Rouanne M, et al. - In patients with high-grade pT1 non–muscle-invasive bladder cancer (NMIBC), researchers determined the association of stromal lymphocytic infiltration with clinicopathological parameters and their correlation with outcomes. They retrospectively analyzed 147 patients with primary high-grade pT1 NMIBC who had transurethral resection of the bladder. For scoring stromal tumour-infiltrating lymphocyte (TIL) density, percentage of the stromal area infiltrated by mononuclear inflammatory cells over the total intratumoural stromal area was calculated. Correlation with cancer-specific survival (CSS) was assessed as the primary end-point. Participants were followed for a median duration of 8.2 years (6.1–9.5). Findings revealed an association between a higher density of stromal TILs and the tumour invasion depth in pT1 NMIBC. There was no link between the level of TILs and survival outcomes. The association of tumour aggressiveness with an increased adaptive immune response in pT1 NMIBC was suggested.