The human digestive apparatus, whose function is to handle the process of digestion through the transport of food, the secretion of digestive juices, the absorption of nutrients and excretion of waste through the process of defecation, is made up by several vital organs.
One of the primary components of the digestive system is the stomach. This “J” shaped, hollow organ is located between the esophagus and the intestine, underneath the diaphragm and adjacent to other important abdominal organs such as the liver, and pancreas.
At the risk of oversimplifying the matter, one could say that the stomach is composed of several layers of muscle and connective tissue. Stomach cancer, also known as gastric cancer, is a disease that occurs when uncontrolled growth of the cells that make up the inner lining of the stomach walls leads to the formation of tumors.
When dealing with stomach cancer, it is extremely important to diagnose it in its localized initial phase, because once it spreads deeper into the muscular layer, it will almost invariably cross the outermost serosal layer, spreading to other organs outside the stomach itself and significantly lowering the chances of survival.
The overwhelming majority of stomach cancer occurs along the glandular tissue of the stomach lining and it is categorized as adenocarcinoma. However, lymphoma and sarcoma, although rare, also occur in the stomach.
How common is stomach cancer?
Stomach cancer is relatively common in certain demographics and risk-groups. In fact, adenocarcinoma of the stomach stands as the fifth most common malignant tumor in the world. Furthermore, if we take into account the other types of tumors that can affect the stomach, we can say that stomach cancer accounts for about 10% of all malignant tumors that are diagnosed each year.
Curiously enough, more than half of all stomach cancer cases are found in Asia. It is also quite common in South America, some parts of eastern Europe and some countries in the Middle East. On the other hand, cancers of the stomach are far less prevalent in the United States, Australia, and Africa.
What causes of stomach cancer?
As is the case regarding many types of cancers, the exact mechanisms behind the formation of gastric tumors remain unknown.
However, the medical community has identified several risk factors that significantly increase the probability of developing stomach cancer, for example:
- Diets that are rich in salted, cured, and smoked foods, as well as foods that have elevated concentrations of nitrates, have been repeatedly associated with a high incidence of stomach tumors.
- Environmental factors, such as poor water sanitation, increase the probability of developing stomach cancer over a lifetime.
- Habits such as smoking tobacco and the consumption of alcohol.
- Specific pathologies of the gastrointestinal tract, such as chronic gastritis or gastric polyps, increase the risk of cancer.
- Having previously undergone gastric surgery.
- The bacterium known as Helicobacter pylori has been linked to stomach cancer.
- A history of stomach cancer in the family.
Stomach Cancer Symptoms
Given that thousands upon thousands of patients die every year from late-stage stomach cancer, compounded by the fact that, in its earliest stages, stomach cancer rarely causes an overt symptomatology, it is crucial that we learn as much as possible about the potential signs of this disease, in an effort to improve the odds of early detection.
Here are the most common signs and symptoms of stomach cancer.
1) Anorexia
Very many pathologies have the capacity to induce a dramatic loss of appetite, also known as anorexia. For example, renal failure, heart disease, hepatic abnormalities, hypothyroidism, and cancer. In fact, a large group of oncologic patients, especially those suffering from gastrointestinal tumors, experience bouts of recurring anorexia.
While not all cancer patients develop anorexia, it is important that the chronic loss of appetite be taken seriously, especially during treatment as it can drastically reduce the patient’s ability to achieve proper nutrition.
2) Cachexia
Given the fact that an estimated two-thirds of cancer patients experience loss of appetite, it should be no surprise that dramatic weight loss and severe malnutrition are commonly seen in cases of stomach cancer. In extreme cases, some of these patients develop a condition known as cachexia. Cachexia is the consumption of the body’s adipose tissues and skeletal muscles. In other words, it can be described as a wasting away of the body, and it stands as one of the main contributing causes of death in cancer patients.
It is important to note that cachexia in cancer patients differs dramatically from a mere case of malnutrition, although its exact mechanisms are still widely debated. Several hypotheses propose that its pathogenesis is affected by diverse variables such as the specific characteristics of the tumor, the general state of health of the patient, as well as the various treatment variables. Unfortunately, in many cases, the appearance of cachexia signifies an irreversible progression of the disease.
3) Abdominal Pain
As is to be expected, the presence of abdominal pain is quite frequent among patients with stomach cancer. Its location is usually located in the upper part of the abdomen, in an area called epigastrium, colloquially known as the mouth of the stomach. However, it is important to note that stomach tumors rarely ever cause pain or discomfort during the initial stages of the disease. As such, the appearance of abdominal pain should be taken as a serious development and a sign of high clinical significance, especially when it is accompanied by other symptoms found on this list.
4) Sense of Fullness After Small Meals
Frequently patients with stomach cancer report feeling overly satiated or full after consuming small meals. This unjustified sensation may be due, in part, to the inability of the stomach to fill up normally as a result of the physical presence of the tumor. In other words, the tumor effectively reduces the volume capacity of the stomach.
5) Pyrosis
More commonly known as acid indigestion or heartburn, pyrosis can be generated due to gastroesophageal reflux, gastroduodenal ulceration, gastritis, and other more severe diseases such as stomach cancer and esophageal cancer. Pyrosis can be best described as an intense sensation of burning heat that originates in the thorax, behind the sternum, and ascends towards the neck, throat, and face. The sensation is typically accompanied by a surge of highly acidic gastric content that often reaches the back of the throat.
6) Asthenia
Although its intensity is quite subjective, asthenia is perhaps the most frequent symptom in patients with advanced stages of cancer and, arguably, the one that most impacts their quality of life. Asthenia can be best described as a chronic weakness and loss of strength that affects the entire body. Asthenia has the potential to dramatically reduce the patient’s ability to function physically and socially, and its presence may last for months or even years after the end of treatment. Asthenia typically worsens as cancer progresses, and treatments that are not specifically directed towards its root cause are not very effective in managing it.
In patients with advanced stomach cancer, asthenia may be caused by the tumor’s constant release of cytokines, as a side effect of the various oncological treatments such as chemotherapy, and to complications such as anemia, infection, and renal or hepatic failure. In most cases, it may be that a complex interrelation of various physical and psychological symptoms exacerbate this condition.
7) Vomiting
Patients with stomach tumors may experience severe irritation of the gastric mucosa, and this often leads to significant nausea and vomiting. One important note is that bleeding caused by the erosion of the underlying blood vessels near the tumor can be evidenced by the presence of blood in the vomit or in the stools. In the event that blood is present in the vomit, and the bleeding is related to gastric cancer, the patient’s stools will likely turn black and have a tarry texture due to the partial digestion of the blood.
Although the presence of blood in vomit and stool is not a determining factor, as it may be caused by more benign conditions such as colitis or Crohn’s disease, it can be a symptom of advanced cancer and as such should be considered a serious development.
8) Fluid Build-up in the Abdomen
Cancer that develops in the stomach almost invariably produces a feeling of swelling in the abdomen as well as alters gastrointestinal function. But beyond that, it is possible that stomach cancer causes a condition known as ascites.
Ascites is defined as the presence of fluid in the peritoneal cavity and is typically observed in various pathologies, mainly in hepatic and oncological diseases. In general, unless the accumulation of fluid in the abdomen is significant, there are no symptoms besides slight abdominal distension, heartburn, indigestion, and pain in the lower back.
9) Diarrhea
Diarrhea, or abnormally frequent bowel movements, causes low absorption of fluids and nutrients and may be accompanied by abdominal pain, fever, nausea, vomiting, weakness, and decreased appetite. In addition to the great loss of water caused by such frequent evacuations, patients, usually children, lose dangerous amounts of important salts, electrolytes, and other nutrients. Depending on its cause, diarrhea may contain mucus, pus, or blood.
10) Constipation
Constipation is a condition that can be best described as a lack of regular movement of the intestines, which produces infrequent defecation that typically consists of scarce and hardened stools. What is considered a normal defecatory frequency varies from one individual to the next, and can range from a couple of times a day to just a few times a week. Anything that falls short of this range, on an individual basis that is, can be considered constipation.
11) Anemia
Anemia, or a low red blood cell count, is a frequent symptom in patients with cancer. In fact, upwards of 70% of the hematological neoplasms and 60% of solid tumors have some element of related anemia during the progression of the disease.
The anemia of the patient with cancer is multifactorial, meaning it can be due to various factors such as blood loss, nutritional deficit, iron deficiency, renal failure, bone marrow infiltration, etc. In cases of stomach cancer, the severity of the anemia is moderate, with hemoglobin levels ranging between 8-10 gr/dl.
Conclusion
How is stomach cancer diagnosed?
Before carrying out any test, the doctor will prepare a medical history and perform a physical examination that will inform him or her about the patient’s habits and the existence of any symptoms and signs that may lead to suspicion of stomach cancer or other conditions.
Tests for diagnosis
Besides a clinical history and physical examinations, in order to accurately diagnose stomach cancer, the physician may request additional tests.
- Endoscopy: It is the test most used in the diagnosis of stomach cancer. Endoscopy allows direct observation of the mucosa of the stomach and a more accurate assessment of the existence or not of lesions.
- Biopsy: If the doctor observes a suspicious lesion during the endoscopy, he may remove a small sample of tissue from the area. This small sliver of tissue will be analyzed by a pathologist using a microscope, allowing him or her to issue a diagnosis confirming or ruling out the existence of cancerous growth.
Other tests that can help determine the presence of stomach cancer:
- Radiographic study with contrast
- Echoendoscopy
- CT Scan
- Abdominal ultrasound
Is an early diagnosis of stomach cancer possible?
Currently, there is no evidence to suggest that healthy individuals with no symptoms benefit from regular endoscopic examinations. However, individuals diagnosed with premalignant lesions such as polyps and chronic atrophic gastritis can greatly benefit from these types of endoscopic procedures. Patients with gastric ulcers should also undergo endoscopic examinations after the conclusion of treatment to confirm that the ulcers have healed completely.
References
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