS: From 1993 through 2001, we randomly assigned 154,900 men and women 55 to
74 years of age either to screening with flexible sigmoidoscopy, with a repeat
screening at 3 or 5 years, or to usual care. Cases of colorectal cancer and
deaths from the disease were ascertained.
RESULTS: Of the 77,445 participants randomly assigned to screening (intervention
group), 83.5% underwent baseline flexible sigmoidoscopy and 54.0% were screened
at 3 or 5 years. The incidence of colorectal cancer after a median follow-up of
11.9 years was 11.9 cases per 10,000 person-years in the intervention group (1012
cases), as compared with 15.2 cases per 10,000 person-years in the usual-care
group (1287 cases), which represents a 21% reduction (relative risk, 0.79; 95%
confidence interval [CI], 0.72 to 0.85; P<0.001). Significant reductions were
observed in the incidence of both distal colorectal cancer (479 cases in the
intervention group vs. 669 cases in the usual-care group; relative risk, 0.71;
95% CI, 0.64 to 0.80; P<0.001) and proximal colorectal cancer (512 cases vs. 595
cases; relative risk, 0.86; 95% CI, 0.76 to 0.97; P=0.01). There were 2.9 deaths
from colorectal cancer per 10,000 person-years in the intervention group (252
deaths), as compared with 3.9 per 10,000 person-years in the usual-care group
(341 deaths), which represents a 26% reduction (relative risk, 0.74; 95% CI, 0.63
to 0.87; P<0.001). Mortality from distal colorectal cancer was reduced by 50% (87
deaths in the intervention group vs. 175 in the usual-care group; relative risk,
0.50; 95% CI, 0.38 to 0.64; P<0.001); mortality from proximal colorectal cancer
was unaffected (143 and 147 deaths, respectively; relative risk, 0.97; 95% CI,
0.77 to 1.22; P=0.81).
CONCLUSIONS: Screening with flexible sigmoidoscopy was associated with a
significant decrease in colorectal-cancer incidence (in both the distal and
proximal colon) and mortality (distal colon only). (Funded by the National Cancer
Institute; PLCO ClinicalTrials.gov number, NCT00002540.).

PMCID: PMC3641846
PMID: 22612596

 

-------------

[2] Intest Res. 2014 Oct;12(4):268-74. doi: 10.5217/ir.2014.12.4.268. Epub 2014 Oct

27.

Impact of sigmoidoscopy and colonoscopy on colorectal cancer incidence and
mortality: an evidence-based review of published prospective and retrospective
studies.

Lin OS(1), Kozarek RA(1), Cha JM(2).

Author information:
(1)Digestive Disease Institute, Virginia Mason Medical Center; Gastroenterology
Division, University of Washington School of Medicine, Seattle, WA, USA.
(2)Gastroenterology Division, Kyung Hee University Hospital at Gang Dong, Kyung
Hee University School of Medicine, Seoul, Korea.

Screening for colorectal cancer (CRC) using sigmoidoscopy or colonoscopy is now
common in many developed countries. This concise, evidence-based review looks at
the impact of sigmoidoscopy or colonoscopy screening on CRC incidence, CRC
mortality and overall mortality. Data from controlled retrospective and
prospective (observational or randomized) studies have generally shown that
sigmoidoscopy and colonoscopy, whether for diagnostic, screening or surveillance
purposes, are associated with a significant reduction in CRC incidence and CRC
mortality. The data on their impact on overall mortality is much more limited,
with most studies unable to report a reduction in overall mortality. The results
of three meta-analyses have confirmed these conclusions. As expected,
sigmoidoscopy has a predominant effect on left-sided CRC, although some studies
have shown modest effects on right-sided colon cancer as well. Most studies on
colonoscopy have demonstrated that the protective effect applies to both right
and left-sided cancer, although the protection seemed better on the left side.
Despite the introduction of other screening and diagnostic modalities for the
colon, such as computed tomography colonography and colonic capsule endoscopy,
lower endoscopy will continue to be an important mode of screening for CRC and
evaluating the colon.

PMCID: PMC4214952
PMID: 25374491

 

------------

[3] Gastrointest Endosc. 2015 Mar;81(3):700-709.e3. doi: 10.1016/j.gie.2014.10.033.

Comparing the effectiveness of competing tests for reducing colorectal cancer
mortality: a network meta-analysis.

Elmunzer BJ(1), Singal AG(2), Sussman JB(3), Deshpande AR(4), Sussman DA(4),
Conte ML(5), Dwamena BA(6), Rogers MA(7), Schoenfeld PS(8), Inadomi JM(9), Saini
SD(8), Waljee AK(8).

Comment in
Gastrointest Endosc. 2015 Mar;81(3):710-2.

BACKGROUND: Comparative effectiveness data pertaining to competing colorectal
cancer (CRC) screening tests do not exist but are necessary to guide clinical
decision making and policy.
OBJECTIVE: To perform a comparative synthesis of clinical outcomes studies
evaluating the effects of competing tests on CRC-related mortality.
DESIGN: Traditional and network meta-analyses. Two reviewers identified studies
evaluating the effect of guaiac-based fecal occult blood testing (gFOBT),
flexible sigmoidoscopy (FS), or colonoscopy on CRC-related mortality.
INTERVENTIONS: gFOBT, FS, colonoscopy.
MAIN OUTCOME MEASUREMENTS: Traditional meta-analysis was performed to produce
pooled estimates of the effect of each modality on CRC mortality. Bayesian
network meta-analysis (NMA) was performed to indirectly compare the effectiveness
of screening modalities. Multiple sensitivity analyses were performed.
RESULTS: Traditional meta-analysis revealed that, compared with no intervention,
colonoscopy reduced CRC-related mortality by 57% (relative risk [RR] 0.43; 95%
confidence interval [CI], 0.33-0.58), whereas FS reduced CRC-related mortality by
40% (RR 0.60; 95% CI, 0.45-0.78), and gFOBT reduced CRC-related mortality by 18%
(RR 0.82; 95% CI, 0.76-0.88). NMA demonstrated nonsignificant trends favoring
colonoscopy over FS (RR 0.71; 95% CI, 0.45-1.11) and FS over gFOBT (RR 0.74; 95%
CI, 0.51-1.09) for reducing CRC-related deaths. NMA-based simulations, however,
revealed that colonoscopy has a 94% probability of being the most effective test
for reducing CRC mortality and a 99% probability of being most effective when the
analysis is restricted to screening studies.
LIMITATIONS: Randomized trials and observational studies were combined within the
same analysis.
CONCLUSION: Clinical outcomes studies demonstrate that gFOBT, FS, and colonoscopy
are all effective in reducing CRC-related mortality. Network meta-analysis
suggests that colonoscopy is the most effective test.

Copyright © 2015 American Society for Gastrointestinal Endoscopy. Published by
Elsevier Inc. All rights reserved.

PMID: 25708757

 

----------

[4] JAMA. 2015 Oct 20;314(15):1615-34. doi: 10.1001/jama.2015.13183.

Benefits and Harms of Breast Cancer Screening: A Systematic Review.

Myers ER(1), Moorman P(2), Gierisch JM(3), Havrilesky LJ(1), Grimm LJ(4), Ghate
S(4), Davidson B(5), Mongtomery RC(6), Crowley MJ(3), McCrory DC(3), Kendrick
A(7), Sanders GD(6).


IMPORTANCE: Patients need to consider both benefits and harms of breast cancer
screening.
OBJECTIVE: To systematically synthesize available evidence on the association of
mammographic screening and clinical breast examination (CBE) at different ages
and intervals with breast cancer mortality, overdiagnosis, false-positive biopsy
findings, life expectancy, and quality-adjusted life expectancy.
EVIDENCE REVIEW: We searched PubMed (to March 6, 2014), CINAHL (to September 10,
2013), and PsycINFO (to September 10, 2013) for systematic reviews, randomized
clinical trials (RCTs) (with no limit to publication date), and observational and
modeling studies published after January 1, 2000, as well as systematic reviews
of all study designs. Included studies (7 reviews, 10 RCTs, 72 observational, 1
modeling) provided evidence on the association between screening with
mammography, CBE, or both and prespecified critical outcomes among women at
average risk of breast cancer (no known genetic susceptibility, family history,
previous breast neoplasia, or chest irradiation). We used summary estimates from
existing reviews, supplemented by qualitative synthesis of studies not included
in those reviews.
FINDINGS: Across all ages of women at average risk, pooled estimates of
association between mammography screening and mortality reduction after 13 years
of follow-up were similar for 3 meta-analyses of clinical trials (UK Independent
Panel: relative risk [RR], 0.80 [95% CI, 0.73-0.89]; Canadian Task Force: RR,
0.82 [95% CI, 0.74-0.94]; Cochrane: RR, 0.81 [95% CI, 0.74-0.87]); were greater
in a meta-analysis of cohort studies (RR, 0.75 [95% CI, 0.69 to 0.81]); and were
comparable in a modeling study (CISNET; median RR equivalent among 7 models, 0.85
[range, 0.77-0.93]). Uncertainty remains about the magnitude of associated
mortality reduction in the entire US population, among women 40 to 49 years, and
with annual screening compared with biennial screening. There is uncertainty
about the magnitude of overdiagnosis associated with different screening
strategies, attributable in part to lack of consensus on methods of estimation
and the importance of ductal carcinoma in situ in overdiagnosis. For women with a
first mammography screening at age 40 years, estimated 10-year cumulative risk of
a false-positive biopsy result was higher (7.0% [95% CI, 6.1%-7.8%]) for annual
compared with biennial (4.8% [95% CI, 4.4%-5.2%]) screening. Although 10-year
probabilities of false-positive biopsy results were similar for women beginning
screening at age 50 years, indirect estimates of lifetime probability of
false-positive results were lower. Evidence for the relationship between
screening and life expectancy and quality-adjusted life expectancy was low in
quality. There was no direct evidence for any additional mortality benefit
associated with the addition of CBE to mammography, but observational evidence
from the United States and Canada suggested an increase in false-positive
findings compared with mammography alone, with both studies finding an estimated
55 additional false-positive findings per extra breast cancer detected with the
addition of CBE.
CONCLUSIONS AND RELEVANCE: For women of all ages at average risk, screening was
associated with a reduction in breast cancer mortality of approximately 20%,
although there was uncertainty about quantitative estimates of outcomes for
different breast cancer screening strategies in the United States. These findings
and the related uncertainty should be considered when making recommendations
based on judgments about the balance of benefits and harms of breast cancer
screening.

PMID: 26501537

 

----------

[5] PLoS One. 2014 Jun 2;9(6):e98105. doi: 10.1371/journal.pone.0098105. eCollection

2014.

Screening mammography & breast cancer mortality: meta-analysis of
quasi-experimental studies.

Irvin VL(1), Kaplan RM(1).

Author information:
(1)Department of Rehabilitation Medicine, Clinical Research Center, National
Institutes of Health, Bethesda, Maryland, United States of America.

BACKGROUND: The magnitude of the benefit associated with screening has been
debated. We present a meta-analysis of quasi-experimental studies on the effects
of mammography screening.
METHODS: We searched MEDLINE/PubMed and Embase for articles published through
January 31, 2013. Studies were included if they reported: 1) a population-wide
breast cancer screening program using mammography with 5+ years of data
post-implementation; 2) a comparison group with equal access to therapies; and 3)
breast cancer mortality. Studies excluded were: RCTs, case-control, or simulation
studies. We defined quasi-experimental as studies that compared either
geographical, historical or birth cohorts with a screening program to an
equivalent cohort without a screening program. Meta-analyses were conducted in
Stata using the metan command, random effects. Meta-analyses were conducted
separately for ages screened: under 50, 50 to 69 and over 70 and weighted by
population and person-years.
RESULTS: Among 4,903 published papers that were retrieved, 19 studies matched
eligibility criteria. Birth cohort studies reported a significant benefit for
women screened <age 50, but not for women screened ages 50-69. Significant
reductions in breast cancer mortality were observed in historical comparisons.
For geographical comparisons, there was a significant 20% reduction in mortality
for women <age 50 and a significant 21-22% reduction for women ages 50-69.
Studies that tested the interaction of geographical and historical comparisons
produced a pooled, significant 13-17% reduction in incident breast cancer
mortality for women ages 50-69, but the effects in most individual studies were
non-significant. All studies of women ages 70+ were non-significant.
CONCLUSIONS: Mammography screening may have modest effects on cancer mortality
between the ages of 50 and 69 and non-significant effects for women older than
age 70. Results are consistent with meta-analyses of RCTs. Effects on total
mortality could not be assessed because of the limited number of studies.

PMCID: PMC4041743
PMID: 24887150

[nicholson]

There is also this conclusion:

 

"This model suggests a 92 percent reduction in mortality from colonoscopy and adenoma removal in this group of high-risk patients."   ........

 

..........  "The model, created by the NCI-sponsored Cancer Intervention and Surveillance Modeling Network (CISNET), uses validated data on the natural progression of adenomas to cancer in order to calculate the risk of death from colorectal cancer in a hypothetical population.  Based on MISCAN-Colon, the researchers estimated that 145 patients whose adenomas had not been removed would have died, whereas only 12 patients whose adenomas were removed died of colorectal cancer in the study. This model suggests a 92 percent reduction in mortality from colonoscopy and adenoma removal in this group of high-risk patients."

 

From:  http://www.cancer.gov/types/colorectal/research/colonoscopy-reduces-deaths

 

I am fairly sure the explanation of the difference between Dean's 57% and my 92% is that Dean's number refers to the reduction in risk if you screen the entire population, the majority of whom never have polyps and will never get colon cancer.  My 92%, refers to the reduction in risk specifically among individuals *who do have adenomatous polyps*. 

 

In other words, for a person who has adenomatous polyps: if you remove them, the risk of death from colon cancer is 92% less than if you do not remove them.  Of course, by the nature of the question, no study will ever be done to test this definitively because no study would ever be authorized to have an unscreened control group of subjects known to have cancer-susceptible polyps.

 

Rodney.

 

"The unverified conventional wisdom is almost invariably mistaken."

[nicholson]

"For anyone who is understandably reluctant ........  "

 

Well yes.  There are other activities I might prefer to be involved in (!) but with the right attitude you might almost call it fun.

 

The prepping is a lot easier than it was when I had my first colonoscopy.  Back then they insisted you swallow an impossibly huge volume of water in a ridiculously short time.  Now, with different prep agents, it is usually taken in two quite manageable doses - one the night before, the second the morning of, the procedure. 

 

Then one can choose to be completely sedated, only minimally sedated, or not sedated at all.  In the complete sedation you are pretty much out cold.  With minimal sedation you don't even know you are sedated.  You can watch the TV images from the camera inside your empty and spotlessly clean colon.  You can see the polyps - that is how I have a very good understanding of the sizes and shapes of the ones removed - and watch them being removed either by a sort of grappling hand, or lassooed and pulled tight until they separate.  And you can discuss what is happening with the doctor doing it.  It is not as much fun as watching Discovery Channel, but certainly far more interesting than the TV programs most people watch.  With minimal sedation there is not much discomfort.  With no sedation at all, which I chose this time, there were a couple of brief moments of discomfort as the gastroenterologist manipulated the equipment around a couple of the bends, and no discomfort at all around others.  But from the gastro's point of view it is better to be not sedated.  That way he can get feedback from the patient, as well as the TV camera, about what is going on inside.

 

All in all, it is probably a tad better than having advanced colon cancer.  So I have no hesitation at all recommending people get checked.

 

If she had had colonoscopies that wonderful young lady Audrey Hepburn would almost certainly still be with us.

 

I asked the doc how many hours he had to spend training with the instrument before being set loose on patients.  His answer was 200 hours.

 

Rodney.

 

"The unverified conventional wisdom is almost invariably mistaken."

[Zeta]

Dean and Rodney, thanks for bringing up this important topic. I put off my need colonoscopy for a long time -- a particularly bone-headed action given that I was diagnosed with Crohn's disease over twenty years ago -- and finally had one a few years ago. The prep was the hardest part. Funniest part? The exclamation of the doctor doing the unusually long procedure: "Jesus, what a $#&! LONG and convoluted colon you have!!" Apparently, people who eat a lot of veggies develop longer colons (she claimed). Might explain my distended gut. Anyway, the results were fine, and, amazingly, she said there were no signs of Crohn's, nor even signs I ever had Crohn's (which is weird: there should have been obvious scarring). ("Healthiest colon I've seen in a long time.") At least one part of me isn't brekaing down. (Knock on wood.)

 

Zeta

[Michael R]

 
As the ACS guidelines linked by Dean indicate, the American Cancer Society favors colon cancer screening using tests that find both cancer and polyps, such as colonoscopy — or flexible sigmoidoscopy, which is strictly the more evidence-grounded technique, and its weaknesses can be substantially eliminated by combination with a fecal test.
 
However, people should also consider the new fecal immunochemical test (FIT), which is an advanced variation on the older guaiac-based fecal occult blood test (gFOBT) that uses an antibody specific to human heme. This feature gives it more sensitivity (because it can pick up extremely small amounts of blood) and more specificity (because it only picks up human heme protein, and so won't pick up the remaining fleck of blood from your last steak — and for this reason also eliminates the gFOBT's (though not Dean's) dietary restrictions). A comparative meta-analysis of FIT vs. gFOBT demonstrated this a couple of years ago.
 
ACS favor sigmoidoscopy or colonoscopy because they detect polyps, while FIT can only detect an actual cancer. None the less, gFOBT is strongly demonstrated to reduce progression of cancer to clinical state and mortality, and FIT shows better performance characteristics. Aside from convenience, the advantages of FIT are that it doesn't require one to undergo a medical procedure with its inherent risks and those of the facility (iatrogenic infections, etc), and doesn't require sedation and painkillers (usually benzodiazepines and opioids, both of which are somewhat risky, in addition to requiring someone to take you home and nurse you for a while) or anaesthesia (even riskier and generally not advised: also requires a "nurse," and often accompanied by medium-term cognitive deficits and possibly long-term cognitive decline, although this may largely be restricted to specific anaesthetics). As well, there is controversy about which dietary restrictions should be required for colonoscopy:fasting is still generally required, with some advocating a high-fiber diet (no problem for us!) and some a low-fiber or even liquid one in the days before — see discussion of some of the debates on colonoscopy prep here. Again, no dietary restrictions are required for FIT.
 
See this good full-text paper on colorectal cancer screening using the Fecal Immunochemical Test (FIT).

[Dean Pomerleau]

Thanks Michael.

 

Your info on colon cancer screening is very helpful, given my family circumstances... Have you looked at the Cologuard stool DNA screening method for detecting colorectal cancer? Based on [1], it appears to have advantages over the FIT test you suggest. 

 

More generally, either of these tests would be a far more convenient than a colonoscopy / sigmoidoscopy for colon cancer screening. But one obviously worries that the 'horse has already left the barn' by the time polyps have gone from benign, to pre-cancerous to cancerous so that they can be reliably detected via FIT or Cologuard testing. 

 

Is it your or the medical community's understanding based on the cancer progress and/or mortality statistics that catching colon cancer via a FIT or Cologuard test within a year or two of its initiation would be as good with respect to long-term outcome as would nipping polyps 'in the bud' before they turn (pre-)cancerous via a colonoscopy / sigmoidoscopy?

 

Or perhaps more accurately, are the extra benefits of a colonoscopy in this regard not worth the risks (e.g. anethesia, puncturing the colon wall, hospital infections etc.) or the hassle (e.g. colonoscopy prep) compared to the FIT / Cologuard type testing?

 

Thanks,

 

--Dean

 

 

 

 

---------

[1] N Engl J Med. 2014 Apr 3;370(14):1287-97. doi: 10.1056/NEJMoa1311194. Epub 2014

Mar 19.

Multitarget stool DNA testing for colorectal-cancer screening.

Imperiale TF(1), Ransohoff DF, Itzkowitz SH, Levin TR, Lavin P, Lidgard GP,
Ahlquist DA, Berger BM.

Author information:
(1)From the Department of Medicine, Indiana University School of Medicine, the
Regenstrief Institute, the Simon Cancer Center, and the Center for Innovation at
Roudebush Veterans Affairs Medical Center - all in Indianapolis (T.F.I.); the
Departments of Medicine and Epidemiology and the Lineberger Comprehensive Cancer
Center, University of North Carolina at Chapel Hill, Chapel Hill (D.F.R.); the
Dr. Henry D. Janowitz Division of Gastroenterology, Department of Medicine, Icahn
School of Medicine at Mount Sinai, New York (S.H.I.); Kaiser Permanente Medical
Center, Walnut Creek, CA (T.R.L.); Boston Biostatistics Research Foundation,
Framingham MA (P.L.); Exact Sciences, Madison, WI (G.P.L., B.M.B.); and the
Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN (D.A.A.).

Comment in
N Engl J Med. 2014 Apr 3;370(14):1350-1.
N Engl J Med. 2014 Jul 10;371(2):187.
N Engl J Med. 2014 Jul 10;371(2):184-5.
N Engl J Med. 2014 Jul 10;371(2):185-6.
N Engl J Med. 2014 Jul 10;371(2):187-8.
N Engl J Med. 2014 Jul 10;371(2):186.
Ann Intern Med. 2014 Jul 15;161(2):JC10.
Turk J Gastroenterol. 2014 Feb;25(1):122-3.
Nat Rev Clin Oncol. 2014 May;11(5):239.
Nat Rev Gastroenterol Hepatol. 2014 May;11(5):269.

BACKGROUND: An accurate, noninvasive test could improve the effectiveness of
colorectal-cancer screening.
METHODS: We compared a noninvasive, multitarget stool DNA test with a fecal
immunochemical test (FIT) in persons at average risk for colorectal cancer. The
DNA test includes quantitative molecular assays for KRAS mutations, aberrant
NDRG4 and BMP3 methylation, and β-actin, plus a hemoglobin immunoassay. Results
were generated with the use of a logistic-regression algorithm, with values of
183 or more considered to be positive. FIT values of more than 100 ng of
hemoglobin per milliliter of buffer were considered to be positive. Tests were
processed independently of colonoscopic findings.
RESULTS: Of the 9989 participants who could be evaluated, 65 (0.7%) had
colorectal cancer and 757 (7.6%) had advanced precancerous lesions (advanced
adenomas or sessile serrated polyps measuring ≥1 cm in the greatest dimension) on
colonoscopy. The sensitivity for detecting colorectal cancer was 92.3% with DNA
testing and 73.8% with FIT (P=0.002). The sensitivity for detecting advanced
precancerous lesions was 42.4% with DNA testing and 23.8% with FIT (P<0.001). The
rate of detection of polyps with high-grade dysplasia was 69.2% with DNA testing
and 46.2% with FIT (P=0.004); the rates of detection of serrated sessile polyps
measuring 1 cm or more were 42.4% and 5.1%, respectively (P<0.001). Specificities
with DNA testing and FIT were 86.6% and 94.9%, respectively, among participants
with nonadvanced or negative findings (P<0.001) and 89.8% and 96.4%,
respectively, among those with negative results on colonoscopy (P<0.001). The
numbers of persons who would need to be screened to detect one cancer were 154
with colonoscopy, 166 with DNA testing, and 208 with FIT.
CONCLUSIONS: In asymptomatic persons at average risk for colorectal cancer,
multitarget stool DNA testing detected significantly more cancers than did FIT
but had more false positive results. (Funded by Exact Sciences;
ClinicalTrials.gov number, NCT01397747.).

PMID: 24645800

[nicholson]

Having read this thread, had several colonoscopies, had polyps removed which eventually would have turned into cancer and eventually gotten bad enough to start shedding blood into the stool, I have no hesitation at all about going for another colonoscopy when due.

 

Certainly there are some risks associated with colonoscopy.  The risk associated with not having them is cancer.  Even sigmoidoscopy will not detect polyps in the ascending or transverse colon.  And colorectal cancer is, of course, the third leading cause of death from cancer among men, after lung and prostate cancers.

 

But we are all free agents here, and can make our own decisions about what we consider best for ourselves.  And I fully respect a decision to choose a course other than periodic colonoscopy.  But it would not be my decision.

 

Rodney.

[Michael R]

First, I should say that I've just realized from reviewing it that the other thread, while subject-lined "COLON CANCER PREVENTION", is so overwhelmingly about screening that I maybe ought to merge the two, probably using the "Colorectal Cancer Screening" subject line of THIS thread, "Colorectal Cancer Screening"... any opinions?
 

Thanks Michael.

Your info on colon cancer screening is very helpful, given my family circumstances...

When you say "my family circumstances," do you "merely" mean alarm over your father-in-law's sad case? To be clear, the actual guidelines would differ in the case of a true family history (parent or sibling with CRC, particularly before age 45 or with more than one first-degree relative affected). In the http://www.abc.net.au/radionational/programs/healthreport/prostate-mri---a-game-changer3f/5967568, and still in the draft 2015 USPSTF Recommendation Statement on Colorectal Cancer Screening, they don't make a specific evaluation for people at high risk, instead directing readers to the "other professional organizations recommend%5Bing%5D that patients with a family history of colorectal cancer (a first-degree relative with early onset of colorectal cancer or multiple first-degree relatives with the disease) be screened at a younger age, more frequently, and with colonoscopy" as opposed to other tests. Those consensus guidelines (PMID 18322143) actually don't recommend colonoscopy for all such cases, but also refer back to still earlier recommendations, which say:
 

In this update of the CRC screening guidelines, we have focused on screening in average-risk adults and have not reviewed recent literature on CRC screening or surveillance for individuals at increased and high risk. Individuals at increased risk due to a history of adenomatous polyps; a personal history of curative-intent resection of CRC; a family history of either CRC or colorectal adenomas diagnosed in a first-degree relative before age 60 years; or high risk due to a history of inflammatory bowel disease of significant duration or the presence of one of 2 hereditary syndromes should continue to follow recommendations issued previously by the ACS or USMSTF.¹⁸,²⁴ These recommendations are summarized in Table 3.

Table 3 is almost unreadable in the web version, but can be viewed in the pdf. It recommends beginning screening at age 40 "or 10 years before the youngest case in the immediate family," and actually only specifies colonoscopy for a subset of family histories; others should still start early, but with "Screening options at intervals recommended for average-risk individuals."
 

Have you looked at the Cologuard stool DNA screening method for detecting colorectal cancer? Based on [1], it appears to have advantages over the FIT test you suggest.

Advantages AND disadvantages, per this study: "In asymptomatic persons at average risk for colorectal cancer, multitarget stool DNA testing detected significantly more cancers than did FIT but had more false positive results."

The main thing, to my mind, is that while this certainly looks to be a rigorous trial (from my very cursory review, which doesn't go far beyond the abstract and doesn't include the multiple letters to the editor, which are likely mostly criticisms) , it seems to be the only large-scale one, and it was sponsored by the producer; this really isn't enough evidence to make a good judgement. One wants to see multiple trials, preferably in different populations (diversity of risk, background genetics, lifestyles etc), plus ideally some epidemiological studies for more real-world performace; lacking all of this, I'm inclined to be conservative on FIT vs. DNA testing, and similarly USPSTF doesn't even include DNA testing in its 2015 analysis.
 

More generally, either of these tests would be a far more convenient than a colonoscopy / sigmoidoscopy for colon cancer screening. But one obviously worries that the 'horse has already left the barn' by the time polyps have gone from benign, to pre-cancerous to cancerous so that they can be reliably detected via FIT or Cologuard testing.

Is it your or the medical community's understanding based on the cancer progress and/or mortality statistics that catching colon cancer via a FIT or Cologuard test within a year or two of its initiation would be as good with respect to long-term outcome as would nipping polyps 'in the bud' before they turn (pre-)cancerous via a colonoscopy / sigmoidoscopy?

First, the options are not only stool screening vs. colonoscopy: as I suggested, a good difference-splitting in risk is FIT combined with sigmoidoscopy, a less-risky procedure. You're right, however, that it is possible to have at least some cases where a premalignant polyp in the upper colon would escape both a stool screen (while still a polyp) and the reach of the scope, where a colonoscopy might have caught it. (OTOH, you do get some chance to catch some fast-developing CRCs in the interim between colonoscopies with stool tests). Again, this has to be balanced against the other risks (which include performations of the colon, to which I didn't refer in my original post). To put it all in perspective, here are the absolute (rather than relative) risks and benefits of different kinds of colorectal cancer screening methods from the sum of evidence from the USPSTF 2015 Draft evidence summary (the stupid Forum software won't let me post the image). It is evident that there are a nontrivial number of years of life "on the table" even with annual FIT + 10 y FS vs. 10 y colonoscopy; OTOH, the number of cancer cases per se actually prevented in average-risk people is almost a blip, and the risk of harms is significantly higher. This is why USPSTF takes a nuanced position, as do I (as I hope was clear: I'm not, eg, screaming and yelling about it, unlike my rants against generic screening (NOT to mean diagnostic use) with PSA. (Not to get too far off topic, but there's some hope on that front: while not yet ready for prime time, there is some very promising data on using MRI to guide biopsy decisions in men with elevated PSA, to greatly reduce harms while maintaining what could be full prevention of cancer deaths.
 

Or perhaps more accurately, are the extra benefits of a colonoscopy in this regard not worth the risks (e.g. anethesia, puncturing the colon wall, hospital infections etc.) or the hassle (e.g. colonoscopy prep) compared to the FIT / Cologuard type testing?

That's the question. I do lean toward FIT + FS for people without family history and esp. CR people, due to lower baseline lifestyle risk for colorectal cancer (most of us have the dietary stuff nailed, and MOST of us are also covered for exercise); CR folks' potentially higher risk of bad outcomes once infected and of bleeding and failing to heal a punctured colon; and fear of dementia.
 

Having read this thread, had several colonoscopies, had polyps removed which eventually would have turned into cancer and eventually gotten bad enough to start shedding blood into the stool, I have no hestation at all about going for another colonoscopy when due.

Certainly there are some risks associated with colonoscopy. The risk associated with not having them is cancer. Even sigmoidoscopy will not detect polyps in the ascending or transverse colon. And colorectal cancer is, of course, the third leading cause of death from cancer among men, after lung and prostate cancers.

Again, the contrast should not be colonoscopy vs. nothing, or even vs. sigmoidoscopy alone, but colonoscopy vs. FIT + sigmoidoscopy.
 

But we are all free agents here, and can make our own decisions about what we consider best for ourselves. And I fully respect a decision to choose a course other than periodic colonoscopy. But it would not be my decision.

Well-said — and conversely ;) .

Here, again, are the American Cancer Society's page on risk factors for colorectal cancer. Happily, as noted, most of us are already doing most of what can be done on modifiable risk factors, tho' age is the biggest risk factor of all, followed by family history in those with it.

---------
[1] N Engl J Med. 2014 Apr 3;370(14):1287-97. doi: 10.1056/NEJMoa1311194. Epub 2014
Mar 19.

Multitarget stool DNA testing for colorectal-cancer screening.

Imperiale TF(1), Ransohoff DF, Itzkowitz SH, Levin TR, Lavin P, Lidgard GP,
Ahlquist DA, Berger BM.


Comment in
N Engl J Med. 2014 Apr 3;370(14):1350-1.
N Engl J Med. 2014 Jul 10;371(2):187.
N Engl J Med. 2014 Jul 10;371(2):184-5.
N Engl J Med. 2014 Jul 10;371(2):185-6.
N Engl J Med. 2014 Jul 10;371(2):187-8.
N Engl J Med. 2014 Jul 10;371(2):186.
Ann Intern Med. 2014 Jul 15;161(2):JC10.
Turk J Gastroenterol. 2014 Feb;25(1):122-3.
Nat Rev Clin Oncol. 2014 May;11(5):239.
Nat Rev Gastroenterol Hepatol. 2014 May;11(5):269.

CONCLUSIONS: In asymptomatic persons at average risk for colorectal cancer, multitarget stool DNA testing detected significantly more cancers than did FIT but had more false positive results. (Funded by Exact Sciences; ClinicalTrials.gov number, NCT01397747.).

PMID: 24645800

[nicholson]

Yes, Michael, thank you for the suggestion.  I think it would be an excellent idea to merge the two.  My purpose in capitalizing the subject line of 'COLON CANCER PREVENTION' was in the hope that, when people have more to contribute on the subject of colon cancer, they would see the thread and add more to the end of it.

 

That way, when someone later is looking for information on colon cancer, they will be able to find it all in one place, rather than having to ferret through hundreds - eventually thousands - of threads hoping to find the information they are looking for.

 

If you agree with this (I.E that it would be a good idea to have just one single thread for all matters relating to colon cancer) then maybe simply "COLORECTAL CANCER" would be a good title for it.  Anyway that is my opinion, fwiw.  But maybe I do not understand the merits of needing to search to find numerous subject lines and threads for a single health issue?

 

Of course my thoughts expressed above - single threads for single topics - do not apply only to colorectal cancer, but to many of the topics we discuss here.

 

Rodney.

[Dean Pomerleau]

Michael,

 

First, I should say that I've just realized from reviewing it that the other thread, while subject-lined "COLON CANCER PREVENTION", is so overwhelmingly about screening that I maybe ought to merge the two, probably using the "Colorectal Cancer Screening" subject line of THIS thread, "Colorectal Cancer Screening"... any opinions?

 

I think having two threads might be a good idea, one about prevention and one about screening. If there isn't enough posted about prevention yet, perhaps having a single thread for now focused on screening would be the best option.

 

When you say "my family circumstances," do you "merely" mean alarm over your father-in-law's sad case? 

 

I mean concern for my wife and her brother & sister. Both my wife and my sister-in-law had colonoscopies at ages earlier than 50, and both had polyps. My sister-in-laws' were pre-cancerous. My wife is scheduled for a followup (3 year) colonoscopy next week. So I guess what I meant is that I've got colonoscopies and colon cancer on the brain at the moment.

 

 

Or perhaps more accurately, are the extra benefits of a colonoscopy in this regard not worth the risks (e.g. anethesia, puncturing the colon wall, hospital infections etc.) or the hassle (e.g. colonoscopy prep) compared to the FIT / Cologuard type testing?

That's the question. I do lean toward FIT + FS [flexible sigmoidoscopy @ 10 year intervals] for people without family history and esp. CR people, due to lower baseline lifestyle risk for colorectal cancer (most of us have the dietary stuff nailed, and MOST of us are also covered for exercise); CR folks' potentially higher risk of bad outcomes once infected and of bleeding and failing to heal a punctured colon; and fear of dementia.

 

 

Thanks - it is very helpful to know your perspective.

 

I had a colonoscopy about 3.5 years ago (no polyps), and was considering another in 1.5 years (5 year interval). But from the data you've shared that seems like too short an interval at the very least, and probably not worth the risk/hassle relative to getting an annual FIT test and getting a flexible sigmoidoscopy in another 5+ years.

 

To put it all in perspective, here are the absolute (rather than relative) risks and benefits of different kinds of colorectal cancer screening methods from the sum of evidence from the USPSTF 2015 Draft evidence summary (the stupid Forum software won't let me post the image).

 

Here is the (very helpful) image in question, posted via screen capture and imgur.com (via the method described in this_post):

 

 

If I'm interpreting it correctly, the top (orange) bar graph shows that colonoscopies provide a few extra years of life gained relative to the other screening methods, but the benefit is marginal. Similarly for the # of colorectal cancer deaths averted (blue graph) - slight advantage to colonoscopies, but pretty small comparatively speaking, especially given the number of screenings (1000) involved.

 

The green graph of harms is harder for me to interpret, but I think it suggests that the expected harm caused by getting a colonoscopy every 10 years (e.g. perforated colon, bleeding, infections, anesthesia side-effects, etc.) are nearly twice that of the other screening methods, when the harms caused by the other methods are translated into "colonoscopy harm equivalents" - or something like that - please correct me if I'm wrong. Finally, the purple chart represents the fact that with the other three screening methods, you are getting yearly tests, which cause an additional burden (hassle), although this burden seems trivial, especially if one is getting a yearly physical anyway.

 

So for me it will be yearly FIT tests plus a sigmoidoscopy in a few years. For my (high familial risk) family members, I lean towards suggesting to them colonoscopies may be best, in the cadence outlined by the federal guidelines for high risk individuals.

 

Thanks again Michael,

 

--Dean

[Dean Pomerleau]

Yes, Michael, thank you for the suggestion.  I think it would be an excellent idea to merge the two.  My purpose in capitalizing the subject line of 'COLON CANCER PREVENTION' was in the hope that, when people have more to contribute on the subject of colon cancer, they would see the thread and add more to the end of it.

 

That way, when someone later is looking for information on colon cancer, they will be able to find it all in one place, rather than having to ferret through hundreds - eventually thousands - of threads hoping to find the information they are looking for.

 

If you agree with this (I.E that it would be a good idea to have just one single thread for all matters relating colon cancer) then maybe simply "COLORECTAL CANCER" would be a good title for it.  Anyway that is my opinion, fwiw.  But maybe I do not understand the merits of needing to search to find numerous subject lines and threads for a single health issue?

 

Of course my thoughts expressed above - single threads for single topics - do not apply only to colorectal cancer, but to many of the topics we discuss here.

 

Rodney.

 

Rodney,

 

I like the idea of highlighting "collector" threads using the capitalization convention you suggest. But at the same time I fear having the collector threads being too broad as well.

 

How about a compromise - having two threads with the titles "COLORECTAL CANCER PREVENTION" and "COLORECTAL CANCER SCREENING"? I think we already have enough post about the latter to make it a valuable thread. The former may not as yet, but very well could/should eventually.

 

--Dean

[nicholson]

Makes sense to me, Dean.

[Saul]

Hi ALL!

 

I had a colonoscopy in my mid 60's, done by an excellent gastroentorologist (remember, my wife is an NP specialized in gastroenterology -- she recommended a good gastroenterologist).  My colon was perfect -- no polyps, everything great.

 

About 11 years later -- a few months ago -- I had another colonoscopy done by a superlative gasgtroenterologist (working at the same hospital -- Rochester General -- and in the same office -- as my wife).  It was extremely comfortable -- and again,my colon is perfect.

 

I strongly recommend that everyone -- male or female -- over the age of 50 have a colonoscopy (not a virtual one), every 10 years.  As noted in some of the posts on this subject, if there is a polyp, or even some progression to the beginning of a cancer, the gastroenterologist can remove it at once, possibly saving your life.

 

Some pointers:  Do NOT eat high fiber prior to your colonoscopy -- be on a liquid diet for two days prior to your exam.  AND, very important:  thoroughly check the reputation of the gastroenterologist who performs the (minor) operation -- and DON'T BE SQUEEMISH -- it's something that you should do, for your own health and peace of mind.

 

(It makes much better sense than an early death from cryonics -- sorry, couldn't resist that.)

 

  -- Saul

[Dean Pomerleau]

Saul,

 

I strongly recommend that everyone -- male or female -- over the age of 50 have a colonoscopy (not a virtual one), every 10 years. 

 

Well that settles it - if Saul recommends a colonoscopy every 10 years, the right thing to do is probably something different, e.g. a yearly FIT test and a 10-year sigmoidoscopy. 

 

(It makes much better sense than an early death from cryonics   -- sorry, couldn't resist that.)

 

Nice Saul, and quite in line with your usual, non-sensical remarks.

 

Just to clarify, in case anyone is duped by your silliness: one dies, or is very close to death, from other causes before a cryonics procedure is employed, to give one an (admittedly slim) chance of being revived sometime in the future.

 

--Dean

[Dean Pomerleau]

I'm happy to report the results of my recent FIT test for colorectal cancer came back negative. Again I highly recommend it as an alternative to colonoscopy for CR folks at low risk of colon cancer.

 

I'm also happy to report that the polyp discovered and removed during my wife's recent colonoscopy was determined to be benign, which is a relief. Unfortunately for her, she has to go back in three years for another colonoscopy, since she's a polyp-generator, and now has a family history of colon cancer.

 

On that note, my father-in-law got out of the hospital today and is (finally) recovered from his colon cancer surgery, two weeks ago today. Unfortunately, his cancer was determined to have spread to his lymph nodes. He's meeting with the oncologist to discuss options next week. 

 

Get screened for colon cancer by whatever method you consider most appropriate for your circumstances everyone!

 

--Dean

[nicholson]

Hi Dean:

 

"I'm happy to report the results of my recent FIT test for colorectal cancer came back negative. Again I highly recommend it as an alternative to colonoscopy for CR folks at low risk of colon cancer."

 

Good to hear that that seems to be good news almost all around.  What I think we may be missing in our discussion here is information (which like everything else will, unfortunately, probably will vary from one individual to another) about how much later it is that these alternate colon cancer tests - those that are less invasive than colonoscopy - locate the problem, and what the prognosis is when blood is eventually found in the stool, and presumably cancer fairly well established.

 

When the cancer is confined to a small section of the colon that section can be excised and the ends sewn back together again.  But, clearly, blood in the stool finds the problem much later than colonoscopy - in the latter case, if done on schedule, almost always well before even pre-cancerous cells have developed.  This is not a rhetorical statement.  If the fecal-occult-blood test done annually almost always finds the cancer when it is thoroughy confined to a small section of the colon, then clearly that would argue quite strongly for it over colonoscopy.  But does it?

 

Rodney.

  

===========

 

"The unverified conventional wisdom is almost invariably mistaken." 

[Dean Pomerleau]

Rodney,

 

Did you read the post about six up from this one in this thread, with the graphs comparing the effectiveness of various colon cancer screening methods in terms of life years saved and deaths averted via various colon cancer screening methods? If not, you should. As far as I can tell, the answers to your questions are contained there.

 

In a nutshell, regular but relatively infrequent colonoscopies (per the ACS guidelines) are only modestly more effective than other methods, including a yearly FIT test. Plus, colonoscopies have a substantially higher risk of complications (and therefore harm) relative to other colon cancer screening methods.

 

For people at risk of colon cancer (like my wife), I strongly advocate colonoscopies. But for CR practitioners who are (naturally - barring a family history) at relatively low risk of colorectal cancer, a yearly FIT test may be preferable, it seems to me.

 

--Dean

[AlPater]

The health service in our province started a FIT screening program for colon cancer screening.  I was clean, as I was by colonoscopy 14 months ago, but will have colonoscopy too since several members in my family geneology, including a brother who died from it and 31 years of age, have had colon cancer.  Adenomas are the most frequent finding of the tests, and while the cancers were not significantly better detected with colonoscopy, the ratio was comparable to that of the adenoma detection rate, and I do not want to miss adenomas which may fast-track into colon cancer.

 

 

"The FIT and stool DNA

tests are moderately sensitive for cancer but much

less sensitive than colonoscopy for precancerous

adenomas (Table 3)."

 

"Optical colonoscopy is associated with a 2 to

9% risk of an interval cancer (one that is detected

between scheduled colonoscopies)6,19,44,71,72,73 and

a risk of major complications. The rate of bleeding

is 0.1 to 0.6% and the rate of perforation is

0.1 to 0.3%; these risks increase with age.74"

 

 

Colorectal Adenomas.

Strum WB.

N Engl J Med. 2016 Mar 17;374(11):1065-75. doi: 10.1056/NEJMra1513581. No abstract available.

PMID: 26981936

http://sci-hub.io/10.1056/NEJMra1513581

 

Table 3. Rates of Detection of Advanced Adenomas and Colorectal Cancer by FIT and Stool DNA Testing, as Compared with Optical Colonoscopy.*

---------------------------------------------------

Trial and Test===Participants no.===Advanced Adenomas Detected no. (%)===P Value===Cancers Detected no. (%)===P Value

---------------------------------------------------

Quintero et al.61

Optical colonoscopy 5,059 493 (9.7) - 27 (0.5) -

FIT 10,507 252 (2.4) <0.001 36 (0.3) 0.09

Imperiale et al.5

Optical colonoscopy 9,989 757 (7.6) - 65 (0.7) -

FIT 9,989 180 (1.8) <0.001 60 (0.6) 0.13

Stool DNA 9,989 321 (3.2) <0.001 48 (0.5) 0.13

---------------------------------------------------

   * The studies were selected on the basis of their large numbers of participants, their randomized, controlled designs, and the comparison of the results of FIT or stool DNA testing with those of optical colonoscopy. FIT was positive in the study by Quintero et al.61 at the level of 75 ng or more of hemoglobin per milliliter of buffer and in the study by Imperiale et al.5 at the level of more than 100 ng of hemoglobin per milliliter of buffer. All P values were determined by means of Pearson’s chi-square analyses.

[mikeccolella]

http://www.bmj.com/bmj/section-pdf/187371?path=/bmj/343/7830/Head_to_Head.full.pdf

 

There does not seem to be an effect on overall mortality and colon cancer screening. Generally disease specific markers can be misleading. You really have to wonder what would happen in a well done study of low risk persons being aggressively screened and a control group of low risk persons not being screened at all and followed for 30 years or so and keeping in mind that hospitalizations are a major cause of death.

 

From the article above:

 

" This argument does not show that disease specific mortality is better than all cause mortality; indeed, it seems to concede the opposite point. It also assumes that huge trials would show a reduction in all cause mortality, whereas this is precisely what is in question. And it ignores the existing data that strongly support an absence of any effect of screening on all cause mortality, as, for example, in the case of bowel cancer screening."

 

https://www.usnews.com/news/articles/2016-05-03/medical-errors-are-third-leading-cause-of-death-in-the-us

[drcha]

We have to consider the populations studied.  Our colons are likely healthier than those in the populations studied, and therefore probably less likely to be perforated and more likely to react appropriately to the initiation of a tumor.  However, Dean is right about screening being a good idea.  I still have a polyp or two every time (and a family history that requires me to have screening every 5 years).  Whatever nice things I feed my bowel now, I can't erase the sins of my past years.  Who knows how long ago some of these little items started growing.  

[mikeccolella]

Yes of course you are right. SOME FOLKS LIVES WILL BR SAVED! That is indisputable. The question That is being raised by the NCI and other reputable organizations is simply why are OVERALL death rates the same? This is the data we have and it suggests harm from screening for some and that some would logically be those with low risk. So it may very well be that many on this list are exposing themselves to potential harm by screening for colon cancer.

[mikeccolella]

http://www.nejm.org/doi/full/10.1056/NEJMoa1300720#t=article

 

This well done research does not Show any reduction in mortality from colorectal screening and suggest low risk people may be increasing their odds of mortality