Many species of bats live longer than that. Like 40. When compared to other mammals, bats live very long lives relative to their tiny size.

Also, short-lived animals get cancer all of the time. Mice, dogs, cats.

The idea of cancer being caused by passive accumulation of mutations over time looks appealing, but does not seem to correspond to actual frequency of cancer mapped by body size (because more cells = more chances of some cell going haywire), nor to maximum age.

Anti-cancer capabilities of a given organism seem to be more important. There are gene variants that are protective against cancer, and the capability of the immune system to kill suspicious cells matters too. (Note that almost all new efficient oncological treatments in the last decade or so involve the immune system of the patient.)