For patients with a past history or family history of colorectal cancer, annual fecal immunochemical tests (FITs) detect neoplasias sooner than scheduled 10-year colonoscopies, according to a new study published in the December issue of Gastroenterology. For patients with FIT-positive results, diagnosis was made sooner by 25 months for cancer and by 24 months for advanced adenomas.
To test if FITs could result in earlier detection of neoplasia, investigators in Australia followed 1736 patients with a family history or past neoplasia who had received at least two prior colonoscopies for a total of 8863 person-years, some for as long as 20 years. Participants were offered yearly FIT, and a colonoscopy performed earlier than scheduled for all positive results.
Among the 1071 asympotomatic patients who received at least one FIT, the test detected 12 of 14 cancers and 60 of 96 advanced adenomas, a sensitivity of 86% and 63%, respectively. Among patients with only negative FIT results, risk for cancer and adenomas decreased by twofold (5.5%) over those who were not tested (10.1%; P = .0004). In addition, the probability of the most advanced neoplastic stage was lowest among those with a negative FIT result (odds ratio, 0.68; P <.001).
These results confirm the value of the 2008 screening and surveillance guidelines issued by the American Cancer Society, the US Multi-Society Task Force on Colorectal Cancer, and the American College of Radiology, which recommended the 10-year interval for average-risk individuals beginning at age 50 as well as the use of FIT to screen between these intervals, with a positive result followed by colonoscopy.