Problems of Radiation Medicine and Radiobiology

O. O. Lytvynenko¹, O. O. Lytvynenko², V. O. Demianov¹, K. V. Barannikov³

¹State Institution «National Research Center for Radiation Medicine, Hematology and Oncology of the National Academy of Medical Sciences of Ukraine», 53 Yuriia Illienka St., Kyiv, 04050, Ukraine
²State Non"profit Institution «National Cancer Institute», 33/43 Zdanovska Julia St. , Kyiv, 03022, Ukraine
³Shupyk National University of Healthcare of Ukraine, 9 Dorohozhytska St., Kyiv, 04112, Ukraine

INFLUENCE OF NEOADJUVANT CHEMOTHERAPY ON THE SIZE AND SPREAD OF THE TUMORAL PROCESS AND INDICATORS OF PROLIFERATIVE ACTIVITY IN BREAST CANCER PATIENTS WHO SUFFERED FROM THE CHRONICLE NUCLEAR POWER PLANT ACCIDENT

Objective. To assess the impact of neoadjuvant chemotherapy on the size and spread of the tumor process and indicators of proliferative activity in breast cancer patients who suffered from the Chornobyl accident.
Materials and methods. The 96 patients with breast cancer (BC) who were exposed to ionizing radiation as a result of the Chernobyl accident were examined. Clinical, radiological, instrumental, morphological, and immunohistochemical research methods were used.
Results and conclusions. Before neoadjuvant cytostatic therapy, criteria T0, Tis, T1 was not diagnosed in any patient. As a result of treatment, complete clinical and morphological regression of the tumor was established in 16.7 % of patients. A decrease in staging criteria after neoadjuvant chemotherapy (NCT) was diagnosed in 60.4 % of patients. Analysis of patients with breast cancer by stage grouping before and after NCT showed that there were no patients at all in the study before the start of treatment. After neoadjuvant therapy, in 29.2 % of women, tumors in the breast gland were classified as stage I by their criteria. Only 2.1 % of women started treatment with stage II A. After NCT, the prevalence of the primary tumor met the criteria for stage II A in 20.8 % of patients. 53.1 % of patients started treatment with stage II B, and after neoadjuvant therapy, this stage was in 14.6 % of patients. Stage III A was detected in 22.9 % of patients before treatment, after therapy the number of patients with this stage decreased to 14.6 % of patients. 14.6 % of women started treatment with stage III B, after treatment only 3.1 % of patients were classified as this stage. Stage III C was detected in 6.2 % of patients at the beginning of treatment, after NCT, no patients with criteria related to this stage were identified. Stage IV was detected in 1.04 % of patients, both before and after NCT. A decrease in Ki-67 values under the influence of NCT was observed in 76 % of patients, and in another 16.7 % of patients complete clinical and pathomorphological regression of the tumor was observed. Thus, according to the values of proliferative activity, positive dynamics for neoadjuvant cytostatic chemotherapy was recorded in 92.7 % of patients.
Key words: breast cancer; neoadjuvant chemotherapy; tumor response to treatment; proliferative activity; extent of spread.

Problems of Radiation Medicine and Radiobiology.
2025;30:480-500. doi: 10.33145/2304-8336-2025-30-480-500

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