Thursday, March 25, 2010

Lifestyle vs. Genetics vs. Chance vs. Risk

And so forth and so on. The European Breast Cancer Conference is being held in Barcelona Spain this week. News came out yesterday regarding a significant reduction in annual breast cancer incidence if certain lifestyle factors or conditions were modified. So the way the research is presented, and I can link you to the conference abstract, is that a certain amount of risk is related to these factors - through scientific causation - obesity and overweight (though it is a higher risk if the weight gain comes in middle age than if it is constant), use of hormone replacement therapy and drinking more than two drinks a day. There is also evidence to suggest that being physically inactive increases breast cancer risk.

What the researchers did next was to take a population of women, in this case, French women, and consider the percent of those women who were, overweight/obese, who had used HRT, who drank 2+ a day and who were inactive. Each condition raised their risk for breast cancer and the quote that made the papers was that 30% of new cases could be avoided if women were lean and active.
A lot of number crunching is going on not just in the research article but with reporters - but even so....

Women have about a 12% risk of getting breast cancer and the American Cancer Society states that obesity in and of itself increases the risk of getting any cancer by 60% . I believe I have my math right when I say that an obese person would then have about a 20% risk of breast cancer.

I have breast cancer in my family. A grandmother, aunt and sister - one had a terminal or fatal case. Genetics cannot be dismissed on an individual level, but a scientist responding to this research noted that genes are not causing the increase cases, something else is and that has to be environment - or exposure to hormones and possibly toxins as well as what has been mentioned.

At the time of diagnosis, the women in my family would not have been described as lean (though none obese either) and to the best of my knowledge, none of them had a regular exercise routine. I am certainly not overweight and have not taken HRT - so I suppose I have just the 12% risk with a little extra for family history. But I have another sister and she would medically be described as obese. She also smokes. She is inactive. She is at increased risk because of this, but even if it were DOUBLE it would still be less than 25% risk. Hypothetically, she has a 75% chance of not getting breast cancer and she may not. Of course, I pray that she does not - surgery is not so safe for smokers! I use her for an example for another reason however.

There are many people who do not get a disease that they are at high risk for - smokers and lung cancer for example. That NEVER means that the risk does not exist or that the behavior is safe. It has to do with odds.

If the outcome is simply- breast cancer diagnosis - okay, but it isn't. Not having a disease does not make one fit and healthy - it does not make them well.

Regardless of the chances for specific disease outcomes, not exercising and being overweight can significantly reduce the quality of the years that you live.

The abstract of the article noted in the press and presented in Barcelona.

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