If you're going to Mars there is plenty of room for cancer research as part of that. Unless spending years exposed to the solar wind is fine with everyone. Plus this argument is bullshit. Why spend more on cancer when only a third or less money is spent on mental illness affecting huge numbers of younger people many of whom turn to suicide? Once you play this game we end up with the poorest of societies focussed on the very bottom of a needs hierarchy exploding a useless population.