There seems to be some reason to support the view advocated by Williams, that tumor formation and growth are but forms of agamogenesis, or non-sexual reproduction of cells, distinctly related to the decline in growth of the body in general. Hence while the forces of growth, development, and reproduction are in greatest activity the tendency to this disease is relatively small: but when growth declines and nutrition is relatively low the cells undergo gemmation, owing to perverted nutriment, and thus hyperplasia and not inflammation is the starting point of every neoplasm.
Experimental work has time and again demonstrated that cell growth, either good or bad, is modified in no uncertain way by the character of the nutrition furnished. Cancer has repeatedly been observed to disappear spontaneously, as such cases are on record by careful and competent medical men: in certain of these instances it has occurred in connection with a radical change in the mode of life and diet, but in the majority of instances there is no record of the special cause of its disappearance. The lesson to be learned from this is that there are conditions of the system which are antagonistic to the abnormal proliferation of cell tissue, even when it has begun to take place, as we must believe that there are other conditions of the system which favor such diseased action of aberrant cells.
An interesting confirmation of this is attributed to Ehrlich, but I cannot find the original reference. He “has shown that mice living upon a rice diet cannot be inoculated with cancer, while mice living on a meat diet can be readily inoculated, cancerous tumors developing quickly and continuing to grow until the animal dies. Ehrlich also found that when mice with cancerous tumors, the result of inoculation, were placed upon a rice diet, the tumors ceased to grow, and in many cases degenerated and disappeared.” Valuable corroboration of this has been given by Sweet, Corson, White, and Saxon. They made a series of experiments in regard to the “influence of certain diets upon the growth of experimental tumors,” all with the same results. Of fifty white mice, 25 fed on glutenin and gliadin, and 25 on normal diet, 23 of the 25 on normal diet acquired tumors, against only 4 in the 25 on the glutenin and gliadin. This was repeated on 50 males, with the result of 18 in 25 against 3 in 25: and in a third series, of 50 females, the figures were 15 in 25 against 7 in 25. Thus, they found that 75 per cent. of 75 mice developed experimentally inoculated tumors when under normal diet, while only 19 per cent. of other 75 mice developed such tumors when under a diet of glutenin and gliadin, that is, vegetable proteins; moreover, the tumors in the latter were in 30 days hardly larger than those in the former in 10 days. Rous has recently shown that large growths of certain transplanted rat and mouse tumors are checked in their development by underfeeding the host on a special diet.
The chemistry of cancer has been studied in most varied directions, and the literature relating thereto is very voluminous and can be hardly more than alluded to here. It is unfortunate, however, that most of the researches have been made in connection with patients who have advanced cancer, and very commonly with the disease affecting internal organs, which of itself interferes very greatly with their function, and so causes many of the perturbations of metabolism observed. What is needed are researches in regard to the metabolism of patients before the development of the disease, or in its earlier stages, before it has exerted its injurious effects on the system, in order to learn of the causes which lead up to and induce the wrong action of the cellular elements, whose invasion and malignant action subsequently become so serious.
It is quite impossible in these lectures to enter at all fully upon the various bio-chemical studies which have been carried on in regard to cancer, but brief mention will be shortly made of some of the salient points. Not only has the structure of carcinomatous tissue been examined chemically, but the blood and urine have been submitted to most painstaking investigation, and metabolism in general has been studied in almost all possible directions, in the search for the cause of cancer; and yet, as Beebe says, “no phase of metabolism has been described in cancer which does not have a counterpart in non-cancerous conditions.” But, as previously mentioned, all these observations and studies have been largely made upon advanced cancer cases, when the system has already felt the unsettling and depressing effect of what is probably an injurious secretion from the deranged and actively proliferating cells of the cancerous mass. In a later lecture we will consider some of these matters in so far as they have relation to the dietetic and medical treatment of cancer.
The essence of our study thus far has been, that in every instance what is called malignant disease is but an aberrant action of originally normal body cells. That, as normal cells find their nutriment in the circulating plasma, so some pathological change in this latter causes them to take on abnormal action, and they no longer develop homologous cells, capable of forming normal tissue, but heterologous elements which have a natural tendency to disintegrate or break down, and exert a destructive influence on adjoining cells of any kind; and in this process they secrete a hormone which is prejudicial to the system and tends to destroy life. In later lectures we shall endeavor to understand this more perfectly, and consider some of the elements in life which tend towards the production and arrest of cancer.
LECTURE II
FREQUENCY AND GEOGRAPHICAL DISTRIBUTION OF CANCER
Cancer in man exists all over the globe, but in different degrees of frequency, according to varying conditions of life, as we shall presently see. Malignant growths occur also in animals and fishes, though also with greatly varying frequency under different conditions; but there are few real tumors in reptiles or amphibians. Tumors are also occasionally found in vegetable organisms, presenting increased growth and proliferation of cells, arising from adventitious, or abnormally evolving buds, as also from parasitic and other external irritants. While these vegetable tumors are very interesting and in a measure instructive, in regard to the peculiarities of cell growth which they exhibit, they bear, of course, no relation to cancer in the animal kingdom, although some have endeavored to argue otherwise. There is, however, a certain suggestion of analogy to be found in the observation made by one writer, that “the origin of buds, as well as their subsequent development, is chiefly determined by the conditions of nutrition. Wherever there is an excess of nutritive material, capable of being utilized for growth by the cells of the part, there buds may arise”; we shall see later that the same thought applies to cancer in man and animals, when we come to the consideration of the relation of overindulgence along certain lines of eating and drinking to cancer.
Cancer has well been styled a disease of modern civilization, like tuberculosis, although of quite a different nature. Interesting studies have been made in regard to the increased death rate from the former in England, coincident with a diminished mortality of the latter, in accordance with nutritional changes which have taken place in certain populations: and in the first lecture I mentioned that in the United States the mortality from tuberculosis had fallen 25 per cent. between 1900 and 1912 while, as we shall see later, the mortality from cancer has certainly risen.
Williams, who quotes very largely from the accurate statistics which have long been carefully recorded in England, says that “while tubercle has declined with great rapidity, cancer has increased at a still faster rate, and these inversely related changes are still in active progress. In illustration of these remarks it may be mentioned that during the last half of the nineteenth century, the cancer mortality for England tripled: while, during the same period the tubercle death rate declined to the extent of nearly one-half. Unless some great change in the national habits takes place, of which there is at the present no well marked indication, cancer will ere long claim more victims than phthisis, as is already the case in many localities—e. g., Hampstead, Clifton, Bath, etc.” He further says, “I regard this decline in the presence of tuberculous diseases as the direct outcome of the better food and improved hygienic conditions, for which we are indebted to our increased national prosperity: and I shall endeavor to show that conditions of this kind, by their action in another direction, are also mainly responsible for the augmented cancer mortality.” We shall see later that cancer has asserted itself where modern civilization has augmented the opportunities of overindulgence along many lines of eating and drinking: for while advancing scientific knowledge has undoubtedly diminished mortality in general, and has added to the average length of life, the various factors included in our modern mode of living have also with certainty increased morbidity along such lines as neurotic and vascular disorders, tumors, etc.