The association of aspirin use with overall survival of patients with inoperable non-small cell lung cancer: a retrospective study

BACKGROUND: Studies have indicated that individuals taking aspirin have a reduced risk of cancers and have also established chemo-preventive benefit of aspirin in colorectal cancer. However, research on the association between aspirin use and the survival in patients with lung cancer has revealed inconsistent results. In this study, we investigated the effect of aspirin use on the survival of inoperable non-small cell lung cancer (NSCLC) patients. METHODS: We identified a cohort of 38,842 patients diagnosed with NSCLC between 2000 and 2012 using the Taiwan’s National Health Insurance Research Database and used propensity score matching to reduce possible confounding factors. In total, 9864 patients (4932 matched pairs) were included in the matched cohort. Aspirin exposure was analyzed to identify a possible association with mortality in patients with inoperable NSCLC. Time-dependent Cox regression models were used to calculate the hazard ratios (HRs) and the 95% confidence intervals (95% CIs) that corresponded with aspirin exposure. RESULTS: A total of 4979 patients used aspirin at the time of diagnosis of NSCLC. The median overall survival (OS) of the aspirin users was 1.73 (interquartile range, 0.94–3.53) years compared with the 1.30 (interquartile range, 0.69–2.62) years of the non-aspirin users. The Cox proportional hazard model with the time-dependent covariate revealed that aspirin use was associated with a significantly longer OS (HR: 0.83, 95.0% CI: 0.80–0.86). After controlling the sociodemographic characteristics (age, sex, income, and level of urbanization) and lung cancer treatments by propensity score matching, the aspirin users still had a significantly longer OS than the non-aspirin users (HR: 0.79, 95.0% CI: 0.75–0.83). CONCLUSION: Aspirin use is associated with a longer OS in patients with inoperable NSCLC, suggesting that aspirin has a potential anticancer effect. These results warrant further randomized clinical trials to evaluate the actual role of aspirin in the treatment of NSCLC patients.