Cause

Many factors have been regarded as playing an important part in the origin of cancer. Thus a trauma in the gastric region has frequently been held responsible for a cancerous affection. There is no doubt but that cases occur in which a few weeks previous to the discovery of a tumor in the abdomen a trauma in the affected region had taken place. But it would certainly be wrong in all these cases to attribute the neoplasm to the preceding trauma; for there are certainly some cases in which the neoplasm already existed before the trauma occurred, and in which the latter merely caused the patient to pay more attention to the injured region, and in this way led to an earlier recognition of the tumor. The frequent use of cider and of sour wines is said (Eichhorst and Cloquet) to favor the formation of a cancer. Mental worry and sad emotions have, probably wrongly, been regarded as playing a part in the causation of this affection.

Brinton suggested the following explanation for cancer of the cardia and pylorus: The muscular fibres of these two orifices are subjected to more work (contraction) than the rest of the stomach. The connective tissue enclosed in them is subject to contraction and distention. All this causes a more vivid nutrition of these parts, and may give rise to proliferation of the glandular tissue, forming a neoplasm.

Inflammatory conditions of the gastric mucous membrane have frequently been described as a predisposing factor of the disease. Menetrier1 tried to show the connection between some forms of chronic gastritis (polypi) and the cancer. I must, however, agree with Ewald and Rosenheim that there is no reason to believe that a chronic gastritis favors the development of cancer, for in most instances we can state that the cancerous trouble developed more or less suddenly without any preceding history of a long-standing dyspeptic trouble. The gastritis found at the autopsy in cases of gastric cancer is rather a secondary or accompanying condition than a primary factor in the disease. Chronic gastric ulcers undoubtedly belong to the predisposing factors. Several cases have been described in which the formation of a cancer on the border of a gastric ulcer or its scar could be clearly seen. Thus Hauser 2 has histologically demonstrated the transition of ulceration into carcinomatous proliferation, and asserts that in one of the cases examined by him he found not only the secondary development of carcinoma in a gastric ulcer of very long standing, but that occasionally a cancer may develop from an affection of the gastric glands.

1 Menetrier: Arch, de physiolog., 15 fevr., 1888. 2Hauser: "Das chronische Magengesehwur und dessen Bezie-hung zur Entwickelung des Mageneareinoms," Leipzig, 1883.

Parasitic Theory

All the etiological factors mentioned may perhaps give us a better understanding of the development of the carcinoma, but do not by any means explain the ultimate cause of this malignant affection. Of late the parasitic theory of infectious diseases has furthered the belief that in cancer also we may have to deal with some micro-organism. Many recent investigators have made numerous studies and experiments in order to elucidate this matter. Scheuerlen1 believed he had discovered a bacillus, to which he ascribed the origin of cancer. Later researches, however, have demonstrated that his assertions were wrong. Coley,2 of New York, and Emmerich.3 of Munich, have seen good results in the treatment of sarcoma, and also carcinoma, from the use of injections of the blood serum of horses which had been treated by the erysipelas cocci. This fact speaks in favor of a parasitic origin of this malignant growth. Psorosperms have frequently been found within the cancer cells. Thus Bra4 asserts to have found the parasite of cancer, which is a coccidium. It-is, however, not as yet determined whether these bodies are real psorosperms or dried-up and changed cells.

Hence we must confess that, notwithstanding the many researches into the pathology of cancer, we are as yet totally ignorant of its origin.

Morbid Anatomy

It was first established by the researches of Waldeyer5 that the cancerous process originates from the glandular elements of the mucous membrane, its character being chiefly an atypical proliferation of the gastric follicles. Hence the origin of the neoplasm is in the mucosa, whence it penetrates the submucosa, forming here a more or less large deposit. Frequently the larger part of the growth is situated beneath the mucosa. After a while this malignant infiltration may attack the muscularis, and thereafter extend to the serosa. The spread of the infiltration, as a rule, takes place along the connective-tissue fibres. The neoplasm, after having reached a certain degree of development, may partly slough, thereby giving rise to irregular, ulcerated spots. This occurrence is most frequent in certain forms of cancer.

1 Sehcucrlcii: "Yerhandl. des Ver. f. innere Medicin." Deutsche med. Worchenschr.. 1887, No. 48.

2Coley: American Journal of the Medical Sciences, 1894. "'Emmerich: Deutsehe med. Woehcnschrift, 1895. 4 Bra: Presumed.. February 22d, 1899. 5 Waldeyer: Virch. Arch.. Bd. lv, p. 54.

Cancer of the stomach, like that of other organs, may present the following varieties: