Prognostic factors for the survival of patients with thoracic esophageal squamous cell carcinoma: the importance of tumor length and lymph node status

Objective To investigate the effect of tumor length and number of positive lymph nodes and the ratio of positive lymph nodes on survival in patients with esophageal squamous cell carcinoma.Methods From July 1995 to July 2005, a total of 6,691 resected lymph nodes were obtained from 526patients who underwent curative resection of the primary tumour with systematic lymphadenectomy. The survivals were analysed by life tables and Kaplan-Meier methods. Results Among patients with regional disease, the number of positive lymph nodes (＞3) was related to an increasing risk. The proportion of positive lymph nodes compared with the number of lymph nodes dissected (20 %) conferred an increased risk. The tumor length (≤5 cm, 5 cm ＜ length ＜ 7 cm, ＞7 cm) was related to an increasing risk (84.74 %, 47.79 %,36.90 %, 35.52 %; 73.41%, 46.29 %, 23.87 %, 20.64 %; 64.44 %, 13.92 %, 0, 0). Conclusion Tumor length,the number of positive lymph nodes, and the ratio of positive lymph nodes are important prognostic factors for survival in patients with esophageal carcinoma. The PTNM classification system for patients with esophageal carcinoma might consider adding number of positive lymph nodes as an important prognostic factor. Key words: Esophageal neoplasms;  Surgical procedures, oporative;  Lymphatic metastasis;  Prognosis; Tumor length