Expression of p16, CD95, CD95L and Helix pomatia agglutinin in relapsing and nonrelapsing very thin melanoma

Abstract

Background: The incidence of malignant melanoma is increasing worldwide and patients are being diagnosed earlier with thinner primary lesions. Most patients with very thin melanoma (Breslow thickness < 0.76 mm) are cured by surgery but 2-18% relapse locally or with distant metastases. Objectives: The objective of this study was to establish potential new prognostic markers in very thin melanoma. Methods: We identified a group of subjects with relapsing very thin primary cutaneous melanoma and a matched control group who had not relapsed. We investigated the expression of p16, Helix pomatia agglutinin (HPA), CD95 and CD95 ligand (CD95L) by immunohistochemistry on paraffin-embedded tissue sections from the subject group, their subsequent metastases and the control group. Results: Reduced p16 expression was significantly associated with relapse in very thin melanoma (P = 0.0129). Loss of p16 expression was also found in 76% of metastases. There was no significant association between HPA, CD95 or CD95L expression and subsequent relapse. Conclusions: This work is the first to show a significant loss of p16 in relapsing very thin melanoma. © 2007 The Authors.