Prognostic impact of tumor infiltrating lymphocytes on patients with metastatic urothelial carcinoma receiving platinum based chemotherapy

The impact of tumor infiltrating lymphocytes (TILs) on survival was confirmed in various cancer types. Our study aims to investigate the prognostic role of TILs on survival in patients with metastatic urothelial carcinoma (mUC) receiving platinum based chemotherapy. Patients who were diagnosed to have pathologically proved mUC between 1997 and 2016 and received palliative chemotherapy with platinum based regimen were recruited into our study. Kaplan-Meier curves and Cox regression analysis were constructed for overall survival (OS). A total of 259 mUC patients were enrolled into our study with median age 63 years and median follow-up visit 13.5 months. Of these patients, 179 (69%) had intense TILs and 80 (31%) had non-intense TILs. The median OS were 15.7 vs. 6.7 months (P = < 0.001) for patients with intense TILs and non-intense TILs, respectively. Subgroup analysis showed that TILs was both prognostically significant no matter for urothelial carcinoma of bladder and upper tract urothelial carcinoma. Multivariate analysis showed that TILs were strongly prognostic factors related to OS. Our study suggested mUC patients with intense TILs were independently associated with survival. Based on our study, TILs is clinically useful for outcomes anticipation and risk stratification, as well as patients counseling.