Some good research behind the anecdotal evidence. Quote:
Exercise is one of the cheapest, most effective methods we have for preventing and treating breast cancer (and cancer more generally). It is also grossly underprescribed. (Research has shown that actually having doctors write a prescription for exercise is one of the best ways to get people to break a sweat.)
My medical team is very keen on exercise and movement, but they do not write out prescriptions (unless physio or occupational therapy needed).