4. ON THE PARASITIC THEORY OF CANCER


Opponents of the parasitic theory invariably content that tumours produced experimentally by the introduction of parasites obtained in pure culture from cancerous blood or tumours, in most cases do not conform of the conditions recognized by pathologists….


By W.SCHMIDT, Munich.

Abstract by Mr.R.Berk.

THE author refer to his collaboration for more than 20 years with Otto Schmidt and his succession director of the institution devoted to cancer research. He essays authorship on the strength of the important results of their combined investigations and the therapeutic success achieved with their vaccine and animal serum.

He comments on the impetus received by the parasitic theory of cancer aetiology from the publication in July, 1925, of the research of Gye and Barnard, who claim that with virus cultivated from a Gye and Barnard, who claim that with virus cultivated from a Rous tumour, adding rabbit serum and a 14-day old fowl embryo in a bouillon containing potassium chloride, fowl sarcoma can be induced even with a billion fold dilution, that this type or growth is also common to mammals and that cancer is an infective disease due to a virus or group of parasites.

Attempts by the author and numerous other investigators to apply Gye’s research to human animal tumours filed. Alexis, Carles, also Murphy and Landsteiner showed that independently of these of a spontaneous tumour and excluding every infectious contamination tumours identical with Rous tumours could be produced experimentally by injecting a seven-day fowl embryo in various quoted authorities shows that contrary to Gye’s assertion, Rous tumour extract can remain active inspite of the addition of chloroform that filtrates of fowl sarcoma are not of necessity free from active cells; that active well preserved cells can survive even after the grinding dessicated tumour mass, and that a microscopic preparation the filtered sediment of tumour centrifuged for 45 minutes still contained well-preserved cells, all suggesting the probability that Gye, when injecting his filtrate, accidentally also transferred cell material. Also it is doubtful if the Rous tumour should be classified with the feminine malignant tumour should be classified with the genuine malignant tumours.

A statement of the antagonistic opinions as to the aetiology of malignant growths follows. Firstly, the cellular theory that cells have an “innate property,” disposition or inherent propensity top unlimited growth, or are stimulated there to and to the invasion and destruction of normal cell tissue by endogenic or exogenic agency and alternately the infection theory, according to which a foreign micro-organism, invades a system,. hitherto, healthy, and excites the cell to boundless proliferation.

Schmidt now summarizes and opinion of a number of authorities who do not hold a parasite responsible for the origin of malignant neoplasms, and still less accept the theory of a universal excitant, maintaining that if a cancer producing agent of he nature of the nature of a virus does exist, it is necessary to assume a whole group of related parasites to provide every biologically distinctive tumour type with it individual excitant.

Opponents of the parasitic theory invariably content that tumours produced experimentally by the introduction of parasites obtained in pure culture from cancerous blood or tumours, in most cases do not conform of the conditions recognized by pathologists. On the other hand, when experimental tumors do receive the cachet of eminent pathologists as being of the requisite blastomatic mature it is asserted that their manifestation is the result of a nonspecific process. The excitant only represent the stimulus which induces the cell, on account of its “innate property,” to commence its boundless growth. the stimulations still non-specific. And the defenders of the cellular theory continue their search for the unknown factor which outlaws the cell from its fellows, perverts its histological and clinical nature, and ultimately, through atypical proliferation, leads to morphologically recognizable cancer growth.

As constituting a very weighty argument against the parasitic theory its opponent refer with particular satisfaction to the constant success attending the experimental production of tumours mice and rabbits by paints with tar and pitch. It is suggested that these results expose the weakness of he parasitic theory. But an objective consideration of these researches raises the quartet as to why they succeed only with certain species of animal;s and fail with others of the same certain species of animal and fail with others of the same genus, which under precisely the same treatment and conditions fail to develop tumours. Does this not after all, suggest that a parasitic plays a role, that only animals where a specific factor, and a micro-organism is present in the systems, develop cancerous neoplasm when their cells are damaged by the systematic application of tar? Is the assumption of two factors, the parasitic infection and the endo-or exogenic stimulus damaging the cell so repugnant to biological teaching? Is it not feasible even logical, that the parasitic infection is he primary and the damage to the cell secondary aetiological factor? Spontaneous tumours are observed in mice more frequently than in other rodents It is significant that it is in mice that the artificial tumour production with tar is most successful. is it wild assumption that a mouse developing tumour after brushing with tar was already a carrier of a specific excitant which is not found in guinea-pigs or other animals which do not develop tumours?

Teuschlander writes: ” The specific impetus we see in the origin of cancer is not derived from an outside source. but is a specific factor within the particular system, and exists or can be developed in any system”; and again: “The deviation from the normal organic stricture or capacity for repair is determined by the focus of influence of the outside destructive agency, but the origin and structure depend on the internal factor.” In other words the bringing into existence of neoplastic growth by the agency of tar brushing is only possible it the “specific impetus” is in some form available in the animal. The defenders of the cellular theory are silent as to their conception of the nature of this “specific impetus.” Why exclude a parasite as representing the wanted factor, already present in or which may invade many systems’ Would it be inconceivable, or even unusual, if in the case of a human or animal carrier of infection the disease appeared in tumour form when to the specific factor of the parasite a second and non-specific impetus were added? The opponents of the parasitic theory generally admit the assumption of a general predisposition, This disposition may be hereditary. Moreover, the disposition may consist of an atypicality of cell or cell complex. here then we have the endogenic or exogenic stimulus, and the appearance of a tar cancer turns out to be a support for the parasitic theory, it can only occur where an infection is already on being, the persistent tar brushing constituting the extrinsic stimulus. Obviously such a latent or labile infection can only be of a protozoic nature, and the character of the tissue selected for invasion determines the histological variety of the tumour. The author quotes the necessary conditions to which a micro organism must conform to prove its specific relationship to a disease and the modification applicable when protozoa or ultramicroscopical agencies are in question. He shows how the parasite firs reported on by Otto Schmidt in 1906 entirely complies with these postulates in respect to malignant disease. It is emphasized that histologically genuine, metastases- forming, transplantable tumours are called forth in mice, rats, pigeons, and even guinea-pigs, with one, at most two, simple injections of the live cultures of the Schmidt protozoid parasite without any extrinsic irritation whatever. That tumours produced by other investigators by injection of the so-called Micrococcus tumefaciens and other bacteria in conjunction with activating mechanical or chemical irritation are open to the criticism that the whole process merely represents the non- specific factor, and that the real originator of the tumour, the true tumour-making parasite and the specific factor, was either already present or was unwittingly introduced during the operation. This applies to the results published by Blumenthal and Meyer and others, and in no less degree to the different class of experiments carried out by Fibiger, &c. In addition to this, whereas other artificially produced tumours, through the agency of tar, parasites, rays, &C., invariably appear at the focus of local irritation, the Schmidt tumours orignate not only at the site of injection, but even more frequently in other parts of the body.

The Schmidt parasite is the causative factor in no other disease. It can be isolated from every cancerous subject, human or animal. It can be cultivated continuously without losing in virulence, and new infections can always be contrived through the agency of the cultures, the only condition being that an atypical cell or cell complex is available. The parasite can be isolated not only from tumours, but also from the blood of cancerous subjects. Artificially infected animals who did not succumb, but recovered from the high grade anaemia which usually develops in those animals which do not show tumours, were proved to be carriers of the parasite two years and more later.

John Henry Clarke
John Henry Clarke MD (1853 – November 24, 1931 was a prominent English classical homeopath. Dr. Clarke was a busy practitioner. As a physician he not only had his own clinic in Piccadilly, London, but he also was a consultant at the London Homeopathic Hospital and researched into new remedies — nosodes. For many years, he was the editor of The Homeopathic World. He wrote many books, his best known were Dictionary of Practical Materia Medica and Repertory of Materia Medica