Immunophenotyping of tumor-infiltrating mononuclear cells in ovarian carcinoma

Infiltrating mononuclear cells play an important role in many types of cancer. The aim of this work was to determine the immunologic characteristics of mononuclear cellular infiltrate in ovarian cancer as compared to benign ovarian tumors. Paraffin-embedded tissues obtained from 52 ovarian carcinomas and 21 benign ovarian neoplasms were examined immunohistochemically to demonstrate suppressor/cytotoxic T cells and macrophages by using CD8 and CD68 monoclonal antibodies, respectively. The mean percentage of CD8+ cells was much higher in the malignant than in the benign group (P=0.00009). Similarly, the mean level of CD68+ cells was significantly higher in carcinomas than in benign cases (P=0.006). There was a significant negative correlation between the percentage of CD8+ cells and CD68+ cells in the malignant group (P=0.000002). Conversely, no correlation could be obtained between the values of these two cell types in the benign lesions. In the malignant group, although the percentages of CD8+ cells and CD68+ cells were not related to tumor differentiation, they were significantly related to tumor type. CD8+ cells were significantly higher in the serous (P=0.02), and CD68+ cells were higher in the mucinous carcinomas (P=0.0005). CD8+ T cells and macrophages constitute a major component of the infiltrating mononuclear cells in ovarian carcinoma. Their frequency seems to be related to the tumor type rather than the degree of tumor differentiation.