Wednesday, February 16, 2011
Cancers Hate a Healthy Body
Feature Blog: Cancers Hate a Healthy Body
In a recent blog, the MoneyWalker boasted that “cancers hate a healthy body!” The observation was based on my own anecdotal data in that I am a long term survivor of bouts with two different cancers—Non-Hodgkin’s Lymphoma and Prostate.
Both were discovered at Stage II, thus relatively early. The Lymphoma resulted in throat surgery to clear the base of tongue tumor from occluding breathing. Treatment required near toxic doses of chemotherapy and radiation. Friends were amazed at how quickly I returned to work and how well I looked.
Four years later and totally unrelated, prostate cancer was diagnosed. Using da Vinci robotic prostatectomy method, out went the Prostate. Again, doctors and friends expressed pleasant surprise at the speed of recovery and my high state of general health. Those remarks continue today.
But what about objective data, do exercisers have higher survival rates than non exercisers? Other than correlational studies with their inherent problems with cause and effect, few controlled studies exist.
Michael Feuerstein reported in his edited Handbook of Cancer Survivorship a 2006 Australian study which utilized 526 cases of individuals with colorectal cancer. Those who reported regular exercise prior to diagnoses had improved cancer-specific survival (73% 5-year survival) as compared to non exercisers (61% 5-year survival). Moreover, cancer-specific mortality was higher in those with higher body weight, percent body fat, and waist circumference; all factors that can be positively influenced by physical activity.
In a second study, 816 patients with Stage III colon cancer observed increases in recurrence-free survival, disease-free survival, and overall survival in association with increasing volumes of physical activity. After controlling for extraneous medical and demographic variables, those exercising 18 MET-hours per week (equivalent to one hour of brisk walking 6 days a week), had a 49% chance of reduction in risk of recurrence or death compared to those with less than 3 MET-hours per week over a three year period following surgery and chemotherapy.
Harvard School of Public Health researcher Stacey A. Kenfeld presented research indicating that getting regular exercise reduces hormones associated with causing prostate cancer. Moreover, the mortality rate for men with prostate cancer who exercise is 12 percent less than men who do not. Examples of recommended exercise include three or more hours of jogging, swimming or biking per week. Walking four hours or more also has been shown to reduce prostate cancer risk.
Using Meta analysis to analyze the literature on exercise and cancer survival rates, Margaret L. McNeely and colleagues identified 14 studies from more than 300 that met strict criteria for research and statistical design standards. Cutting through McNeely’s esoteric findings, those that exercised before, during, and after diagnoses and treatment faired better than non exercises in terms of quality of life especially in terms of fighting fatigue. Although the trends were positive, there were not statistically significant differences in survival rates between the exercisers and non exercises.
In summary, in terms of cancer, while anecdotal evidence abounds, and while a limited number of studies support claims that exercisers recover faster, survive longer, and have a higher quality of life than non-exercisers, more and tighter controlled studies are needed.
So for now, you will have to trust the MoneyWalker, “Cancers hate a healthy body!” When diagnosed, if you are in good physical shape and a regular exerciser, your body will positively respond to the required treatment faster and more completely than if you were “out-of-shape” before treatment. Moreover, you will experience fewer of the negative side effects of chemo treatment, surgery, and radiation than those that have been non-exercisers.