Clinical characteristics and prognostic factors of patients with lymph node metastasis of thoracic esophageal squamous cell carcinoma

Objective: To investigate clinical characteristics and prognostic factors of patients with lymph nodes metastasis (LNM) of thoracic esophageal squamous cell carcinoma (ESCC) so as to provide reference basis for the clinical prevention and treatment of LNM of thoracic ESCC. Methods: Through a retrospective analysis on the clinical and follow-up data collected from 96 patients with LNM of thoracic ESCC admitted in our hospital from 1 February 2008 to 1 March 2012, this study described clinical characteristics of these patients. Meanwhile, Cox proportional hazard regressive model was used to investigate factors influencing the prognosis of patients with LNM of thoracic ESCC. Results: 121 patients with LNM of thoracic ESCC accounted for 39.0% of ESCC patients (121/310) in the same period. During operation, a total of 2531 lymph nodes were dissected. 312 were found to be positive nodes in postoperative pathological diagnosis. The rate of lymphatic metastasis was 12.3%. For 57.9% (70/121) patients, the carcinoma metastasized to >= 3 nodes. For 28.9% (35/121) patients, LNM involved >= 2 areas. Among these cases, there were 33 patients with neck lymphatic metastasis (19.1%), 90 patients with thoracic lymphatic metastasis (52.0%) and 50 patients with abdominal lymphatic metastasis (28.9%). The median survival time of patients with LNM of thoracic ESCC postoperation was 35 months with a 1-, 3- and 5-year survival rate of 80.2%, 48.8% and 21.5%, respectively. Univariate analysis showed that there was statistically significant difference (P < 0.05) in terms of postoperative survival condition for patients with LNM of thoracic ESCC of different sex, length, degree of differentiation and invasion depth of tumor, blood vessel invasion, with different number of nodes and areas involved, as well as rate of lymphatic metastasis (%). Multivariate Cox regression analysis indicated that poorly differentiated esophageal carcinoma (HR = 2.14, 95% CI: 1.08-4.26), depth of invasion in T3/T4 (HR = 1.87, 95% CI: 1.02-3.45), rate of lymphatic metastasis > 20% (HR = 3.07, 95% CI: 1.72-5.47) and areas involved >= 2 (HR = 2.60, 95% CI: 1.44-4.70) were factors influencing the prognosis of patients with LNM of thoracic ESCC. Conclusion: The prognosis of patients with LNM of thoracic ESCC is poor. In particular, the prognosis of patients with LNM of thoracic ESCC combined with poorly differentiated esophageal carcinoma, depth of invasion in T3/T4, high rate of lymphatic metastasis and multiple areas involved is poor. Comprehensive treatment measures should be taken to prolong patients' survival time and improve their quality of life.