Effect of postoperative adjuvant therapy on the prognosis of patients with stage pT3N0M0 thoracic esophageal squamous cell carcinoma: a preliminary analysis

Abstract

Objective To determine the prognostic factors in patients with stage pT3N0M0 thoracic esophageal squamous cell carcinoma (TSCC) after esophagectomy, and to compare the effects of different treatment modalities on the prognosis of patients. Methods A retrospective analysis was conducted on 480 patients with stage pT3N0M0 TSCC from 2007 to 2010 to determine the prognostic factors in the patients, and to compare the effects of different treatment modalities on their prognosis. Survival rate was calculated using the Kaplan-Meier estimator, and multivariate analysis of prognostic factors was performed using the Cox model. Results Of the 439, 333, and 278 patients who completed the 1-, 3-, and 5-year follow-up, respectively, the 1-, 3-, and 5-year overall survival (OS) rates were 90.0%, 68.7%, and 57.9%(median 87 months, 95% confidence interval (CI=74.7-99.4), respectively, and the 1-, 3-, and 5-year disease-free survival (DFS) rates were 82.3%, 60.4%, and 52.3%(median 71.3 months, 95%CI=55.1-87.5), respectively. In order to account for the different constituent ratios of some clinical and pathological data between the three groups of patients, 55 patients in each group were matched using propensity score matching (PSM)(all P>0.05). It was found that the post-PSM 1-, 3-, and 5-year OS and DFS were significantly different between patients who received surgery only, postoperative chemotherapy (POCT), and postoperative chemoradiotherapy/radiotherapy (POCRT/RT)(P=0.000 and 0.006, respectively). Multivariate Cox analysis showed that age, lesion location, and treatment modality were independent prognostic factors for OS and DFS (P=0.029, 0.004, 0.000 and P=0.009, 0.003, 0.002), and the length of lesion was also an independent prognostic factor for DFS (P=0.003). Conclusions Although the rate of post-operative treatment failure is still high among patients with stage pT3N0M0 TSCC, POCRT/PORT can improve the prognosis and the 5-year OS and DFS of these patients. However, further large-sample prospective studies will be required to confirm these findings. Key words: Esophageal neoplasms/surgery; Esophageal neoplasms/postoperative radiotherapy; Esophageal neoplasms/postoperative chemotherapy; Prognosis