I'm not sure I buy the logic of ignoring improved detection when it comes to survival chances. As the article and pretty much everyone else tells you, early detection is the key to a better prognosis in most cancers. If all malignancies proceeded to stage IV before detection, survival rates would be very low despite the medical advances we've made. Successfully treating a cancer, usually indicated by being cancer-free 5 years post-treatment, is not discussed in this article at all and seems like it would provide some evidence for or against cancer treatment getting better from the perspective that matters most -- the likelihood that a diagnosed cancer will kill you.