Prognostic role of intramuscular adipose tissue content in patients with urothelial carcinoma treated with pembrolizumab.

BACKGROUND

Pembrolizumab is a standard treatment for previously treated advanced urothelial carcinoma (UC); however, individual differences in treatment responses remain a significant problem. This study aimed to evaluate the prognostic factors, particularly muscle mass, and quality, in patients with UC receiving pembrolizumab.

METHODS

This retrospective study included 56 patients with UC treated with pembrolizumab between May 2017 and December 2024. The influence of neutrophil-to-lymphocyte ratio (NLR), albumin-bilirubin (ALBI) score, psoas major index, and intramuscular adipose tissue content (IMAC) on progression-free survival (PFS) and overall survival (OS) was investigated. Survival analysis was performed using the Kaplan-Meier method, and time-dependent Cox proportional hazards models were used to identify the prognostic factors for PFS and OS.

RESULTS

The median follow-up period was 24.3 months (range: 0.7-61.2 months). Multivariable analysis identified low IMAC [hazard ratio (HR) 0.884, 95% confidence interval (CI), 0.804 - 0.971; p = 0.010] and low NLR (HR 0.405, 95% CI, 0.192 - 0.856; p = 0.018) as independent prognostic factors for prolonged PFS. Similarly, a low NLR (HR 0.231, 95% CI, 0.092 - 0.578; p = 0.002) was significantly associated with improved OS, and the presence of liver metastasis (HR 3.037, 95% CI, 1.061 - 8.694; p = 0.038) was identified as a poor prognostic factor.

CONCLUSIONS

This study suggested that IMAC and NLR may serve as potential prognostic biomarkers for patients with UC treated with pembrolizumab. The evaluation of muscle quality and inflammatory markers could contribute to improved risk stratification and personalized treatment strategies for immunotherapy.