An increasing number of regional lymph node metastases (N1 burden) is associated with a worsening prognosis in patients with esophageal carcinoma. Aim: To quantify the effect of N1 burden on survival and to identify predictors of N1 burden.
Methods: Analysis of a prospective database of 606 patients undergoing resection of esophageal carcinoma at a single institution. The effect of N1 burden on survival was quantified by multivariable hazard function analysis. The predictors of N1 burden were identified by ordinal logistic regression.
Results: Of 606 patients, 243 with pathologic N1 nodes (pN1) received surgery without preoperative induction therapy. One-year and 5-year survival according to N1 burden is displayed in Fig. 1. Multivariable analysis of 606 patients identified total number of nodes resected (odds ratio (OR)=1.08/node, P<.0001), adenocarcinoma (OR=2.9, P<.0001), depth of tumor invasion (T) (T1 OR=4.9, P=.002, T2 OR=12.0, P<.0001, T3 and T4 OR=54, P<.0001) and non-regional lymph node metastases (M1a) (OR=5.0, P<.0001) as predictors of increased N1 burden. Treatment with induction chemoradiotherapy (OR=0.60, P=.02) was the only predictor of decreased N1 burden.
Conclusions: 1) Lymphadenectomy is essential for prognostication. 2) Survival decays exponentially with increasing N1 burden, thus there is no evident survival difference for patients with more than 3 N1 nodes or more than 15% of N1 nodes in the resection specimen. 3) A patient with adenocarcinoma invading beyond the esophageal wall (T3 or T4) and not receiving induction therapy is at highest risk of increased N1 burden and thus poor survival.