Abstract
Purpose::
To evaluate the possible role of the level of serum TPS (tissue polypeptide specific antigen, a cytokeratin 18 fragment), previously shown to be over-expressed in metastatic uveal melanoma, in differentiating between uveal melanoma patients with and without metastases.
Methods::
The study included three groups of patients: 64 uveal melanoma patients who remained disease-free (DF) for at least 10 years; 37 patients with liver metastases of uveal melanoma, in 20 of whom we had documented pre- and post-metastasis levels; and 53 controls without a history of any malignant disease. Serum levels of TPS (µ/L) were detected by ELISA (IDL, Sweden). Statistical analysis included t-test, sign test (non-parametric), ANOVA, and ROC analysis. The TPS analysis was compared to markers we have studied previously: Osteopontin (OPN), MIA, and S-100ß.
Results::
The study demonstrated a statistically significant difference between TPS levels in patients with metastatic uveal melanoma (139.63 + 22.20), DF patients (69.29 + 9.76), and controls (54.23 + 0.01), p < 0.0001. Significant differences were found between the levels of TPS in the pre-and post-metastatic stage, p < 0.01. ROC analysis of the metastatic group vs. DF patients revealed AUC for TPS alone - 71%; for TPS and OPN - 82%; for TPS, OPN AND S-100 - 84%; and for the combination of all four markers - 86%.
Conclusions::
Serum TPS, like OPN, MIA and S-100ß levels, distinguishes well between metastatic and DF patients or controls, and therefore may serve as a marker for early detection of metastases in patients with uveal melanoma.
Keywords: melanoma • tumors • oncology