Postoperative adjuvant three-dimensional conformal radiotherapy improves long-term survival in patients with pathological T2-3N0M0 esophageal cancer

Abstract

Objective To assess the clinical value of three-dimensional conformal radiotherapy (3DRT)in postoperative adjuvant therapy after initial radical surgery for pathological T2-3N0M0 thoracic esophageal squamous cell carcinoma(pT3 N0 M0 TESCC) . Methods The recurrence, survival, and radiotherapy adverse events in 96 patients with pT3N0M0 TESCC who received adjuvant 3DRT after radical surgery from a prospective nonrandomized phase Ⅱ clinical study from 2004 to 2011 were compared with those in 820 patients undergoing surgery alone. The survival rate was determined by the Kaplan-Meier method and analyzed using the log-rank test. Multivariate prognostic analysis was performed using the Cox proportional hazard model. Results Postoperative 3DRT group had a significantly higher ratio of patients with tumor length ≥ 5 cm and stage T3 than surgery alone group. The 5-year sample sizes for the postoperative 3DRT and surgery alone groups were 35 and 270, respectively. The 5-year overall survival(OS)and disease-free survival(DFS)rates for the postoperative 3 DRT versus surgery alone group were 74.3% vs. 59.9% (P=0.010) and 71.0% vs. 51.7% (P=0.002) , respectively. Multivariate analysis revealed that 3 DRT was independently associated with an improved OS (P=0.030) and DFS (P=0.004). The overall recurrence rate, locoregional recurrence rate, and distant metastasis rate in the postoperative 3DRT group versus surgery alone group were 22.9% vs. 43.0% (P=0.000) , 18.8% vs. 35.2% (P=0.001) , and 11.5% vs. 21.3% (P=0.024) , respectively. Both early and late grade 3 adverse events developed in 25 patients (26.0%) in the postoperative 3DRT group. Conclusions Compared w:th surgery alone, adjuvant 3DRT reduces the recurrence rate and improves the 5-year DFS and OS in patients with pT3N0M0 TESCC. Adjuvant 3DRT is recommended for pT2N0M0 patients inview of the similar recurrence to that of pT3 N0 M0 patients. Prospective randomized phase III clinical study is still needed. Key words: Esophageal neoplasms/ surgery; Esophageal neoplasms/ radiotherapy; Radiotherapy, postoperative; Radiotherapy, intensity-modulated; Radiotherapy, three-dimensional conformal; Prognosis