CD81tumor-infiltrating lymphocytes at primary sites as a possible prognostic factor of cutaneous angiosarcoma

Tumor-infiltrating lymphocytes (TILs) have been reported as a prognostic factor in various cancers and are a promising target for immunotherapy. To investigate whether TILs have any impact on the prognosis of angiosarcoma patients, 55 non-treated patients (40 patients at stage 1 with cutaneous localized tumors, 4 patients at stage 2 with lymph node metastases and 11 patients at stage 3 with distant metastases) with angiosarcoma were evaluated retrospectively by immunohistochemistry stained CD4, CD8, FOXP3 and Ki67. The Kaplan-Meier method was used to estimate overall survival with patients at stage 1. Survival differences were analyzed by the log-rank test. Patients with higher numbers of CD8(+) TILs in their primary tumors survived significantly longer compared with patients with lower values. Moreover, the number of CD8 in TILs was positively correlated with a distant metastasis-free period. The total number of primary TILs (CD4 plus CD8) and CD8(+) primary TILs of stage 3 patients with distant metastases was positively correlated with their overall survival. To evaluate whether CD8(+) effector T cells are activated or differentiated, flow cytometric analysis of peripheral blood mononuclear cells (PBMC) was performed. The percentages of CD8(+) T cells producing IFN- in PBMC were significantly higher in patients with angiosarcoma (n=10) compared not only with that of healthy controls (n=20) but also patients with advanced melanoma (n=11). These results suggest that anti-tumor immunity is clinically relevant in angiosarcoma. What's new? Tumor-infiltrating lymphocytes (TILs) have been reported to be a prognostic factor in various cancers. In this study, the authors investigated whether TILs have any impact on the prognosis of angiosarcoma. They found that higher numbers of CD8(+) TILs correlated with both a longer period free of distant metastases, and a more favourable prognosis. PBMC analysis showed that patients with angiosarcoma also had higher numbers of CD8(+) effector T cells than did healthy controls. TIL-based immunotherapy may thus provide a promising approach to the treatment of angiosarcoma.