Study Reevaluates Colon Cancer Screening Methods Interview with:
Jennifer S. Lin, MD, MCR, FACP
Director, Kaiser Permanente Research Affiliates Evidence-based Practice Center
Investigator, The Center for Health Research, Kaiser Permanente Northwest
Portland, OR 97227 What is the background for this study? What are the main findings?

Dr. Lin: Our systematic review was commissioned by the USPSTF, in tandem with a separate modeling exercise, to help update their 2008 colorectal cancer screening recommendations. Since the previous recommendation, there has been a wealth of new evidence, including more evidence on the long-term effectiveness of flexible sigmoidoscopy for reducing colorectal cancer mortality, the screening accuracy and decreasing radiation exposure from CT colonography, and the screening accuracy for a number FDA-approved stool tests using fecal immunochemical testing (FIT).

While we have large, well-designed RCTs demonstrating that screening for colorectal cancer using flexible sigmoidoscopy and older generation stool testing reduces colorectal cancer mortality, these screening tests are no longer widely used in the United States. Well-designed diagnostic accuracy studies of screening colonoscopy, CT colonography, and various stool based tests using FIT demonstrate adequate sensitivity and specificity to detect adenomas and/or colorectal cancer, making each of them viable screening options. However, each screening option has potential harms associated with their use, particularly those allowing for direct visualization of the colon. Colonoscopy harms include perforations and major bleeding events. CT colonography requires exposure to radiation; and CT colonography not uncommonly results in detection of extra-colonic findings which necessitate additional diagnostic follow-up which may result in a benefit or harm. What should readers take away from your report?

Dr. Lin:  A number of colorectal cancer screening modalities have been studied. Colonoscopy, flexible sigmoidoscopy, CT colonography, and stool tests (including FITs) have differing levels of evidence to support their use in colorectal cancer screening, ability to detect cancer and precursor lesions, as well as risk of serious harm. Although there exists a large body of supporting evidence for these various screening options, additional research is still needed to weigh the relative benefits and harms of each test option in within a program of screening. Is there anything else you would like to add?

Dr. Lin: Stool based FITs should not be thought of as a single class of tests. Not all FITs or FIT-based stool testing have the same screening accuracy, and some of these tests have been better studied than others. Thank you for your contribution to the community.


Lin JS, Piper MA, Perdue LA, et al. Screening for Colorectal Cancer: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force. JAMA.Published online June 15, 2016. doi:10.1001/jama.2016.3332.

Note: Content is Not intended as medical advice. Please consult your health care provider regarding your specific medical condition and questions.

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