Meta-Analysis Adds Support for FIT for Colorectal Cancer Screening

By Amy Orciari Herman

Edited by David G. Fairchild, MD, MPH

Fecal immunochemical tests (FITs) for human globulin have moderate-to-high sensitivity and specificity for colorectal cancer among average-risk adults, according to a meta-analysis in the Annals of Internal Medicine.

The analysis included 31 cross-sectional studies that examined screening FITs among asymptomatic, average-risk adults. Here are the main findings, with colonoscopy as the reference standard:

• For colorectal cancer, FITs had a sensitivity of 0.91 at a threshold of 10 µg/g and 0.71 at a threshold of greater than 20 µg/g. FITs' specificity ranged from 0.90 to 0.95.

• For advanced adenomas, FITs' sensitivity was lower, ranging from 0.40 to 0.25. The specificity was the same as that for colorectal cancer.

An editorialist calls for "better education to inform patients and physicians that regular screening with FITs is not a 'second-best' strategy or less than a 'gold standard' strategy for average-risk persons." Of FITs' lower sensitivity for advanced adenomas, he adds, "Even 'advanced' adenomatous polyps are not cancerous, and most never progress to cancer."