LIFE-SPAN AND CANCER MORTALITY IN THE BEAGLE DOG AND HUMANS

This study compares the age-dependence and rate of cancer mortality in untreated Beagles over a lifetime with that of Japanese and US white men and women. The purpose of the study was to determine the extent to which there is a linkage between life span and cancer mortality in Beagle dogs and humans. The two human populations were chosen to represent contrasting races and environments. Using the age at 10% survival as the measure of life span, about 5.5 years in humans was equivalent to 1 year of life in Beagles. The age dependence and total cancer mortality was the same in men and male Beagles. The age dependence was the same in female Beagles and women, but the total cancer mortality was somewhat greater in female Beagles due to more breast cancer. Cancer in Beagles, other than breast cancer in females, consisted mostly of sarcomas and lymphomas. There was very little cancer in environmentally exposed tissues (lung and intestine). There was also some contrast between Japanese and Americans in the relative rates of cancer at certain sites. The study provides support for the life span linkage of adult cancer mortality in the two species, in spite of the different patterns of cancer types and environments.