When tested in the validation cohort , the nomograms discriminated well the high and intermediate risk from low risk patients ( hazard ratio [ HR ] for OS 3.83 , 95 % confidence interval [ CI ] 1.71-8 .56 ; and 2.48 , 95 % CI 1.12-5 .50 ; for PFS 2.84 , 95 % CI 1.66-4 .87 ; and 1.45 , 95 % CI 0.87-2 .41 , respectively ) .