BOB HIRSHON (host):
Revving up exercise to slow down cancer. I’m Bob Hirshon and this is Science Update.
Exercise spurs the growth of blood vessels, including ones that supply oxygen to solid tumors. You might think that would make them grow faster. But Duke University oncologist Mark Dewhirst and his colleagues report in the Journal of the National Cancer Institute that at least in mice, the opposite is true.
Mark Dewhirst (Duke University):
It turns out that increasing the blood flow in the tumor reduces its level of hypoxia, or low oxygen concentration. And that is actually a major benefit to the host in that it slows down the tumor growth. So more oxygen to the tumor slows tumor growth.
Dewhirst says many cells divide more slowly in high oxygen. Also, the added blood flow brings more cancer-fighting immune cells to the tumor. But he stresses that the work is preliminary, and it’s not yet known how exercise works in combination with other treatments and drugs. I’m Bob Hirshon, for AAAS, the science society.