Effectiveness and safety of adjuvant treatment of tislelizumab with or without chemotherapy in patients with high-risk upper tract urothelial carcinoma: a retrospective, real-world study

Background Upper tract urothelial carcinoma (UTUC) is a rare subset of urothelial cancers with poor prognosis. No consensus exists on the benefit of adjuvant immunotherapy for patients with UTUCs after nephroureterectomy with curative intent and the existing studies are limited. Herein, this study aimed to evaluate the effectiveness and safety of adjuvant treatment of tislelizumab with or without chemotherapy in patients with high-risk UTUC. Methods A retrospective study was conducted on 63 patients with high-risk UTUC who received tislelizumab with or without gemcitabine-cisplatin (GC) chemotherapy regimen after surgery between January 2020 and December 2022. Data on demographic and clinical characteristics, surgical, outcomes, prognostic factors, and safety were collected and analyzed. Results Among the 63 patients with high-risk UTUC, the median age was 66 years (interquartile range 57-72), with 33 (52%) being male. The majority of patients with staged pT3 (44%) and pN0 (78%) disease. Fifty-one patients (81%) received tislelizumab plus GC chemotherapy, and 12 (19%) were treated with tislelizumab monotherapy. After the median follow-up of 26 months (range 1-47), 49 (78%) patients achieved stable disease. The 2-year disease-free survival (DFS) and 2-year overall survival were 78.68% (95% CI: 60.02-87.07%) and 81.40% (95% CI: 68.76-89.31%), respectively. The cycles of GC chemotherapy were independent prognostic factors for survival, with higher DFS (hazard ratio = 0.68, 95% CI, 0.50-0.93; p = 0.016) observed in the subgroup undergoing >= 3 cycles versus < 3 cycles of GC chemotherapy. Fifty-eight patients (92%) experienced at least one treatment-related adverse event (TRAE), with grade 3-4 TRAEs occurring in 13%. The most common grade 3-4 TRAEs were decreased white blood cells, thrombocytopenia, and ulcers. Conclusions The study demonstrates promising clinical benefits and a manageable safety profile of the tislelizumab-based adjuvant regimen for patients with high-risk UTUC. This suggests that adjuvant immunotherapy represents a potential therapeutic strategy for this population.