37. Angiotropism is an independent predictor of microscopic satellites in primary cutaneous melanoma

Abstract

Background Melanomas may utilise anatomic structures such as the external surfaces of blood vessels as tracks for progressive tumour cell migration and the eventual establishment of metasta-ses. Angiotropism describes melanoma cells ensheathing the ablu-minal surfaces of microvascular channels. Microscopic satellites (MS) in primary melanomas are considered localised micrometas-tases developing in close proximity to the main tumoral portion of melanomas. MS have been reported as predictors of diminished survival in AJCC stage I and II melanoma patients, regional lymph node metastases, and distant metastases. Aim This case-control study aimed to examine the relationship between angiotropism and MS in a series of primary cutaneous melanomas. Methods Patients with MS and controls without MS from 1996–2009 were evaluated for the presence or absence of angiotropism according to established criteria. Fourty-four cases and controls were matched for tumour thickness, mitotic rate, ulceration, age (by decade), gender and primary site. Results Factors correlating with angiotropism on univariate analysis included increased Clark level (p = 0.046), absence of regression (p = 0.02) and MS (p = 0.017). On multivariable analysis MS formation was predicted by angiotropism (p = 0.026), Clark level V (p = 0.01), absent regression (p = 0.009) and an acral site (p = 0.02). Conclusions In conclusion, angiotropism predicts MS development. These data provide additional evidence for the importance of angiotropism as a means of melanoma metastasis and as a prognostic factor.