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.

That cuts out in 2015, but 5 year survival rates keep increasing with the USA just crossing 70%. Though across longer timeframes some of that is from early detection; even limited to late stage diagnosis the statistics still show significant improvement. https://acsjournals.onlinelibrary.wiley.com/doi/10.3322/caac...