Comparative analysis of the effectiveness of neoadjuvant systemic therapy and primary surgical treatment of patients with BRCA-associated triple-negative T1 breast cancer

BACKGROUND: BRCA-associated triple-negative breast cancer does not only have a better overall survival rate, but also a longer recurrence-free period in compatison to patients with sporadic breast cancer. BRCA-associated triple-negative breast cancer shows high sensitivity to chemotherapeutic agents, but the benefit of systemic neoadjuvant therapy for patients with tumor size T1 in triple-negative breast cancer is unclear. AIM: The aim of the study is to determine the recurrence rate in the patients with BRCA-associated triple-negative breast cancer and to determine the recurrence rate for the group of patients with tumor size T1, depending on the initial treatment. MATERIALS AND METHODS: The study includes the data of 129 patients diagnosed with BRCA-associated triple-negative breast cancer treated in the period from 2010 to 2022 at the Department of Breast Tumors of the N.N. Petrov National Medical Research Center of Oncology. All the patients have been divided into two groups depending on the initial treatment. Group I included 93 (72.1%) patients whose treatment was started with systemic neoadjuvant therapy, group II, whose initial treatment involved surgery, included 36 (27.9%) patients. RESULTS: In group I, the number of recurrences was 22 (23.6%), and in group II 6 (16.6%). Depending on the pathomorphological response to systemic neoadjuvant therapy, the patients of group I have been separated: in the group of patients with a complete pathomorphological response, the number of relapses was 6 (13.3%), and in the group of patients with a partial pathomorphological response 16 (33.3%). A comparative analysis of 2 groups with tumor size T1 has shown that in group I the number of patients with tumor size T1 was 11 (11.8%) cases, and in group II 16 (44.4%). Subgroup comparative analysis in group I, taking into account tumor size T1, has shown that recurrence has not been observed when a complete pathomorphological response was achieved in 8 (17.7%) patients, and in the group with partial pathomorphological response in 3 (6.25%) patients with tumor size T1. A relapse has been observed in 1 (2%) case. With clinical tumor size T1 (n = 16), there was no recurrence in group II. CONCLUSIONS: Patients diagnosed with BRCA-associated triple-negative breast cancer remain at a high risk of recurrence at a later stage of the disease, but this does not apply to patients with a tumor size T1 since the difference in relapse-free survival [AP1] between patients, whose treatment was started with neoadjuvant systemic therapy and patients, whose initial treatment involved surgery % with a clinical tumor size T1, is not confirmed.