A couple of months ago, the U.S. Preventive Services Task Force (USPSTF) stirred the cancer screening pot with its opinion that mammograms are of limited use as cancer screenings for younger women and that, mostly, only women 50 and older should get them regularly. This month, its recommendation (in draft form) received support from the World Health Organization.
As NPR explained, “The WHO’s International Agency for Research on Cancer has just finished its review of mammography to screen for breast cancer, and it, too, concludes that the value of these screening X-rays is ‘limited’ for women in their 40s.”
Both organizations fully support regular mammography for women in their 50s and 60s, and offer their advice for younger women only if they don’t have complicating factors, such as a family history of breast cancer. As usual, mammography is not a one-size-fits-all diagnostic tool, and the USPSTF and the WHO advise women in their 40s to discuss with their doctors their individual circumstances.
What seems like wise counsel and conservative use of medical resources has important implications. In the U.S., a restrictive official policy might mean that women in their 40s won’t be subsidized by their insurance for mammograms; under the Affordable Care Act (ACA, or “Obamamcare”), insurance companies and government programs must provide free mammograms for them. “Insurance companies may still choose to keep covering these screening tests at no cost,” NPR noted, and,”[m]ammograms must be provided free to women 50 to 74 years old.”
And Congress could always mandate coverage, regardless of age.
Many younger women, especially those who have been diagnosed with breast cancer, believe the restriction to be discriminatory, never mind the science behind the recommendations.
And the science is significant. The International Agency for Research on Cancer (IARC, the WHO’s cancer arm) reviewed research studies worldwide that evaluated the benefits and risks of mammography. Its findings, published by New England Journal of Medicine, found “sufficient” evidence to conclude that mammography reduces breast cancer mortality in women 50 to 69 years old, but “limited” evidence that it does so among women in their 40s.
“We carefully reviewed the results of all available, randomized controlled trials and reaffirmed the findings from the previous evaluation of the efficacy of mammographic screening in women 50 to 69 years of age,” according to the IARC. “The evidence of efficacy for women in other age groups was considered inadequate.”
But it was close. “The vote was almost evenly divided between limited and sufficient evidence [for women in their 40s].”
As NPR explained, both the U.S. and international reviews weighed the benefits against the harms of mammograms. The tests can detect tumors, but many such results are actually false positives. False alarms can be silenced fairly easily, but the researchers noted that some women undergo procedures, surgery, radiation and drug treatment they don’t need. As we often point out, that not only causes unnecessary worry and stress, it opens the door to complications like infection.
Radiation from the test can raise the risk of breast cancer, but it’s slight – the IARC estimated it to be between 1 and 10 cases of breast cancer for every 100,000 women screened. That’s “smaller by a factor of 100 than the estimates of death from breast cancer that are prevented” by mammograms, said the IARC. Because the effects of radiation are cumulative, the fewer X-rays you have, the better, so you probably don’t want to get mammograms earlier in life if you’re not at increased risk of cancer.
The USPSTF is reviewing public comments it sought after the release of its draft recommendations. It’s uncertain when the final recommendations will be issued.