What are we to make of yet another mammogram recommendation?
Just when we thought the issue was settled, yet a new study has come out of the Annals of Internal Medicine suggesting that low-risk women will spare themselves a lot of grief – and save the medical community a whole lot of money – by having less frequent mammograms. The study appears to contradict an earlier study reported this month, which concludes quite the opposite, namely, that women between 40 and 49 benefit from yearly mammogram screenings.
The new study does not say all women in their forties need not bother with yearly mammograms, just the ones in the low risk group. Low-risk is defined as no family history of the cancer, no previous biopsy from a cancer scare and breasts that are not very dense.
In order to determine breast density, at least one mammogram is necessary to determine that factor. High-density breast tissue is not associated with the size or the firmness of breasts as perceived on the outside, but can only be determined through radiography.
Current U.S. government guidelines for mammograms advise women to have a mammogram every two years. The new study’s lead researcher John Schouseboe said the study provides a more personalized set of mammogram guidelines than what is currently available.
"The benefits of mammography are going to depend a lot on what your underlying risk is, and the current guidelines look only at age," said Schousboe, a doctor at Park Nicollet Health Services in Minneapolis.
The team used data from two national surveys, which tracked the frequency of mammograms and the breast cancer rates of more than a million women, to form hypothetical scenarios. In one, they were not screened, while in another they got mammograms every two years. In a third scenario they received a mammogram every three to four years.
All scenarios assumed that at age 40, every woman received a mammogram to reveal her breast density.
For women in their 40s with less dense breasts and no other risk factors, the study found that screening at any interval, whether biennially or every three to four years, was not cost effective.
Many women will be left feeling less than impressed, since the study’s bottom line seems to be financial. Even if it would cost $228,000 to save a life for a year if low-risk women in their 40s were screened every three to four years, as the study estimates, that is little comfort to the one woman who is diagnosed.
The study also found that to save one life among women in their 40s, 8,000 would need to be screened. How many women would object to being one of the 8,000 with unremarkable findings on their breast scans?
The only compelling argument that might make a woman pause is the chance of a false-positive result, which the study estimates at 17 out of 100 – much higher than another study out of Sweden reported on here on June 28th, which estimated that risk at 5% or less.