Antithrombotic Drugs May Not Have Large Effect on FIT for Detecting Colorectal Neoplasms

Investigators examined the effects of antithrombotic drugs on fecal immunochemical tests (FITs) for detection of colorectal neoplasms (CN).

Antithrombotic drugs have been known to affect the screening performance of fecal immunochemical tests (FIT) for colorectal tumors. However, a recent study suggests antithrombotic therapies may not largely impact the sensitivity, specificity, positive predictive value (PPV), or negative predictive value (NPV) of FIT in detecting colorectal neoplasms. Findings from this study were published in Scientific Reports.

The study enrolled 758 patients who had positive FIT or symptoms of abdominal discomfort, constipation, or hematochezia. All patients subsequently underwent colonoscopy following FIT. Electronic medical charts were reviewed by investigators to identify patient clinical characteristics and information regarding antithrombotic drug intake. In total, 144 patients were taking antithrombotic agents vs 614 who were not. Patients undergoing antithrombotic therapies were significantly older (median age, 75 vs 63 years, respectively; P <.0001).

No significant difference was found between the patients taking antithrombotic agents vs not taking antithrombotic agents in regard to the proportion of patients with colorectal neoplasms (42.4% vs 35.3%, respectively; P =.1157) or colorectal cancer (9.7% vs 7.0%; P =.2655).

In terms of detecting colorectal neoplasms, there was no significant difference between the 2 groups for the sensitivity (62.3% vs 56.0%; P =.3964), specificity (60.2% vs 56.2%; P =.4960), PPV (53.5% vs 41.2%; P =.0604), or NPV (68.5% vs 70.1%; P =.7840) for FIT.

Limitations of this study included its retrospective nature, small sample size, and the lack of a randomized design.

The investigators concluded that “there may not be as many false positives as previously thought” with FIT in patients who take antithrombotic drugs.


Ibuka T, Adachi S, Horibe Y, et al. Effects of antithrombotic drugs on the results of fecal immunochemical test in colorectal neoplasms screening. Sci Rep. 2021;11(1):4348. doi: 10.1038/s41598-021-83007-4