| RAT TUMOR TYPE | SEX | DOSE (MG/KG/DAY) | DOSE (MG/KG/DAY) | DOSE (MG/KG/DAY) |
| 0 | 25 | 50 | ||
| squamous cell papilloma | M | 1/77 | 1/77 | 13/77* |
| 1% | 1% | 17% | ||
| F | 0/77 | 2/77 | 8/77* | |
| 0% | 3% | 10% | ||
| squamous cell carcinoma | M | 0/77 | 0/77 | 4/77 |
| 1% | 1% | 5% | ||
| squamous cell papilloma and carcinoma combined | M | 1/77 | 1/77 | 17/77* |
| 1% | 1% | 22% |
*= p<0.05 Fisher's Exact Test.
Upon examination of forestomach tissues, a significant number of squamous cell papillomas (abnormal tissue growths) were found for both male and female high dosage rats. The number of squamous cell carcinomas was not significant. However, the abnormal and carcinogenic growths were added together in order to demonstrate a significant increase in carcinogenicity in male rats. The rational for this appears to be that if the trial would have been continued longer (which was not possible because of the normal rat lifespan) it was possible that the papillomas might have progressed to carcinomas.