Preclinical studies suggest that non-aspirin non-steroidal anti-inflammatory drugs (NSAIDs) may improve survival of ovarian cancer. We examined the association between non-aspirin NSAID use and ovarian cancer mortality.

All women in Denmark with a first diagnosis of epithelial ovarian cancer between 2000 and 2012 were identified. We obtained information on drug use, mortality outcomes, and potential confounding factors from nationwide registries. Cox regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between postdiagnosis non-aspirin NSAID use (≥1 prescription) and ovarian cancer-specific or other-cause mortality compared with non-use (no prescriptions). The influence of competing risks was evaluated using the sub-distribution hazards model proposed by Fine and Gray.

Among 4117 patients, any postdiagnosis use of non-aspirin NSAIDs was not associated with either ovarian cancer (HR = 0.97, 95% CI = 0.87-1.08) or other-cause (HR = 0.99, 95% CI = 0.77-1.27) mortality, however, inverse associations for ovarian cancer mortality were observed with high cumulative (HR = 0.75, 95% CI = 0.60-0.94) or high-intensity (HR = 0.86, 95% CI = 0.72-1.03) postdiagnosis use of non-aspirin NSAIDs. The associations differed substantially with histological subtype of ovarian cancer, with only inverse associations observed for serous ovarian cancer (HR = 0.87, 95% CI = 0.77-0.99). Among a smaller number of patients with a non-serous tumor, postdiagnosis non-aspirin NSAID use was associated with increased ovarian cancer mortality.

Any postdiagnosis use of non-aspirin NSAIDs did not influence ovarian cancer mortality overall, however, more intensive use was associated with improved survival of serous ovarian cancer.