In the latest studies done in humans - cardarine had cancer preventive properties.
There are a couple reasons for that:
1. The rat study everyone talks about where the rats developed cancer used absurd dosages no one in their sane mind would take
2. In the above study, all the rats were injected with genes to cause the development of cancer and the rats given the cardarine developed the cancer faster. The cardarine didn't actually cause the cancer, it just accelerated the rate at which the cancer grew
3. Rats develop cancer MUCH more easily then human and that's why they are so commonly used in cancer studies