Abstract 1051P
Background
Sarcopenia (low skeletal muscle index, SMI) and myosteatosis (low skeletal muscle density, SMD) have been associated with worse survival in various cancers. This study’s objectives were to assess impacts of body composition on survival in patients with resected stage III melanoma.
Methods
A retrospective review was performed of resected stage III melanoma patients in Alberta, Canada from 2007-2017. Pre-operative CT scans were analyzed at L3 to determine SMI and SMD. Cohort-specific SMI and SMD cut-offs that optimally predicted overall survival (OS) were identified through stratification, in addition to testing cut-offs previously established in the literature. OS, melanoma-specific survival (MSS), and recurrence-free survival (RFS) were determined from date of surgery and analysed using Cox regressions. Age, sex, stage subgroup, ECOG PS, and tumor location were included in multivariate analyses.
Results
330 patients were included in the final analysis. Mean age was 56 years, 62.4% of patients were male, and 97% had a baseline ECOG status of 0-1. At time of censoring 150 patients (45.6%) had died, with 110 deaths (73.3%) attributable to melanoma recurrence. Based on literature cut-offs, 46.7% had sarcopenia and 46.4% had myosteatosis. Both sarcopenia (HR 1.50, 95% CI 1.08-2.09, p=0.016) and myosteatosis (HR 1.57, 95% CI 1.10-2.24, p=0.013) were associated with decreased OS in multivariate analysis. Based on cohort-specific cut-offs, sarcopenia prevalence was 20% and myosteatosis prevalence was 18.2%. Sarcopenic patients defined by cohort-specific cut-offs had decreased OS (HR 2.38, 95% CI 1.64-3.45, p<0.001) and MSS (HR 1.85, 95% CI 1.16-2.95, p=0.009) in multivariate analysis. Myosteatosis defined by cohort-specific cut-offs predicted worse OS (HR 2.30, 95% CI 1.56-3.37, p<0.001), MSS (HR 2.33, 95% CI 1.48-3.69, p<0.001) and RFS (HR 1.50, 95% CI 1.03-2.19, p=0.035) in a multivariate model.
Conclusions
Sarcopenia and myosteatosis are prevalent in stage III melanoma. Both factors, defined using two sets of cut-offs, are associated with decreased OS. In addition, sarcopenia and myosteatosis defined using cohort-specific cut-offs predicted decreased MSS.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Alberta Health Services.
Disclosure
J. Walker: Financial Interests, Personal, Funding: BMS; Financial Interests, Personal, Funding: Merck; Financial Interests, Personal, Funding: Sanofi. M. Smylie: Financial Interests, Personal, Funding: BMS; Financial Interests, Personal, Funding: Merck; Financial Interests, Personal, Funding: Sanofi. M.B. Sawyer: Financial Interests, Personal, Funding: BMS; Financial Interests, Personal, Funding: Merck. All other authors have declared no conflicts of interest.