Dual aspirin, clopidogrel safe, reduces cancer risk
Adults treated with a combination of aspirin and clopidogrel demonstrated a reduced risk for a wide range of cancer on long-term follow-up compared with aspirin only or no treatment, according to a study published in The American Journal of Medicine.“Multiple studies have shown an association between aspirin treatment and a reduction in newly diagnosed cancer,” Avi Leader, MD, from the Institute of Hematology at the Davidoff Cancer Center in Israel, and colleagues wrote.
“Conversely, there are conflicting clinical and laboratory data on the effect of combined clopidogrel and aspirin therapy on cancer incidence, including analyses suggesting an increased cancer risk. No large-scale cohort study has been performed to address this issue in a heterogeneous real-world scenario.”
Leader and colleagues conducted a population-based historical cohort study of 183,912 adults aged 50 years and older (median age, 54.9 years; 53.7% female) to determine how clopidogrel and aspirin affects cancer incidence compared with aspirin alone.
The researchers excluded patients who had been treated with newer antiplatelet drugs Effient (prasugrel, Eli Lilly) or Brilinta (ticagrelor, AstraZeneca) as well as those who previously had cancer. Patients were categorized into three groups: no antiplatelet treatment (41%), aspirin only (49%) or clopidogrel and aspirin (9.6%).
During the study period, there were 21,974 new cases of cancer. Of these new cancers, a majority were solid malignancies (87%), while the rest were hematological malignancies (13%). The most common cancer types were breast (13.3%), colorectal (13.7%), prostate (9.5%) and lung (7.4%).During long-term follow-up, the researchers found that participants receiving aspirin with (HR = 0.46; 95% CI, 0.44-0.49) or without clopidogrel (HR = 0.54; 95% CI, 0.52-0.56) had a 54% and 46% lower risk for cancer than nonusers, respectively. In addition, participants receiving clopidogrel and aspirin had an 8% reduction in cancer risk compared with those receiving aspirin only (HR = 0.92; 95% CI, 0.86-0.97).“This study shows that combined aspirin and clopidogrel use is at least as safe as prolonged aspirin use with regard to cancer incidence, and generates the hypothesis that clopidogrel may reduce cancer incidence,” Leader and colleagues concluded.
“This, along with a recent analysis by the [FDA] goes a long way toward allaying recent concern about the effect of combined antiplatelet treatment on cancer incidence. We eagerly await more clinical and basic research about the anticancer effect of clopidogrel and other newer antiplatelet agents.”