Gastric cancer can develop in any part of the stomach and may spread throughout the stomach and to other organs; particularly the esophagus, lungs, lymph nodes, and the liver. Stomach cancer causes about 800,000 deaths worldwide per year.
Stomach cancer is often asymptomatic or causes only nonspecific symptoms in its early stages. By the time symptoms occur, the cancer has often reached an advanced stage (see below), one of the main reasons for its poor prognosis. [Citation needed] Stomach cancer can cause the following signs and symptoms:
Abdominal pain or discomfort in the upper abdomen
Nausea and vomiting Diarrhea or constipation Bloating of the stomach after meals
Weight loss Weakness and fatigue
Bleeding (vomiting blood or having blood in the stool) which will appear as black. This can lead to anemia. Dysphagia; this feature suggests a tumor in the cardia or extension of the gastric tumor in to the esophagus.
These can be symptoms of other problems such as a stomach virus, gastric ulcer or tropical sprue and diagnosis should be done by a gastroenterologist or an oncologist.
Stomach Cancer Surgery
Surgery is the most common treatment and is the only hope of cure for stomach cancer. The surgeon removes part or all of the stomach, as well as the surrounding lymph nodes, with the basic goal of removing all cancer and a margin of normal tissue. Depending on the extent of invasion and the location of the tumor, surgery may also include removal of part of the intestine or pancreas. Tumors 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 (tumor only involves the mucosa) that has been pioneered in Japan, but is also available in the United States at some centers. In this procedure, the tumor, 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 tumor, the patient would need a formal stomach resection.
Surgical interventions are currently curative in less than 40% of cases, and, in cases of metastasis, may only be palliative.
The use of chemotherapy to treat stomach cancer has no established standard of care. Stomach cancer has not been especially sensitive to these drugs until recently, and historically served to palliatively reduce the size of the tumor and increase survival time. Some drugs used in stomach cancer treatment include: 5-FU (fluorouracil), BCNU (carmustine), methyl-CCNU (Semustine), and doxorubicin (Adriamycin), as well as Mitomycin C, and more recently cisplatin and taxotere in various combinations. The relative benefits of these drugs, alone and in combination, are unclear. Scientists are exploring the benefits of giving chemotherapy before surgery to shrink the tumor, or as adjuvant therapy after surgery to destroy remaining cancer cells. Combination treatment with chemotherapy and radiation therapy is also under study. Doctors are testing a treatment in which anticancer drugs are put directly into the abdomen (intraperitoneal hyperthermic chemoperfusion). Chemotherapy also is being studied as a treatment for cancer that has spread, and as a way to relieve symptoms of the disease. The side effects of chemotherapy depend mainly on the drugs the patient receives.
Radiation therapy (also called radiotherapy) 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 tumor for palliation of incurable disease
While previous studies of multimodality therapy (combinations of surgery, chemotherapy and radiation therapy) gave mixed results, the Intergroup 0116 (SWOG 9008) study showed a survival benefit to the combination of chemotherapy and radiation therapy in patients with nonmetastatic, completely resected gastric cancer. Patients were randomized after surgery to the standard group of observation alone, or the study arm of combination chemotherapy and radiation therapy. Those in the study arm receiving chemotherapy and radiation therapy survived on average 36 months; compared to 27 months with observation.