COMMENTARY
article addendum
J Interv Gastroenterol 3:2, 57-58; April/May/June 2013; © 2013 Landes Bioscience
Changes in colonoscopy: new tricks for an old dog David Siegel1,2 Medical Service, Department of Veterans Affairs, Northern California Health Care System, Mather, CA, USA; 2Department of Medicine, School of Medicine, University of California, Davis, CA, USA
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Key words: colonoscopy, colorectal cancer, fecal immunochemoical testing Abbreviations: SER, Surveillance, Epidemiology, and End Results; FIT, fecal immunochemoical testing; FOBTs, fecal occult blood tests; ADRs, adenoma detection rates Submitted: Jun/19/2013 Revised: Jun/19/2013 Accepted: Jun/19/2013 DOI: 10.7178/jig.120 Correspondence to: David Siegel; Email:
[email protected]
www.jigjournal.org
olorectal cancer is the third most common cancer worldwide and the second most common cause of cancer death in the United States.1,2 For the United States in 2013, there will be an estimated 73680 new colorectal cancer cases among men, and 69140 cases among women, with an estimated 26300 deaths from colorectal cancer among men and 24530 deaths among women.2 This amounts to a lifetime risk of colorectal cancer in the United States of approximately 5%. Colorectal cancer accounts for 9% of all cancer deaths. Fortunately, colorectal cancer incidence rates, as well as mortality rates, have been declining for most of the past two decades which has mainly been attributed to increases in the use of colorectal cancer screening tests that result in the detection and removal of colorectal polyps (adenomas) before they progress to cancer. Early in the course of the disease, colorectal cancer typically does not have symptoms, and thus, the screening of asymptomatic individuals is necessary for the detection of the disease at an early stage when it is potentially curable. The risk of colorectal cancer increases with age with 90% of colorectal cancer cases diagnosed in individuals >50 years of age. Other modifiable risk factors for colorectal cancer include long-term smoking, alcohol consumption, physical inactivity, obesity, and a diet high in processed food and red meat.2 Black persons have the highest incidence of and mortality rates from colorectal cancer among all racial and ethnic groups.3 Both the US Preventive Services Task Force and the American Cancer SocietyUS Multi-Society Task Force guidelines
J Interv Gastroenterol
recommend colonoscopy every 10 years starting at age 50 if the preceding colonoscopy is normal.4,5 More frequent colonoscopies depend on the size and number of adenomas in the preceding colonoscopy. A recently reported study found a reduction in colorectal cancer mortality of 53% after a mean follow-up of 15.8 years in patients who had colonoscopic removal of an adenomatous polyp when compared with a reference group from the Surveillance, Epidemiology, and End Results (SER) Program.6 This figure may give an inflated estimate of colonoscopy benefit because the study mimics a situation in which 100% of the population complies with screening, which is not a real-life scenario.1 Another study compared fecal immunochemoical testing (FIT) and colonoscopy in a randomized controlled trial of asymptomatic adults 50 to 69 years of age.7 Subjects in the FIT group were more likely to participate in screening than were those in the colonoscopy group. The numbers of subjects in whom colorectal cancer was detected were similar in the two groups, but more adenomas were identified in the colonoscopy group. While it appears logical that colonoscopy is the best test to detect colorectal cancer, particularly right-sided colon cancer, this has been surprisingly difficult to prove in cost-effective analyses.3,8 Other tests including fecal occult blood tests (FOBTs), the newer FIT test, flexible sigmoidoscopy (with or without FOBTs), double contrast barium enema, in addition to colonoscopy, are recommended as screening options. This ambiguity may be because different tests have varied adenoma detection rates (ADRs), potential morbidity and mortality, accessibility, acceptability to 57
patients and cost. Additionally, the routine use of propofol sedation is associated with a somewhat higher frequency of complications, specifically aspiration pneumonia.9 Changes in colonoscopy techniques that lead to increased ADRs, improved patient safety and acceptance, and reduced cost are of interest. In this context, the studies reported in this issue of the Journal of Interventional Gastroenterology by S. Tejaswi et al., A. Bak et al., and F.W. Leung et al. add important information to discussions of colonoscopic colorectal cancer screening.10-12 These papers were originally presented at a conference chaired by Dr. Joseph W. Leung at the Sacramento Veterans Administration (VA) Medical Center on March 16, 2013. With some differences among studies, these reports suggest that water exchange colonoscopy has the potential to improve ADRs, particularly in the proximal colon, increase the proportion of colonoscopies that result in cecal intubation, and decrease sedation requirements (thus decreasing
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total time in the endoscopy unit), patient discomfort and cost. These benefits occurred in both the community and VA settings. Further, Dr. F. W. Leung discusses combining water exchange colonoscopy with chromoendoscopy, which appears to further increase ADRs. Clearly, innovations in colonoscopy have resulted in important improvements in colorectal cancer screening and detection. I am confident that the following articles will be of interest to readers of the Journal of Interventional Gastroenterology. References 1. Bretthauer M, Kalager M. Colonoscopy as a triage screening tool. N Engl J Med 2012; 366:759-60. 2. American Cancer Society. Cancer Facts and Figure 2013. Accessed at www.cancer.org/downloads/STT/2013 CAFFfinalsecured.pdf on 7 June 2013. 3. Whitlock EP, Lin JS, Liles E, Beil TL, Fu R. Screening for colorectal cancer: a targeted, updates systematic review for the U.S. Preventive Services Task Force. Ann Intern Med 2008; 149:638-58. 4. U.S. Preventive Services Task Force. Screening for colorectal cancer: U.S. Preventive Services Task Force recommendation statement. Ann Inter Med 2008;149:627-37. 5. Levin B, Liverman DA, McFarland B, Andrew KD, Brooks D, Bond J, et al. American Cancer Society Colorectal Cancer Advisory Group, US Multi Society
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Task Force, American College of Radiology Colon Cancer Committee. Screening and surveillance for the early detection of colorectal cancer and adenomatous polyps, 2008: a joint guideline from the American Cancer Society, the US Multi-Society Task Force on Colorectal Cancer, and the American College of Radiology. Gastroenterology 2008; 134:1570-95. 6. Zauber AD, Winawer SF, O’Brien MJ, LansdorpVogelaar I, van Ballegooijen M, Hanley BF, et al. Colonoscopic polypectomy and long-term prevention of colorectal-cancer death. N Engl J Med 2012; 366:68796. 7. Quintero E, Castells A, Bujanda L, Cubiella J, Salas D, Lanas A, et al. Colonoscopy versus fecal immunochemical testing in colorectal-cancer screening. N Eng J Med 2012; 366:697-706. 8. Pignone M, Saha S, Hoerger T, Mandelblatt J. Costeffectiveness analyses of colorectal cancer screening: a systematic review for the U.S. Preventive Services Task Force. Ann Intern Med 2002;137:96-104. 9. Cooper GS, Kou TD, Rex DK. Complications following colonoscopy with anesthesia assistance: A populationbased analysis. JAMA Intern Med 2013; 173:551-6. 10. Tejaswi S, Stondell J, Ngo C, Wilson M. Increase in proximal adenoma detection rate after transition from air to water method for screening colonoscopy in a community based setting in the United States. J Interv Gastroenterol 2013; 3:55-8. 11. Bak AW, Perini RF, Schroeder T, Leung FW. Experience with water-aided colonoscopy in a Canadian community population. J Interv Gastroenterol 2013; 3:51-4. 12. Leung FW, Friedland S, Leung JW, Mann S, Ramirez FC, Yen AW. Water-aided methods for colonoscopy- a review of VA experience. J Interv Gastroenterol 2013; 3:46-50.
Volume 3 Issue 2
