Endoscopic resection (ER) of early neoplastic lesions in the gastrointestinal tract has become increasingly important in recent years, both as a diagnostic tool and as a method of performing definitive treatment when the cancer meets certain criteria in which the risk of lymph node metastasis is negligible.1 Endoscopic treatment offers similar clinical outcomes with a less invasive approach in a subset of patients with early esophageal cancer.
INDICATIONS FOR ENDOSCOPIC RESECTION OF EARLY ESOPHAGEAL CARCINOMA
Adenocarcinoma in Barrett Esophagus
The indication for ER in esophageal adenocarcinoma is a nodular area of high-grade or low-grade dysplasia within a segment of Barrett epithelium with adenocarcinoma limited to the mucosa. Early esophageal adenocarcinoma invading into a superficial submucosal (SM1) lesion can be managed with endoscopic resection if the depth of invasion is less than 500 μm. Risk stratification should be carried out in accordance with known risk factors such as grade of differentiation, lymphatic or venous infiltration, and the infiltration depth of the carcinoma.2 The limitations of ER in early Barrett cancers should be deep submucosal infiltration or infiltration of the lamina muscularis mucosa in combination with another risk factor, such as poor tumor differentiation or lymphatic or vascular invasion.
Squamous Cell Carcinoma of the Esophagus
In esophageal squamous cell neoplasia (SCN), ER should only be carried out if the carcinoma is limited to the mucosal layer as has been shown in several publications.3
Accurate staging is mandatory before endoscopic treatment of early esophageal cancer. Essential to the staging procedure is a careful evaluation of the neoplastic borders of the lesion using a high-resolution endoscope and a thorough search for multifocal neoplasia. In addition, the macroscopic type of the lesion should be determined, as it has been shown to have significant correlation with infiltration depth.4 Granularity, surface nodularity, and deep depressions have been associated with invasive lesions in patients with SCN.5 Narrow-band imaging (NBI) is a method where narrow bandwidths of blue and green light are used. The depth of light penetration into the tissue is dependent on its wavelength. This technique relies on vascularity to predict the depth of a lesion. Intrapapillary capillary loops (IPCLs) seen on NBI can predict the depth of invasion in SCN based on the irregularity and dilations of capillary loops.2 Conventional endoscopic ultrasound (EUS) and EUS with miniprobes (20 or 30 MHz) can be carried out to evaluate the depth of infiltration and the lymph node status of the tumor. However, the accuracy of T staging is limited, particularly for distinguishing between the important stages of T1 m and T1 sm. The diagnostic accuracy of submucosal cancer ranges from 33% to 85%.6 Underdiagnosis by EUS has been shown in 12.5% to 67% of cases.7 In contrast, EUS is highly accurate in differentiating T1 and ...