Sex hormone-binding globulin and estrogen receptor in breast cancer: technique and preliminary clinical results.

The binding capacities of SHBG (sex hormone-binding globulin) and ER (estrogen receptor) were measured by agar gel electrophoresis with dextran-coated charcoal treatment and also by sucrose density gradient ultracentrifugation in the sera from 19 women with breast cancer to assay the correlation between SHBG and ER in breast cancer. SHBG levels were also measured by agar gel electrophoresis with dextran-coated charcoal treatment in control sera from 20 normal women. Two kinds of 17 beta-estradiol-binding substances were recognized in the cytosol of breast cancer cells and they were confirmed to be ER and SHBG. Out of 13 postmenopausal patients with breast cancer, the SHBG levels in 6 ER-positive cases (66 +/- 13 pmol/ml plasma, mean +/- SD) were significantly higher than the levels of 10 controls (35 +/- 7.6 pmol/ml; P less than 0.005). SHBG levels in 7 ER-negative patients (34 +/- 7.9 pmol/ml plasma) did not significantly differ from the levels of the controls, but differed significantly from the levels of ER-positive patients (P less than 0.005). Out of 6 premenopausal breast cancer patients, the SHBG levels in 5 ER-positive cases (63 +/- 7.5 pmol/ml plasma) tended to be higher than the levels in 10 controls (55 +/- 4.7 pmol/ml plasma), but did not achieve statistical significance (P greater than 0.05). The findings suggest that correlation between SHBG and ER in postmenopausal breast cancer is possible, but no significant difference was noted between the SHBG levels in ER-positive premenopausal breast cancer patients and premenopausal normal women.