GO significantly improved EFS ( 3 years : 53.1 % v. 46.9 % ; hazard ratio [ HzR ] , 0.83 ; 95 % CI , 0.70 to 0.99 ; P. 04 ) but not OS ( 3 years : 69.4 % v. 65.4 % ; HzR , 0.91 ; 95 % CI , 0.74 to 1.13 ; P = .39 ) .