I HORMONAL FACTORS 843 



Similarly, adrenalectomy may affect the progression of prostatic cancer, in this 

 instance the result being attributed to the withdrawal of androgen of adrenal 

 cortical origin (Huggins and Bergenstal, 1952). Whether the effects oUiypophysec- 

 tomy on breast cancer (Luft and Olivecrona, 1955) are due to ovarian and adrenal 

 cortical insufficiency is still not decided. Pituitary stalk section also lias been reported 



HYPOTHALAMUS 



(3) 



DECREASED 

 FSH AND LH 



(I) 

 •STALK SECTION 



(BLOCK OF PORTAL VESSELS) 



(2) 



INCREASED LACTOGENIC AND/OR 

 LUTEOTROPIC EFFECTS. 



>HYPOTHALAMUS 



EFFECT EQUIVALENT 

 TO STALK SECTION 



(3) 

 INCREASED LACTOGENIC AND/OR 

 LUTEOTROPIC EFFECTS 



Fig. 34. Figure indicates role 

 the hypothalamus may play in 

 controlling certain pituitary 

 functions. Follov^'ing pituitary 

 stalk section in the human 

 female (a) output of gonado- 

 trophic hormones (alsoACTH, 

 TSH and STH) is decreased 

 (EcklesandEhni, 1957) where- 

 as lactogenic effects are in- 

 creased. In the rat, luteotro- 

 phic and lactogenic activities 

 are correlated. A similar re- 

 ciprocal relationship between 

 FSH and LH on the one hand, 

 and lactogenic hormone on the 

 other, may exist following the 

 administration of appropriate 

 amounts of estrogen and pro- 

 gesterone (b), suggesting that 

 the ovarian steroids may in- 

 fluence the pituitary gland via 

 the hypothalamus. That drugs 

 {e.g., reserpine, Sawyer, 1957) 

 may act upon the hypothala- 

 mus to give an effect equivalent 

 to stalk section is indicated by 

 experimentally induced lacta- 

 tion in rabbits. The neurogenic 

 stimulus provided by suckling 

 induces pituitary lactogenic activity and the mating of female rats with vasectomized males 

 results in pseudo-pregnancy (Rothschild, 1957). The lowermost chart (c) indicates the 

 probability that chemical and neurogenic stimuli may act upon the hypothalamus to 

 produce the same pituitary activities which result from stalk section. In the other charts 

 which diagram reciprocal relations between the pituitary gland and target endocrine organs 

 the hypothalamus has not been included. This figure indicates the likelihood that the 

 hypothalamus may be concerned in the regulation of secretion of other pituitary trophic 

 hormones which are involved in tumorigenesis. 



DRUG 

 (•.g. RESERPINE) 



NEUROGENIC STIMULUS 

 (eg SUCKLING) 

 OR COITUS 



EFFECT EQUIVALENT 

 TO STALK SECTION 



(3) 

 INCREASED LACTOGENIC AND/OR 

 LUTEOTROPIC EFFECTS (PSEUDO- 

 PREGNANCY) 

 (4) 

 DECREASED 

 FSH AND LH 



to be associated with amelioration of human metastatic breast cancer (Ehni and 

 Eckles, 1957) ; whether the benefits are mediated through the ovary and adrenal, or 

 are due primarily to pituitary hormone withdrawal, or are associated with lactoge- 

 nic effects (Fig. 34) has not been demonstrated. Although cortisone may dramati- 

 cally ameliorate the signs (such as hypercalcemia) of breast cancer, the benefits have 

 only rarely been associated objectively with tumor regression (Eckles, unpublished) . 

 Lactation occurs following pituitary stalk section ; regression of metastatic breast 

 cancer occurs coincidentally with the development of functional activity of the mammary gland. 



Literature p. 870 



