Improved survival for patients with upper and/or middle mediastinal lymph node metastasis of squamous cell carcinoma of the lower thoracic esophagus treated with 3-field dissection

Objective: To evaluate the outcomes with 2 and 3 lymph node dissection for patients with squamous cell carcinoma of the lower thoracic esophagus at a single institution. Background: Extensive lymph node dissection, including the upper mediastinum, for carcinoma of the lower thoracic esophagus is advocated as a standard surgical procedure with curative intent in Japan. However, its efficacy remains controversial. Methods: From January 1988 to December 1997, 532 patients with carcinomas of the thoracic esophagus underwent transthoracic esophagectomy and extensive lymph node dissection with curative intent at the National Cancer Center Hospital, Tokyo. Of these, 495 (93%) had squamous cell carcinomas. A total of 156 (29%) with tumors of the lower thoracic esophagus were retrospectively analyzed. Results: Of the 156 patients, 55 (35%) underwent 2-field and 101 (65%) underwent 3-field lymph node dissection. The operative morbidity and 30-day and in-hospital mortality rates were 68.0%, 1.3%, and 2.6%, respectively. The overall 5-year survival rate for the entire series was 49.3%. One hundred and seven (69%) had lymph node metastases. Upper and/or middle mediastinal lymph node metastases occurred in 42% of the series. The 5-year survival rate for patients with lymph node metastases in the upper and/or middle mediastinum was 23.3%. Among them, the values after 2- and 3-field lymph node dissection were 5.6% and 30.0%, respectively (P = 0.005). Thirteen (27%) of 48 patients with upper and/or middle mediastinal lymph node metastases treated with 3-field dissection had simultaneous cervical lymph node metastases and their 5-year survival rate was 23.1%. Conclusion: The 3-field approach for extensive lymph node dissection provides better survival benefit for patients with squamous cell carcinoma of the lower thoracic esophagus compared to 2-field lymph node dissection when lymph node metastases are present in the upper and/or middle mediastinum.