Table 4.
Risk factors for survival

LRFFS, locoregional failure-free survival; DMFS, distant metastasis-free survival; PFS, progression-free survival; OS, overall survival; RM, resection margin; PNI, perineural invasion; LVI, lymphovascular invasion; ECE, extracapsular extension; CCRT, concurrent chemoradiotherapy; RT, radiotherapy.