What is gastric cancer?
Gastric cancer refers to a malignant tumor arising from the stomach. Ninety percent of the cases of gastric cancer are adenocarcinomas (arising from the epithelial layer of the stomach). Sarcomas (arising from the connective tissue) and lymphomas are less common. Gastric cancer is classified by the tissue type and location in the stomach.
It is thought that gastric cancer develops in a multistep process. The earliest lesion is atrophic gastritis, followed by dysplasia, adenoma and then adenocarcinoma. Molecular and genetic events trigger these changes from step to step.
What causes gastric cancer?
The cause of gastric cancer is unknown. However, certain factors and conditions are linked to the development of gastric cancer including poor nutrition, poor sanitation and inadequate handling of food and water supplies. Untreated Helicobacter pylori (a bacterial organism) may lead to development of gastric cancer. Gastric polyps may also be contributory. Pernicious anemia and atrophic gastritis may also increase the risk.
What are the symptoms of gastric cancer?
Often no symptoms appear until late in the disease process, then abdominal pain and weight loss are the first symptoms. Early satiety (feeling full before enough food is consumed), nausea, loss of appetite and difficulty swallowing may be experienced (depending on the location of the tumor). If the cancer has metastasized, symptoms may arise from the area to which the cancer has spread. Gastrointestinal bleeding occurs in about 20 percent of the cases.
How is gastric cancer diagnosed?
A physical examination may reveal a palpable mass. Anemia and occult blood in the stool require further investigation to rule out malignancy. A patient with suspected gastric cancer should have an esophagogastroduodenoscopy (EGD) to obtain tissue for biopsy. Metastatic disease can be evaluated by further tests, including a computed tomography (CT) scan.
Can gastric cancer be prevented?
Attention should be given to any ongoing abdominal pain, bleeding, gastric polyps, ulcers or H. pylori. Documentation that a gastric ulcer has healed is critical, because non-healing ulcers may be a result of an underlying cancer.
Food and water supplies should be handled with regard to appropriate sanitation. Diets high in fresh fruits, leafy vegetables, ascorbic acid, and beta-carotene may reduce the risk of developing gastric cancer.
Recent data suggested families with hereditary diffuse gastric cancer may benefit from prophylactic gastrectomy if there is a mutation in the E-cadherin gene.
What is the treatment for gastric cancer?
Treatment for gastric cancer includes resection (surgical removal of the cancerous portion of the stomach), chemotherapy and radiation. The goal of resection is to remove the tumor by means of a total or subtotal gastrectomy. Endoscopic mucosal resection may be useful for early superficial cancers. Chemotherapy with multi-drug regimens has been successful. Radiation alone has not been shown to be effective against gastric cancer.
What is the goal of treatment? Can gastric cancer be cured?
The goal is to completely remove the cancer with clear margins. Often, gastric cancer is diagnosed late in the disease process and palliative therapy is offered to relieve symptoms.
What is the survival of patients with gastric cancer?
The five-year survival rate is only 23 percent due to the late diagnosis of gastric cancer in the majority of patients. Early diagnosis may lead to a five-year survival rate of 60 percent.
What are the complications of this disease?
Complications related to gastric cancer are two-fold. If the cancer is not treated, many complications are associated with the disease progression. These include pain, weight loss, difficulty swallowing, nausea, vomiting and bleeding. The cancer may spread to the liver and cause such complications as jaundice, ascites (fluid collection in the abdominal cavity), fever and malaise.
Complications may be associated with the treatment. Gastrectomy may necessitate lifestyle changes. Some patients may need to eat smaller meals more frequently. There may be a change in bowel habits.
Will I need an endoscopy, biopsies or other tests to diagnose cancer?
Yes. An endoscopy is performed to visualize the stomach. Biopsies are obtained during the procedure and are sent to the laboratory to confirm the diagnosis. Further endoscopies or additional tests may be necessary depending upon the location and staging of the cancer.