Introduction. An important aspect of cancer treatment today is the concept of immuno-targeted therapy, which requires a deep understanding of the characteristics of immune reactions in the body of a cancer patient. Bone marrow is the central organ of immunopoiesis, therefore, along with the study of tumor characteristics, attention is paid to the bone marrow. The study of the cellular composition of the bone marrow in some types of cancer revealed a number of features of hematopoiesis, which requires further deeper analysis.Purpose. To study the parameters of hematopoiesis in patients with primary and recurrent ovarian cancer.Materials and methods. The paper presents data from 68 patients with a verified diagnosis of primary (n = 43) and recurrent (n = 25) ovarian cancer. The study was dominated by serous adenocarcinoma of high grade. Stage I was established in 13.2 % of cases, II – in 5.9 %, III – in 60.3 %, IV – in 20.6 %. The bone marrow was harvested by puncture of the posterior iliac spine (spina iliaca posterior superior). Parameter assessment and myelogram calculation were performed by two physicians, morphologists. The content of myelokaryocytes, indicators of granulocyte, erythroid lineage, the content of lymphocytes, monocytes were analyzed, and myelogram indices were assessed. In all patients microscopy of bone marrow samples excluded metastatic lesions. Statistical data processing was performed using the SPSS Statistics v. 21 package.Results. The analysis of bone marrow samples from patients with ovarian cancer revealed differences with the norm for both primary and recurrent ovarian cancer. Most punctates were normocellular, but average myelokaryocyte count in both groups was below normal. With recurrent ovarian cancer, a reduced content of promyelocytes and metamyelocytes was noted, whereas with primary cancer, all young forms of neutrophils was below normal. An increase in segmented neutrophils without a change in the percentage of cells of the granulocytic lineage was observed in primary ovarian cancer, and in one third of the samples of bone marrow an increased number lymphocytes and monocytes were noted. With recurrent ovarian cancer lymphocytes were increased in 2/3 of samples, monocyte – in 48 %. A change in the proportion of cells of the erythroid lineage was observed in both recurrent and primary cancers: depletion of the pool of basophilic normoblasts and polychromatophils with an unchanged number of erythrokaryocytes, an increase in oxyphilic forms were noted.Conclusion. The revealed changes in hematopoiesis in ovarian cancer reflect the aggressive course of high-grade tumors, which can be considered as a result of the systemic influence of the tumor, and the obtained data can serve as the basis for a detailed immunophenotypic study of bone marrow in ovarian cancer.

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