Comparison of short-term outcomes between 2- and 3-field lymph node dissection for esophageal cancer

Although 3-field lymph node dissection (3-FLD) is often performed for thoracic esophageal squamous cell carcinoma (ESCC), the clinical effects of cervical lymph node dissection in addition to mediastinal and abdominal dissections on postoperative complications remain unclear. A total of 367 ESCC patients who underwent curative esophagectomy for thoracic esophageal cancer in our hospital from 2010 to 2015 were included in the study: 157 patients who underwent 2-field lymph node dissection (2-FLD) and 210 patients who underwent 3-FLD. Clinicopathological parameters and postoperative complications based on the Clavien-Dindo classification were compared between the two groups. We performed propensity score matching (PSM) analyses to compare the groups with well-balanced backgrounds. In terms of patient background, clinical T (p < 0.001), N (p < 0.001), and M (p = 0.002) stage of tumor was significantly more advanced; therefore, preoperative treatment was more frequently performed in the 3-FLD group than in the 2-FLD group (91.0% vs. 79.0%, P< 0.001). However, perioperative parameters including operation time, blood loss, and the number of dissected mediastinal and abdominal lymph nodes did not differ between the groups. In terms of postoperative complications, the occurrence rate of pneumonia increased significantly in patients with 3-FLD compared to 2-FLD (grade III or higher: 10.5% vs. 3.2%, P= 0.025). Although the duration of systemic inflammatory response syndrome (SIRS) was longer in the 3-FLD group than in the 2-FLD group (median 3 days vs. 2 days, P= 0.025), other postoperative parameters (including the highest level of postoperative serum C-reactive protein, intensive care unit stay, re-operation rate, and postoperative hospital stay) were similar between the groups. After PSM, the differences in the background between the groups disappeared. PSM analysis showed that there was no significant difference in each complication between the groups. The duration of SIRS tended to be longer in the 3-FLD group than in the 2-FLD group, but the difference was not significant. The field of lymphadenectomy negatively impacted the short-term outcome in ESCC patients in terms of pneumonia and inflammatory response. However, because the results of the PSM analyses indicate that the short-term outcome was similar between the two groups, 3-FLD could be as feasible as 2-FLD in ESCC patients.