Neuropeptide Y expression in primary cutaneous melanoma

Neuropeptide Y (NPY) is involved in the carcinogenesis of different tumours, especially neural crest-derived tumours.The aim of our study is to investigate the expression of NPY on melanoma and its relation with prognostic histological parameters and survival.This is a retrospective observational study of two independent series, with a total of 79 primary melanomas, diagnosed in two independent University Hospitals in Spain, from January 2000 to December 2004.We found a significant higher expression of NPY on superficial spreading melanoma and lentigo maligna (40%) (P = 0.030). Thinner tumours were associated with higher NPY expression (Clark level, P = 0.003; Breslow level, P = 0.012). Melanomas with low NPY expression were associated with intense cell proliferation (Ki-67, P = 0.034), high density of peritumoral mast cell infiltrates (P = 0.033) and low E-cadherin expression (P = 0.031). Melanomas with high NPY expression exhibited significant differences in terms of relapse time (median: 114 vs. 68 months, P = 0.008) and overall survival (114 vs. 74 months, P = 0.004).High expression of NPY was associated with better prognostic histological parameters, low peritumoral mast cells density, presence of adhesion proteins and better outcome.