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How often should you get a mammogram? After writing for years about how research shows we may be too aggressive in screening for breast cancer, it's only fair that I acknowledge the newer – and more conservative – recommendations from the USPSTF. This it Healthcare Triage News:

For those of you who want to read more, go here:

John Green -- Executive Producer
Stan Muller -- Director, Producer
Aaron Carroll -- Writer
Mark Olsen -- Graphics
Aaron: After writing for years about how research shows we may be too aggressive in screening for breast cancer, it's only fair that I acknowledge the newer and more conservative recommendations from the USPSTF, this is Healthcare Triage News.

(HT Intro plays)

First, the USPSTF now recommends screening mammography every two years for women age 50-74 years.  This will certainly upset many advocacy groups, which have long pushed for yearly screening to start long before age 50.  The ACA also mandates that such yearly mammograms be paid for without copayments or coinsurance, so following these new guidelines means refusing free care.  

However, the new recommendations are an acknowledgment of the fact that the harms of yearly screening might outweigh the benefits.  The accompanying review and meta-analysis found that if 10,000 women age 50-59 are screened, there will be eight fewer deaths from breast cancer.  In 10,000 women age 60-69, there would be 21 fewer deaths from breast cancer.  But about 20% of women who are diagnosed with and treated for breast cancer are getting therapy for something that otherwise would never have caused a health problem or even been diagnosed.  One in five women is over-treated and the treatment for breast cancer is not benign.  False positives are common too, and these have costs, financial, emotional, and physical.  They happen even more often than over-treatment and over-diagnosis.  

The models that they used found that using yearly screenings instead of every other year screenings, had a pretty incremental benefit, but they had a significant increase in harms, so they recommended five, not ten, screens over a decade.

Second, the current evidence is insufficient to assess the balance of benefits and harms in screening mammography in women 75 years and older.  There are no randomized controlled trials that show a benefit in this age group at all.  The harms are still there, though, so no recommendation is made.  

Third, the decision to start screening mammography in women before age 50 years should be an individual one.  Women who place a higher value on the potential benefit than the potential harms may choose to begin screening between the ages of 40 and 49 years, but they don't have to.  This is a real change, too.  It's saying it's totally fine not to start screening until age 50.  Why?  'Cause there's a reasonable case to be made here that the harms overwhelm the benefits.  It we screen 1000 women age 50-74, we may prevent seven breast cancer deaths.  If we drop the screening age to 40, then we might prevent eight breast cancer deaths.  One more death.  But it's totally possible that person might die of other causes, meaning that there's no real gain overall.  

But there are real problems here.  Each time we screen 1000 women between age 40 and 49, there are 121 false positives.  There are 10 biopsies that didn't need to happen.  There's also one false negative, or real breast cancer that's missed.  That's each time, not the whole ten years.  So multiply those harms by the number of times you screen over a decade.  It adds up, and it might overwhelm the benefit.  So the USPSTF hedges, they say that women should make personal decisions with the help of their physicians, and I think that's the right call.  Recommendations should say what we know to be true, and in this case, we know the benefits and we know the harms.  When they're not clearly overwhelmed in the direction of benefits, we should let personal preferences come into play.  

Obviously, women at higher than usual risk for breast cancer should be treated differently.  That's how it should be, too.  Recommendations should be applied carefully to the populations they're meant for.