Impact of sarcopenia on the efficacy of pembrolizumab in patients with advanced urothelial carcinoma: a preliminary report

Sarcopenia, the degenerative and systemic loss of skeletal muscle mass, is a multifactorial syndrome reflecting frailty, poor general health status, and the possible presence of cancer cachexia. Here, we aimed to investigate the effect of sarcopenia on the efficacy of pembrolizumab in patients with advanced urothelial carcinoma (aUC). This retrospective study included 28 patients with aUC treated with pembrolizumab as a second or later-line therapy. Sarcopenia was determined based on computed tomography images. Associations of sarcopenia with objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) were evaluated. In total, 19 (68%) patients had sarcopenia. ORR was 21% in the patients with sarcopenia, while those without sarcopenia showed significantly higher ORR (67%,P = 0.019). PFS was significantly shorter in patients with sarcopenia than in those without (median, 3 vs. 15 months,P = 0.038). Although the statistical significance was not reached, OS was shorter in patients with sarcopenia than in those without (median, 7 months vs. not reached;P = 0.086). Our preliminary results demonstrated that more than half of patients with aUC who received pembrolizumab had sarcopenia, which was significantly associated with poor therapeutic efficacy. This indicates the clinical relevance of sarcopenia in pembrolizumab therapy for patients with aUC.