It will be observed that the obscurity which surrounds the ultimate causation of gastric cancer is in no way cleared up by the points which have been here considered and which are usually considered under the head of etiology. It is impossible to avoid the assumption of an individual—and in my opinion a local—predisposition to gastric cancer, vague as this assumption appears. All other supposed causes are at the most merely occasional or exciting causes. The attempts to explain in what this predisposition consists are of a speculative nature, and will be briefly considered in connection with the pathenogenesis of gastric cancer.
SYMPTOMATOLOGY.—We may distinguish the following groups of cases of gastric cancer:
First: Latent cases, in which the cancer of the stomach has produced no symptoms up to the time of death. Many secondary cancers of the stomach belong to this class. Here also belong cases in which a cancer is found unexpectedly in the stomach when death has resulted from other causes. I have found a medullary cancer, slightly ulcerated, as large as a hen's egg, seated upon the posterior wall and lesser curvature of the stomach of a laboring man suddenly killed while in apparent health and without previous complaint of gastric disturbance. These cases, in which life is cut short before any manifestation of the disease, are without clinical significance, save to indicate how fallacious it is to estimate the duration of the cancerous growth from the first appearance of the symptoms.
Second: Cases in which gastric symptoms are absent or insignificant, whereas symptoms of general marasmus or of progressive anæmia or of cachectic dropsy are prominent. Cases of this class are frequently mistaken for pernicious anæmia, and occasionally for Bright's disease, heart disease, or phthisis. It is difficult to explain in these cases the tolerance of the stomach for the cancerous growth, but this tolerance is most frequently manifested when the tumor does not invade the orifices of the organ.
Third: Cases in which the symptoms of the primary gastric cancer are insignificant, but the symptoms of secondary cancer, particularly of cancer of the liver or of the peritoneum, predominate. In some, but not in all, of these cases the primary growth is small or has spared the orifices of the stomach.
Fourth: Cases in which the symptoms point to some disease of the stomach, or at least to some abdominal disease; but the absence of characteristic symptoms renders the diagnosis of gastric cancer impossible or only conjectural.
Fifth: Typical cases in which symptoms sufficiently characteristic of gastric cancer are present, so that the diagnosis can be made with reasonable positiveness.
It is not to be understood that these groups represent sharply-drawn types of the disease. It often happens that the same case may present at one period the features of one group, and at another period those of another group. Nor is it supposed that every exceptional and erratic case of gastric cancer can be classified in any of the groups which have been mentioned.35
35 In the thesis of Chesnel may be found many curious clinical disguises which may be assumed by cancer of the stomach, such as simulation of Bright's disease, heart disease, phthisis, chronic bronchitis, cirrhosis of the liver, etc. (Étude clinique sur le Cancer latent de l'Estomac, Paris, 1877). Layman (Med. Annals Albany, 1883, p. 207) reports a case of gastric cancer in which extra-uterine foetation was suspected.
A typical case of gastric cancer runs a course about as follows: A person, usually beyond middle age, begins to suffer from disordered digestion. His appetite is impaired, and a sense of uneasiness, increasing in course of time to actual pain, is felt in the stomach. These symptoms of dyspepsia are in no way peculiar, and probably at first occasion little anxiety. It is, however, soon observed that the patient is losing flesh and strength more rapidly than can be explained by simple indigestion. He becomes depressed in spirits. The bowels are constipated. Vomiting, which was usually absent at first, makes its appearance and becomes more and more frequent. After a while it may be that, without any improvement, the vomiting becomes less frequent, comes on longer after a meal, but is more copious. In the later periods of the disease a substance resembling coffee-grounds and consisting of altered blood is often mingled with the vomit. By this time the patient has assumed a cachectic look. He is wasted, and his complexion has the peculiar pale yellowish tint of malignant disease. Perhaps there is a little oedematous pitting about the ankles. During the progress of the disease in the majority of cases an irregular hard tumor can be felt in the epigastrium. While one or another of the symptoms may abate in severity, the general progress of the disease is relentlessly downward. Within six months to two years of the onset of the symptoms the patient dies of exhaustion.