The surgery of the endocrine system in carcinoma of the breast.

Metastatic cancer may be treated either by excision of endocrine glands (surgical deprivation) or administration of hormones (addition therapy). This article deals only with deprivation. Addition will only be considered as it directly affects deprivation and not as a method of therapy in its own right. The purpose of surgical deprivation is to terminate the production of the specific hormones essential for the proliferation by mitosis of normal mammary epithelium and presumably of the malignant growths arising in this epithelium. The pituitary hormones concerned are probably prolactin and somatotrophin. This combination may be non-commitally labelled as the 'mammotrophic principle.' Pituitary ablation apart from removing this will remove the trophic control exercised by the pituitary over the ovaries and adrenals and in that way cause a depression of their function and a lowering of oestrogen production (see Figs. i and 2). The purpose of bilateral oophorectomy and adrenalectomy is to abolish the production of the steroid hormones oestrogen and progesterone. As it is thought that a third hormone, progestational in nature, forms the third partner controlling normal and cancerous mammary growths. Progestational hormone production is abolished by adrenalectomy, or hypophysectomy which induces secondary adrenal cortical atrophy. The concept of control of breast growth by a triad of hormones, oestrogen, pituitary mammotrophin and progesterone is the basis of our present ideas in surgical deprivation and the existence of the hypothetical state of simple oestrogen dependence is no longer tenable for the following reasons: