Skin cutaneous melanoma is characterized by significant heterogeneity in its molecular, genomic and immunologic features. Whole transcriptome RNA sequencing data from The Cancer Genome Atlas of skin cutaneous melanoma (n = 328) was utilized. CIBERSORT was used to identify immune cell type composition, on which unsupervised hierarchical clustering was performed. Analysis of overall survival was performed using Kaplan-Meier estimates and multivariate Cox regression analyses. Membership in the lymphocyte:monocytelow, monocytehi gh and M0high cluster was an independently poor prognostic factor for survival (HR: 3.03; 95% CI: 1.12-8.20; p = 0.029) and correlated with decreased predicted response to immune checkpoint blockade. In conclusion, an M0-macrophage-enriched, lymphocyte-to-monocyte-ratio-low phenotype in the primary melanoma tumor site independently characterizes an aggressive phenotype that may differentially respond to treatment.
Keywords: RNA sequencing; cutaneous melanoma; immunotherapy; lymphocytes; macrophages; monocytes; tumor immune microenvironment.
© 2020 Neil Kunal Jairath.