Pre- and Post-Diagnostic Non-Steroidal Anti-Inflammatory Drug Use and Colorectal Cancer Survival in Seattle Colon Cancer Family Registry

Abstract

Abstract Purpose: Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used in the general population, and regular NSAID use is associated with improved survival among colorectal cancer (CRC) patients. We examined the association of NSAID use prior to, and after, diagnosis in relation to CRC-specific and overall survival. Methods: Study subjects were incident, invasive CRC cases from the population-based Seattle Colon Cancer Family Registry. Eligible cases were 20–74 years of age, diagnosed from 1997 to 2008, and identified from the Puget Sound Surveillance, Epidemiology and End Results (SEER) Registry. NSAID use two years prior to the interview date (“pre-diagnosis period”) was collected by telephone interview at study enrollment an average of eight months after diagnosis. A follow-up questionnaire was administered approximately five years after the cases' CRC diagnosis (“post-diagnosis period”). Regular NSAID use was defined as having taken aspirin or ibuprofen at least twice per week for more than a month. Follow-up for survival and cause of death was completed through linkage to the National Death Index. Cox proportional hazard regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for associations of pre- and post-diagnostic NSAID use, and initiation, continuation and discontinuation of NSAIDs between pre- and post-diagnostic periods with survival after CRC diagnosis. Results: Compared to never users, regular NSAID use after diagnosis was associated with better overall survival (HR = 0.69, 95% CI, 0.54–0.89) and CRC-specific survival (HR = 0.48, 95% CI, 0.29–0.80). Among people who survived five years after diagnosis, both overall and CRC-specific survival were better for patients who initiated NSAID use post-diagnosis compared to never users, with HRs (95% CI) of 0.70 (0.51–0.95) and 0.43 (0.23–0.82), respectively. HR estimates were stronger for CRC-specific survival among those with non-advanced (local and regional) CRC (HR = 0.38, 95% CI, 0.18–0.77). Conclusion: Our results suggest that among long-term CRC survivors, regular use of NSAID after CRC diagnosis, including when initiated after diagnosis, is significantly associated with longer CRC-specific survival. This association is more pronounced for patients with non-advanced CRC.