In addition to other answers, there are also genetically modified animals that make them predisposed to certain tumors.

In the US, scientists at academic institutions who use animals are required to abide by institutional guidelines as well as local and federal laws governing the care and use of animals (mostly applying to vertebrates only).

While not all animal studies translate to humans, it is important to keep in mind that all of the major breakthroughs in cancer treatment in recent decades (checkpoint blockade, CAR-T, etc) have been discovered in and developed using animal models. They also relied on basic immunology knowledge generated primarily from animal models.