Gut Check

Over the past few weeks there has been a lot of media coverage on the new guidelines for mammograms and breast self exams. Analysis of scientific research indicates that mammograms can do more harm than good. This is not what anti-breast cancer crusaders like the Susan G. Komen Foundation want to hear. Women are worried and confused because they have been told that they must have mammograms to detect and prevent breast cancer. Now the scientists are saying that is not the case and that, in fact, they can be counter-productive.

For every women correctly diagnosed with cancer after a mammogram there are significantly more women who endure the trauma of a false positive reading. They have no disease but undergo what turn out to be needless breast biopsies where they run the risk of a lung puncture from a poorly-performed needle biopsy. Unless a woman has a family/genetic history of breast cancer, the odds of her getting it prior to age 70 are actually quite low.

No one wants to be the one to tell the average 40-year-old woman without a family history of breast cancer to stop getting mammograms and then find out 3 years later that she developed breast cancer. But, again, the odds of her developing it are low. The cancer foundations and some health professionals appear to be operating under the “better safe than sorry” mantra while ignoring the fact that false positives can also lead to a sorry situation.

In 2002, Gerd Gigerenzer, author of Calculated Risks: How to Know When Numbers Deceive You, pointed out that the general public and many medical professionals do not really understand statistics. This lack of understanding leads them to judge inaccurately the actual risks and benefits of health screenings.

According to Gigerenzer, the vast majority of physicians who participated in the research described in his book cannot accurately determine risks and benefits when these are presented in the form of probabilities. (e.g. There is a 25% risk reduction in death from breast cancer with mammography.) Only when the results are presented in the form of natural frequencies do the risks and benefits become clear. (e.g. 1000 women got mammograms each year for 10 years and 1000 women did not. At the end of 10 years, 3 women in the first group and 4 women in the second group died of breast cancer.) If we and our physicians cannot accurately determine risks and benefits when they are presented as probabilities, we could be unnecessarily risking our health. How many of the 997 women who got mammograms each year for 10 years also had false positives during that time? How many experienced the trauma, pain, and potential negative outcomes of the additional testing required to rectify that false positive?

Rather than relying on mammograms (and other types of screenings) to safeguard their health, it would be better for women in their 40s and 50s to actively employ measures that we know can help prevent cancer. These measures include eating plenty of richly-colored fruits and vegetables; eliminating dairy and other saturated fats; getting plenty of exercise; sleeping around 8 hours each night; and taking a minimum supplement of 1000 IU/day of vitamin D3. More vitamin D supplementation may be required to get the blood levels of 25 OHD to the optimal level of 50 ng/mL.

By following these preventive measures all women, even those with a family history of breast cancer, will reduce their odds of developing the disease. And those without a family history will be able to ignore their guts and go with their brains in accepting the scientific data which states that we in the United States have been over-using mammograms. Look at the natural frequency data. Mammograms haven’t been as much help as we thought. Eat right, exercise, sleep well, and take vitamin D. That’s where the science is.