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.