Importance of Lymph Node Response After Neoadjuvant Chemoradiotherapy for Esophageal Adenocarcinoma.

Abstract

Tumor response and lymph node involvement are the most important prognosticators in resected patients with esophageal adenocarcinoma after neoadjuvant chemoradiotherapy (nCRT). We hypothesize that lymph node response (LNR) is also a valuable prognosticator in these patients, potentially revealing the added effect of nCRT. Hematoxylin and eosin slides of 193 esophageal adenocarcinoma patients with clinical suspicion of lymph node involvement (cN+) and treated with nCRT between 2008 and 2015 were assessed. Lymph nodes containing viable tumor cells were considered ypN+, and those negative for viable tumor were ypN0. LNR was also described according to an earlier defined method. Three groups were obtained: ypN0/LNR-, ypN0/LNR+, and ypN+. They were compared with 188 cN+ patients being pN0 (n = 45) or pN+ (n = 143) after upfront esophageal resection. Forty-four patients were ypN0/LNR-, 55 were ypN0/LNR+, and 94 were ypN+. Median overall survival was 96.4, 31.2, and 20.6 months, respectively, and was significantly different between ypN0/LNR- and ypN0/LNR+ groups (P = .020). Survival was comparable between ypN0/LNR- and pN0 (104.2 months) groups (P = .519) and between ypN+ and pN+ (21.6 months) groups (P = .966). In ypN0 patients, risk of death in LNR+ patients was tripled compared with LNR- patients. In cN+ esophageal adenocarcinoma patients treated with nCRT with postoperative final pathology being ypN0, median overall survival is tripled when no signs of LNR were found and comparable to cN+/pN0 upfront esophagectomy patients, suggesting that 23% of patients treated with nCRT were in fact true N0 and overtreated by nCRT. ypN+ patients have no survival benefit compared with pN+ patients.