From the outset, it is necessary to appreciate the divergence in epidemiologic pattern between the East and the West. The most striking finding on esophageal cancer in the past three decades was the dramatic rise in the incidence of adenocarcinomas of the lower esophagus and cardia in the West, which has surpassed squamous cell cancers as the predominant cell type. In Asia, however, esophageal cancers, when diagnosed, are predominantly squamous cell in type and mostly located in the middle third of the esophagus. There has not been a noticeable rise in the incidence of adenocarcinoma of the esophagus and gastric cardia in published Asian data.
The exact reasons accounting for this difference are uncertain but are widely believed to be related to gastroesophageal reflux disease, obesity, and Barretts esophagus, which are uncommon in Asian populations. The prevalence of Helicobacter pylori infection is decreasing in Europe and the United States, and this has been paralleled by an increasing incidence of gastroesophageal reflux disease and adenocarcinomas of the esophagus and of the gastroesophageal junction. These epidemiologic data suggest a protective role of H. pylori against reflux. The high prevalence of H. pylori infection in Eastern populations may guard against reflux and Barretts esophagus, hence accounting for the differences in cancer cell type. This association, however, remains controversial.
Regardless of the reasons for the difference in epidemiology, there are practical implications in management strategies. The Barretts esophagus-dysplasia-cancer sequence, for instance, may allow surveillance programs to be instituted in Western countries, with the possibility of diagnosing the disease at a readily treatable stage. High-grade dysplasia is amenable to surgical resection or other forms of ablative therapies, such as endoscopic mucosal resection or photodynamic therapy. There is evidence that patients with Barretts esophagus who are recruited into surveillance programs have a better prognosis. The optimal surveillance interval, its cost-effectiveness, the relative merits of the various treatment approaches, and the impact on the population at large are still debated. In the East, except in very high incidence areas, population screening for squamous cell cancers is not cost-effective, especially when there is no good marker for the precancerous stage and early cancer, so most patients still present with symptomatic, advanced stage of disease.
In this review, we concentrate on discussing management issues for patients presenting with symptomatic esophageal cancer. Although the aims and treatment options are essentially the same for patients with squamous cell cancers or adenocarcinomas, selecting the most appropriate strategies is to a certain extent affected by many of the differences, such as those listed in Table 1. These are discussed where appropriate in this review. When the data from the literature are interpreted, it is important to be mindful of this epidemiologic difference between East and West.