Gastric Cancer: Diagnosis and Treatment Options - American Family Physician

Etiology Many risk factors have been associated with the development of gastric cancer, and the pathogenesis is most likely multifactorial (Table 1).2,5,6 Although significant, genetic abnormalities (such as DNA aneuploidy, oncogene amplification or mutation, and allelic loss of tumor suppressor genes) are not understood well enough to allow formulation of a sequence of progression to the development of gastric carcinoma. One postulation on the development of this disease involves a succession of histologic changes that commence with atrophic gastritis, advance to mucosal metaplasia, and eventually result in a malignancy.2 Certain genetic or familial syndromes, gastric colonization by H. pylori, and conditions resulting in gastric dysplasia have been reported T he overall incidence of gastric cancer in the United States has rapidly declined over the past 50 years. Gastric cancer is now the 13th most common cause of cancer mortality in the United States, with an estimated 12,100 deaths in 2003.1 However, in developing countries, the incidence of gastric cancer is much higher and is second only to lung cancer in rates of mortality. The typical patient with gastric cancer is male (male-to-female ratio, 1.7:1) and between 40 and 70 years of age (mean age, 65 years). Native Americans, Hispanic Americans, and blacks are twice as likely as whites to have gastric carcinoma. Ninety-five percent of all malignant gastric tumors are adenocarcinomas; the remaining 5 percent include lymphomas, stromal tumors, and other rare tumors.2 The overall declining incidence of gastric carcinoma is related to distal stomach tumors caused by Helicobacter pylori infection. Proximal stomach tumors of the cardiac region have actually increased in incidence in recent years.3 This trend has been Although the overall incidence of gastric cancer has steadily declined in the United States, it is estimated that more than 12,000 persons died from gastric cancer in 2003. The incidence of distal stomach tumors has greatly declined, but reported cases of proximal gastric carcinomas, including tumors at the gastroesophageal junction, have increased. Early diagnosis of gastric cancer is difficult because most patients are asymptomatic in the early stage. Weight loss and abdominal pain often are late signs of tumor progression. Chronic atrophic gastritis, Helicobacter pylori infection, smoking, heavy alcohol use, and several dietary factors have been linked to increased risks for gastric cancer. Esophagogastroduodenoscopy is the preferred diagnostic modality for evaluation of patients in whom stomach cancer is suspected. Accurate staging of gastric wall invasion and lymph node involvement is important for determining prognosis and appropriate treatment. Endoscopic ultrasonography, in combination with computed tomographic scanning and operative lymph node dissection, may be involved in staging the tumor. Treatment with surgery alone offers a high rate of failure. Chemotherapy and radiotherapy have not improved survival rates when used as single modalities, but combined therapy has shown some promise. Primary prevention, by control of modifiable risk factors and increased surveillance of persons at increased risk, is important in decreasing morbidity and mortality. (Am Fam Physician 2004;69:1133-40,1145-6. Copyright©2004 American Academy of Family Physicians.) Gastric Cancer: Diagnosis and Treatment Options