Part 94

Primary cancers may be present at the same time in different organs of the body; for instance, in the uterus and in the stomach. The possibility of multiple primary cancers is to be borne in mind in considering some of the apparently secondary cancers of the stomach, as well as in determining whether certain cancers are secondary to gastric cancer or not. Here the microscopical examination is often decisive.

{566} Gastric cancer often causes important secondary changes in the coats and the lumen of the stomach. In the neighborhood of the tumor are often found hypertrophy of the muscular coat and fibrous thickening of the submucous coat. Polypoid hypertrophy of the mucous membrane near the cancer is not rare. Not only near the tumor, but over the whole stomach, chronic catarrhal gastritis usually exists.

The most important alterations are those dependent upon obstruction of the orifices of the stomach. This obstruction may be caused either by a tumor encroaching upon the orifice or by an annular thickening of the walls of the orifices. Even without apparent stenosis, destruction of the muscular layer at or near the pylorus may be an obstacle to the propulsion of the gastric contents into the duodenum. As a result of obstruction of the pyloric orifice the stomach becomes dilated, sometimes enormously, so as to occupy most of the abdominal cavity. The walls of the dilated stomach, particularly the muscular coat, are usually thickened, but exceptionally they are thinned. Sometimes with pyloric stenosis the stomach is reduced in size. This occurs particularly when a scirrhous growth extends diffusely from the pyloric region over a considerable part of the stomach. Obstruction of the cardiac orifice or in the oesophagus leads to atrophy of the stomach, although here also there are exceptions. Above the obstruction the oesophagus is often dilated. An existing obstruction may be reduced or removed by ulceration or sloughing of the tumor.

Both dilatation and contraction of the stomach may attend gastric cancer without any involvement of the orifices of the stomach in the cancerous growth. The cavity of the stomach may be so shrunken by scirrhous thickening and contraction of the gastric walls that it will hardly contain a hen's egg. Irregular deformities in the shape of the stomach, such as an hour-glass shape and diverticular recesses, may be caused by gastric cancer.

Changes in the shape of the stomach and the weight of the tumor may cause displacements of pyloric cancers, so that these tumors have been found in nearly all regions of the abdomen, and even in the true pelvis. Such displaced cancers usually contract adhesions with surrounding parts.

It is not necessary to dwell upon the formation of adhesions which may bind the stomach to nearly all of the abdominal organs, most frequently to the liver, the pancreas, the intestine, and the anterior abdominal wall. Adhesions of pyloric cancers are found in at least two-thirds of the cases, and probably oftener.

Cancer of the stomach in the majority of cases is accompanied with {567} metastases in other parts of the body. In 1120 cases of gastric cancer secondary cancers were present in 710, or 63.4 per cent., and absent in 410, or 36.6 per cent. In about two-thirds of the cases, therefore, secondary deposits were present.

In order to determine the relative frequency of the secondary deposits in various organs of the body, I have constructed the following table, based upon an analysis of 1574 cases of cancer of the stomach in which the situation of the metastases were given:

Lymphatic glands. 551 35.0% Liver. 475 30.2% Peritoneum, omentum, and intestine. 357 22.7% Pancreas. 122 7.8% Pleura and lung. 98 6.2% Spleen. 26 1.7% Brain and meninges. 9 0.6% Other parts of the body. 92 5.8%

Secondary cancerous deposits are probably even more frequent in the lymphatic glands than appears from the table. In 1153 cases of gastric cancer in which the situation of the affected lymphatic glands is specified, the abdominal glands, and chiefly those near the stomach, were the seat of cancer in 32½ per cent. In Lange's 210 cases the cervical glands were affected in 4.3 per cent. In other statistics this percentage is much smaller. In nearly one-third of the cases there are secondary cancers in the liver. These may attain an enormous size in comparison with the tumor of the stomach. Cancer of the peritoneum and of the omentum is found in about one-fifth of the cases of gastric cancer. The spleen is rarely involved, except by continuous growth of a cancer of the fundus or in cases of widespread distribution of cancer through the aortic circulation. Cancer of the liver increases the liability to metastases in the lungs, but the latter may be present without any cancerous deposits in the liver. Secondary cancers may be present in the suprarenal capsules, the kidneys, the ovaries, the heart, the thoracic duct, the bones, the skin, etc. In an interesting case reported by Finlay the subcutaneous tissue of the trunk was thickly studded with small nodules, of which two were excised during life and found to be cylindrical epitheliomata. This led to the diagnosis of a primary tumor of the same nature in the stomach or in the intestine. At the autopsy was found a cylindrical epithelioma of the stomach which had not given rise to characteristic symptoms. Secondary cancer of the intestine is rare if the deposits in the peritoneal coat be {568} excepted. Several cancerous ulcers or multiple cancerous nodules may be found along the intestinal tract, involving the mucous and the submucous coats. These metastases seem best explained by the theory of implantation of cancerous elements which have been carried from the primary growth in the stomach into the intestine. In some of the cases the idea of multiple primary cancers may also be entertained.

It is not rare for gastric cancer to cause secondary deposits in the stomach itself. Sometimes it is difficult to decide which of two or more cancers in the stomach is the primary growth, as in Ripley's case of ulcerated cancer of the cardiac orifice with a similar growth around the pyloric orifice. It is probable that in very rare instances multiple primary cancers may develop in the stomach.

Cancerous metastases are produced by the transportation of cancerous elements by the lymphatic current or by the blood-current. In a number of instances the portal vein or some of the branches which help to form it have been found plugged with a cancerous mass which may or may not be organized. The cancer in these cases has burst through the walls of the vessel into the lumen, where it may grow both in the direction and against the direction of the current. On serous surfaces, and probably also, although rarely, on mucous surfaces, secondary cancers may develop from cancerous particles detached from a parent tumor and scattered over the surface as a kind of seminium.

Mention has already been made of the invasion of parts adjacent to the stomach by the continuous growth of gastric cancer. In this way lymphatic glands, the liver, the pancreas, the omenta, the transverse colon, the spleen, the diaphragm, the anterior abdominal wall, the vertebræ, the spinal cord and membranes, and other parts may be involved in the cancerous growth.

Under the head of Complications reference has already been made to various lesions which may be associated with gastric cancer. As regards the manifold complications caused by perforation of gastric cancer, in addition to what has already been said the article on gastric ulcer may be consulted. In general, the various fistulous communications caused by gastric cancer are less direct than those produced by gastric ulcer. The wasting of various organs of the body in cases of gastric cancer may be found on post-mortem examination to be extreme. Habershon mentions a case in which the heart of a woman forty years old weighed only 3½ ounces after death from cancer of the pylorus. As in other profoundly anæmic states, the embryonic or lymphoid alteration of the marrow of the bones is often present in gastric cancer.

PATHENOGENESIS.--The problems relating to the ultimate causation and origin of gastric cancer belong to the pathenogenesis of cancer in general. Our knowledge with reference to these points is purely hypothetical. It will suffice in this connection simply to call attention to {569} Virchow's doctrine, that cancer develops most frequently as the result of abnormal or of physiological irritation, hence in the stomach most frequently at the orifices; and to Cohnheim's theory, that cancer as well as other non-infectious tumors originate in abnormalities in development, more specifically in persistent embryonic cells. According to the latter view, gastric cancer develops only in those whose stomachs from the time of birth contain such embryonic remnants. These unused embryonic cells may lie dormant throughout life or they may be incited to cancerous growth by irritation, senile changes, etc. According to Cohnheim's theory, the orifices of the stomach are the most frequent seat of cancer on account of complexity in the development of these parts.

For a full consideration of these theories the reader is referred to the section of this work on General Pathology.

DIAGNOSIS.--The presence of a recognizable tumor in the region of the stomach outweighs in diagnostic value all other symptoms of gastric cancer. The detection of fragments of cancer in the vomit or in washings from the stomach is of equal diagnostic significance, but of rare applicability. The discovery of secondary cancers in the liver, in the peritoneum, or in lymphatic glands may render valuable aid in diagnosis. Of the local gastric symptoms, coffee-ground vomiting is the most important. The relation between the local and the general symptoms may shed much light upon the case. While anorexia, indigestion, vomiting, and epigastric pain and tenderness point to the existence of a gastric affection, the malignant character of the affection may be surmised by the development of anæmia, emaciation, and cachexia more rapid and more profound than can be explained solely by the local gastric symptoms. The value to be attached in the diagnosis of gastric cancer to the absence of free hydrochloric acid from the contents of the stomach must still be left sub judice. The age of the patient, the duration, and the course of the disease are circumstances which are also to be considered in making the diagnosis of gastric cancer. These symptoms of gastric cancer have already been fully considered with reference to their presence and absence and to their diagnostic features.

It remains to call attention to the differential diagnosis between gastric cancer and certain diseases with which it is likely to be confounded. The points of contrast which are to be adduced relate mostly to the intensity and the frequency of certain symptoms. There is not a symptom or any combination of symptoms of gastric cancer which may not occur in other diseases. Hence the diagnosis is reached by a balancing of probabilities, and not by any positive proof. Notwithstanding these difficulties, gastric cancer is diagnosed correctly in the great majority of cases, although often not until a late stage of the disease. Errors in diagnosis, however, are unavoidable, not only in cases in which the symptoms are ambiguous or misleading, but also in cases in which all the symptoms of gastric cancer, including gastric hemorrhage and tumor, are present, and still no gastric cancer exists. Cases of the latter variety are of course rare.

In the absence of tumor the diseases for which gastric cancer is most liable to be mistaken are gastric ulcer and chronic gastric catarrh. In the following table are given the main points of contrast between these three diseases: {570}

GASTRIC CANCER. | GASTRIC ULCER. | CHRONIC CATARRHAL | | GASTRITIS. | | 1. Tumor is present | 1. Tumor rare. | 1. No tumor. in three-fourths of | | the cases. | | | | 2. Rare under forty | 2. May occur at any | 2. May occur at any years of age. | age after childhood. | age. | Over one-half of the | | cases under forty | | years of age. | | | 3. Average duration | 3. Duration | 3. Duration about one year, | indefinite; may be | indefinite. rarely over two | for several years. | years. | | | | 4. Gastric hemorrhage| 4. Gastric hemorrhage| 4. Gastric frequent, but rarely | less frequent than in| hemorrhage rare. profuse; most common | cancer, but oftener | in the cachectic | profuse; not uncommon| stage. | when the general | | health is but little | | impaired. | | | 5. Vomiting often has| 5. Vomiting rarely | 5. Vomiting may or the peculiarities of | referable to | may not be present. that of dilatation of| dilatation of the | the stomach. | stomach, and then | | only in a late stage | | of the disease. | | | 6. Free hydrochloric | 6. Free hydrochloric | 6. Free hydrochloric acid usually absent | acid usually present | acid may be present from the gastric | in the gastric | or absent. contents in cancerous| contents. | dilatation of the | | stomach. | | | | 7. Cancerous | 7. Absent. | 7. Absent. fragments may be | | found in the washings| | from the stomach or | | in the vomit (rare). | | | | 8. Secondary cancers | 8. Absent. | 8. Absent. may be recognized in | | the liver, the | | peritoneum, the | | lymphatic glands, and| | rarely in other parts| | of the body. | | | | 9. Loss of flesh and | 9. Cachectic | 9. When strength and | appearance usually | uncomplicated, development of | less marked and of | usually no cachexia usually more| later occurrence than| appearance of marked and more rapid| in cancer; and more | cachexia. than in ulcer or in | manifestly dependent | gastritis, and less | upon the gastric | explicable by the | disorders. | gastric symptoms. | | | | 10. Epigastric pain | 10. Pain is often | 10. The pain or is often more | more paroxysmal, more| distress induced by continuous, less | influenced by taking | taking food is dependent upon taking| food, oftener | usually less severe food, less relieved | relieved by vomiting,| than in cancer or in by vomiting, and less| and more sharply | ulcer. Fixed point localized, than in | localized, than in | of tenderness ulcer. | cancer. | usually absent. | | 11. Causation not | 11. Causation not | 11. Often referable known. | known. | to some known cause, | | such as abuse of | | alcohol, | | gormandizing, and | | certain diseases, as | | phthisis, Bright's | | disease, cirrhosis | | of the liver, etc. | | 12. No improvement or| 12. Sometimes a | 12. May be a history only temporary | history of one or | of previous similar improvement in the | more previous similar| attacks. More course of the | attacks. The course | amenable to disease. | may be irregular and | regulation of diet | intermittent. Usually| than is cancer. | marked improvement by| | regulation of diet. |

{571} The diagnosis between gastric cancer and gastric ulcer is more difficult than that between cancer and gastritis, and sometimes the diagnosis is impossible. The differential points mentioned in the table are of very unequal value. An age under thirty, profuse hemorrhage, and absence of tumor are the most important points in favor of ulcer; tumor, advanced age, and coffee-ground vomiting continued for weeks are the most important points in favor of cancer. As cancer may have been preceded by ulcer or chronic gastritis for years, it is evidently unsafe to trust too much to the duration of the illness. As has already been said, it is best to place no reliance in the differential diagnosis upon the character of the pain. Any peculiarities of the vomiting, the appetite, or the digestion are of little importance in the differential diagnosis. Cachexia is of more importance, but it is to be remembered that ulcer, and even chronic gastritis in rare instances, may be attended by a cachexia indistinguishable from that of cancer. Cases might be cited in which very decided temporary improvement in the symptoms has been brought about in the course of gastric cancer, so that too much stress should not be laid upon this point. Enough has been said under the Symptomatology with reference to the diagnostic bearings of the absence of free hydrochloric acid from the stomach, of the presence of cancerous fragments in fluids from the stomach, and of secondary cancers in different parts of the body.

One must not lose sight of the fact that the whole complex of symptoms, the order of their occurrence, and the general aspect of the case, make an impression which cannot be conveyed in any diagnostic table, but which leads the experienced physician to a correct diagnosis more surely than reliance upon any single symptom.

In the early part of the disease there may be danger of confounding gastric cancer with nervous dyspepsia or with gastralgia, but with the progress of the disease the error usually becomes apparent. What has already been said concerning the symptomatology and the diagnosis of gastric cancer furnishes a sufficient basis for the differential diagnosis between this disease and nervous affections of the stomach.

Chronic interstitial gastritis or fibroid induration of the stomach cannot be distinguished with any certainty from cancer of the stomach. Fibroid induration of the stomach is of longer duration than gastric cancer, and it is less frequently attended by severe pain and hemorrhage. Sometimes a hard, smooth tumor presenting the contours of the stomach can be felt, but this cannot be distinguished from diffuse cancerous infiltration of the stomach.

Non-malignant stenosis of the pylorus is of longer duration than cancer of the pylorus. The symptoms of dilatation of the stomach are common to both diseases. Cicatricial stenosis is the most common form of non-malignant pyloric stenosis. This is usually preceded by symptoms of gastric ulcer which may date back for many years. Non-malignant stenosis more frequently occurs under forty years of age than does cancer. The diagnosis between malignant and non-malignant stenosis of the pylorus is in some cases impossible.

Although the surest ground for the diagnosis of gastric cancer is the appearance of tumor, there are cases in which it is difficult to decide whether the tumor really belongs to the stomach, and even should it be {572} established that the tumor is of the stomach, there may still be doubt whether or not it is cancerous.

The diagnosis between cancerous and non-cancerous tumors of the stomach, such as sarcoma, fibroma, myoma, etc., hardly comes into consideration. The latter group of tumors rarely produces symptoms unless the tumor is so situated as to obstruct one of the orifices of the stomach. Even in this case a positive diagnosis of the nature of the tumor is impossible.

Of greater importance is the distinction between cancerous tumors of the stomach and tumors produced by thickening of the tissues and by adhesions around old ulcers of the stomach. Besides the non-progressive character of the small and usually indistinct tumors occasionally caused by ulcers or their cicatrices, the main points in diagnosis are the age of the patient and the existence, often for years, of symptoms of gastric ulcer antedating the discovery of the tumor. The long duration of symptoms of chronic catarrhal gastritis and of dilatation of the stomach is also the main ground for distinguishing from cancer a tumor produced by hypertrophic stenosis of the pylorus.