Age, male sex, smoking and metabolic syndrome as risk factors of advanced colorectal neoplasia for fecal immunochemical test negative patients

Background: Fecal immunochemical test (FIT) is worldwide strategy for colorectal cancer screening. The subjects with negative FIT still have the risk of an advanced colorectal neoplasia (AN), including adenoma with villous histology, high grade dysplasia or larger than 1 cm in size, or adenocarcinoma. The study determined the risk factors associated with AN in FIT-negative subjects. Methods: The study included asymptomatic subjects who received health checkup colonoscopy and have provided FIT study within 6 months prior to colonoscopy. The risk factors to have AN in cases with negative FIT were analyzed. The numbers of colonoscopies needed to detect one AN were calculated for the subjects with different risk factors. Results: There were 1411 cases, 85 with positive FIT and 1326 with negative FIT within 6 months before colonoscopy. In FIT positive and FIT negative cases, 45.9% and 34.6% were found to have colorectal adenoma, while 20.2% and 4.6% had AN, respectively. The univariate and multivariate logistic regression analyses showed that age more than 50 years old, male sex, smoking history and metabolic syndrome were the significant risk factors to have AN in the FIT negative cases. For cases with negative FIT to have these risk factors, the number of colonoscopies needed to detect one AN was 3.7, lower than 4.5 of the cases with positive FIT. Conclusion: For the cases with negative FIT, colonoscopy screening should be considered for those male patients over 50 years old, with a history of smoking and metabolic syndrome to detect AN.