Postoperative adjuvant chemotherapy for thoracic pathological T3N0M0 esophageal cancer: A propensity score-matched analysis (APEC Study 1).

Abstract

e15537 Background: The role of postoperative chemotherapy (POCT) in thoracic esophageal squamous cell carcinoma (TESCC) has not been addressed . The aim of this study was to investigate whether POCT after an R0 resection improves outcomes in pT3N0M0 TESCC compared with operation alone. Methods: This study included 604 patients with pT3N0M0 TESCC who were treated at Sichuan Cancer Hospital from January 2009 to December 2017. The patients were divided into two groups: a surgery plus postoperative chemotherapy group (PORT group) comprising Surgery alone patients who underwent after an R0 resection and a surgery group (S group). Propensity score matching was used to create patient groups that were balanced across several covariates (n= 246 in each group). Outcome measures included overall survival (OS), disease free survival (DFS). Results: In the whole group 5-year OS and PFS were 58.4% and 56.0%. In the overall study cohort, 5-year OS (68.3% versus 50.4%, p < 0.0001) and DFS (65.5% versus 45.8%, p < 0.0001) rates were significantly higher in the POCT group than in the S group. These data were confirmed in the matched samples (5-year OS, 68.3% versus 49.5% [p < 0.0001]; DFS, 65.5% versus 42.5% [p < 0.0001]). Multivariate Cox analyses in the matched samples revealed that surgery and postoperative POCT were independently associated with longer OS (hazard ratio = 0.553, 95% confidence interval: 0.391–0.726, p < 0.0001) and longer DFS (hazard ratio = 0.556, 95% confidence interval: 0.416–0.744, p < 0.0001) than resection alone. Subgroup analysis found : POCT with IIA in pT3N0M0 have not longer OS and DFS ( p = 0.122 and p = 0.193). POCT with IIB in pT3N0M0 have the longer OS and DFS(p < 0.0001 both). Conclusions: Postoperative adjuvant Chemotherapy is strongly associated with improved OS and DFS in patients with pT3N0M0 TESCC. A multicenter, randomized phase III clinical trial is warranted to confirm these findings.