Madam Chair, it's so interesting that I can provide some precision on this aspect.
For each of our guidelines on cancer screening, we look at the balance between benefits and harms. One of the harms would be to have what's called a “false positive”, a term that we renamed as “additional testing with no breast cancer”.
The other harm is overdiagnosis.
When you look at the numbers for women in their forties that I provided in my opening statement, and which you can find very easily on our website, on the 1,000-person diagram, you see that if you screen 1,000 women aged 40 to 49 for 10 years, you will avoid one death from breast cancer in those 1,000 women. There will be 368 who will need to have additional testing, and two will be overdiagnosed. When we present those numbers to women—and when I say “we”, I'm not saying the task force, but the more than 86 studies on choice about breast cancer screening—we found that women in their forties may weigh the harms as greater than the benefit.
We did acknowledge that there are a lot of variabilities for that. Some women may want to be screened and others may not. That's why we made the recommendation that we made.