Use of aspirin, but not other non-steroidal anti-inflammatory drugs is associated with decreased prostate cancer risk at the population level
A partir de données de registres nationaux finlandais portant sur la période 1995 - 2002, cette étude montre une association entre l'utilisation d'aspirine et une diminution du risque de cancer de la prostate (24 657 cas et 24 657 témoins)
The cyclooxygenase 2 (COX-2) enzyme overexpression in prostate cancer has led to the hypothesis that COX-2 inhibition may reduce prostate cancer growth. Some previous studies have linked the usage of COX-2 inhibiting non-steroidal anti-inflammatory drugs (NSAIDs) with a decreased prostate cancer risk. We estimated the association between cumulative COX-2 inhibition by NSAID usage and prostate cancer risk at population level. All new prostate cancer cases in Finland during 1995–2002 and matched controls (24,657 case–control pairs) were identified from national registries. Detailed information on medication purchases was obtained from a national prescription database. A total cumulative COX-2 inhibition value was calculated based on total cumulative mg amount of each NSAID drug and the drug-specific COX-1/COX-2 inhibition ratio. Prostate cancer risk was analysed with propensity score-matched conditional logistic regression model. In total, 53.8% of the cases and 46.5% of the controls had any prescription-use of NSAIDs, while 8.1% and 7.9%, respectively, had used aspirin. Compared to the non-users, any NSAID use was associated with an elevated overall prostate cancer risk (46.4% versus 53.6%, respectively; odds ratio [OR] 1.3, 95% confidence interval [CI] 1.3, 1.4) and risk of advanced cancer (11.8% versus 14.1%; OR 1.6, 95% CI 1.5, 1.8). The risk remained elevated despite the amount of cumulative COX-2 inhibition. In a separate analysis, the risk increase was similar for each NSAID with the exception of aspirin, which was associated with a decreased overall prostate cancer risk (OR 0.90, 95% CI 0.84, 0.96) in a dose-dependent fashion. NSAID use is associated with an increased prostate cancer risk at the population level regardless of the COX-2 inhibition. This may be explained by systematic differences between prescription NSAID users and non-users. In contrast, aspirin use is associated with a decreased overall prostate cancer risk. Further studies on aspirin and prostate cancer will be needed.