In terms of your first point, I'm not sure I understand how the overall cancer rate being increased by dubious activities on the part of some people implies tha

In terms of your first point, I'm not sure I understand how the overall cancer rate being increased by dubious activities on the part of some people implies that efforts to cure cancer on the part of others are "not entirely noble". On the surface, this seems like a non-sequitur -- could you explain your reasoning further?