Esophagectomy With Three-Field Versus Two-Field Lymphadenectomy for Middle and Lower Thoracic Esophageal Cancer: Long-Term Outcomes of a Randomized Clinical Trial.

Abstract

The optimal extent of lymphadenectomy during esophagectomy remains unclear. In this trial, we aim to clarify whether three-field (cervical-thoracic-abdominal) lymphadenectomy improved patient survival over two-field (thoracic-abdominal) lymphadenectomy for esophageal cancer. Between March 2013 and November 2016, a total of 400 patients with middle and lower thoracic esophageal cancer were included and randomly assigned to undergo esophagectomy with either three- or two-field lymphadenectomy at a 1:1 ratio. Analyses were done according to the intention-to-treat principle. The primary end point was overall survival (OS), calculated from the date of randomization to the date of death from any cause. Demographic characteristics were similar in the two arms. The median follow-up time was 55 months (95% confidence interval [CI]: 52-58). OS (hazard ratio [HR]= 1.019, 95% CI: 0.727-1.428, p= 0.912) and the disease-free survival (DFS) (HR= 0.868, 95% CI: 0.636-1.184, p= 0.371) were comparable between the two arms. The cumulative 5-year OS was 63% in the three-field arm, as compared with 63% in the two-field arm; 5-year DFS was 59% and 53%, respectively. On the basis of whether the patients had mediastinal or abdominal lymph node metastasis or not, OS was also comparable between the two arms. In this cohort, only advanced tumor stage (pathologic TNM stages III-IV) was identified as the risk factor associated with reduced OS (HR= 3.330, 95% CI: 2.140-5.183, p<0.001). For patients with middle and lower thoracic esophageal cancer, there was no improvement in OS or DFS after esophagectomy with three-field lymphadenectomy over two-field lymphadenectomy.