Lymph node dissection for esophageal cancer.

The prevalence of lymph node (LN) metastasis in esophageal cancer (EC) is widely spread to all three fields, namely, to the neck region, the mediastinal region and the abdominal region. Furthermore, the status of LN metastasis has been recognized as a key factor that influences the outcome after EC surgery. Therefore, the latest version of the UICC/AJCC TNM classification (7th edition) applied the number of metastatic LNs as an N factor. However, the precise clinical diagnosis of metastatic LNs is still difficult. This is mainly because there are many micrometastases in EC. Therefore, the Japanese Classification of Esophageal Cancer (10th edition) has not incorporated the number of LN metastases into the N factor for its staging system and the accurate preoperative diagnosis of LN status is currently one of the most important issues to be resolved for EC. Given the frequency and extent of LN metastasis and its significance for the survival, controlling LN metastasis is a rational therapeutic strategy, and an extended LN dissection, such as three-field lymph node dissection may be logical, although appropriate patient selection is necessary. On the other hand, recent arguments have supported a reduction of unnecessary LN dissection in esophagectomy. To curtail unnecessary LN dissection, one of the current topics is sentinel lymph node-guided surgery and is being investigated as part of the next generation surgeries for EC. In this article, recent literatures were reviewed and we discuss the current status of lymph node dissection in EC.