Prognostic significance of nutritional and muscular indices in immune checkpoint inhibitor therapy for metastatic urothelial carcinoma: A preliminary study.

[INTRODUCTION] The shift from chemotherapy to immune checkpoint inhibitors (ICIs) for metastatic urothelial carcinoma (UC) highlights the need for effective prognostic markers. Since traditional markers have limitations, we investigated whether the easily accessible psoas muscle index (PMI) and prognostic nutritional index (PNI) could predict treatment outcomes.

[METHODS] This retrospective study involved 55 metastatic UC patients. All patients initially received platinum-based chemotherapy before starting ICI therapy with pembrolizumab or avelumab. We calculated baseline PMI from CT scans at the L3 vertebral level and PNI from serum albumin and lymphocyte counts. A multivariate Cox proportional hazards regression model was used to identify independent prognostic factors for overall survival (OS).

[RESULTS] Multivariate analysis showed that PMI (HR = 0.72, 95% CI: 0.51-0.99, P = 0.044), liver metastasis (HR = 10.6, 95% CI: 1.78-63.6, P = 0.010), and PNI (HR = 0.84, 95% CI: 0.71-0.97, P = 0.022) were significant, independent prognostic factors for OS. The results of the multivariate analysis are unadjusted for potential confounding factors and should be interpreted with caution. When we stratified patients into high- and low-risk groups based on these three factors, there was a statistically significant difference in OS between the groups (log-rank test, P < 0.001).

[CONCLUSION] PMI and PNI are valuable, independent prognostic markers for metastatic UC patients. They could serve as practical prognostic markers to guide personalized treatment strategies, such as more intensive therapies or nutritional support for high-risk patients. Future large-scale studies are necessary to validate these results and establish standardized cutoff values.