Predictors of Lymph Node Metastasis in Surgically Resected T1 Esophageal Cancer

Abstract

The application of endoscopic therapies for early cancers of the esophagus is limited by the possible presence of regional lymph node metastases. Our objective was to determine the prevalence and predictors of lymph node metastases in patients with pT1 carcinoma of the esophagus and the gastric cardia. The National Cancer Institute's Surveillance Epidemiology and End Results Database (2004 to 2010) was used to identify all patients with pT1 carcinomas who underwent primary surgical resection for squamous cell carcinoma (SCC) or adenocarcinoma (EAC) of the esophagus and of the esophagogastric junction (AEG). Prevalence of lymph node metastases was assessed, and survival in all types of cancer was calculated. Multivariate logistic regression was used to identify factors predicting positive lymph node status. There were 1,225 patients (84% male), with a mean age of 64 ± 10 years, and 90% were white. Intramucosal disease was present in 44% of patients, and submucosal invasion (T1b) was present in 692 (56%). Prevalence of lymph node metastases in EAC, SCC, and AEG was 6.4%, 6.9%, and 9.5% for pT1a tumors and 19.6%, 20%, and 22.9% for pT1b tumors, respectively. In patients with more than 23 lymph nodes removed during resection, prevalence of lymph node metastases in EAC, SCC, and AEG was 8.1%, 25%, and 7.4% for pT1a tumors and 27.8%, 33.3%, and 22% for pT1b tumors, respectively. Positive lymph node status was associated with worse overall 5-year survival in EAC (N0 vs N+: 78% vs 52%) and AEG (N0 vs N+: 83% vs 44%) but did not have a significant effect on the long-term survival of patients with SCC. Infiltration of the submucosa, tumor size exceeding 10 mm, and poor tumor differentiation were independently associated with the risk of nodal disease. Prevalence of lymph node metastasis negative for these three risk factors was only 4.8%. Prevalence of lymph node metastasis in early esophageal cancer is high in patients with T1 cancer. Inadequate lymphadenectomy underestimates lymph node status. Endoscopic treatment can be considered only in a select group of patients with early esophageal cancer.