Major breakthroughs of the kind you’re talking about are extremely uncommon. Instead it’s lots of little gains that keep adding up because cancer isn’t adapting overall people still get the same mutations they got 10,000 years ago.

So average person with cancer does better when any individuals cancer treatment improves and it keeps compounding over time. This doesn’t mean everyone with cancer gets a slight improvement, often it’s specific types or stages that improve without impacting others. Where general progress comes from is it’s not the same improvements year after year.

https://en.wikipedia.org/wiki/Timeline_of_cancer_treatment_d... I won't debate what merits a major breakthrough. I will say, that while there hasn't been any major developments in the past five years, I can't draw any conclusions from that tidbit of information.