Improved prognosis with induction chemotherapy in pathological complete responders after trimodality treatment for esophageal squamous cell carcinoma: Hypothesis generating for adjuvant treatment

Abstract Purpose To compare the locations of recurrences and survival outcomes in esophageal squamous cell carcinoma (ESCC) patients with pathological complete response (pCR) after neoadjuvant concurrent chemoradiotherapy (CCRT) with or without preceding induction chemotherapy (IC) followed by esophagectomy. Methods Among 276 patients with locally advanced ESCC undergoing trimodality treatment during 2004–2014, 94 (34.1%) with pCR were eligible. The cohort included 26 patients undergoing IC before CCRT (IC group), and 68 patients who did not receive IC (non-IC group). Results At a median follow-up of 51.4 months (95% confidence interval; 42.9–62.1), 19 patients experienced recurrences. There was a trend toward fewer distant failures in the IC group (0% vs.14.7%, p = 0.057), while locoregional recurrence was similar (7.7% vs. 7.4%). IC was associated with significantly improved survivals with the 5-year RFS and OS rates for the IC group of 85.1% and 90.5%, respectively, compared to of 46.2% and 48.1% for the non-IC group (p = 0.008 for RFS, and p = 0.015 for OS). By multivariable analyses, IC remained the only significant factor associated with survivals (HR:0.18 for RFS, p = 0.020 and HR:0.18 for OS, p = 0.025). The effect of IC in the whole cohort, irrespective of pathological response, was also assessed. Patients with non-pCR in the IC group had a trend toward worse survivals compared to the non-IC group Conclusions In ESCC patients with pCR after trimodality treatment, IC was associated with favorable survivals. The benefits of IC might be a hypothesis generation for adjuvant treatment for patients with pCR.