Suppression by 1-(2-tetrahydrofuryl)-5-fluorouracil in combination with uracil of preneoplastic mammary hyperplastic alveolar nodule formation in SHN virgin mice.

It is known that hyperplastic alveolar nodule (HAN) is a representative preneoplastic state in mammary glands of mice. We examined the effect of 1-(2-tetrahydrofuryl)-5-fluorouracil and uracil (UFT) on HAN formation in a high mammary tumour strain of SHN virgin mice. Oral administration of UFT for 5 months beginning at one month of age significantly reduced the number of HAN and DNA-synthesizing enzyme activities in the mammary glands. These results indicate that long-term administration of low dose UFT reduces the de novo and salvage synthesis of DNA and suppresses preneoplastic HAN.