Mammography Risks Part 4

If you missed the prior articles on Mammography Risks, you may review them here:

• Part 1
• Part 2
• Part 3

And here we are for Dr. Boyce’s conclusions on whether or not the risk of mammograms adding to the development of breast cancer outweigh the benefits.

“Does x-ray mammography put women at an even higher risk of developing a radiation induced breast cancer?

The controversy today surrounding screening of healthy women is not whether the radiation exposures are hazardous, but whether young women, under the age of 50, benefit from mammograms.

A 30 percent reduction in death from breast cancer has been convincingly demonstrated in randomized trials of women over the age of 50. The benefit for younger women is less clear, but apparently lower. The possible hazard from mammography x-rays is very low and should not be a factor in individual decisions to undergo this procedure.

The same is true for most diagnostic x-ray procedures. Nonetheless, unnecessary radiation exposures should be avoided and continued vigilance is required to ensure that the benefits associated with specific procedures outweigh the future risks.

When the mammography is performed because of symptoms that may be cancerous or because risk factors place a woman at especially high risk of breast cancer, such as known genetic conditions or prior high dose radiation to the chest, the benefit from the low dose radiation procedure substantially outweighs the possible future risk.

And if you are over the age of 50, the risk benefit equation is clearly in your favor since radiation exposures at these ages are thought to have little connection to increases in breast cancer later in life.

In other words, the small presumed risk is more than offset by the benefit of the procedure, and this is especially true for women at high risk for breast cancer.

Should women be concerned about the radiation they receive when having periodic mammography x-rays or other procedures involving chest irradiation?

As stated earlier, cancer risk is related to age at the time of radiation exposure and the dose of radiation received. A mammography x-ray might result in a breast tissue dose of about 0.3 cGy. If a woman received 10 mammograms as a young woman, the total dose would be about 3 cGy.

What is the risk associated with such exposure?

Keeping in mind that epidemiologic studies have not detected statistically significant increases below a dose of about 20 cGy, we do know that 100 cGy increases risk by about 40%. One can estimate that the 3 cGy from periodic mammography screenings would increase your risk by about 1.2% or a relative risk of 1.012. Such low risks are not detectable in human studies.

Nonetheless, all unnecessary radiation should be avoided and although the presumed risk is very small, it should be clear that the benefit from the medical exposure would far outweigh it. Decisions to have diagnostic procedures because of medical symptoms, however, should not be delayed because of the concern over presumed radiation risk.

Conclusions

Women with clinical symptoms of a serious disease should not refuse an x-ray diagnostic procedure because of possible radiation risk (the risk associated with these procedures is very low and the immediate benefit may be great).

Most women who received radiation exposures in the past will not develop a radiation-related breast cancer.”

Dr. Jo’s comments:

Dr. Boyce brings out some important facts as known through the various studies that he presented. Perhaps those of us over 50 can feel more assurance that we won’t live long enough for the radiation effects of mammography to trigger cancer in our breasts. And having the mammograms performed may detect early and more treatable cancer that would be life saving or prolonging.

That’s the main stream medical perception of mammograms.

But I know many of you pursue the very healthiest practices for your bodies and continue to be skeptical about the risks of mammography and I tend to side with you.

So in the next series of articles we will look at another perspective and review alternative and perhaps healthier, less risky ways to diagnose breast cancer in its early stages.

Blessings,

Dr. Jo

* John D Boyce, Jr, DSC, Scientific Director,
International Epidemiology Institute, Rockville, MD 20850

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