Possible Implications of MCAM Expression in Metastasis and Non-Metastatic of Primary Uveal Melanoma Patients

Purpose: To evaluate the expression of melanoma cell adhesion molecule (MCAM) as prognostic factor in uveal melanoma patients. Methods: Paraffin sections from 35 primary uveal melanomas were analyzed immunhistochemically for the expression of MCAM. Further known prognostic factors such as cell type, ciliary body invasion, tumor stage, and local extension were evaluated. In 16 cases, patients had developed metastatic disease. The patients without metastasis (n = 19) had a mean follow-up of 10.6 (9-13) years. Results: All tumors were positive for MCAM (mean: 57.05%). In the group without metastasis, an average MCAM expression of 35.37% (SD 19.66%) compared to 82.78% (SD 11.73%) in the metastasis group was found. The Cox regression analysis showed a significant association of an enhanced MCAM expression and death due to metastasis (HR: 365.48, 95% CI: 18.51, 7217.85). Conclusion: MCAM expression of primary uveal melanomas can serve as a possible prognostic parameter for metastasis. If further experiments approve the cellular adhesion molecules to account for early micrometastasis of tumor cells, a possible target might be available for future treatment.