Melanoma genotypes and phenotypes get personal

Abstract

Traditionally, the diagnosis of metastatic melanoma was terminal to most patients. However, the advancements towards understanding the fundamental etiology, pathophysiology, and treatment have raised melanoma to the forefront of contemporary medicine. Indeed, the evidence of durable remissions are being heard ever more frequently in clinics around the globe. Despite having more gene mutations per cell than any other type of cancer, investigators are overcoming complex genomic landscapes, signaling pathways, and immune checkpoints by generating novel technological methods and clinical protocols with breath-taking speed. Significant progress in deciphering molecular genetics, epigenetics, kinase-driven networks, metabolomics, and immune-enhancing pathways to achieve personalized and positive outcomes has truly provided new hope for melanoma patients. However, obstacles requiring breakthroughs include understanding the influence of sunlight exposure on melanoma etiology, and overcoming all too frequently acquired drug resistance, complicating targeted therapy. Pathologists continue to have critically important roles in advancing the field, particularly in the area of transitioning from microscope-based diagnostic reports to pharmacogenomics through molecularly informed tumor boards. Although melanoma is no longer considered just 'one disease', pathologists will continue this rapidly progressing and exciting journey to identify tumor subtypes, to utilize tumorgraft or so-called patient-derived xenograft (PDX) models, and to develop companion diagnostics to keep pace with the bewildering breakthroughs occurring on a regular basis. Exactly which combination of drugs will ultimately be required to eradicate melanoma cells remains to be determined. However, it is clear that pathologists who are as dedicated to melanoma as the pioneering pathologist Dr Sidney Farber was committed to childhood cancers, will be required as the battle against melanoma continues. In this review, we describe what sets melanoma apart from other tumors, and demonstrate how lessons learned in the melanoma clinic are being transferred to many other types of aggressive neoplasms.