Assessing adherence to hormone therapy (HT) in breast cancer (BC) patients receiving care at BC unit in a Uruguayan university of Hospital de Clínicas.

Abstract

e12026 Background: Adjuvant HT in Hormone Receptors (HR) + BC increases overall survival (OS). Adherence to therapy is a complex and multifaceted issue that can alter outcomes; however, not much of it is known abouth this in routine clinical practice. Methods: This was a retrospective study that enrolled patients treated with HT because of HR+ BC (stages I-III) at the BC unit in the 2002-2012 period. Methods: The proportion remaining on endocrine therapy was analysed by Kaplan-Meier curve. Univariate analysis (log rank test) was used to identify the factors that might independently impact on such discontinuation. The study was approved by the Ethics Committee of the Hospital de Clínicas. Results: 139 (73.1%) of the 190 patients enrolled were postmenopausal; their median age being 61 years. Most patients were single or divorced or widowed (121, 63.7%) and resided in the capital (125, 65.7%). Most tumors (166, 87.3%) were ductal carcinomas and most presented at a low histological grade: HG 2-3: 112 (58.9%). The distribution by stage was: SI: 63 (33.1%); SII: 82 (43.1%); SIII 39 (20.5%); S0 6 (3.1%). At the end of their first, second, third, fourth and fifth years of treatment; 95.3%, 87.9%, 80.6%, 76.4% and 69.5% of the patients still adhered, respectively. Adherence was not associated with either age (p = 0.687), menopausal status (p = 0.449), marital status (p = 0.221), origin (p = 0.5640), or stage (p = 0.168). The patients who received combined HT (tamoxifen followed by AI) adhered better than those who received one drug alone (p = 0.017). Conclusions: we assessed the adherence to HT in real life and found that it was reduced by 30.5% in 5 years, despite patients were well informed about the well-known benefit in terms of OS, of being a well-tolerated treatment and of being provided for free. These results are similar to or even better than those reported in several international studies. Further investigation is needed to understand why patients interrupt HT. We need to work harder to increase compliance, given the potential impact this may have on the patients’ OS.