Prognostic Significance of CD4+ and CD8+ T Cell Infiltration Within Cancer Cell Nests in Vulvar Squamous Cell Carcinoma

Background: The clinicopathological significance of the local spontaneous immune reaction in vulvar squamous cell carcinoma remains unclear. The purpose of this study was to clarify the role of the subtypes of tumor-infiltrating lymphocytes, both individually and synergistically. Methods: Seventy-six patients with verified histopathological data and complete clinical history were included into the study. We collected 76 paraffin-embedded samples of the primary tumor. The presence of CD4(+) and CD8(+) T cells was evaluated by immunohistochemistry and compared with commonly recognized prognostic factors. The primary end point analyzed was the overall survival. Results: CD4(+) and CD8(+) T cells were detected both within the nests of carcinoma and in the stroma, but only the infiltration within cancer cell nests was further analyzed. There was significant positive correlation (Spearman rho test R = 0.282, P = 0.014) between the number of intratumoral CD4(+) and CD8(+) T cells. No correlation was observed between the number of tumor-infiltrating CD4(+) and CD8(+) T cells and the patients' survival. Patients were classified into the following 4 groups (CD4(+)/CD8(+), CD4(-)/CD8(-), CD4(+)/CD8(-), CD4(-)/CD8(+)), but none of them correlated with overall survival. Conclusions: These data support the statement that CD4(+) and CD8(+) T cells cooperate within cancer cell nests, but this spontaneous immune reaction is an individual feature not influencing the prognosis. Intratumoral CD4(+) T cells might control or reflect the immune responses against cancer cells, whereas CD8(+) T cells do not seem to work as sufficient effectors in tumor tissues.