brand logo

Am Fam Physician. 2019;99(10):online

Clinical Question

What is the yield of a screening program based on fecal immunochemical testing (FIT) every two years for 10 years?

Bottom Line

Over a 10-year period, the rates of detection of colorectal cancer (CRC) and advanced adenomas using FIT are similar to those seen in studies of screening colonoscopy. This does not prove that FIT reduces morbidity and mortality due to CRC as effectively as colonoscopy. Modeling concludes that a FIT-based screening program will result in half as many colonoscopies as a program based on colonoscopy, a significant reduction in cost, burden, and harm of screening. (Level of Evidence = 2b)

Synopsis

The two most widely recommended strategies for CRC screening are FIT and colonoscopy. Several trials are currently underway to compare these approaches, with cancer-specific mortality as the primary outcome. Until then, we have to rely on observational studies and modeling to understand the benefit of each approach. Although colonoscopy is more sensitive than FIT, especially for the detection of advanced adenomas, what matters is the performance over a long-term screening program, not one-time accuracy. This study reports the results of five rounds of biennial FIT in a screening population 50 to 69 years of age in the Veneto region of northern Italy. The rate of detection of CRC was the highest in the first round of screening when prevalent lesions were detected (3.3 per 1,000 people), declining in subsequent rounds and stabilizing after the third round (approximately 1 per 1,000 people). Between rounds three and six, the CRC detection rate declined slightly from 0.95 to 0.84 per 1,000 people. A similar pattern was seen for advanced adenomas, declining from 15.9 per 1,000 people to approximately 10 per 1,000 people in subsequent rounds. Over the 10-year study period, the cumulative rate of positive FIT results was 25% for men and 17.6% for women. The cumulative rate for advanced adenoma was 60 per 1,000 people, and for CRC was 8.5 per 1,000 people. These rates are similar to those seen in studies of colonoscopy in Italy and the United States.

Study design: Cohort (prospective)

Funding source: Government

Setting: Population-based

Reference:ZorziMHassanCCapodaglioGet alLong-term performance of colorectal cancer screening programmes based on the faecal immunochemical test. Gut2018;67(12):2124–2130.

POEMs (patient-oriented evidence that matters) are provided by Essential Evidence Plus, a point-of-care clinical decision support system published by Wiley-Blackwell. For more information, see http://www.essentialevidenceplus.com. Copyright Wiley-Blackwell. Used with permission.

For definitions of levels of evidence used in POEMs, see http://www.essentialevidenceplus.com/product/ebm_loe.cfm?show=oxford.

To subscribe to a free podcast of these and other POEMs that appear in AFP, search in iTunes for “POEM of the Week” or go to http://goo.gl/3niWXb.

This series is coordinated by Sumi Sexton, MD, editor-in-chief.

A collection of POEMs published in AFP is available at https://www.aafp.org/afp/poems.

Continue Reading


More in AFP

More in Pubmed

Copyright © 2019 by the American Academy of Family Physicians.

This content is owned by the AAFP. A person viewing it online may make one printout of the material and may use that printout only for his or her personal, non-commercial reference. This material may not otherwise be downloaded, copied, printed, stored, transmitted or reproduced in any medium, whether now known or later invented, except as authorized in writing by the AAFP.  See permissions for copyright questions and/or permission requests.