(HealthDay)—Fecal hemoglobin concentration, sex, and age can be used to classify the risk of advanced colorectal neoplasia among individuals with positive results from fecal immunochemical tests (FITs), according to a study published in the September issue of Gastroenterology.

Josep M. Auge, M.D., from Hospital Clínic in Barcelona, Spain, and colleagues retrospectively analyzed data from a consecutive series of 3,109 with positive results from FITs (≥20 µg/g of feces) included in the first round of the Barcelona colorectal cancer screening program (December 2009 through February 2012). A colonoscopy was performed in all patients and they were classified according to advanced or nonadvanced .

The researchers found that participants with advanced colorectal neoplasia had significantly higher median fecal hemoglobin concentrations compared with participants with nonadvanced colorectal neoplasia (105 versus 47 µg/g; P < 0.001). Using arbitrary fecal hemoglobin concentrations, positive predictive values for advanced colorectal neoplasia varied by sex and age. Independent predictive factors for advanced colorectal neoplasia were male sex (odds ratio [OR], 2.07); of 60 to 69 years (OR, 1.24); and fecal >177 µg/g (OR, 3.80). Sixteen risk categories were identified based on these factors, and the risk for advanced colorectal neoplasia was increased 11.46-fold among those in the highest risk category versus the lowest category.

"These factors should be used to prioritize individuals for colonoscopy examination," the authors write.