stomach cancer

Stomach cancer: description

Gastric cancer occurs when cells of the stomach begin to divide uncontrollably. Depending on which cell type exactly the tumor emanates, one distinguishes different types of gastric carcinoma:

Mostly degenerate glandular cells of the gastric mucosa, which form the gastric juice. Physicians then speak of a so-called adenocarcinoma. In rare cases, the tumor is caused by lymphoid cells (MALT lymphoma) or by muscle and connective tissue cells (sarcoma).

Gastric cancer: frequency

The incidence of gastric cancer has declined in recent years, yet it is still a very common cancer. Men are more affected than women. For example, stomach cancer is the fifth most common in men and the sixth most common in women.

Gastric cancer is a disease of old age. The incidence peak of gastric cancer is beyond the 50th year of life. The incidence of gastric cancer has been linked to dietary and lifestyle habits. Therefore, the incidence of gastric cancer differs between different continents: In Japan and parts of South America, stomach cancer is much more prevalent than in Germany or the US.

Gastric cancer stages

Gastric carcinoma is classified according to its malignancy and after the spread of the cancer cells in the stomach itself as well as in the lymph nodes or other body regions:

Malignancy: The extent to which gastric cancer cells differ from healthy gastric cells is assessed by grading four stages (G1 to G4). At the G1 stage, gastric cancer cells are still very similar to healthy cells. At the G4 stage, the gastric cancer cells are already very undifferentiated and very different from healthy cells. The more advanced the stage, the more aggressive the tumor usually grows.

Spread of the tumor: How far the tumor has already spread to the surrounding tissue is determined with the help of the TNM classification (T = tumor, N = lymph nodes, M = metastases) recorded.

Tumor size (T):

• T1: an early tumor that borders on the innermost layer of mucous membrane
• T2: Tumor additionally affects the smooth muscle layer of the stomach
• T3: Tumor additionally affects the outer connective tissue layer (serosa) of the stomach
• T4: tumor additionally affects surrounding organs

Lymph nodes (N):

• N1: One to two regional lymph nodes are affected by cancer cells
• N2: Three to six regional lymph nodes are affected by cancer cells
• N3: More than seven lymph nodes are affected by cancer cells

Metastases (M):

• M0: There are no distant metastases in other organs
• M1: There are distant metastases in other organs

Example: A T2N2M0 tumor would be a gastric carcinoma that has already entered the muscle layer of the stomach (T2), affecting three to six surrounding lymph nodes (N2), but has not yet caused gastric cancer metastases (M0).

Stomach cancer: symptoms

Read all about the signs of stomach cancer in the article Gastric Cancer: Symptoms.

Gastric cancer: causes and risk factors

A clear cause for the presence of gastric cancer is not yet known. However, there are numerous risk factors that favor gastric carcinoma development.

eating habits

Frequent consumption of high-salt diets and low fiber intake (fresh fruits and vegetables) are known risk factors for stomach cancer. In addition, smoked, cured and grilled foods seem to increase the risk of gastric cancer. The smoking and grilling of food produces carcinogenic substances, so-called carcinogens. For curing, nitrate and nitrite salts are used. From these arise during warming and in the stomach also strong carcinogens.

Toxins from mold fungi (aflatoxins) are also carcinogenic, which is why moldy foods should not be consumed.

Smoking and alcohol

Nicotine and alcohol are also carcinogenic substances that promote the development of stomach cancer (and other cancers).

Other diseases

Certain diseases are associated with the development of gastric cancer:

• some types of gastric mucosal polyps (usually benign, bud-like neoplasms of the gastric mucosa)
• Gastric ulcer (a wound of the gastric mucosa due to too much stomach acid)
• Ménétrier’s disease (“giant-fold-gastric mucosal inflammation” with proliferating gastric mucosa)
• Infection with the “stomach germ” Helicobacter pylori (this bacterial infection (also causes gastritis)
• Chronic atrophic gastritis (chronic gastritis with concomitant tissue loss)

Genetic factors

In some families, gastric cancer is more common, due to a genetic predisposition to this type of tumor.

Gastric cancer: examinations and diagnosis

If gastric cancer is suspected (eg due to vomiting or blood in the stool = black tarry stool), one should first Gastroscopy (gastroscopy) be performed. In the context of this examination, not only the stomach can be examined from the inside – at the same time a tissue sample (biopsy) can be taken. This is examined in the laboratory for the presence of gastric cancer cells. Gastroscopy can also provide information about the spread of an existing tumor.

A blood test can show iron deficiency anemia (anemia due to iron deficiency) in gastric cancer. The reason: stomach cancer can cause bleeding in the stomach. The escaping blood can stain the chair dark (tarry stool) and lead to anemia. However, iron deficiency anemia may have numerous other causes and is not specific for gastric cancer.

Unlike other cancers, gastric cancer can not detect a suitable tumor marker for diagnosis in the blood. The tumor markers are used for gastric cancer alone for follow-up. Occasional tumor markers (gastric carcinoma) are: CEA (Carcinoembryonic antigen), CA-72-4, CA 19-9 (CA = Cancer antigen).

An insightful stomach cancer can be Ultrasound of the abdomen. It can be performed in the form of endosonography by inserting a thin tube with a transducer and a camera at the tip through the esophagus into the stomach. This study can identify which tissue layers are affected by gastric cancer. A general ultrasound examination of the abdominal cavity from the outside over the abdominal wall can help in the search for possible metastases.

One X-ray photograph the lungs as well as one Computed tomography (CT) can also be used to search for metastases. A laparoscopy (Laparoscopy) is a surgical procedure in which an endoscope (with optical system and light source) is introduced via a small incision in the abdomen to examine in more detail.

Stomach cancer: treatment

The therapeutic measures are dependent on the gastric cancer stage. The more advanced the tumor is, the more radical is the therapy.

Surgical measures for gastric cancer

If gastric cancer is detected very early, a minimally invasive surgery can be performed. This procedure is also called a “keyhole surgery”, as it can be removed in the context of a gastroscopy, the tumor on very small skin incisions. However, this procedure is only possible if gastric cancer has not yet spread beyond the gastric mucosa.

For more advanced gastric cancer, a partial to complete removal of the stomach (gastric resection) should be done. In order to continue feeding, the remainder of the stomach or esophagus (with complete gastric removal) is connected directly to the small intestine. If the gastric carcinoma already affects the surrounding lymph nodes or the spleen, these are also removed.

After a gastric resection, the digestive function and nutrient utilization may be impaired. As a result, those affected usually lose a lot of weight initially. However, this weight loss usually ceases after some time on its own. To ensure digestion, digestive enzymes must be replaced by medication. Often, the intake of minerals and vitamins is necessary, such as vitamin B12: To absorb this from the diet, the body needs a sugar-protein complex that is produced in the gastric mucosa (intrinsic factor). In gastric cancer patients may therefore come after a gastric resection to a lack of vitamin B12.

Chemo- and radiotherapy for gastric cancer

Following surgery for gastric cancer, patients often receive chemotherapy, more rarely radiotherapy. Chemotherapy is often started before surgery to reduce the size of the tumor before surgery and make it (better) operable. After surgery, chemotherapy should prevent relapse.

Antibody therapy in gastric cancer

In some cases, the gastric cancer has progressed so far that a cure is no longer possible (gastric cancer end stage). Then only with palliative measures can be tried to extend the life of the patients and to relieve the symptoms.

Antibody therapy can be used as a more recent treatment approach: in about 20 percent of all gastric cancer patients, so-called HER2 receptors are increasingly found on the surface of the cancer cells – docking sites for growth factors that are important for tumor growth. For such HER2-positive gastric carcinomas, the administration of HER2 antibodies may be useful. These occupied the HER2 receptors to affect tumor growth.

The antibodies are infused every three weeks. In addition, patients receive chemotherapy.

Nutrition tube & medication

Some stomach cancer patients need an artificial diet in the medium or long term in order to be sufficiently supplied with nutrients and vital substances. Then, so-called PEG probe (PEG = percutaneous endoscopic gastrotomy) can be created. This artificial feeding tube is placed through the abdominal wall directly into the stomach and provides the patient with nutrients. Many patients suffer from severe pain in advanced stages of gastric cancer. Analgesic medications can then significantly improve the quality of life of those affected.

Gastric cancer: disease course and prognosis

Is stomach cancer curable? The answer to this question depends on the stage of the cancer. The gastric cancer healing chances are good if the tumor is detected at an early stage. However, this is often not the case. The further the gastric carcinoma has spread at the time of diagnosis, the worse the gastric cancer prognosis looks. Five years after diagnosis, the stomach cancer life expectancy according to recent research results on average 31 percent for women and 35 percent for men.

When there is no hope for recovery, the time remaining for those affected should be as painless and comfortable as possible. In Germany, there are specialists for palliative care, who specialize among others, patients with stomach cancer and to care for their relatives optimally.