Significance of extended systemic lymph node dissection for thoracic esophageal carcinoma in Japan.

In 1986, several institutions in Japan began to employ extensive lymphadenectomy for thoracic esophageal cancer. The aim of this article is to point out several confusing factors concerning the use of the terms "tow-field" and "three-field" lymph node dissection for thoracic esophageal cancer. In two-field nodal dissection, two components are included with (modern two-field) or without (traditional two-field) nodal dissection around both recurrent laryngeal nerve chains in the upper mediastinum. We studied a series of 353 patients resected for thoracic esophageal cancer in our institution. The patients were divided into three groups. Group A was the traditional two-field group of patients who underwent thoracoabdominal lymphadenectomy without upper mediastinal lymph node dissection after preoperative irradiation; group B was the modern two-field group, with additional upper mediastinal lymph node dissection; and group C was the three-field group with additional neck lymph node dissection. Groups B and C were operated on during the same period and did not received preoperative irradiation. The 5-year survival rate in group B was 54.9%, which was better than the 47.6% rate after three-field dissection (group C). The key to extensive lymphadenectomy for thoracic esophageal cancer does not lie in "cervical dissection" but in the meticulous dissection of the lymph nodes around the right and left recurrent laryngeal nerves.