Adjuvant radiation therapy and survival for adenoid cystic carcinoma of the breast.

PURPOSE: The assess the clinical value of different types of surgical procedures and further analyze the effect of adjuvant radiation therapy (RT) for adenoid cystic carcinoma (ACC) of the breast.

METHODS: Patients with ACC of the breast were identified using a population-based national registration database (Surveillance, Epidemiology, and End Results, SEER). The Kaplan-Meier method and Cox regression models were performed to determine the impact of the surgical procedures and adjuvant RT associated with cause-specific survival (CSS) and overall survival (OS).

RESULTS: A total of 478 patients with ACC of the breast were identified. The median follow-up was 59 months. The 10-year CSS and OS were 87.5% and 75.3%, respectively. For the Kaplan-Meier analysis, the 5-year CSS were 96.1%, 91.8%, 90.2%, and 94.1% in patients that received lumpectomy + adjuvant RT, lumpectomy alone, mastectomy alone, and mastectomy + adjuvant RT, respectively (p = 0.026). In the multivariate Cox analyses, lumpectomy + adjuvant RT was an independent prognostic factor for CSS and OS. Patients that received lumpectomy + adjuvant RT had better survival rates than patients that underwent lumpectomy only (CSS, p = 0.018; OS, p = 0.031) and mastectomy only (CSS, p = 0.010; OS, p = 0.004).

CONCLUSION: ACC of the breast has an excellent prognosis. Breast-conserving surgery is a reasonable alternative for patients with ACC of the breast, and adjuvant RT after lumpectomy improved survival rates.