With people not having access to sunscreen and potentially having to be in the sun for many hours before things like farming could be industrialized, would there not be significantly greater amounts of people affected by this?
u/atomfullerene, u/Whoosier, u/Khnagar and others worked on How common was skin cancer among Caucasian farm workers before the invention of sunscreen? which has a lot of information that is relevant to your question.
There is plenty of information which can be expanded on though, so someone else may have a new submission for you as well.