Exercise Improves Colon Cancer Survival

People who have been treated for colon cancer can substantially reduce the risk that the disease will return and improve their overall chance of survival by engaging in regular exercise, new studies have found.

Researchers at the Dana-Farber Cancer Institute (Boston, MA, USA), examined two different sets of data to arrive at a shared conclusion. One study involved 832 patients with stage III colon cancer (involving the lymph nodes around the tumor but with no signs of having spread outside the area) who had received surgery and follow-up chemotherapy as part of the cancer and leukemia group B (CALGB) U.S. national clinical trial. The other study involved 573 participants in the nurses' health study, a project organized by Brigham and Women's Hospital (New York, NY, USA) which tracks the health of 121,700 female registered nurses by questionnaires mailed every two years. The nurses included in the current study had undergone surgery intended to cure stage I to III cancer at least six months earlier.

The researchers found that the two studies concurred: colon cancer patients engaging in moderate levels of exercise six to 12 months after completing therapy had an approximately 50% higher survival rate than those who did not exercise. The improvement took place in patients with very early and more advanced (but non-spreading) colon cancer, all of whom had undergone surgery intended to cure the disease. The studies were published online in the Journal of Clinical Oncology during July 2006.

"From previous studies we know that regular physical activity reduces the risk of developing colon cancer,” said lead author Jeffrey Meyerhardt, M.D. "While our work found a significant benefit for patients who exercise, it's important that exercise be seen as a supplement to, not a replacement for, standard therapies.”

Scientists do not have a definite physiologic explanation for the benefit of exercise for colon cancer survivors, but they speculate it may be tied to a reduction in the body's production of insulin and a similar, insulin-like growth factor, which fuels the growth of some cancer cells.



Related Links:
Dana-Farber Cancer Institute