LAUSR

Introduction: The most frequent subtype of breast cancer is the luminal one, in 70 to 80% of cases; the poor response to neoadjuvant chemotherapy of these tumors positions neoadjuvant hormone therapy as a treatment option. Materials and Methods: An observational, descriptive, historical cohort study was conducted in patients with hormone receptor (HR positive and HER2-positive breast cancer, managed with neoadjuvant hormone therapy in the INC (National Cancer Institute, for its initials in Spanish), with the aim of evaluating their clinical and pathological response. Results: 57 patients were managed with neoadjuvant hormone therapy. Most stage IIA patients (40.3%, n = 23). 86% (n = 49) had luminal A tumors. Letrozole was the most widely used drug, in 78.9% (n = 45). The overall response rate (ORR) was reached in 94.6% (n = 53); and 10.7% of the patients (n = 6) achieved complete clinical response (cCR). Complete pathological response (pCR) was achieved only in one patient. Conservative surgery was possible in 56.9% (n = 29) of the patients. There was no difference between the type of aromatase inhibitor (AI) and the duration of neoadjuvant hormonal treatment with the clinical response. With a median follow-up of 3 years (0.6 and 6 years), no disease progression was reported in any of the patients in the study. Conclusion: The results of this study support the neoadjuvant hormone therapy recommendations for postmenopausal patients older than 65 years with luminal breast cancer, with well or moderately differentiated tumors, strongly HR positive and low Ki 67.