Prognostic effect of beta blockers (BB) in triple-negative breast cancer (TNBC) patients.

Abstract

1061 Background: BB drugs have been used for decades worldwide, typically to treat hypertension and arrhythmias. Despite its therapeutic indication, evidence from recent epidemiological studies suggested that BB intake can improve prognosis of patients (pts) with cancer. With the present study we aimed at assessing whether BB intake is associated with improved prognosis in postmenopausal pts with TNBC, which represents one of the most aggressive cancers. Methods: We retrospectively identified 659 postmenopausal pts operated between 1997 and 2008 at the European Institute of Oncology, Milan, for a primary TNBC. Pts with advanced disease at diagnosis, presurgical systemic treatment or history of other cancers were excluded. The effect of BB intake on the risk of breast cancer recurrence and death from breast cancer (BC) was evaluated through competing risk survival analyses and multivariable Cox regression models. Results: At the time of cancer diagnosis, 61 pts (9.3%) out of 659 were currently using BB, while 598 (90.7%) were not. Median age was 63 years for the BB users and 60 years for the non-users (p value 0.048). All other characteristics—such as tumor size, lymph-nodal involvement, Ki-67, tumor grade, perivascular invasion, type of surgery and adjuvant therapy—were equally distributed between BB users and non-users. Median follow-up was 6 years for both groups. The 5-year cumulative incidence of BC recurrences was 11.7% and 24.1% for BB users and non-users, respectively (p = 0.030). After adjusting for age, tumor size, lymph nodal involvement, grade, perivascular invasion and use of other antihypertensive drugs, the beneficial impact of BB use remained statistically significant, with an hazard ratio of 0.44 (95% CI 0.21-0.98; p = 0.044). The 5-year cumulative incidence of BC deaths was 8.2% and 12.5% for BB users and non-users, respectively (p = 0.185). Hypertension and antihypertensive drugs other than BB did not have any significant impact on recurrence and survival. Conclusions: In this series of postmenopausal pts with primary TNBC, BB intake was associated with a significantly decreased risk of BC recurrence. Additional studies evaluating the potential benefits of BB on cancer prognosis are warranted.