Aspirin, DOAC use may compromise diagnostic performance of FIT for colorectal cancer
Regular use of aspirin and direct oral anticoagulants (DOACs) appears to be associated with a lower positive predictive value (PPV) of faecal immunochemical test (FIT) for detecting colorectal cancers and advanced adenomas, a study has found.
The cross-sectional study included 4,908 individuals aged 50–74 years with a positive result from FIT (>15-μg haemoglobin/g faeces) and subsequent colonoscopy (reference standard). Of these, 1,008 individuals used aspirin, 147 used warfarin and 212 used DOACs. Nonusers (n=3,541) were matched to users according to age, sex, screening centre and screening round. The primary outcome was the PPV of FIT.
Colorectal cancers were detected in 234 individuals and advanced adenomas in 1,305. The PPV for colorectal cancer was significantly lower in users than in nonusers: 3.8 percent in aspirin users vs 6.4 percent in matched nonusers (p=0.006) and 0.9 percent in DOAC users vs 6.8 percent in matched nonusers (p=0.001).
The PPV for advanced adenoma was likewise lower in users: 27.2 percent in aspirin users vs 32.6 percent in matched nonusers (p=0.011) and 20.5 percent in DOAC users vs 32.4 percent in matched nonusers (p=0.002).
PPVs for colorectal cancer or advanced adenoma did not significantly differ between warfarin users and matched nonusers.
FIT is the most frequently used tool for colorectal cancer screening worldwide. The present data suggest that regular use of aspirin and DOACs may risk the diagnostic performance of FIT, researchers said.