45 Years –The New Recommendation for Colorectal Cancer Screening

Related blog posts:

Video for Patients: Benefits and Risks of IBD Treatment & Risks of Untreated IBD

A recent study (NE Newman, KL Williams, BJ Zikmunde-Fisher, J Adler. JPGN 2020;70: e33-36) highlights work to communicate the benefits and risks of the treatment for inflammatory bowel disease (IBD) along with the risks of untreated IBD.  “We developed a simple video aid to illustrate competing risks associated with medications and underling disease in context of inflammatory bowel disease…Those who viewed the video aid had more realistic perceptions than those who did not view it.”

Here is a link to the ~13 minute online video: IBD: Risk of Disease and Treatments

Overall, the presentation is very helpful and thoughtful.  I think this would be an excellent overview for families.  For practitioners, a few points that could benefit from some nuance are noted below some screenshots.  It is worth stating that the authors had started this project a few years ago and some of the points below are related to more information that has emerged.

In the section of treatment benefits (above), the presentation suggests that thiopurines (azathioprine, 6-mercaptopurine) and methotrexate both are effective in about 50%; this is probably an overestimate; in addition, methotrexate as monotherapy is definitely less effective (if effective at all) for ulcerative colitis .  Also, it would be worthwhile to indicate that anti-TNF monotherapy with therapeutic drug monitoring may help achieve similar benefits as dual therapy.

In the section of colon cancer, the authors provide useful data that current treatments lower this risk substantially.  It is notable that more recent reports suggest that there have been improvements in the rates of colon cancer associated with IBD.

Overall, the section on lymphoma is very good.

In the section on other complications, the presentation suggests that there may be impaired wound-healing with anti-TNFs.  I think this risk is overstated in this slide. Also, I think the risk of severe infection with thiopurines is a little bit higher than stated; though, this can be mitigated with careful monitoring.

I think this summary slide could be improved by noting that the overall risk of serious cancers is likely lowered by treating IBD.  Since colon cancer is a fairly common cancer and IBD treatment reduces the risk, this likely outweighs the increased risk of other cancers (eg. lymphoma) which are much less common.

Another link to video: https://tinyurl.com/IBDTreatments

Related posts:

Disclaimer: This blog, gutsandgrowth, assumes no responsibility for any use or operation of any method, product, instruction, concept or idea contained in the material herein or for any injury or damage to persons or property (whether products liability, negligence or otherwise) resulting from such use or operation. These blog posts are for educational purposes only. Specific dosing of medications (along with potential adverse effects) should be confirmed by prescribing physician.  Because of rapid advances in the medical sciences, the gutsandgrowth blog cautions that independent verification should be made of diagnosis and drug dosages. The reader is solely responsible for the conduct of any suggested test or procedure.  This content is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a condition.

Colon Cancer at Younger Ages

From USA Today: Colon and rectal cancers surge in millennials and GenX

An excerpt:

Someone born in 1990 has double the risk of early colon cancer and quadruple the risk of early rectal cancer as someone born in 1950…

Most of the nation’s 135,000 annual cases and 50,000 deaths related to colon and rectal cancer still occur among people over age 55. But the share of cases involving younger adults has risen to 29% for rectal cancer and 17% for colon cancer, the study showed. About 11,000 people in their 40s and 4,000 under 40 were diagnosed in 2013…

Known risk factors for colon and rectal cancer include obesity, inactivity and diets high in red and processed meat and low fruits, vegetables and whole grains.


“The Couric Effect”

A recent commentary (Am J Gastroenterol advance online publication 29 March 2016; doi: 10.1038/ajg.2016.118) by Katie Couric provides a summary of her personal journey as an advocate for preventing colon cancer.

A good read: An Unexpected Turn: My Life as a Cancer Advocate

Here’s an excerpt:

“April is the cruelest month,” T.S. Eliot wrote in “The Waste Land,” and in 1997 it certainly was for my family. That’s when my husband Jay and I discovered he had stage IV colon cancer that had spread to his liver…and the beginning of a 9-month nightmare…

the University of Michigan found that my televised colonoscopy and educational outreach contributed to a sustained 19% increase in the number of colonoscopies performed nationwide. They called it “The Couric Effect”

Screen Shot 2016-03-29 at 4.59.42 PM

Polyps: Clinical Decision Tool

The best approach to polyps from the U.S. Multi-Society Task Force: Gastroenterology 2014; 146: 305-306.  This paper’s simple chart on page 306 could help reduce many follow-up colonoscopies that are performed at shorter than recommended intervals.

Polyp Guideline

Related blog post:  Consensus guidelines after polypectomy | gutsandgrowth)

Thiopurines associated with reduced risk of colon cancer

A recent study provides some good news for those using thiopurines (6-mercaptopurine and azathioprine) (Gastroenterol 2013; 145: 166-75).

Using the observational cohort enrolled in the French CESAME study (Cancers et Surrisque Associe aux Maladies Inflammatoires Intestinales En France), the authors followed 19,486 patients with IBD.  60.3% had Crohn’s disease, and 30.1% were receiving thiopurine therapy.  The study period was 2004-2007.  At the start of the study, 2841 patients (14.6%) had long-standing extensive colitis.

Among patients with long-standing extensive colitis, the hazard ratio for colrectal high grade dysplasia and cancer was 0.28 for those who received thiopurine therapy compared with those who never received thiopurine therapy.

Thus, this prospective study showed that while colorectal cancer (CRC) was increased in IBD patients with long-standing colitis, this risk was less among the subset who were treated with thiopurines.  Some previous studies have not found a reduction in CRC risk, though they may have been underpowered and biased as these studies came from referral centers.

The authors also cautioned that more than 1/3rd of CRC cases occurred in those without extensive colitis which may necessitate a lower threshold for screening colonoscopy.

Related blog posts:

Consensus guidelines after polypectomy

The US Multi-Society Task Force (MSTF) on colorectal cancer has updated their recommendations and provided an update on the literature as well (Gastroenterol 2012; 143: 844-57).

Their recommendations are summarized in Table 1 of this article.  In brief, repeat colonoscopy is recommended at the following interval:

  • 10 years –If no polyps or small (<10 mm) hyperplastic polyps in rectum/sigmoid
  • 5-10 years –if 1-2 small (<10 mm) tubular adenomas
  • 3 years –if 3-10 tubular adenomas or if adenoma with high-grade dysplasia
  • ❤ years –if >10 adenomas
  • 1 year  –if serrated polyposis syndrome

Other important points include the recommendation of adopting split-dose bowel preparations and avoiding interval fecal testing within 5 years after colonoscopy.  If the bowel preparation is poor, the MSTF recommends that in most cases colonoscopy should be repeated within 1 year.  Newer techniques like chromoendoscopy, narrow band imaging, and magnification endoscopy have not been adequately studied to recommend them as part of  a surveillance strategy.

Related blog entries:

Colonoscopy, Split-dosing bowel preps, and Ottawa scores

Aspirin prophylaxis for colorectal cancer?

Additional references:

  • -Gastroenterol 2010; 138: 73, 27 (ed). Overutilization of colon screening in low risk situations and underutilization in high risk situations in clinical practice.
  • -Clin Gastro & Hep 2010; 8: 795. Juvenile Polyps. Describes frequent rate of recurrence (3 of 18 among single polyps) & 45% overall. n=257. 39% with at least 2 polyps. Among those with multiple polyps, 7 had mutations in either SMAD4 (mothers against decpentaplegic drosophilia), BMPR1A (bone morphogenetic protein), or PTEN (phosphatase & tensin homolog). Their recs: recheck with scope in 1-3 years depending on polyp burden and presence of dysplasia.
  • -Clin Gastro & Hep 2009; 7: 1217. Fewer polyps detected as day progresses at a VA hospital n=477 pts. 27% decline in polyp detection.
  • -NEJM 2009; 361: 1179. Review of screening for colorectal cancer.
  • -Gastroenterol 2009; 137: 792. Use of CT colonography -current appraisal.
  • -Ann Intern Med 2009; 150: 1-8. Says endoscopists miss most cancers on right side & colonosopy reduces cancer by ~60% primarily due to left-sided cancers.  Most, 73%, of colonoscopies not done by GI/colorectal surgery.
  • -Gastroenterol 2008; 134: 1570. Update recommendations from ACS, ACR, US Multi-society task force.
  • -Clin Gastro & Hep 2005; 3: 633.  Inherited polyposis syndromes & genetic testing.
  • -Clin Perspectives in Gastro 2002; 5: 329.  Polyp techniques & complications. If entrapped snare, consider cutting off snare handle & pulling on 1 wire. Alternative us to use snare as guidewire & push scope beyond wire. For large stalks, consider using snare as tourniquet for 5 min. Consider pure (or blended) coagulation at settings 20-30W.
    Injection of fluid into the submucosa beneath the polyp increases the distance between the polyp and the deeper layers of the colon. Using a sclerotherapy needle normal saline is injected at the edge of the polyp raising a bleb. No specific volume of normal saline is used. The objective is to raise a large bleb with marked elevation of the polyp. The snare is then placed around the base of the polyp and it can be removed with electrocautery. If bleeding is a consideration then a solution of epinephrine can be used at a 1:10,000 concentration. The advantage of cautery is that residual tissue is usually destroyed although this is usually not a consideration when removing juvenile polyps.Hot biopsy forceps are usually used to ablate diminutive polyps (< 5 mm in diameter). The coagulation current applied should be low. 10-15 watts applied for 1-2 seconds. The technique is generally safe but serious complications including bleeding or perforation have been reported.The cold snare technique is safe in small polyps. (< 5 mm) The rationale is that the vessels feeding the polyp are small and the risk of bleeding is low. The advantage is that without cautery there is not deep tissue damage. Submucosal injection may make the procedure safer.

What is the risk of colon cancer in IBD?

Some recent studies have shown that colorectal cancer complicating IBD may not be as common as previously thought or may be decreasing in incidence (Gastroenterology 2012; 143: 375-81 & Gastroenterology 2012; 143: 382-89 ).

The first study used a nationwide cohort of 47,374 Danish patients with IBD over a 30-year period.  During a 178 million person-years of follow-up evaluation, 268 patients with ulcerative colitis (UC) and 70 patients with Crohn’s disease (CD) developed colorectal cancer (CRC).  The risk was comparable to the general population (RR 1.07)!  Furthermore, the relative risk for CRC decreased over sequential time periods: 1.34  (1979-88) to 0.57 (1999-2008).

Increased risk:

  • UC diagnosed in childhood or adolescence
  • longer disease duration
  • patients with primary sclerosing cholangitis

Their conclusion, ‘the overall risk of CRC in patients with UC has decreased markedly over time and no longer exceeds that of the general population, at least in the first decade after diagnosis.”  And, based on their data, patients with Crohn’s disease are not at increased risk for CRC.

The second study from California used a large Kaiser Permanente database from 1998-June 2010.  29 cancers were identified in CD (n=5603) and 53 in UC (n=10,895) patients.  The incidence per 100,000 for CRC was 75 for CD, 76 for UC, and 47 for general population.

These authors conclude that there is an increased risk of CRC in a community-based IBD population between 1998-2010 despite advances in medical treatment.

To understand the discrepancy of these reports, the same issue provides an editorial (page 288).  My take is that the current incidence of CRC is lower than in previous reports but that the risk factors identified in the Danish cohort (see above) likely remain important.

Additional references:

  • -Gastroenterol 2009; 136: 718. 22% of cancers occurred before recommended surveillance in adults (only 9% if exclusion of patients who had IBD and cancers diagnosed at same time).
  • Colon Cancer Survival Calculator http://www.mayoclinic.com/calcs-Gastro 2010; 138: 207-2177 (entire issue)
  • -JAMA 2009; 302: 649. Aspirin use likely increases survival after dx of colon cancer. Commentary-Gastro 2010;138: 2012.
  • -NEJM 2009; 361: 2449. molecular basis of colorectal cancer
  • -Gut 2008; 57: 1246. IBD and colon cancer
  • -IBD 2007; 4: 367. 5ASA Rx did not reduce rate of cancer in large study of UC/CD -review of 18,000 colorectal cancer cases. IBD increased risk of CRC 6-7-fold..
  • -Clin Gastro & Hep 2006; 4: 1346. aminosalicylates reduce CRC.
  • -Gastroenterol 2006; 130: 1030, 1039, 1350. 600 patients followed for 35 yrs: CRC by colitis duration: 2.5% @ 20yrs, 7.6% @ 30yrs, 10.8% @ 40yrs. 5 year survival was 73% among those with cancer. 2nd study showed main CRC risk in UC pts is among those with extensive colitis.
  • -Clin Gastro & Hepatol 2004; 2: 1088. Lower cancer risk in this cohort, n=1460. CRC 0.4 @10yrs, 1.1% @ 20yrs, 2.1% @ 30yrs. Lower CRC may be due to more surgery in Rx failures & use of 5-ASA.
  • -Clinical perspectives in Gastro 1999; 2: 9 & 25. (review) surveillance/ overview take 4 bx q10cm. start p 8yrs in pancolitis & 15yrs for left-sided dz. Cancer risk: ~5% at 20yrs + 1%/yr p 20yrs in pancolitis.
  • -Gastroenterol 2003; 125: 1311. Advancement of dysplasia to cancer in UC.

Aspirin prophylaxis for colorectal cancer?

A recent article in The Lancet has provided additional information about the use of aspirin for cancer prevention, especially colorectal cancer (Rothwell PM et al. Lancet 2012; published online March 21. DOI: 10: 1016/S0140-6736 (11)61720-0).  In the commentary on this article (DOI: 10: 1016/S0140-6736 (11)61654-1), the potential benefits of aspirin are placed into context and previous studies are reviewed.  In short, the data from a number of studies suggest that aspirin lowers the risk of cancer.

In Rothwell’s study, which pooled data from 51 randomized trials, aspirin at any dose reduced the risk of non-vascular death by 12% and cancer death by 15%.   Benefit was seen within 3 years for high-dose (>300 mg/day) and after 5 years for low doses (<300 mg).  The cumulative numbers of patients in the reviewed studies was approximately 40,000 in each arm.  These studies were divided and examined under separate categories to assess primary prevention for vascular events and to assess effects on cancer deaths.

Yet, these encouraging results though have not been seen in several large randomized trials; the editorial notes that “the Women’s Health Study (WHS) of 39,876 women treated with alternated day 100 mg aspirin over 10 years and the Physicians’ Health Study (PHS) of 22,071 men treated with alternate-day 325 mg aspirin for 5 years.  After 10-12 years of folllow-up, aspirin was not associated with reduced risk of colorectal cancer.”  In addition, as noted in previous post, ( Who needs aspirin?/Arch Intern Med 2012; 119: 112-8) a large study with over 100,000 patients also did not show reduction in mortality from vascular or non-vascular events.

Whether alternate-day dosing of aspirin (in WHS and PHS studies) undermines its efficacy in preventing cancer is not clear.  Until more data are available, aspirin for chemoprevention is best-suited for those with increased cancer risk (eg. history of colorectal cancer & hereditary cancer syndrome) and low risk of GI bleeding.  Rates of bleeding due to aspirin are about 4% per year and for serious bleeding about 2% per year. In addition, other adverse effects, including macular degeneration, have been reported with aspirin use (Ophthalmology 2012; 119: 112-8).

Additional references:

  • Link to pdf copy of cited article:http://extremelongevity.net/wp-content/uploads/asa-ca.pdf
  • -Lancet 2011; 377: 31-41. Aspirin effect on cancer mortality -decreased by 30-40% (esophageal, gastric, pancreatic, colorectal)
  • -Lancet 2010; 376: 1741 – 1750. Long-term effect of aspirin on colorectal cancer incidence and mortality: 20-year follow-up of five randomised trials. Lowers risk of colon Ca.
  • -JAMA 2009; 302: 649. Aspirin use likely increases survival after dx of colon cancer.
  • -Gastro 2010;138: 2012. Commentary on aspirin for decreasing risk after diagnosis of colon cancer.
  • -NEJM 2007; 356: 2131, 2195. Aspirin can decrease high-expressing COX-2 colon adenoca; not recommended as routine prophylaxis at this time