Twice the number surviving one year without the side effects of chemotherapy seems like a pretty big improvement to me, although there are a lot of news articles prematurely hyping "cures for cancer" that will probably never see the light of day.
Let's revisit which medications have harmful side effects a century from now. It's impractical to run studies with thousands of patients, and we haven't had more than half a century of data on most drugs. Not that there's much interest in replicating studies anyways.
I'm not keen to pop a bunch of pills unless there is significant (absolute, not relative) benefit. Drugs are overprescribed in my part of the world, partly because people assume "cuts risk by 50%" must mean "a lot." It might... it might not.