marginally significantp=0.053
In a multivariable analysis, age was identified as independent risk factor for OSR (HR, 1.609; 95% CI, 1.028 to 1.111; p=0.001) and AJCC 8th staging groups was marginally significant (compared with stage I: HR of II, 4.357; 95% CI, 0.981 to 19.355; p=0.053; HR of III, 5.310; 95% CI, 1.001 to 28.154; p=0.050; and HR of IV, 6.509; 95% CI, 0.808 to 52.472; p=0.079).