Serum globulin assay of estrogen-binding ability during endocrine treatment of postmenopausal advanced breast cancer.

Estrogen-binding ability of sex hormone binding globulin (SHBG) was assayed in sera of 18 postmenopausal patients with advanced breast cancer during the treatment of diethylstilbestrol by agar gel electrophoresis at low temperature. In eight cases showing high level of SHBG, seven cases (88 per cent) responded to the estrogen therapy. On the contrary, only one case (13 per cent) responded out of eight patients with low levels of SHBG. This result may indicate that the level of estrogen binding ability of SHBG (SEBA) is a useful tool in predicting response to estrogen therapy for breast cancer.