He would need to first understand that there are many different kinds of cancer, each with different characteristics, "cancer" is just kind of a grab bag.

Next we do "cure cancer", it's called being in complete remission. Some cancers it's easier than others, again because there are different kinds. A good example is that when discovered rapamycin was viewed as a cancer cure, but there are still things like pancreatic cancer or leukemia that it doesn't affect.

There is some ground for his statement, at least in America, that if research discovers something that cannot be done in a way that is profitable then it's not likely to be implemented, at least not as enthusiastic. And even if it is, the time between development and distribution can be long from redtape.

But if a couple very expensive pills that treated all cancer were made, and kept it in partial remission leaving the patient in good functional health as a worker, while keeping them coming back for more like the pills made for HIV afflicted people, it would be much more profitable than our current situation. And those pills haven't been made, let alone any simple ones than can provide catch all full remission.

I think just mentioning that having healthy workers, in partial remission, on an expensive pill covered by insurance every day for the rest of their life, is a safe and profitable means of making money compared to all the cancer patients who die with no estate to pay off their debts. And since that expensive pill does not exist then it's probably not that easy to make.

Not that he will believe it anyway.