Sex hormone binding globulin (SHBG) in breast cancer: a correlation with obesity but not with estrogen receptor status.

Plasma sex hormone binding globulin (SHBG) levels were determined in a group of 82 patients suffering from breast carcinoma with a known estrogen receptor status (ER). Overweight (greater than 20% of ideal weight) premenopausal patients had a significantly lower SHBG plasma level than their non-obese counterparts (43 pmol/ml vs 72.7 pmol/ml, P less than 0.001). No difference in plasma levels of SHBG was found between obese and non-obese postmenopausal patients. No correlation was found between SHBG levels and ER status either in non-obese premenopausal patients or in postmenopausal patients in general. Breast carcinoma patients had significantly higher SHBG plasma levels than a group of normal controls (57.9 pmol/ml vs 40.6 pmol/ml, P less than 0.01), but the stage of the disease did not influence the SHBG level within the breast carcinoma patients. Results of this study do not support a correlation between SHBG levels and ER status. SHBG plasma levels are significantly influenced by a patient's weight, particularly in those who are premenopausal.