Cancer, it is said, is nature's way of telling us to 'get the hint'. At a certain age, we all have more friends who get cancer. The older we get, the more often it happens. Even if we somehow slow aging, we would end up with cancer eventually, just like Gilles-Eric Séralini's experimental rats were predestined to get cancer when he let them live long enough.
Cancer is inevitable.
Perhaps not all cancer. The risk of developing several common cancers decreases with age, which has been a mystery. Mystery or not, it is what it is and researchers want to be able to take advantage of what they know.