The Ki-67 score fell after treatment but there was no significant difference between the reduction in the two arms ( anastrozole 16.7 % ( 95 % CI = 13.3-21 .0 ) before , 3.2 % ( 95 % CI = 1.9-5 .5 ) after , n = 43 ; fulvestrant 17.1 % ( 95 % CI = 13.1-22 .5 ) before , 3.2 % ( 95 % CI = 1.8-5 .7 ) after , n = 38 ) or between the reduction in Ki-67 in clinical responders and non-responders .