Esophageal resection (esophagectomy) has been a standard surgical treatment option for any resectable esophageal cancer. Esophagectomy is one of the most complex, invasive procedures in the upper gastrointestinal tract, and is associated with high mortality and morbidity even with the recent refinement of surgical techniques and perioperative care.1,2 Accumulating data have suggested that the probability of lymph node involvement in patients with early esophageal cancer (T1a intramucosal cancer) is unlikely (<2%), and esophagectomy may be unnecessarily invasive for patients with early esophageal cancer.3-5 With the introduction of endoscopic surveillance program and advancement in optic technology, patients with early esophageal cancer have been increasingly encountered, and interest in esophageal-preserving endoscopic treatments has grown. Esophageal-preserving treatments include any endoluminal procedure that is performed in an attempt to completely eradicate disease while preserving the anatomical structure of esophagus. There are primarily two esophageal-preserving treatments: endoscopic ablation (radiofrequency ablation and cryotherapy) and endoscopic resection (endoscopic mucosal resection and endoscopic submucosal dissection). However, the concept of esophageal-preserving treatments has caused confusion in the decision-making among health care providers. Patients with early esophageal cancer have a chance for cure, and it is therefore extremely important to determine if esophageal-preserving treatments are adequate to achieve complete cure, that is, minimizing residual or recurrent disease. In this chapter, we focus on esophageal-preserving treatments for patients with early esophageal cancer.
The most critical step for esophageal-preserving treatments is appropriate patient selection, and patients with high risk of lymph node involvement and/or metastatic disease need to be excluded as candidates for esophageal-preserving treatments. Esophageal-preserving treatments start with meticulous endoscopic examination of esophageal epithelium with extensive biopsies for tissue diagnosis. To provide high-quality endoscopic images, several new endoscopic technologies (e.g., optical coherent tomography, autofluorescent imaging, confocal laser endomicroscopy) combined with enhancement techniques (e.g., narrow band imaging, chromoendoscopy) have been introduced and investigated; however, none of them has been routinely used in general practice. For early esophageal cancer, the depth of tumor invasion and assessment of certain pathological features such as ulceration or grade are extremely important to estimate potential lymph node involvement. Therefore, endoscopic mucosal resection for staging purposes is essential for accurate clinical staging and risk stratification based on pathological assessment. Endoscopic ultrasound (EUS) has been utilized to exclude lymph node metastasis and to determine the depth of tumor invasion, and EUS can accurately differentiate T1 and T2 tumors;6 although EUS6 has a limited accuracy, it still has a limited accuracy7 to discriminate between T1a and T1b tumors even with high-frequency miniprobe (20 or 30 MHz).
T1a (Intramucosal) Esophageal Cancer
Esophageal-preserving treatments can be indicated for patients with T1a adenocarcinoma with low risk or no risk of lymph node involvement or metastatic disease. High-risk factors for lymph node involvement include submucosal invasion (T1b), lymphovascular invasion (L+ and/or V+), poor differentiation, and a nodule >3 cm in diameter.8-11 By contrast, low-risk factors include type I, IIa < 2 cm, IIb, IIc < 1 cm, well or moderately differentiated adenocarcinoma, and no lymphovascular invasion (L- and V-).9,...