Assessing Cancer Signal during Oral Antiplatelet Therapy in the Food and Drug Administration Adverse Event Reporting System: Mission Impossible

Whether aggressive prolonged dual antiplatelet therapy (DAPT) promotes solid cancer risks remains a critical unsolved issue. Since the evidence from randomized trials, affiliated U.S. Food and Drug Administration (FDA) reviews, meta-analyses, and national registries is mixed, the search is ongoing. The FDA Adverse Event Reporting System (FAERS) is a global passive surveillance repository requiring mandatory updates for serious events. We assessed the frequencies of co-reporting any cancers with oral antiplatelet agent (OAA) strategies in FAERS. We examined the entire FAERS database ( n = 8,604,889) with regard to monotherapy or DAPT with OAA, suspected causative role, and co-reporting any cancers ( n = 433,111). We extracted cancer cases during monotherapy with aspirin (20,984 out of 462,371 or 4.54%), clopidogrel (2,797 out of 62,791 or 4.45%), prasugrel (119 out of 4,364 or 2.73%), and ticagrelor (144 out of 8.268 or 1.71%). DAPT with clopidogrel reported (2,453 out of 58,101, or 4.22%); prasugrel (162 out of 4,036, or 4.01%); and ticagrelor (195 out of 5,302 or 3.68%) cancer reports all on top of aspirin. We conclude that FAERS is currently unreliable for adequate assessment of cancer risks during DAPT. The retrieved evidence appears random and sporadic, while associated cancers are heavily underreported or/and missed. Without stricter rules, better surveillance, and enforcements, oncology outcome research options in FAERS are challenging.