PATHOLOGICAL BIOMINERALIZATION IN OVARIAN TUMORS

In 2018, 3,539 new cases of malignant ovarian neoplasms and 1,808 related deaths were registered in Ukraine. The one-year survival rate for ovarian cancer patients is 65 %, while the three-year and five-year survival rates are 40 % and 32 %, respectively. The aim of the work is to analyze the scientific literature to estimate the prevalence, mechanisms of development and diagnostic value of pathological biomineralization (PBM) in ovarian tumors. Calcification is one of the clinical features of ovarian cancer. Approximately 8% of cases are diagnosed by computed tomography. PBM in ovarian tumors can be divided into 2 groups: calcification of the tumor parenchyma, capsule or stroma and biomineralization as psammoma bodies (PB). Calcification of the ovarian cancer parenchyma is a secondary change in tumor tissue due to the secretion of collagen and direct effect of hormones. Nevertheless, the PBM development in the ovarian capsule, stroma or PB is one of the possible protective responses of tissues to the tumor spread and invasive growth. The presence of PT is a reliable pathognomonic sign of malignant ovarian tumors and can be identified both by instrumental diagnostic tests (ultrasound, CT and MRI) and histology. Also, the presence of biominerals contributes to an increase of five-year survival rates for patients with ovarian tumors up to 50%. The study of the chemical composition of calcifications of serous ovarian tumors by various methods showed the presence of inorganic elements such as aluminum (Al), cadmium (Cd), potassium (K), cobalt (Co), chromium (Cr), iron (Fe), zinc (Zn) and copper (Cu), magnesium (Mg) and sodium (Na). It was found that Calcium (Ca) and phosphorus (P) formed the biomineral basis of ovarian tumor calcifications. It has also been found that biomarkers of mineralization such as BMP-2, OPN, Runx2 and Osterix were also involved in pathological calcification in serous ovarian carcinomas. It was shown that ovarian tumors PBM development involves a few different mechanisms. It may indicate a link between the tumor stage and the diagnostic value of calcifications in ovarian tumors, as well as the subsequent prognosis of this disease. There is also a variation in the prevalence of calcification in different histological types of ovarian tumors. PBM is detected predominantly in the serous ovarian adenocarcinoma. However, for serous adenocarcinoma with a large number of PB, a separate nosology, “Psammocarcinoma”, was identified. It is obvious that the small calcifications (less than 200 μm) are not detected by radiology. That is why their detection occurs most often with histology. However, there is a lack of information on the prevalence of PBM in ovarian tumors, which would be based on a detailed histological and histochemical study.