Osteopontin as a serologic marker for metastatic uveal melanoma: results of a pilot study

PURPOSE: To evaluate the protein osteopontin (OPN) as a potential new marker for screening and detection of metastatic uveal melanoma. DESIGN: Prospective, clinical study. METHODS: Twenty-eight plasma samples of 27 patients with uveal melanoma were analyzed, and the OPN plasma levels were quantified. Eight of these patients showed liver metastasis. As a control, we measured OPN levels in eight healthy, age-matched individuals. RESULTS: The median plasma concentration of OPN in patients with melanoma without metastasis was 46.78 ng/ml (range, 14.5 to 118.67 ng/ml). In contrast, increased median levels of OPN of 170.72 ng/ml (range, 87.37 to 375.54 ng/ml, P <.001) were seen in eight patients with proven metastatic disease. Healthy patients without uveal melanoma showed a median plasma concentration of OPN of 54.6 ng/ml (range, 38.23 to 71.21 ng/ml). CONCLUSION: The protein OPN seems to be a promising tumor marker for detecting metastatic disease in patients with uveal melanoma.