The addition of cetuximab showed a trend toward improved DFS ( hazard ratio [ HR ] , 0.53 ; 95 % CI , 0.26-1 .1 ; P = .09 ) and OS ( HR , 0.45 ; 95 % CI , 0.17-1 .16 ; P = .10 ) in the overall group , regardless of KRAS status , and in patients with wild type KRAS .