The effects of a low-fat dietary intervention and tamoxifen adjuvant therapy on the serum estrogen and sex hormone-binding globulin concentrations of postmenopausal breast cancer patients.
The purpose of the study was to determine the effect of a low-fat dietary intervention, with or without concomitant tamoxifen adjuvant therapy, on serum estrogen and sex hormone-binding globulin (SHBG) levels in postmenopausal patients with resected breast cancer. Ninety-three patients were randomized to either reduce their fat intake to 15-20% of total calories, or to a dietary control group. Serum estradiol, estrone, estrone sulfate, and SHBG concentrations were assayed at baseline, and at 6, 12, and 18 months thereafter. In 19% of patients, the preintervention serum estradiol levels were below the sensitivity of the assay (5 pg/ml). Tamoxifen had no significant effect on serum estrogen levels, but produced an elevation in SHBG. Patients with reliably quantifiable preintervention estradiol concentrations (> or = 10 pg/ml) showed a significant reduction in serum estradiol after 6 months on the low-fat diet (average, 20%; p < 0.005); this was sustained over the 18 month study period. Serum SHBG levels were increased by tamoxifen therapy, but were reduced significantly (p = 0.01) after 12 months on the low-fat diet in patients not receiving tamoxifen. No changes in serum estrone or estrone sulfate resulted from the dietary intervention. While the low-fat diet produced significant weight loss, patients treated with tamoxifen without dietary intervention showed a gain in body weight. These weight changes produced disruptions in the normal positive correlation between body weight and serum estrone sulfate, and the negative correlation with SHBG concentration.
Rose
D P
DP
Division of Nutrition and Endocrinology, American Health Foundation, Valhalla, NY 10595.
Connolly
J M
JM
Chlebowski
R T
RT
Buzzard
I M
IM
Wynder
E L
EL
D000368:Aged; D001943:Breast Neoplasms / Q000097:blood / Q000628:therapy*; D004041:Dietary Fats / Q000008:administration & dosage*; D004967:Estrogens / Q000097:blood*; D005260:Female; D006801:Humans; D008593:Menopause; D008875:Middle Aged; D012738:Sex Hormone-Binding Globulin / Q000032:analysis*; D013629:Tamoxifen / Q000627:therapeutic use*; D015430:Weight Gain
D004041:Dietary Fats; D004967:Estrogens; D012738:Sex Hormone-Binding Globulin; D013629:Tamoxifen