EVALUATION OF THE EFFECTIVENESS OF NEOADJUVANT CHEMOTHERAPY IN BREAST CANCER

Relevance: Breast cancer is the most common cancer among women. Modern treatment of locally advanced breast cancer requires a multidisciplinary approach, including local treatment: surgical and radiotherapy, systemic treatment, and a wide range of medications. The importance of systemic therapy is to improve relapse-free survival based on the control of micrometastases with the potential to spread throughout the body. Systemic therapy for operable breast cancer includes adjuvant therapy and neoadjuvant therapy. Hormone therapy, chemotherapy, and targeted therapy represent systemic therapy, which can be prescribed individually or in combination. For the most effective breast cancer treatment, tumors are classified into subtypes depending on the expression of biological markers. The presence of expression of the estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), and the rate at which tumor cells divide are determined by determining the Ki67. It is known that neoadjuvant chemotherapy (NCT) has clinical significance in locally advanced and inoperable breast cancer. NCT increases the frequency of organ-preserving operations and the overall survival rate when a complete pathomorphological regression of the tumor (pCR) is achieved. The study aimed to conduct a literature review of previously published publications on the effectiveness and expediency of neoadjuvant chemotherapy for breast cancer. Methods: The search and analysis of scientific publications were carried out in the databases Web of Science, Pubmed, and Scopus for ten years, from 2013 to 2023. According to the search, about 3000 articles were found, and 39 sources were left during the selection according to the inclusion and exclusion criteria Results: Efficiency of NСT depending on different immunophenotypes in breast cancer patients was established. Tumor response was assessed according to RECIST criteria. A complete pathological response was observed more often in more aggressive subtypes of breast cancer – Her2-positive and triple-negative cancer. The relationship between pCR and long-term outcomes – OS and DFS have also been established. Conclusion: Neoadjuvant chemotherapy is a systemic treatment of breast cancer, the main purpose of which is to reduce the size of the tumor for the possibility of performing organ-preserving surgery, as well as to increase the overall and relapse-free survival rates. NCT allows for evaluating the effectiveness of therapy in vivo and using alternative treatment regimens without tu-mor response to the therapy.