TIM-3 expression in tumor and stromal cells are associated with the prognosis in patients with epithelial ovarian cancer.

T-cell immunoglobulin and mucin domain-containing molecule 3 (TIM-3) has been reported to be overexpressed and associated with poor prognosis in solid tumors. However, its features and prognostic value in epithelial ovarian cancer (EOC) remain undetermined. In this study, we aimed to characterize TIM-3 expression and its prognostic significance in patients with EOC. A total of 134 EOC patients and 20 healthy controls from North China were included. TIM-3 mRNA and protein expression in EOC tumor tissues and benign ovarian tissues were detected by real-time quantitative PCR and immunohistochemistry. The distribution of TIM-3 protein in different regions of EOC tissue (tumor cells and the tumor microenvironment) were evaluated by multicolor immunofluorescence. Associations between their expression and clinicopathological parameters as well as survival analyses were performed. The results showed that high expression levels of TIM-3 mRNA were significantly associated with shorter progression-free survival (PFS; P < .001, hazard ratio [HR] = 1.57, 95% confidence interval [CI] = 1.29-1.91) and overall survival (OS; P = .013, HR = 1.31, 95% CI = 1.06-1.63) durations in EOC patients. High TIM-3 expression levels in tumor cells had shorter PFS (HR = 1.62, 95% CI = 1.09-2.46, P = .018) and OS (HR = 1.81, 95% CI = 1.19-2.75, P = .006) compared with those low TIM-3 expression levels. Similarly, TIM-3 in the tumor microenvironment was also an independent factor that affected the clinical outcome of EOC patients (PFS: HR = 1.99, 95% CI = 1.29-3.08, P = .002; OS: HR = 2.13, 95% CI = 1.37-.30, P = .001). These findings indicated that IM-3 may be a potential biomarker for predicting prognosis and immunotherapy efficacy in patients with EOC, exerting different roles on tumor cells and tumor microenvironment.