in groups given 2 % bha , although marked hyperplastic changes of the forestomach epithelium were observed in all animals , co-administration of 0.25 % ra significantly ( p less than 0.05 ) increased the incidence of forestomach tumors ( squamous cell papilloma and carcinoma ) to 60 % ( 9/15 , 2 rats with carcinoma ) from 15 % ( 3/20 , one rat with carcinoma ) in the group given ra-free water .
C0014609
epithelium
C0007097
carcinoma