Expression of the cell adhesion molecules ICAM-1, VCAM-1 and NCAM in uveal melanoma: a clinicopathological study.

To investigate the relationship between the expression of the cell adhesion molecules intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and neural cell adhesion molecule (NCAM) in uveal melanoma and the metastatic spread in the first 5 years after diagnosis, we performed a hospital-based case-control study with human tissue from 90 patients who underwent enucleation for primary uveal melanoma (iris melanoma excluded). Thirty-five patients developed metastasis within the first 5 years, and 55 patients lived metastasis-free for at least 5 years after enucleation. The paraffin-embedded and formalin-fixed globes were studied by immunohistochemistry with monoclonal antibodies for ICAM-1, VCAM-1 and NCAM. A strong ICAM-1 positivity (more than 75% of the tumor cells stained positive) was detected in 73 tumors (81%). The expression of 75% or less ICAM-1 positive cells in tumors was strongly associated with the development of metastases (odds ratio: 7.5, p = 0.001). Multiple logistic regression models showed that ICAM-1 is an independent risk factor for metastasis even after control for important prognostic markers like extraocular growth, ciliary body involvement, scleral infiltration and cell type. VCAM-1 was expressed in 24 out of 88 tumors (27.3%) and NCAM only in 14 out of 87 tumors (16%). Only spindle cells stained positive with anti-NCAM. NCAM and VCAM-1 expression was not related to metastasis. Our results show that the loss of ICAM-1 expression is associated with an increased risk of metastasis within the first 5 years after diagnosis.