I have set forth an hypothesis which leans towards the older ideas, namely, that the disposition to the formation of tumors is a congenital one; in other words, that we may assume a congenital diathesis for tumor formation in the same way that we have already long assumed a con genital diathesis for chronic inflammations resulting in purulent, caseat ing products (scrofulosis, tuberculosis). Though both diatheses are not absolutely antagonistic, it is certain that their coincidence in the same individual is very rare; individuals with scrofula and tuberculosis repro duce—even when occurring in those years disposed to the formation of carcinoma—carcinoma only in the most exceptional cases, and, as excep tionally, other tumors, which belong to earlier periods of life; whilst, on the other hand, individuals who have tumors, at whatever age they may be, very rarely become tuberculous. Individual exceptions do not invali date the accuracy of these observations.
On this hypothesis, all factors which were formerly regarded as irrita tions of different kinds may retain their complete importance as so-called exciting causes.
When I say that such a diathesis must be assumed as congenital, I do not at all mean that it is identical with hereditary, though since most of our congenital peculiarities are hereditary, and, for example, the scrofulo-tuberculous diathesis is known to be in a high degree heredi tary, we may also expect that the diathesis for the formation of tumors is also hereditary. The indications of this are not very great in litera ture. Al. v. Winiwarter has selected from the reports of my clinic the few certain observations; five cases are there noted in which the mother died of carcinoma of the uterus, then there are other cases in which either the mother or father died of cancer of the stomach. Yet, from his observations von Winiwarter draws the conclusion that, in only ten cases of 170, (lid carcinoma certainly exist in the parents; according to this, the number of cases of heredity proved amounted to only 5.8 per cent. of all cases observed. It is to be considered with regard to this that, as the question has not been put methodically, nothing is said in many reports as to heredity, either because nothing was asked about it, or because the patients were unable to give the cause of their parents' death. It is to be further considered that the hereditary peculiarities are seldom known beyond one generation, and questions as to the cause of death of the grand-parents are seldom put, and could just as seldom be answered. The consideration that frequently several sisters from non
carcinomatous mothers are affected with mammary carcinoma, as is repeatedly mentioned in the reports, also well indicates the constitutional disposition and heredity of former generations.
Though it is dangerous to base far-reaching conclusions on the remem brances of former cases, I must say that, according to my recollections of consultations, it does not seem to me so rare that several consanguineous women were affected with carcinoma; for it is quite frequent that women with slight induration of the mamma come to the surgeon especially early, because the frightful course of carcinomas of the mamma has been observ ed in their family. It will scarcely be possible, even from the carefully prepared clinical reports, to form a correct idea of the frequency of the heredity of carcinoma, for were we confined to such reports alone, we would gain no correct conception of the much more frequent scrofulo tuberculous diathesis. Only the old family physician could give us any valuable information on that point. I think, however, that in further statistical investigations on this point, which is more of purely scientific than practical interest, we should not restrict ourselves especially to the heredity of carcinoma in a particular organ, but we should endeavor to find out whether the formation of tumors became more frequent in the different generations of a family. When we inquire into the heredity of the scrofulo-tuberculous diathesis we do not restrict ourselves to the question of pulmonary tuberculosis, of laryngeal, intestinal, or tubercu losis of the cord, caries of the knee, etc., but we know very well that, with the same hereditary disposition, one organ in this, another in that generation may be affected. So also may different forms of tumors of hereditary disposition altogether change in different organs and in differ ent generations. That the investigations are thus made more difficult stands to reason.
Broca has given an especially interesting report on the descent of carcinoma through several generations, which 'I will quote: 1. Generation: Mrs Z. died 1788, 60 years old, of cancer of the breast.
2. Generation: 4 daughters all married.
A, died of cancer of the liver, aged 62, 1820.
B. of the same, aged 43, 1808.
C. died of cancer of the breast, aged 51, 1814.