Prognostic Relevance of Skip Metastases in Esophageal Cancer

Background. Presence of nodal skip metastasis is an established prognostic factor for patients with non-small cell lung cancer. Little is known about this form of lymphatic spread in esophageal cancer. The aim of this study was to assess nodal skip metastasis and its clinical importance for patients with cancer of the esophagus. Methods. Resected lymph nodes of 128 patients with esophageal cancer and pN1 status (adenocarcinoma, n = 67; squamous cell cancer, n = 61) were mapped according to the Japanese lymph-node classification for esophageal cancer. Skip metastases were defined as tumor-free N1 lymph nodes, whereas N2 through N4 lymph nodes harbor metastases. Results. Skip metastases were present in 26 of 128 (20%) patients. There was a higher rate of skip metastasis in early tumors (39% versus 23% versus 14% for T1, T2, and T3 tumors; p = 0.032) and tumors in the middle and upper third of the esophagus (37% versus 15% for upper- and middle-third and lower-third tumors; p = 0.022). Patients with skip metastasis had a significantly better 5-year survival rate than patients with continuous metastasis (53% versus 15%; p < 0.0001). Multivariate analysis revealed skip metastasis as an independent prognostic factor. Conclusions. Skip metastasis is a common form of lymphatic spread in esophageal cancer, which is associated with a favorable prognosis. (Ann Thorac Surg 2010;90:1662-8) (C) 2010 by The Society of Thoracic Surgeons