Breast cancer (BC) is a significant medical and social problem, as it is the leading cause of cancer-related mortality in women worldwide. The dissertation study studies and solves a significant problem - optimization of diagnosis and assessment of the course of BC with biomineralization. In the process of solving the current situation, the following research methods were used: macroscopic, histological, histochemical, morphometric, immunohistochemical, and physicochemical methods (scanning and transmission electron microscopy, energy dispersive X-ray spectroscopy), statistical data processing using parametric and non-parametric criteria. The study was conducted on material obtained during surgical operations at the Sumy Regional Clinical Oncology Center (SRCOC). Also, during the retrospective analysis, 469 cases of puncture biopsies of invasive breast cancer from the archive of the Scientific Center for Pathomorphological Research of the Department of Pathological Anatomy of Sumy State University for the period 2014- 2019 were studied. Puncture biopsies were examined for immunohistochemical expression of ER, PR, Her2-neu receptors, and microcalcifications. The preliminary study was conducted on 60 BC tissue samples. The work planned to study 30 samples of tumor tissue with signs of pathological biomineralization in microcalcifications and 30 samples of breast cancer without signs of biomineralization. The dissertation research results revealed the clinical and epidemiological features of breast cancer in the Sumy region in the form of exceeding the national incidence rates of BC and their decrease with the onset of the COVID-19 pandemic. According to the results of the study of the prevalence of breast cancer in Ukraine by region (per 100,000 female population) in the period 2015-2020, the most significant number of cases was registered in Kyiv, Kirovohrad, Zaporizhzhia, Sumy, Kharkiv, and Kherson regions, and the lowest incidence rates in Chernivtsi, Ternopil, Rivne, Ivano-Frankivsk and Transcarpathian regions. The increase in the number of detected breast cancer cases in the Sumy region is influenced by a complex of factors, particularly improving the quality of clinical and morphological diagnostics in the area.The reasons for the high level of detection of morbidity in the Sumy region are the improvement of laboratory-instrumental methods of diagnosis, the comprehensive implementation of immunohistochemical examination of tumors of BC for all patients, diagnostic trepanobiopsy of BC, modern mammographs, computer and magnetic resonance imaging machines, access to molecular genetic testing, improved financing of the oncology industry through the mechanisms of the National Health Service of Ukraine (NHSU). This is confirmed by exceeding the national indicators of detection of early stages of BC during 2015-2020. A complex histochemical study of the samples (staining with alizarin red and by the von Koss method) revealed the presence of microcalcifications of BC of different phase compositions - oxalates and calcium phosphate. The common finding of microcalcifications of hydroxyapatite and oxalate phase composition in some cases of invasive gastric cancer demonstrates different spatial localization of microcalcifications, which indicates that biomineral deposits have other conditions for the formation of microcalcifications. This fact suggests that the development of malignant tumors of the gastrointestinal tract occurs against the background of preexisting benign pathology, the legacy of which is microcalcifications consisting of calcium oxalate. The dissertation research results can be used as a theoretical basis for optimizing diagnosis and assessing the risk of breast cancer complications using pathomorphological diagnostic methods. The obtained results, conclusions, and practical recommendations of the dissertation supplement and deepen the theoretical understanding of the epidemiology, the pathogenesis of breast cancer, and the development of bone metastases. The data presented in the dissertation research are used in the educational process of training specialists in medicine based on theoretical and clinical departments of pathological anatomy, pathological physiology, and oncology. During the dissertation work, the "Method of study of breast cancer microcalcifications from paraffin histological blocks" was patented. The developed technique is already used in scientific activity and is promising for implementation in medical and diagnostic practical work.
