Pretty amazing, but if they came out with an engineered virus that cured all cancers 100% of the time with absolutely no side-effects, 100% proven, the FDA would approve it in say...oh..the year 2045, 2345 if Hitlery became POTUS, because it would be an emergency treatment that could say 100s of thousands of lives and we don’t want that now do we. But they’ll continue to approve every drug in existence for every slight discomfort a person has. “Polyslipaphobia - the fear of being chased around a table by timber wolves while wearing socks on a newly waxed floor” Oh we have a drug for that, but it may cause stomach pain, diarrhea, vomiting, bleeding, blurry vision, deafness, joint paint, bloating, skin lesions, loose teeth, gangrene, liver and kidney failure, hair loss and rigor mortis.
In reality, it takes about 12 years to bring a drug through clinical testing to market.
It is also unlikely that any one treatment will cure all cancers, since cancers are a diverse group of diseases of disregulation of cell function.