Let me start with the American recommendations.
The U.S. preventive services task force, for their recommendations released earlier this year, started their methodology with the principle that they knew screening mammography was effective at reducing breast cancer mortality. They did not re-evaluate the old randomized controlled trials, recognizing that it had already been proven effective. They only looked at data from 2016 onward, and they included some of the up-to-date evidence showing the benefit of early-stage diagnosis with screening and the increased incidence of breast cancer in women in their forties. That was the basis.
They also looked at the evidence of the disparities among races and ethnicities that showed they were not able to access screening. That was one of the big reasons to change the guidelines to include women in their forties.
You had a question about Sweden, about the more recent observational trial. They were able to compare no screening...and then the trial initiated screening and compared the mortality from breast cancer. Once they initiated screening, they compared the women who did not participate in screening with the women who did participate. What they found was a 60% reduction in breast cancer mortality by comparing women who did not choose to participate in screening with those who did participate. It was a huge benefit in lowering mortality. This accommodated all the recent advances in treatment, and it showed that even for the same treatment of breast cancer, screen detection was associated with a marked improvement in breast cancer mortality.