Is cardia cancer aetiologically different from distal stomach cancer?

ABSTRACT

The coexistence of two aetiologically distinct types of cardia cancer, with distinctive histological characteristics of the neoplastic and nonneoplastic gastric mucosa, may explain the heterogeneous evidence of its association with Helicobacter pylori infection. We compared gastric cardia and noncardia cancers with regard to the frequency of H. pylori infection, the histological characteristics of the nonneoplastic gastric mucosa and the tumour histological type. We evaluated 41 cardia and 339 noncardia cancer cases undergoing gastrectomy, and 380 community controls. H. pylori infection and CagA infection status were assessed by enzyme-linked immunosorbent assay and western blot, respectively. Histological characteristics of the neoplastic and nonneoplastic mucosa were obtained from pathology reports. The association between infection and cancers with different location was quantified in a case-control analysis and cardia and noncardia cancers were further compared. No positive relation was found for H. pylori infection, but CagA-positive strains were associated with an increased risk of noncardia cancer (odds ratio=1.60, 95% confidence interval=1.17-2.18). Twenty-seven (65.8%) cardia cancer cases, predominantly of the intestinal type (66.7%), had nonneoplastic atrophic mucosa and 208 (61.4%) noncardia cancers (56.7% of the intestinal type). Among the cases occurring in nonatrophic patients, the proportion of cancers of the Laurén's intestinal type was 71.4% for cardia and 54.2% for noncardia gastric cancers. Cardia and noncardia cancers were similar with regard to the relation with infection, histological type and condition of the nonneoplastic mucosa, supporting the predominance of cardia cancers determined by H. pylori infection in this European high-risk setting.