Primary adenocarcinomas of lower esophagus, esophagogastric junction and gastric cardia: in special reference to China

Abstract

Gastric cardia adenocarcinoma (GCA) is an under-studied subject. The pathogenesis, molecular changes in the early stage of carcinogenesis and related risk factors have not been well characterized. There is evidence, however, that GCA differs from cancer of the rest of the stomach in terms of natural history and histopathogenesis. Adenocarcinomas of the lower esophagus, esophagogastric junction (EGJ) and gastric cardia have been given much attention because of their increasing incidences in the past decades, which is in striking contrast with the steady decrease in distal stomach adenocarcinoma. In China, epidemiologically, GCA shares very similar geographic distribution with esophageal squamous cell carcinoma (SCC), especially in Linzhou (formerly Linxian County), Henan Province, North China, the highest incidence area of esophageal SCC in the world. Historically, both GCA and SCC in these areas were referred to as esophageal cancer (EC) by the public because of the common syndrome of dysphagia. In Western countries, Barrett's esophagus is very common and has been considered as an important precancerous lesion of adenocarcinoma at EGJ. Because of the low incidence of Barrett's esophagus in China, it is unlikely to be an important factor in early stage of EGJ adenocarcinoma development. However, Z line up-growth into lower esophagus may be one of the characteristic changes in these areas in early stage of GCA development. Whether intestinal metaplasia (IM) is a premalignant lesion for GCA is still not clear. Higher frequency of IM observed at adjacent GCA tissues in Henan suggests the possibility of IM as a precancerous lesion for GCA in these areas. Molecular information on GCA, especially in early stage, is very limited. The accumulated data about the changes of tumor suppressor gene, such as p53 mutation, and ontogeny, such as C-erbB2, especially the similar alterations in GCA and SCC in the same patient, indicated that there might be some similar risk factors, such as nitrosamine, involved in both GCA and SCC in Henan population. The present observations also suggest that GCA should be considered as a distinct entity.

Gastric cardiac carcinomas involving the esophagus are more adequately staged as gastric cancers by the 7th edition of the American Joint Commission on Cancer Staging System

“…31 Taken together, the data from our and others studies indicate that gastric cardiac carcinomas involving the esophagus should be classified and staged as gastric cancer, rather than esophageal. 2,11,29,31 There are several major limitations of this study. First, this is a retrospective study, and most surgical procedures were carried out by different surgeons using nonstandardized surgical approaches.…”

“…25,27 Whether or not the patient population under study influenced our results is worth investigating, gastroesophageal junction cancer is common in China, and almost all tumors in this population are centered in the proximal stomach, in contrast to the vanishingly rare distal esophageal adenocarcinoma above the gastroesophageal junction. 2,11,[28][29][30] In a recent study from a high-volume medical center in China, Taiwan, the investigators did not find a single case of such cancer over a 20-year period. 2 In our most recent comparison study on gastroesophageal junction cancer, we discovered different clinicopathological features of this cancer between Chinese patients in Nanjing, China and American Caucasian patients in Boston, the United States.…”

Effect of body mass index on adenocarcinoma of gastric cardia

“…Based on previous studies, we know that GCA is not rare in China [24] . Great differences exist in life styles and diet habits between Chinese and the Westerners.…”

Polymorphisms of glutathione S-transferase M1, T1 and P1 in patients with reflux esophagitis and Barrett’s esophagus

“…Gene frequencies are different among both racial groups (frequencies of the GSTP1*B allele in patients with RE were 40% in China vs. 23% in Czech patients), which may explain the differences in association between gene polymorphisms and disease in different studies. However, although the prevalence of RE seems to be increasing in China, the occurrence of Barrett's epithelium and esophageal adenocarcinoma in Chinese population is much lower than in Western countries (Wang et al 2003). The prevalence of H. pylori infection in the RE group in China was highest in patients with the lowest grade of inflammation (A-grade according to Los Angeles classification).…”