Analysis of FoxP3+ T-Regulatory Cells and CD8+T-Cells in Ovarian Carcinoma: Location and Tumor Infiltration Patterns Are Key Prognostic Markers

PURPOSE: Tumor infiltrating CD4+CD25+FoxP3+ regulatory immune cells (Treg) have been associated with impaired anti- tumor immune response and unfavorable prognosis for patients affected by ovarian carcinoma, whereas CD8+ T-cells have been found to positively influence survival rates in a large panel of solid tumors. Recently, density, location and tumor infiltration patterns of the respective immune cell subtypes have been identified as key prognostic factors for different types of tumors. PATIENTS AND METHODS: We stained 210 human ovarian carcinoma samples immunhistochemically for FoxP3 and CD8 to identify the impact different immune cell patterns have on generally accepted prognostic variables as well as on overall survival. RESULTS: We found that FoxP3+ cells located within lymphoid aggregates surrounding the tumor were strongly associated with reduced survival time (P = 0.007). Central accumulation of CD8+ effector cells within the tumor bed shows a positive effect on survival (P = 0,001). CONCLUSION: The distribution pattern of immune cells within the tumor environment strongly influences prognosis and overall survival time of patients with ovarian carcinoma.