Wang B, et al. - In a discovery (n=226; 60 deaths) cohort and a validation cohort (n=417; 103 deaths), researchers illustrated the prognostic ability of stromal lymphocytic infiltration (SLI) in resectable urothelial carcinoma of the bladder (UCB). In this analysis, they categorized SLI into intense (≥50% SLI) and non-intense (<50% SLI). The median follow-up time for the discovery cohort was 58.1 and for the validation cohort it was 64.9 months. In the discovery cohort, SLI were intense in 38.1% of patients vs 20.9% in the validation cohort. In both cohorts, findings suggested a positive association of SLI score with histological grade, tumor stage, and lymph node status. Investigators reported that intense preexisting SLI was validated as a reliable poorer prognostic marker for survival in UCB, which can add to the prognostic importance of the AJCC/UICC TNM classification.