At base level, all anarchism claims to do is to resolve one major problem in interpersonal relationships: the forceful interjection of the state. Curing cancer would make things a lot better for many people. Yes, there would be costs: oncologists would be out of work, and cancer researchers would need new subjects to explore. An anarchist world would still have murderers, and thieves, and evil men and women. It simply wouldn't put them in a position to enforce their evil on everyone else via getting elected and decreeing the law.
Michael Malice