INTRODUCTION
Esophageal adenocarcinoma is one of the fastest growing cancers in
incidence in the Western world (1). Despite advances in cancer care,
esophageal cancer remains difficult to treat, and is associated with a
poor survival rate of 14% at 10 years (2). Barrett’s esophagus is a
significant risk factor for development of esophageal adenocarcinoma.
Endoscopic surveillance has become the standard of care in following
patients with Barrett’s esophagus and has allowed an increase in the
diagnosis of earlier disease such as high-grade dysplasia and
intramucosal adenocarcinoma (IMC) (3). Once diagnosed, however, there
remains some controversy as to the best modality of treatment with the
recent advent of advanced endoscopic techniques such as endoscopic
mucosal resection (EMR).
Esophagectomy has been the traditional treatment for patients with
intramucosal adenocarcinoma in the setting of Barrett’s esophagus. This
was based on the previous thought that up to 40% of patients with
high-grade dysplasia or IMC will have concomitant invasive disease in
their esophagus (4, 5). This risk is now seen as having been
overestimated (6). Moreover, esophagectomy is associated with
significant postoperative morbidity and mortality (7). Advanced
endoscopic techniques such as endoscopic mucosal resection (EMR) have
the potential to treat selected patients with early esophageal cancer
while preserving the esophagus and avoiding a complex and morbid
operation.
Early (T1) esophageal cancer is defined as tumours that do not extend
beyond the submucosal layer of the esophagus. The AJCC staging system
distinguishes between T1a tumours, which are limited to the mucosal
layer, and T1b tumours, which extend into the submucosal layer (8). One
of the limitations of esophagus-preserving endoscopic techniques is the
potential for spread of adenocarcinoma into the regional lymph nodes (9,
10). With tumours limited to the mucosa (T1a), the risk of lymph node
positive disease is very low at < 2% (11, 12). For tumours
involving the submucosa (T1b), lymph node involvement can rise to up to
20%, but rates with superficial involvement of the submucosa (T1sm1)
remains acceptable around 6% (13). Beyond this level of invasion, the
propensity for lymph node positive disease favours esophageal resection.
Esophageal intramucosal carcinoma remains a relatively rare disease and
there is currently little literature on the success rates and long-term
outcomes associated with EMR in comparison to esophagectomy in this
setting (14-16). The purpose of this study is therefore to investigate
the transition of therapy from esophagectomy to EMR at our institution
for IMC with respect to successful eradication rates, number of EMRs
required, post-operative morbidity, and long-term recurrence and
survival.