Vascular involvement in the prognosis of primary cutaneous melanoma

Objective: To examine the role of vascular invasion as a prognostic factor in melanoma. Design: Retrospective survival analysis. Setting: Academic medical center. Patients: A total of 526 patients with primary cutaneous melanoma from the University of California, San Francisco, Melanoma Center database with 2 ye ars of follow-up or documented relapse. Main Outcome Measures: (1) Presence of vascular involvement defined as vasc ular invasion with tumor cells within blood or lymphatic vessels; or uncert ain vascular invasion, with melanoma cells immediately adjacent to the endo thelium. (2) Percentage with metastasis or death and relapse-free and overa ll survival. Results: The presence of either type of vascular involvement significantly increased the risk of relapse and death and reduced the survival associated with melanoma. The impact of vascular involvement on these outcomes was si milar to that of ulceration. In a multivariate analysis, vascular involveme nt was the second most important factor (after tumor thickness) in the prim ary tumor in predicting survival. Conclusions: Vascular involvement is an important independent predictor of metastasis and survival in melanoma. The phenomenon of uncertain vascular i nvasion describes an earlier step than definite vascular invasion in tumor progression.