Role of endocrine function tests in the evaluation of transsphenoidal hypophysectomy for advanced breast cancer.

Forty-three women underwent transsphenoidal hypophysectomy for metastatic breast cancer. Endocrine tests (luteinizing hormone, follicle-stimulating hormone, thyrotropin, prolactin and growth hormone) were done in 28 patients to evaluate the completeness of the procedure. Response of the metastatic breast cancer and duration of survival after hypophysectomy were determined and statistically compared with the posthypophysectomy hormone levels. Only one patient had an endocrinologically complete hypophysectomy, but the objective remission rate (32 percent) is comparable to the 30 to 40 percent objective remission rate reported in other studies that claim to have achieved complete hypophysectomy. No statistically significant associations were found between the levels of the hormones measured and the type of response (objective, subjective or none) to hypophysectomy. However, objective responders survived longer than nonresponders (p = 0.01). When analyzing the associations of the various hormone levels with the duration of survival after hypophysectomy, a positive correlation (p less than 0.05) of peak thyrotropin levels with duration of survival was found. Our data indicate that the clinical benefit advanced breast cancer patients received from an endocrinologically incomplete hypophysectomy is probably as great as that received from an endocrinologically complete hypophysectomy. It appears that a nonspecific disturbance of the hormonal milieu may adversely affect the growth of breast cancer. More studies are needed to elucidate the nature of the endocrine disturbance produced by hypophysectomy and its effects on hormone-sensitive tumors.