Pattern of lymph node metastasis in limited-stage primary esophageal small-cell carcinoma and its clinical significance: a preliminary study

Abstract

Objective To study the pattern of lymph node metastasis (LNM) in limited-stage primary esophageal small-cell carcinoma (PESC) and its guiding significance for clinical target volume delineation in radiotherapy.Methods A retrospective analysis was performed on the clinical data of 21 patients with limited-stage PESC who underwent esophagectomy in our hospital from January 2006 to July 2012 to analyze the rate and degree of LNM and distribution of metastatic lymph nodes.Results The mean number of dissected lymph nodes per patient was 27.9.There were 15 patients who had LNM ;8 patients had dispersed distribution of metastatic lymph nodes,and 7 patients had aggregated distribution of metastatic lymph nodes.The LNM rate was 71.4％,and the LNM degree was 17.2％.The Logistic univariate analysis showed that advanced T stage and long PESC lesion were the risk factors for LNM (P =0.004,P =0.044) and that advanced T stage and angiolymphatic invasion were the risk factors for dispersed distribution of metastatic lymph nodes (P =0.007,P =0.005).Conclusions The rate and degree of LNM are higher in PESC than in esophageal squamous cell carcinoma.Among the patients with limited-stage PESC,38％ have dispersed LNM.More research is recommended to evaluate the distribution of metastatic lymph nodes according to T stage and angiolymphatic invasion and investigate the value of prophylactic irradiation to the lymphatic drainage area of PESC. Key words: Esophageal neoplasms; Lymph node metastases; Clinical target volume; Radiotherapy