An Inhibitory Effect of Vitamin A on the Induction of Tumors of Forestomach and Cervix in the Syrian Hamster by Carcinogenic Polycyclic Hydrocarbons

The oral administration of 7,12-dimethylbenzanthracene (DMBA) or benzo(a)-pyrene(Bp) to Syrian hamsters induced dyskeratotic lesions and carcinoma of the forestomach and small intestine but only the DMBA induced dyskeratotic lesions of the esophagus. Painting the uterine cervix of Syrian hamsters with DMBA induced perineal skin and vaginal carcinoma in 100% of the animals and cervical carcinoma in 22% of the animals.

In animals similarly treated with DMBA or Bp the addition of 0.5% vitamin A-palmitate to the diet prevented the development of carcinoma of the gastrointestinal tract; adding the vitamin A-palmitate to the fluid used for painting the cervix prevented the development of carcinoma of cervix and vagina but did not inhibit the development of carcinoma of the perineal skin. The implication of the inhibitory effect of vitamin A on the induction of squamous cell carcinoma of the mucous membranes in the hamster is considered.