Would you recommend aspirin 600 mg daily for two years to a patient with Lynch syndrome and a history of colon cancer based on the results of the CAPP2 study for cancer prevention?

Yes, I would recommend this, with some caveats/considerations. 600 mg of aspirin daily x 2 years was the dose/duration shown to be effective in CAPP2--recently updated outcomes data from this trial (Lancet 2020) demonstrated an IRR of 0·50 (0·31–0·82; p=0·0057) for CRC among participants who were able to continue on aspirin for at least 2 years--so the magnitude of benefit is substantial. So what are the caveats/considerations? First, I do not recommend 600 mg aspirin in PMS2 carriers, as this group of patients was not included in CAPP2 and is at substantially lower lifetime risk of CRC (15-20%) than MLH1, MSH2, and MSH6 carriers (who were included in CAPP2). Secondly, I take a careful medical history and generally do not recommend aspirin ...