What women really know about mammogram benefits, risks

By Rachel Stockton (rachels@foodconsumer.org)

According to a report published in the Journal of the National Cancer Institute, many women are unaware of exactly what they are and are not getting from mammography screening.

In a study of 479 in 2000, researchers discovered that only 8% of women were unaware that a mammogram could actually harm them. And a whopping 94% didn't realize that some breast cancers that are caught in the early stages may not progress on their own.

Most women assign greater relevance to mammography screening than is actually warranted. It is simply a diagnostic tool, and an imperfect one at that. According to the study, of 1000 women receiving a screening, only 1 will avoid dying from breast cancer. Moreover, 10-15 will learn they have breast cancer sooner, yet the prognosis would remain unchanged.

The British Medical Journal published a similar report in July, based on a study by the Nordic Cochrane Centre in Copenhagen. According to the researchers, fully 1/3 of all breast cancers detected are those that will automatically regress on their own. For those women who constitute that percentage, radically invasive and toxic treatment will have to be endured when it isn't necessary.

In other words, "screening causes 10 times as many women to become cancer patients unnecessarily as it prevents from dying from breast cancer," says lead author Karsten Jorgensen, a researcher at the Nordic Cochrane Centre in Copenhagen.

The problem is that at this point in time, mammograms cannot tell physicians whether or not the cancer they are detecting is aggressive or slow growing, or whether it would eventually disappear on its own without ever causing any symptoms.

The British Medical Journal cites these examples as indicative that mammograms are an example of "a delicate balance between benefits and harms." But for now, they are the best diagnostic tool we've got.