Fewer mammograms needed for low-risk women: study

By Kerry Grens

NEW YORK (Reuters Health) - Less-frequent mammograms for women at low risk for breast cancer can be a cost-effective way of saving lives, according to a new study that challenges current screening guidelines for the disease.

Researchers found that women with no family history of the cancer, no previous biopsy from a cancer scare, and breasts that are not very dense might get a similar benefit from having a mammogram every three to four years, instead of every two as advised by the U.S. Preventive Services Task Force (USPSTF), an expert panel with federal support.

Dr. John Schousboe, a doctor at Park Nicollet Health Services in Minneapolis and the lead researcher, said his 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," Schousboe told Reuters Health.

The USPSTF recommendations that guide cancer screening practices say women aged 50 to 74 should get a mammogram every two years, unless the woman and her doctor feel there is a reason to make an exception.

Schousboe's study took into account three other risk factors to develop more tailored recommendations.

Those include a woman's family history of breast cancer, the density of her breast tissue, and whether she has had a breast biopsy.

There is a four-fold increase in the risk of breast cancer among women with the most dense breasts compared to those with the least dense breasts, Schousboe said.

His 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 case, women were not screened, in another case they got a mammogram every two years, and in a third scenario they received mammograms every three to four years.

They then determined which situations were "cost-effective," meaning each year of life saved through screening would cost no more than $100,000.

The scenarios for screening assume that at age 40, every woman would receive a mammogram that would 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.

It would cost $228,000 to save a life for a year if low-risk women in their 40s were screened every three or four years, compared to no screening.

The study also found that to save one life among women in their 40s, 8,000 women would need to be screened, and 17 out of every 100 of them would experience a false cancer scare.

Such false positives lead to additional testing, which exposes women to more radiation, and sometimes a painful, invasive and expensive biopsy is done.

"I think that, other things being equal, it's reasonable for a patient and their doctor at that point to say, 'we're going to put off the next mammogram until age 50,'" said Schousboe, whose findings appear in the Annals of Internal Medicine.

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