Transsphenoidal hypophysectomy in breast cancer: evidence for an individual role of pituitary and gonadal hormones in supporting tumor growth.

Transsphenoidal hypophysectomy was performed in 212 consecutive patients with metastatic breast cancer: 11 died within 30 days, two of surgical complications and nine of advanced metastatic disease. Two patients were unevaluable because of inadequate follow-up in one and simultaneous radiation treatment in the other. Of 199 evaluable patients 42% had an objective remission. Duration of remission averaged 18+ months with 10 out of 84 patients still in remission. Presence of estrogen receptors in the tumor significantly predicted response to hypophysectomy. Of 156 patients in whom completeness of hypophysectomy was assessed, 128 were thought to have a complete removal as shown by the fact that their growth hormone and prolactin were undetectable after stimulation with arginine or chlorpromazine, respectively. Of 26 patients in whom TRH test was performed, TSH and prolactin were undetectable in 20. Of 23 patients where autopsy was performed only six had microscopic pituitary tissue remaining. Hypophysectomy induced remission in eight of 15 patients who had previously responded and then relapsed to the antiestrogen Tamoxifen and in four of 17 who had failed. Conversely, antiestrogen therapy induced remission in six of 26 patients who had previously responded to hypophysectomy and in whom serum estrogens were present in small amount. These data indicate that both gonadal and pituitary hormones play a role in the growth of some human breast cancers.