Low muscle mass as a poor prognostic factor in patients with advanced melanoma.

BACKGROUND & AIMS: Low muscle mass is associated with poor immune checkpoint inhibitor (ICI) efficacy in patients with melanoma; however, whether this is true in all populations remains to be explored. The current study aimed to investigate the effect of low muscle mass on overall survival (OS) and progression-free survival (PFS) of patients with advanced melanoma treated with ICI.

METHODS

muscle index (SMI) at the third lumbar spine was calculated from computed tomography (CT) images, and SMI values < 42 cm2/m2 for men and <38 cm2/m2 for women diagnosed low muscle mass. The association of low muscle mass, OS, and PFS with ICI treatment in patients was investigated.

RESULTS

Seventy-six patients with advanced melanoma were assessed retrospectively at our institution; 32 were in the low muscle mass group, while 44 were in the normal muscle mass group. The median OS in patients with and without low muscle mass was 7.1 and 26.6 months (hazard ratio [HR] 3.12, 95 % confidence interval [Cl], 1.65-5.89; p < 0.001) and median PFS was 2.1 and 14.8 months, respectively (HR, 3.10; 95 % Cl 1.74-5.54, p < 0.001). Multivariate analysis showed significantly poor differences in OS (HR, 2.46; 95 % CI, 1.20-5.03; p = 0.01) and significant differences in PFS independently in the low muscle mass group (HR, 3.10; 95 % CI, 1.74-5.54; p < 0.001).

CONCLUSIONS

Low muscle mass may be a poor prognostic factor for patients with advanced melanoma treated with ICI.