Stomach cancer or gastric cancer, refers to cancer developing in any part of the stomach. These cancers are classified according to the type of tissue they originate in. The most common type of stomach cancer is adenocarcinoma, which starts in the glandular tissue of the stomach and accounts for 90-95% of all stomach cancers.
Other forms of stomach cancer include lymphomas, which involve the lymphatic system and sarcomas, which involve the connective tissue (such as muscle, fat or blood vessels). Stomach cancer is often curable, if found and treated in an early stage.
In the early stages of stomach cancer, the symptoms are not very clear. But in the later stages the following symptoms manifest themselves:
These symptoms are similar to those caused by a peptic ulcer. If you are experiencing any of these symptoms, you should see your health care provider so that a proper diagnosis can be made and timely treatment given. A stomach cancer can grow very large before it causes other symptoms.
In more advanced cancer, you may have:
The exact cause of stomach cancer is unknown, but a number of factors can increase the risk and causes of the disease, including:
If anyone of the following symptoms occurs, such as indigestion, weight loss, nausea and loss of appetite, screening tests may be recommended. These tests may include:
Once stomach cancer is diagnosed, more tests may be performed to determine whether the cancer has spread. These tests may include CT scans, PET scans, bone scans, laparoscopy and endoscopic ultrasound.Other tests undertaken:
Cancer of the stomach is difficult to cure unless it is found in an early stage. Unfortunately, because early stomach cancer causes few symptoms, the disease is usually advanced when the diagnosis is made. Treatment for stomach cancer may include surgery, chemotherapy and/or radiation therapy. New treatment approaches such as biological therapy and improved ways of using current methods are being studied in clinical trials.
Surgery is the most common treatment. The surgeon removes part or all of the stomach, as well as the surrounding lymph nodes, with the basic goal of removing all of the cancer tissue and a margin of normal tissue. Depending on the extent of invasion and the location of the tumour, surgery may also include removal of part of the intestine or pancreas. Tumours in the lower part of the stomach may call for a Billroth I or Billroth II procedure.
Endoscopic Mucosal Resection (EMR) is a treatment for early gastric cancer (tumour only involves the mucosa) that has been pioneered in Japan, but is also available in the United States at some centres. In this procedure, the tumour, together with the inner lining of stomach (mucosa), is removed from the wall of the stomach using an electrical wire loop through the endoscope. The advantage is that it is a much smaller operation than removing the stomach. Endoscopic Submucosal Dissection (ESD) is a similar technique pioneered in Japan, used to resect a large area of mucosa in one piece. If the pathologic examination of the resected specimen shows incomplete resection or deep invasion by tumour, the patient would need a formal stomach resection.
Surgical interventions are currently curative in less than 40% of all cases, and in cases of metastasis may only be palliative.
The use of chemotherapy to treat stomach cancer has no firmly established standard of care. Unfortunately, stomach cancer has not been particularly sensitive to these drugs and chemotherapy, if used, palliatively reduces the size of the tumour, relieves symptoms of the disease and increases survival time.
Radiation therapy is the use of high-energy rays to damage cancer cells and stop them from growing. When used, it is generally in combination with surgery and chemotherapy, or used only with chemotherapy in cases where the individual is unable to undergo surgery. Radiation therapy may be used to relieve pain or blockage by shrinking the tumour for palliation of incurable disease.