Not sure why you're being downvoted. Most parts of the world yes. Somehow in the US, no. My sister had cancer for 7 years and I think I probably paid close to $50k on her treatments because the treatments her insurance covered weren't sufficient so we had to take her to an out of network clinic (Mayo).
The "most parts of the world yes" is absolutely not true. Unless you consider G20 countries to be most of the world. In most parts of the world if you want actual state of the art treatment, you've got to pay from your own pocket.