Low-dose aspirin mitigates acute radiation-induced genitourinary toxicity in patients with prostate adenocarcinoma

Objective Patients undergoing radiotherapy for prostate adenocarcinoma (PCA) primarily experience genitourinary (GU) and gastrointestinal (GI) toxicity. Recent publications indicate associations between aspirin and PCA outcomes. The effect of daily low-dose aspirin on radiotherapy toxicity was assessed in a large patient population. Methods A prospectively acquired database of PCA patients treated at Emory-affiliated hospitals was queried. For patients treated with definitive radiotherapy, the association between aspirin use and physician-graded acute/late GI/GU toxicity scores was measured. Patient and treatment-related factors were used as covariates. Univariate/multivariate analyses were performed. Results Between 2001 and 2013, 877 patients were eligible for analysis. One hundred ninety patients were on daily low-dose aspirin during treatment. On multivariate analysis, aspirin was associated with reduced acute GU toxicity (odds ratio (OR) 0.71, 95 % confidence interval (CI) 0.52–0.97, p = 0.032). There was no difference in acute GI (OR 0.90, 95 % CI 0.66–1.24, p = 0.534), late GU (OR 0.94, 95 % CI 0.67–1.30, p = 0.695), or late GI toxicity (OR 0.78, 95 % CI 0.52–1.18, p = 0.246). Conclusion Aspirin use was associated with reduced acute GU toxicity in patients undergoing radiotherapy for PCA. While these results require prospective validation, aspirin use during radiotherapy for PCA should be considered, as low-dose aspirin is a safe, inexpensive medication separately indicated for many patients.