Abstract
Plasma levels of luteinizing hormone, sex hormone binding globulin, and antithrombin III were measured in pre- and postmenopausal breast cancer patients receiving adjuvant combination chemotherapy or combination chemotherapy and long-term tamoxifen therapy. The aim was to determine the estrogen-like effects of tamoxifen. The premenopausal patients had received tamoxifen for between 434 and 2592 days and postmenopausal patients between 91 and 1560 days. Tamoxifen caused a consistent rise in sex hormone binding globulin in premenopausal (P < 0.03) and postmenopausal (P < 0.01) patients compared to chemotherapy controls. Luteinizing hormone levels were only significantly lowered (P < 0.008) in premenopausal patients compared to chemotherapy controls. Antithrombin III levels were significantly depressed (P < 0.001) in postmenopausal patients compared with chemotherapy controls. However, none of the patients had a value that was depressed by more than 30% of the laboratory control (the level of clinical significance). The mean for the group was 90% ± 4 (mean ± SD, N = 11).
The estrogen-like rise in sex hormone binding globulin produced by adjuvant tamoxifen therapy could be advantageous for maintaining the antiestrogenic action of the drug. A decrease in antithrombin III occurred but was not within a range of clinical concern. We recommend, however, that patients with a history of thromboembolic disorders should be monitored carefully if placed on tamoxifen therapy.
Footnotes
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↵1 Supported by NIH Grants P30-CA-14520 and P01-CA-20432.
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↵2 To whom requests for reprints should be addressed, at Department of Human Oncology, University of Wisconsin Clinical Cancer Center, 600 Highland Avenue, Madison, WI 53792.
- Received February 24, 1987.
- Revision received May 21, 1987.
- Accepted May 27, 1987.
- ©1987 American Association for Cancer Research.
