Low-dose aspirin and survival in men with prostate cancer: a study using the UK Clinical Practice Research Datalink

Aspirin use is associated with reduced risk of, and death from, prostate cancer. Our aim was to determine whether low-dose aspirin use after a prostate cancer diagnosis was associated with reduced prostate cancer-specific mortality. A cohort of newly diagnosed prostate cancer patients (1998-2006) was identified in the UK Clinical Practice Research Datalink (confirmed by cancer registry linkage). A nested case-control analysis was conducted using conditional logistic regression to compare aspirin usage in cases (prostate cancer deaths) with up to three controls (matched by age and year of diagnosis). Post-diagnostic low-dose aspirin use was identified in 52 % of 1,184 prostate cancer-specific deaths and 39 % of 3,531 matched controls (unadjusted OR 1.51, 95 % CI 1.19, 1.90; p < 0.001). After adjustment for confounders including treatment and comorbidities, this association was attenuated (adjusted OR 1.02 95 % CI 0.78, 1.34; p = 0.86). Adjustment for estrogen therapy accounted for the majority of this attenuation. There was also no evidence of dose-response association after adjustments. Compared with no use, patients with 1-11 prescriptions and 12 or more prescriptions had adjusted ORs of 1.07 (95 % CI 0.78, 1.47; p = 0.66) and 0.97 (95 % CI 0.69, 1.37; p = 0.88), respectively. There was no evidence of a protective association between low-dose aspirin use in the year prior to diagnosis and prostate cancer-specific mortality (adjusted OR 1.04 95 % CI 0.89, 1.22; p = 0.60). We found no evidence of an association between low-dose aspirin use before or after diagnosis and risk of prostate cancer-specific mortality, after potential confounders were accounted for, in UK prostate cancer patients.