Comparison between a purified and standard diet on FANFT-induced murine bladder cancer

We investigated the effect of two diets containing equal amounts of the carcinogen FANFT on the incidence and induction time of murine bladder carcinoma in mice. At each time interval, the tumor incidence in the mice ingesting a purified, high-calorie diet, was equal or greater than the tumor incidence in the animals fed standard mouse chow. The mean animal weight of the mice ingesting the purified diet was consistently higher than that of the mice fed the standard diet. The bladder weights (an index of tumor volume) showed no significant difference between the mice receiving the two diets. Since mice eat to fulfill their caloric requirements, the animals ate less of the purified diet and the cost per mouse per year was lower.