Fig. 4

Multivariable cox analysis of diseases-free survival. a Multivariable Cox analysis of diseases-free survival including all clinical pathological characteristics. Days of radiotherapy was transformed as 2-class categorical variable as it didn’t satisfy proportional hazards assumption as continuous variable (Schoenfeld Individual Test, P = 0.046). b Multivariable Cox analysis of diseases-free survival with the stepwise forward procedure of variables selection on the basis of the likelihood ratio statistic. c The graph of hazard rate for of accumulated dose of GCs for diseases against its value adjusted by ypTNM. Abbreviations: GCs, glucocorticoids; CEA, carcinoembryonic antigen; CA19-9, carbohydrate antigen 19–9; NCRT, neoadjuvant chemoradiotherapy; CCT, concurrent chemotherapy; SIB, simultaneous integrated boost; GTV, gross tumor volume; ypTNM, yield pathological tumor node metastasis stage