Epidemiology

Although the incidence of esophageal adenocarcinoma and gastroesophageal junction malignancies is increasing, by all measures, the incidence of true gastric cancers appears to be in decline. Even through the late 1990s, stomach cancer was the second most common cancer worldwide. In 2008 there were an estimated 974 000 new cases/year. In 2008, the age-adjusted incidence of gastric cancer was about 15% less than that for 1985. Nonetheless, gastric cancer remains a leading cause of morbidity and mortality, particularly in Asia.

Pathology and staging

The most commonly used staging system is that approved by the American Joint Committee on Cancer and the International Union Against Cancer (Table 5.1). This system classifies lesions on the basis of the depth of invasion of the gastric wall, the number of regional lymph nodes involved, and the presence or absence of distant metastasis. The staging system is discussed inChapter 7.

Neoadjuvant therapy

One of the more important developments in the treatment of gastric cancer has been the demonstration of the clinical efficacy in a large randomized trial studying preoperative chemoradiation. For several decades chemotherapy has been an accepted part of the treatment in patients with advanced gastric cancer (AGC), with multiple prior studies demonstrating a survival advantage over surgery alone.