Influence of Local Treatment or Metastatic Disease on Melanoma Inhibitory Activity (MIA) Serum Levels in Patients with Uveal Melanoma

Abstract

Abstract: : Purpose: Recently the protein MIA was detected immunhistochemically in primary and metastatic uveal melanomas. Elevated serum levels of MIA were proven in patients with systemic uveal melanoma (Schaller UC et al.: Melanoma inhibitory activity: a novel serum marker for uveal melanoma. Melanoma Res. 2002 Dec;12(6):593-9). In this study we wanted to evaluate the changes of MIA serum level after local treatment of uveal melanomas as well as developing metastatic disease. Methods: 61 of initially metastatic disease-free patients were followed over time (median follow up: 240 days, 95 % CI: 60-883 days) and MIA was assesed repeatedly. 21 of these patients were observed for uveal melanoma without treatment, 40 patients were treated (Brachytherapy, γ-Knife) for uveal melanoma during follow up. Three of 40 patients developed metastatic disease. The difference of MIA serum levels were calculated from the first and last measured serum level in each patient. A one step ELISA was used to quantify the MIA serum levels. Results: In 21 not treated patients the median difference was –0.2 (95 % CI: -2.8-2.3) ng/ml. In the 37 treated patients the median difference was –0.6 (95 % CI: -5.9-3.1) ng/ml. There was no significant difference of the MIA serum levels between the treated and untreated group. During follow-up 3 initially metastatic free patients developed overt metastatic disease. The difference/increase of MIA serum levels was median 13.6 (95% CI: 5.1-25) ng/ml. The differences between the MIA serum level increase of three patients with and 58 patients without metastatic disease were statistically highly significant (student t-test: p<0,001). Conclusions: Local treatment of uveal melanomas had no significant influence on MIA serum levels in our patients. In contrast a statistically significant elevation of MIA serum levels was found in patients who develop metastatic disease. This indicates a promising role of MIA as a serum marker for monitoring uveal melanoma patients for metastasis.

Keywords: tumors • melanoma • oncology