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Now the trends for esophageal cancer become
clearer when divided by cell type. Once an uncommon tumor, esophageal
adenocarcinoma in white men has risen more rapidly (about 8 to 9% per year)
than any other cancer, shooting past the rate for esophageal squamous cell
cancer, which is on the decline. The racial disparities are also striking,
with adenocarcinoma being 5 to 6 times more common in the white compared to
the black population, while the opposite occurs for squamous cell cancer. In
collaboration with groups at Columbia, Yale and the University of
Washington, our study of esophageal adenocarcinoma revealed two major risk
factors that are increasing in prevalence in the population –
gastroesophageal reflux disease and obesity. Obesity in turn promotes
reflux, but it also appears to act at a later stage in the transition from
Barrett’s esophagus to cancer. In addition, we found an inverse association
with Helicobacter pylori infection, which has declined along with the
incidence of gastric cancer in the general population. A protective effect
of H. pylori would be consistent with the intriguing hypothesis of Martin
Blaser that H. pylori, by colonizing the gastric mucosa, may actually block
the secretion and reflux of gastric acid. |
