Neck Dissection for Thoracic Esophageal Squamous Cell Carcinoma

Subtotal esophagectomy with extended lymph node dissection is a standard procedure for thoracic esophageal squamous cell carcinoma. Three-field lymphadenectomy, including neck dissection, is a standard type of lymph node dissection for complete clearance of tumor cells. Based on various series of analyses for lymph node metastases, the appropriate indication for neck dissection has been clarified. Herein, we describe the established techniques of neck dissection and review recent topics of three-field lymph node dissection for thoracic esophageal squamous cell carcinoma. 1. Introduction Neck dissection was introduced in the early 1980s based on analyses of the spreading pattern of lymph node metastases from thoracic esophageal squamous cell carcinoma (SCC) [1, 2]. Extended lymph node dissection including neck, mediastinal, and abdominal lymph nodes has been called three-field lymph node dissection (3FLD) [3]. The neck dissection includes cervical paraesophageal nodes, deep cervical nodes, and supraclavicular nodes, and it was subsequently adopted as the standard surgical procedure for thoracic esophageal SCC at high-volume centers in Japan in the late 1980s [4, 5]. A similar surgical procedure was also introduced in Western nations in the late 1990s [6, 7]. 2. Indications for Neck Dissection Despite recent advances in preoperative staging, including computed tomography, positron emission tomography, and ultrasonography, the pathological findings after 3FLD indicate that the overall accuracy, sensitivity, and specificity of clinical staging remain too low. More than 75% of cervical metastases are not detected before surgery. Therefore, the indication for neck dissection should be determined by tumor location, tumor depth, and/or intraoperative nodal assessment of recurrent nerve nodes. A summary of the prevalence of positive cases of cervical lymph node metastases and overall 5-year survival after 3FLD is shown in Table 1. Table 1: Positive rates of cervical lymph node metastases and overall five-year survival rates after three-field lymph node dissection. The prevalence of positive cervical lymph nodes associated with tumors in the upper part of the thoracic esophagus was significantly higher than that derived from tumors in the lower part of the esophagus (upper, 48%; middle, 28%; lower, 13%) [4]. Among the patients with lower third esophageal tumors, none of those with T1b tumors had cervical metastasis, whereas 16% of those with T2-T4 tumors did. Moreover, 29% of patients with tumors in the upper third of the esophagus had initial lymph node