There have been 10 controlled trials of mammograms and not all of them were randomized controlled trials. We need another.
Treatment for breast cancer has improved since the advent of mammography. Drugs like tamoxifen and trastuzumab have improved survival in selected patients (though trastuzumab costs a fortune, but it actually helps).
What if the tumors now slowed or cured by these drugs are the same ones that mammograms impacted in the 1960s through 1980s, but the nasty tumors are still lethal no matter when they’re detected? A study from Norway suggests this might be the case for many women. They looked at breast cancer deaths in the nine years after a nationwide effort to provide mammography was implemented. They concluded that only a third of the reduction in breast cancer deaths compared to the pre-1996 era could be attributed to mammography. The authors calculated that 2,500 women ages 50-69 (the Europeans don’t screen most women in their 40s) would have to be screened over 9 years to prevent one breast cancer death.
Mammogram supporters would correctly argue that the evidence still shows mammograms are effective. However, one problem with this test is its cost-effectiveness. Even under optimistic assumptions of the cost of the mammogram and its impact on deaths, mammography is marginally cost-effective at best. If these new estimates of the effectiveness of mammography are closer to reality, the cost-effectiveness of mammograms just went from bad to lousy.
The only way to settle the issue and know for sure if mammograms really make a difference in this era of improved treatments is a randomized controlled trial where women have modern treatment options no matter how the cancer was diagnosed. Previous mammogram studies that concluded mammograms did not extend lives were criticized by the radiologists as using poor quality mammography. Let’s be sure this new trial uses whatever technology the radiologists say is best. For that matter, let’s nest some other approaches in this mega-trial such as digital mammograms and MRI screening.
This kind of trial would cost over $100 million to conduct I suspect, but it would be worth it in the long run. America spends billions of dollars a year on mammograms so in the big picture this research budget is chump change.
Do you want the U.S. healthcare system to continue spending billions of dollars a year on technology that is probably marginal at best without knowing its current impact? It’s your money.