A narrative review of predictive and prognostic biomarkers in skin tumors

Merkel cell carcinoma (MCC), melanoma, and keratinocyte carcinomas (KC), basal cell carcinoma (BCC) and squamous cell carcinoma, are among the most common and/or aggressive malignancies of the skin. Traditional staging parameters remain the most important and widely utilized prognostic and predictive tools. However, given the recent explosion in the literature on immunohistochemical and molecular-genetic markers for these skin tumors, novel predictive and prognostic biomarkers are emerging. Herein, we sought to summarize well-established and emerging predictive and prognostic biomarkers in these cutaneous malignancies. We present the following article in accordance with the Narrative Review Reporting Checklist (available at: http:// dx.doi.org/10.21037/pcm-21-6).