Gastric Adenocarcinoma Information - symptom, cause, picture, treatment of
Gastric Adenocarcinoma Information
Although gastric adenocarcinoma is the most common cancer (other than skin cancer) worldwide, its incidence in the United States has declined by two-thirds over the last 30 years to 20,000 cases annually. Gastric cancer is uncommon under age 40 years; the mean age at diagnosis is 63 years. Men are affected twice as often as women. The incidence is higher in Latinos, African-Americans, and Asian-Americans. Certain regions such as Chile, Colombia, Central America, and Japan have rates as high as 80 per 100,000 population. Although most gastric cancers arise in the antrum, the incidence of proximal tumors of the cardia and fundus is increasing dramatically.
Chronic H pylori gastritis is a strong risk factor for gastric carcinoma of the distal (but not proximal) stomach, increasing the relative risk four- to sixfold. It is estimated that 35–90% of cases of distal gastric carcinoma may be attributable to H pylori. Less than 1% of chronically infected individuals will develop carcinoma. Other risk factors for gastric cancer include chronic atrophic gastritis with intestinal metaplasia (often secondary to chronic H pylori infection), pernicious anemia, and a history of partial gastric resection more than 15 years previously.
Gastric cancer may occur in a variety of morphologic types: (1) polypoid or fungating intraluminal masses; (2) ulcerating masses; (3) diffusely spreading (linitis plastica), in which the tumor spreads through the submucosa, resulting in a rigid, atonic stomach with thickened folds (prognosis dismal); and (4) superficially spreading or "early" gastric cancer—confined to the mucosa or submucosa (with or without lymph node metastases) and associated with an excellent prognosis.