Ten-Year Results of Complex Treatment of Patients with Primary Local Advanced Breast Cancer

Purpose: To present ten-year results of complex treatment of patients with primary locally advanced breast cancer, depending on the type of ionizing radiation used and chemotherapy regimens. Material and methods: The study included 250 patients with stage T2‒4N0‒3M0 breast cancer, aged 34–69 years (mean age 48.1±5.6 years), who underwent complex treatment (courses of NChT and AChT, hormonal and targeted therapy (according to indications), radical mastectomy and radiation therapy with various types of ionizing radiation) at the Research Institute of Oncology from 2007 to 2020. The mean follow-up period was 10±2.7 years. Main group (n=110) ‒ neutron therapy, comparison group I (n=80) ‒ photon therapy, comparison group II (n=60) ‒ electron therapy. Results: Ten-year relapse-free survival of patients with locally advanced breast cancer (PL BC) after adjuvant neutron therapy on the area of the anterior chest wall was 92.5±3.5 %, after photon therapy ‒ 70.9±5.6 %, after electron therapy ‒ 73.6±7.1 %. There were statistically significant differences between the main group and comparison groups (p<0.05). Overall survival over a ten-year follow-up period in the main group was 87.5±3.8%, in comparison group I ‒ 73.6±8.6 %, in comparison group II ‒ 38.8±10.0 %. Between neutron and electron therapy – p<0.05. In the group with neutron therapy and chemotherapy according to doxorubicin + taxane regimens, ten-year metastatic-free and overall survival was 72.8±10.0 % and 96.7±3.3 %, respectively, compared with neutron therapy and chemotherapy according to FAC/CAF regimens ‒ 44.0±14.7 % and 83.7±6.7 %, respectively (p<0.05). Neutron therapy was well tolerated by all breast cancer patients. Radiation reactions of the skin predominantly I‒II degree. Radiation pneumonitis after neutron therapy ‒ in 6 (5.4 %) out of 110 patients, after photon therapy ‒ in 17 (21.25 %) out of 80 patients with PL BC (p=0.023). Conclusion: Thus, the use of adjuvant neutron therapy in patients with breast cancer T2‒4N0‒3M0 is a safe method and has significantly better results in ten-year relapse-free survival, which makes it possible to increase the effectiveness of complex treatment. In combination with doxorubicin + taxane chemotherapy regimens, neutron therapy increases the 10-year metastatic-free and overall survival rates.