Long-Term Outcome of Definitive Chemoradiotherapy and Induction Chemoradiotherapy Followed by Surgery for T4 Esophageal Cancer with Tracheobronchial Invasion

T4 esophageal cancer (EC) that invades the trachea or bronchus often has poorer prognosis than other T4 ECs. We investigated the long-term results of definitive chemoradiotherapy (dCRT) or induction chemoradiotherapy followed by surgery (iCRT-S) in patients with T4 EC with tracheobronchial invasion (TBI). From 2003 to 2013, 71 patients with T4 EC with TBI were treated in our institution; 58 underwent dCRT, and 13 underwent iCRT-S. The long-term results associated with survival were retrospectively analyzed, and prognostic factors were examined by univariable and multivariable analysis. The 1-, 2-, and 5-year overall survival for all patients with T4 EC with TBI treated by dCRT or iCRT-S was 57, 29, and 19%, respectively. Multivariable analysis revealed that clinical lymph node (LN) metastasis and the treatment period were significant prognostic factors. Clinical LN positivity had significantly poorer prognosis than LN negativity. The treatment outcome in the later period was significantly better than that in the earlier period. In particular, the outcome after dCRT revealed significantly better prognosis in the later compared with the earlier period, whereas the outcome after iCRT-S did not show such a difference. With respect to treatment modality, no significant difference in survival was observed between dCRT and iCRT-S. Clinical LN negativity and later treatment period were significantly good prognostic factors for T4 EC with TBI. The recent improvements in dCRT outcomes may help to achieve survival comparable to that of iCRT-S.