Estramustine binding protein in primary tumours and metastases of malignant melanoma

The presence of estramustine binding protein (EMBP), a 54 kD cytosolic glycoprotein, which is distinct from the estrogen receptor, was investigated in a pilot study of primary malignant melanomas and their metastases. In 11 primary melanomas EMBP was demonstrated by immunohistochemistry. The percentage of positive melanoma cells ranged between 11-91% with a mean of 57%. Radioimmunoassay on metastatic tissue revealed significant amounts of EMBP, with values ranging between 0.6-4.2 with a mean of 1.6 ng/mg protein. A high number of cells with a positive stain for EMBP in the primary tumours was significantly correlated to a short interval between diagnosis and the occurrence of metastases. Presence of EMBP in malignant melanoma may have prognostic significance and the role of hormone-linked cytostatic drugs in the treatment of this disease needs further investigation.