Molecular aspects of melanoma.

Melanoma is the most serious type of skin cancer. Unfortunately, treatment has progressed little and advanced melanoma has appalling survival rates. A goal of molecular analysis is to fully describe the alterations that underpin melanoma's clinical phenotype so that diagnosis can be more accurate, outcome can be predicted with greater confidence, and treatment that is tailored to the patient can be given. This article describes the handful of "signature" changes that are known to occur, describes how some recent studies have shed light on changes beyond this signature, and finally discusses the impact of molecular pathology for practicing histopathologists.

Molecular Aspects of Melanoma.

Melanoma is the most serious type of skin cancer. Unfortunately, treatment has progressed little and advanced melanoma has appalling survival rates. A goal of molecular analysis is to fully describe the alterations that underpin melanoma's clinical phenotype so that diagnosis can be more accurate, outcome can be predicted with greater confidence, and treatment that is tailored to the patient can be given. This article describes the handful of "signature" changes that are known to occur, describes how some recent studies have shed light on changes beyond this signature, and finally discusses the impact of molecular pathology for practicing histopathologists.

WNT5A expression increases during melanoma progression and correlates with outcome.

PURPOSE: Wnt ligands play a major role in development and are important in cancer. Expression microarray analysis correlates one member of this family, WNT5A, to a subclass of melanomas with increased motility and invasion. There are no large studies of clinical samples primarily addressing the importance of WNT5A in melanoma progression or outcome. Therefore, this study aimed to assess the protein expression of WNT5A during melanoma progression and its effect on outcome. EXPERIMENTAL DESIGN: Expression of WNT5A was determined in a series of 59 primary melanomas with matched metastases. To provide a benchmark of progression against which to assess WNT5A, expression of p16(ink4a) was analyzed, as this has been previously well documented in melanoma. The effect of WNT5A protein expression on outcome was assessed in 102 melanomas. RESULTS: Cytoplasmic WNT5A showed a trend of increasing expression with melanoma progression (P = 0.013), whereas there was diminishing p16(ink4a) expression (P = 0.006). Nevi showed relatively strong WNT5A expression. Strong cytoplasmic WNT5A was an independent risk factor for reduced metastasis-free and overall survival in multivariate analysis (P = 0.001 and 0.003, respectively). CONCLUSION: Cytoplasmic WNT5A increases with melanoma progression and strong expression is associated with poor outcome.