Objectives: Ovarian cancer is a heterogeneous disease, where chronic inflammation plays a key role in carcinogenesis. In this study, it is aimed to analyze the relationship with prognosis and chemotherapy response to clinicopathologicalnvariables in epithelial ovarian cancers such as proliferation of PD-1 +, CD8 +, CD4 +, CD3 + T-lymphocytes infiltrating the tumor and tumor stroma.Material and methods: Seventy-six cases diagnosed with primary epithelial ovarian tumor from biopsy or surgical resection materials were included in the study. Immunreactivity of CD3, CD4, CD8, PD1 was evaluated immunohistochemically in lymphocytes in tumor infiltrating lymphocytes and stromal lymphocytes.Results: Seventeen (22.4%) of the cases were Type I, 59 (77.6%) of them were Type II ovarian carcinoma. PD-1 positivity was observed in stromal and intraepithelial lymphocytes in 22 (28.9%) of 76 cases. In the presence of PD-1 + T-lymphocytes that infiltrate tumor and stroma, disease-free survival are shorter (p = 0.037). The presence of stromal CD4 + and CD8 + T-lymphocytes was more common in late stage patients (p = 0.012, p = 0.036; respectively). The disease-free and overall survival rate was statistically significantly shorter in the presence of CD8 + T lymphocytes (p = 0.009, p = 0.003; respectively).Conclusions: CD3, CD4 and CD8 may contribute to PD-1 mediated tumor control. Anti PD-1 therapy may be an alternative to chemotherapy in PD-1 positive patients. Identifying patients who do not respond to chemotherapy through PD-1 expression prior to immunotherapy will help develop potential personalized immunotherapy
