['The role of adjuvant radiation therapy (RT) for adenoid cystic carcinoma (ACC) of the breast remains unclear.', 'We queried the Surveillance, Epidemiology, and End Results database for patients with breast ACC resected between 1988 and 2005, and divided patients based on the receipt of RT. Univariate and multivariate survival comparisons were made for overall and disease-specific survival.', 'Three hundred seventy six patients met criteria for inclusion. Demographics and staging were similar between groups. Univariate analysis revealed an absolute overall and cause-specific survival benefit of 21% and 7% at 10 years (P = 0.005 and P = 0.12 respectively). In the multivariate analysis, RT was a significant predictor of overall and cause-specific survival with hazard ratios of 0.44 (95% Confidence interval (CI) = 0.22-0.88) and 0.1 (95% CI: 0.01-0.88), respectively.'] Is adjuvant radiation therapy associated with improved survival for adenoid cystic carcinoma of the breast?