SEX HORMONES AND CANCER WII.LIAM S. MURRAY, Sc.D. (Front tlzr Ro~cor B. Jark~on Mrw~oiicll Laboratory, Bar Harbor, Maine, C. C. Liltl~, Director. and stat^ Inrtit~lte for the SIudy oj Mnli~naizl Diseases, Bzcffalo, New York, Burton T. Simpson, Director) During the last decade many investigators have interested themselves in the study of the hormones of the sex glands and the parts which they play in the physiology of the individual. As often happens when a mass of data is collected by a number of individuals, many divergent and conflicting findings have been published. Out of this mass of data, however, certain principles seem to be generally accepted. Among these is the opinion that the secre- tions of the various organs do not act independently but are all dependent, one upon the other, and work in a system of checks and balances, any upset in which leads to abnormal physiological function. From the results of the work done with the ovarian hormones and some of the closely allied synthetic hydrocarbons, it appears that these substances, acting upon or accumulating in the mammary tissue of mice, upset the hor- monal balance and instigate the formation of neoplasms. In the dilute brown strain of mice, for instance, the hormones of estrus, pregnancy, and lactation stimulate the appearance of adenomas and adenocarcinomas of the breast in 65 to 100 per cent of the breeding females. If, however, females of this strain are kept as virgins, the stimulation of the hormones which pro- duce estrus alone is sufficient to cause the glands to become cancerous in but 50 per cent of the individuals (1). It appears, therefore, that both quantita- tive and qualitative variations in the carcinogenic stimulants may bring about changes in the incidence of cancer in these animals. In the males of this strain, which have never been observed to become cancerous, although they are potentially cancerous (2) the hormonal balance is such that the mammary tissue is stimulated to proliferate or to become malignant. In order to determine whether this difference between the males and females is due to some inhibiting hormone or to some variation in quality or quantity of secretion between the males and females, the present esperi- ment was undertaken. It attempts to determine the interaction of the male and female hormones when they are mingled in a common blood stream. The early work in parabiosis was largely concerned with the establishing of a common blood stream and devising methods for determining whether 1 This study was supported, in part, by The International Cancer Research Foundation. Kcad before the American Association for Cancrr Research, Chicago, Ill., March 24, 1937. For discussion see p. 591. 517
Transcript
SEX HORMONES AND CANCER
WII.LIAM S. MURRAY, Sc.D.
(Front tlzr R o ~ c o r B . J a r k ~ o n Mrw~oiicll Laboratory, Bar Harbor, Maine, C . C . Li l t l~ , Director. and stat^ Inrt i t~l te for the SIudy o j Mnli~naiz l Diseases, Bzcffalo, New Y o r k ,
Burton T. Simpson, Director)
During the last decade many investigators have interested themselves in the study of the hormones of the sex glands and the parts which they play in the physiology of the individual. As often happens when a mass of data is collected by a number of individuals, many divergent and conflicting findings have been published. Out of this mass of data, however, certain principles seem to be generally accepted. Among these is the opinion that the secre- tions of the various organs do not act independently but are all dependent, one upon the other, and work in a system of checks and balances, any upset in which leads to abnormal physiological function.
From the results of the work done with the ovarian hormones and some of the closely allied synthetic hydrocarbons, it appears that these substances, acting upon or accumulating in the mammary tissue of mice, upset the hor- monal balance and instigate the formation of neoplasms. In the dilute brown strain of mice, for instance, the hormones of estrus, pregnancy, and lactation stimulate the appearance of adenomas and adenocarcinomas of the breast in 65 to 100 per cent of the breeding females. If, however, females of this strain are kept as virgins, the stimulation of the hormones which pro- duce estrus alone is sufficient to cause the glands to become cancerous in but 50 per cent of the individuals (1). I t appears, therefore, that both quantita- tive and qualitative variations in the carcinogenic stimulants may bring about changes in the incidence of cancer in these animals.
In the males of this strain, which have never been observed to become cancerous, although they are potentially cancerous ( 2 ) the hormonal balance is such that the mammary tissue is stimulated to proliferate or to become malignant. In order to determine whether this difference between the males and females is due to some inhibiting hormone or to some variation in quality or quantity of secretion between the males and females, the present esperi- ment was undertaken. I t attempts to determine the interaction of the male and female hormones when they are mingled in a common blood stream.
The early work in parabiosis was largely concerned with the establishing of a common blood stream and devising methods for determining whether
1 This study was supported, in part, by The International Cancer Research Foundation. Kcad before the American Association for Cancrr Research, Chicago, Ill., March 24, 1937. For discussion see p. 591.
517
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or not substances in the blood of one partner could be transferred to the other. Thus, Sauerbruch and Heyde (3) in 1908 found that iodine solution when injected into one animal might be recovered fro111 the other and that anthrax bacilli would pass from one partner to the other. I n the following year, Friedberger and Nasetti ( 4 ) observed that agglutinins from typhoid bacilli in one parabion might be recovered from the other, and that a partner might be passively immunized by injecting its parabion. hlorpurgo ( S ) , in 1909, established the fact that bilateral nephrectomy in one partner was com- pensated for by the enlargement of the kidneys in the other. I t remained for Hill (6 ) , using the technic of Bunster and Meyer ( 7 ) , to establish a method of measuring the volu~ne of blood exchange. By use of a colorimetric method, in which the amount of brilliant vital red injected into one partner could be measured in the other, he established the fact that 50 per cent of the dye had passed over at the end of one hour and that a t the end of six hours the exchange was con~plete.
During the period 1909 to 1921, experiments with parabions dealt largely with immunity. In 1909, Albrecht and Hecht (8) found that parabiosis ex- erted a distinct retarding influence which was similar to the iminunizing ac- tion of subcutaneous injections of blood, embryos, or nor~nal tissue. In 192 1 , Kross (9 ) found that parabiosis does not increase the susceptibility of the immune animal nor does it give i~nmunity to the susceptible one. Rous ( l o ) , in 1909, and Lambert ( 1 I ) , in 19 11, published conflicting findings on the ef- fect of parabiosis upon transplanted tumors. The former found that par- abiosis had no effect upon tumor growth, and the latter that growth of tumors in rats was definitely promoted by parabiosis, the percentage of successful inoculations being increased, while growth was accelerated and lasted longer.
More recent work in parabiosis has been largely along the line of estab- lishing the r81e of the hypophysis in sexual function. In this work, a number of types of pairs have been used and results obtained which are in general agreement.
Normal Female United to Normal Fcmulc: Zacherl ( 12) found that in this type of pair there was apparently no effect of one animal upon the other. The estrous cycles did not become synchronous and pregnancy in one did not stop the cycle in its partner. These findings were confirmed by Fels (13 ) . Hill (6 ) , however, observed that there was some disturbance; that, while the estrous cycles did not become synchronous, they were affected by the parabiotic condition. Hill also found that pregnancy in one individual was reflected by changes in the mammae of its partner.
Normal Female Attached to a Spayed Fcmalc: Fels ( 13) found precocious egg development, increased numbers of follicles, and luteinization in the nor- mal female of this type of pair. This was confirmed by Martins and Rocha (14) and by Hill (6) . The latter observed prolonged cycles in the normal female. Mgller-Christensen (15) found that macerated testes did not pre- vent this precocity and Martins (16) concluded that the effects varied with the amount of blood which passed over.
Normal Frmale Attachcd t o a Castrated Male: Zacherl found in this type of pair that heat appeared in from fourteen to twenty-two days. This change was accompanied by a more glandular uterus and corpora lutea were present.
SEX HORMONES AND CANCER 5 19
Fels confirmed the work of Zacherl and observed that this type of pairing caused abortion in the normal female unless pregnancy was well advanced when the animals were united. Kallas (17 ) reported that sexual precocity was obtained at the end of six or seven days, the female going into heat periods which lasted a week. Corpora lutea were present. Kallas found, also, that these effects might be accelerated by the injection of anterior pit- uitary hormones. Hill, R.l@ller-Christensen and Pfeiffer (18) obtained per- manent estrus with this type of pair.
Normal Malc Attached to a Normal Female: Hill, deMello ( 1 9 ) and Fels found no change in the ovaries in females attached to normal males.
Zacherl describes a smear condition in which some epithelial cells persisted for a long time, eventually disappearing. Fels observed that the testes of the males of such pairs degenerated and that the hypophysis took on the appearance typical of the castrated animal. He found that pregnancy was not affected so long as the testes remained functional.
Spayed Female Attached to a Normal Male: In this type of pair, Fels found hypertrophy in the testes. This condition was also observed in the normal male of pairs in which a normal male was attached to a castrated male.
Normal Female Attached to a Cryptorchid Male: That the same effect is obtained with a cryptorchid male as with a castrated male was demonstrated
520 WILLIAM S. MURRAY
by Witschi and Levine (20) and also by Fels. deMello obtained similar re- sults in pairs in which the spermatic arteries were ligated.
E j e c t of Parabiosis on Hypophysectomizcd Partner: The effect of a cas- trated male upon a hypophysectomized female was demonstrated, by Witschi
and Levine (20), to be similar to that in a normal female attached to a cas- trated male. Mpiller-Christensen obtained estrus in a hypophysectomized female united with a castrated female. Martins was able to induce estrus in two spayed females by transplanting an ovary to one of them.
The consensus of opinion among all of these workers seems to be that variations in results are largely dependent upon the amount of blood anas- tomosis established. The most striking result obtained is the fact that the hypophysis is definitely established as playing a prominent r61e in the pro- duction of long estrous periods and that the male type of hypophysis is more potent in this respect than is the female type. That the hormones of the sex glands are passed over the bridge is indicated by the work of Martins.
MATERIAL AND METHOD
In the present investigation 189 parabiotic pairs, consisting of a normal male and a normal female, were made up according to the technic described by Bunster and Meyer. The operation was performed when the animals were one month of age. This technic does not attempt to join any of the large blood vessels but depends upon the anastomosis of the arterioles and capillaries across the wound for the mingling of the blood streams. Accord- ing to the work of Hill, who measured the blood exchange following this op- eration in rats, there is an intermingling of the blood of the two individuals which amounts to 40 to 50 per cent at the end of one hour, and is complete at the end of six hours. That the blood exchange is relatively greater in mice than in rats is indicated by the results obtained in the present experiment.
SEX HORMONES AND CANCER 521
Mortality among the parabions was high, especially during the first three months following operation. During this period nearly 75 per cent of the animals died. These deaths were due, especially during the first week or so, to operative shock, inability of the animals to adapt themselves to being at-
Flc. 2. SECTION THROCGH OVARY TWO MOSTHS AFTER OPIZR~\TION. SIIOWI~'C LAR(;E NUMBER OF
FOLLICL~S HUT NO CORPORA LUTEA
tached to each other, and wounds incident to struggling. Death from infection was relatively rare. After the first week, many of the animals died as the result of what was apparently physiological antagonism. The symptoms of this were the gradual emaciation of one or the other of the members of a
522 WILLIAM S. MURRAY
pair (usually the female). Following the third month, the individuals seemed to be adjusted to each other and died at about the rate of normal animals.
T h n r . ~ I : Percentage of Those Living r ~ t llte Beginning of Each Age Period Which Die of Breast Cancer Dztring I'ltis Period or Later
By the end of a week after operation, changes were apparent in the estrous cycles of the females. The animals seemed to be in constant heat or at least to be going through very rapid cycles, which involved a first stage in which nothing but cornified cells appeared and a second stage in which the smear was made up of cornified and nucleated cells with a scattering of leukocytes. This condition persisted for months.
Upon histologic examination of the ovaries, mammary glands, and testes of these animals, the following changes were noticed:
(1) At the end of the first month the ovaries were greatly enlarged, being made up of a mass of follicles in all stages of development. Many atretic fol- licles were found, but there were no corpora lutea. There were signs of proliferation in the glandular layer of the uterus, but these organs were still small. Mammary tissue was present in the females but not in the males. The testes were still infantile, showing no mature spermatozoa.
( 2 ) By the end of the second month the ovaries showed still further en- largement; atretic follicles were numerous but there was no sign of corpora lutea. The uterus was distended, the glandular structure being well de- veloped. Mammary tissue was again present in the females but not in the males. The testes showed a few spermatozoa.
( 3 ) Following the second month, the ovaries began to show degenerative changes. The stroma of the hilum began to fill up with a fatty infiltration which as the months progressed gradually migrated toward the periphery. As this type of tissue reached the cortex, it seemed to push the developing follicles before it until a t the age of nine or ten months the ovary consisted of a ring of follicles around the periphery. The medulla of the gland was made up entirely of the fatty tissue. During this period, the mammary tissue did not seem to develop beyond the stage of large ducts. Terminal buds and acini were seldom seen. 'I'he testes during this period developed somewhat but spern~atozoa were not as numerous as in normal animals. With the excep- tion of one animal, which died a t the end of the sixth month, no corpora lutea were found in any of the age groups (one to eighteen months).
SEX HORMONES AND CANCER 525
From these data, it seems that the introduction of the male hormones into the blood stream of the female causes an upset in her sexual cycle. The ovaries are stimulated to a precocious and prolonged production of follicles which degenerate within the gland, with the result that no luteal tissue is formed.
Since none of these females developed mammary tumors, it seems reason- able to assume that the proliferation and change to malignancy in the mam- mary glands may be due, in some measure, to the luteal fraction of the ovarian
hormone. On this hypothesis, the observed difference in cancer incidence between the breeding and virgin females may be explained as being due to the prolonged luteal phase of pregnancy. I t is also supported by the observa- tion of Lacassagne ( 2 I ) , who found a correlation between the rapidity of nor- mal estrous cycles and the incidence of cancer in mice.
1. MURRAY, W. S.: Am. J. Cancer 20: 573, 1934. 2. MURRAY, W. S . : J. Cancer Research 12: 18, 1928. 3. SAUERBRUCH, F., AND HEYDE, M. : Miinchen. med. Wchnschr. 55 : 153, 1908. 4. FRIEDBERGER AND NASETTI: Ztschr. f . Immunitatsforch u. exper. Therap. 2: 509, 1909. 5. MORPURGO: Verhandl. d. deutsch. path. Gesellsch. 13: 150, 1909; 14: 259, 1910. 6. HILL, R. T.: J. Exper. Zool. 63: 203, 1932.
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7. BUNSTER, E. , AND MEYER, R . K.: Anat. Rec. 57: 339, 1933. 8. ALBRECHT, H., AND HECHT, V.: Centralbl. f . allg. Path. u. path. Anat. 20: 1039, 1909. 9. K ~ o s s , I.: J. Cancer Research 6: 25, 1921.
10. Rous, P.: J. Exper. Med. 11: 810, 1909; Proc. Soc. Exper. Biol. & Med. 7: 12, 1909- 1910.
11. LAMBERT, R. A.: J. Exper. Med. 13: 257, 1911. 12. ZACHERL, H.: Krankheitsforschung 6: 174, 1928. 13. FELS, E.: Arch. f . Gynak. 138: 16, 1929; Centralbl, f . allg. Path. u. path. Anat. 58:
69, 1933; Med. Klinik 25: 557, 1929. 14. MARTINS, T., AND ROCHA, A. : Endocrinology 15 : 421, 1931
MARTINS. T., AND DE MELLO, P. F.: Compt. rend. Soc. de biol. 117: 1258, 1934. 15. M$LLER-CHRISTENSEN, E. : Acta. path. et microbial. Scandinav. 9 : 55, 1932; 10, 296,
1933. 16. MARTINS, T . : Compt. rend. Soc. de biol. 115: 1342. 1934. 17. RALLAS, HELMUTH: Arch. f . d. ges. Physiol. 223: 232, 1929. 18. PFEIFFER, C. A. : Proc. Soc. Exper. Biol. Pr Med. 32 : 603, 1935. 19. DEMELLO, R. F.: Compt. rend. Soc. de biol. 114: 964, 1933. 20. WITSCHI, E., AND LEVINE, W. T . : Anat. Rec. 55: 41, 1933; Proc. Soc. Exper. Biol. &
