Background: Milk fat globule epidermal growth factor-VIII (MFG-E8) is a secreted protein that binds phosphatidylserine and promotes apoptotic cell ingestion by phagocytes, mediating the immune tolerance and maintenance of homeostasis. A recent study has shown that MFG-E8 expression in human melanoma is increased with tumour progression; however, the effect of its expression on patient survival has not yet been clarified.
Objective: To analyse MFG-E8 expression in melanoma, and to determine whether it can serve as a marker for diagnosis, tumour progression and/or prognosis.
Methods: MFG-E8 expression was examined by immunohistochemistry in 60 primary melanomas, 22 metastatic lesions and 30 benign naevi. The following clinicopathological variables were evaluated: age, gender, histological type, tumour site, Breslow thickness, Clark's level, the presence or absence of ulceration and tumour-infiltrating lymphocytes, and survival periods. Statistical analyses were performed to assess associations and melanoma-specific survival.
Results: MFG-E8 expression was significantly higher in primary and metastatic melanoma than in naevus. Furthermore, it increased according to tumour progression and metastasis. Patients with MFG-E8 expression in primary tumours had significantly shorter survival periods than those without MFG-E8 expression. Univariate and multivariate analyses revealed that MFG-E8 expression was a statistically significant and independent prognostic factor.
Conclusion: MFG-E8 expression may serve as a tumour progression marker and can predict an unfavourable prognosis in patients with melanoma.
© 2011 The Authors. BJD © 2011 British Association of Dermatologists.