Features of distribution of intratumoral lymphocytes in ovarian epithelial tumours of different histological types and degree of malignancy

Ovarian cancer is the leading cause of death from gynaecological cancers worldwide. In Georgia, ovarian cancer ranks fourth in terms of prevalence, and third in terms of mortality rate. According to the latest epidemiological data, there will be 21,421 new cases of ovarian cancer and 13,770 deaths from ovarian cancer in the United States in 2021. Due to the lack of early screening methods and asymptomatic clinical courses, most ovarian cancer is diagnosed at an advanced stage, when the prognosis of the disease is already poor. Despite the advances in modern medical treatment and surgery, ovarian carcinoma remains the most lethal gynaecological cancer. The 5-year survival rate is 46% for all stages combined. The microenvironment of ovarian carcinomas is mainly represented by macrophages, dendritic cells, neutrophils and lymphocytes. Epithelial ovarian carcinoma-infiltrating lymphocytes (TIL) have attracted much interest in the last five years. Ovarian cancer is a heterogeneous disease concerning tumour-infiltrating lymphocytes and TILs. In terms of histological subtypes, most studies include only high-grade serous carcinomas of the ovary, and studies on other histological types are scarce. The results of our study show that the quantitative evaluation of T lymphocytes and their subpopulations does not show a statistically reliable correlation between different histological types of tumours, which may be due to the intratumoral heterogeneity and individual specificity of tumours.