Among wild-type KRAS patients , those with LC had significantly improved PFS when treated with cetuximab compared to BSC ( median 5.4 versus 1.8 months , HR 0.28 [ 0.18-0 .45 ] , p < 0.0001 ) , whereas those with RC did not ( median 1.9 versus 1.9 months , HR 0.73 [ 0.42-1 .27 ] , p = 0.26 ) , [ interaction p = 0.002 ] .