Screening for Colorectal Cancer Is Associated With Lower Disease Stage: A Population-Based Study

Background & Aims Screening for colorectal cancer (CRC) using fecal occult blood tests (FOBT) is associated with reduced CRC incidence and mortality. Population-based FOBT screening has led to identification of CRCs at earlier stages and longer patient survival times. We investigated the stage distribution of CRCs detected by colonoscopy in a large outpatient cohort. Methods We performed a retrospective analysis of colonoscopies performed on 524,954 outpatients (age, ≥55 y) in Germany from January 2006 through December 2009. Patients with chronic inflammatory bowel diseases, and those with a personal history of adenoma or CRC, were excluded. Colonoscopy findings were categorized on the basis of the most advanced lesion found; histologic samples were obtained from all patients with suspected cancer and analyzed. Cancers were staged based on Union Internationale Contre le Cancer criteria. We analyzed absolute and relative frequencies of CRCs identified and tumor stages for patients who underwent colonoscopy for screening, evaluation of a positive FOBT, and evaluation of symptoms. Results Of the 6065 CRCs identified, 1750 were found in the screening group, 1075 in subjects with positive FOBT, and 3240 in patients with symptoms. Stage I CRC was detected more frequently in subjects who received screening colonoscopies (41.15%) or in those with positive FOBT (39.10%), than in individuals with symptoms (24.42%; P P Conclusions In this large population-based study, CRC detected by colonoscopies performed for screening and evaluation of positive FOBTs had a lower stage than those diagnosed by colonoscopies in symptomatic patients. These findings support the value of screening colonoscopy to reduce the burden of CRC.