May 30, 2006

You can fight cancer with exercise

Dr Andrew M M Haydon and colleagues at Monash Medical School in Melbourne have looked at baseline body mass index and levels of physical activity for subjects in the Melbourne Collaborative Cohort Study, a prospective study of 41,528 adults recruited between 1990 and 1994, and compared baseline levels of IGF-1or IGFBP-3 with those measurements. Insulin-like binding protein-3 (IGFBP-3) is a protein that inhibits another protein called insulin-like growth factor-1 (IGF-1) and in this way blocks IGF-1's proliferative effect on cell growth. Cancer is uncontrolled cell growth.

The researchers have identified new cases of colorectal cancer in this way as they analysed 443 colon cancer patients followed over more than five years: :::[SMH]

Among subjects who were physically active, an increase in
IGFBP-3 was associated with a 48 per cent reduction in colon
cancer-specific deaths. No association was apparent for IGF-1.

For the physically inactive, there was no association between
IGF-1 or IGFBP-3 and colon cancer survival.

Haydon said that "physical activity can increase IGFBP-3 levels,
which, in turn, reduces the amount of free IGF-1". IGF-1 has been
shown to stimulate cell growth, inhibit cell death, and promote
angiogenesis - the formation of new blood vessels, which tumours
need to grow.

This is not the first time a link between reduced cancer risk and exercise has been found:
"Other studies that have looked at this have shown a
dose-effect, meaning the more exercise the lower the risk, however
our study did not try to address this issue. We were examining the
effect of physical activity on one's prognosis following a
diagnosis of bowel cancer and the possible mechanisms behind this
effect."
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1 comment:

Anonymous said...

If the relationship between regular exercise and cancer survival is true, why do cancer survivors (such as myself) are not seriously advised to have an active lifestyle? Has this impressive 50% survival improvement due to exercise been confirmed? If so, there is something in this bussiness that I do not understant. Let me explain it to you:
After I was diagnosed and treated colon cancer in ye. 2000 I enjoyed almost 5 years of free of cancer: now I suspect that it was probably thanks to the fact that I exercised on a day-to-day basis. For several reasons I stopped doing exercise and started to work too much (in from of the computer) a few months later I was diagnosed methastasis in several limph nodes and some other parts of my body. After that I have had several combinations of very expensive drugs (including a clinical trial with avastin that did not work). Doesn't it sound as though there are interests other than the best treatment/advice for the cancer patient? Why does my oncologist treat me with avastin (which I am sure that has an effectivity much lower that 50%) and never has treated me with a regular exercise program?