PROGNOSTIC IMPLICATION OF ESTRAMUSTINE-BINDING PROTEIN IN ASTROCYTOMA

Estramustine-binding protein (EMBP) is a glycoprotein shown to be expr essed in the cytoplasm of astrocytoma cells. Originally, it was found in rat prostatic tissue and described as a secretory protein. Its expr ession has been demonstrated to positively correlate with the degree o f neoplastic transformation in astrocytoma tissue. EMBP has been propo sed to be responsible for a specific and high affinity binding of estr amustine in astrocytoma tumor tissue. In this study the expression of EMBP was evaluated by immunohistochemistry and radioimmunoassay in a s eries of astrocytoma of different grades. Staining intensity and the n umber of stained cells increased with the degree of malignancy. The le vels of EMBP were 1.3-6.2 ng/g tumor tissue with higher levels in tumo rs of grade III to IV compared to grade I and II. It was found that a high expression of EMBP always implied a short survival of the patient s. On the other hand, a low expression of EMBP did not always assure a favorable prognosis. It is proposed that EMBP might have a value to p redict survival in patients with astrocytoma, especially if estramusti ne is to be included in the treatment schedule. However, further exten ded studies are needed before final conclusions can be made.