So here is what we now know: the mortality benefit of mammography is much smaller, and the harm of overdiagnosis much larger, than has been previously recognized.

But to be honest, that general message has been around for more than a decade. Why isn’t it getting more traction?

The reason is that no other medical test has been as aggressively promoted as mammograms — efforts that have gone beyond persuasion to guilt and even coercion (“I can’t be your doctor if you don’t get one”). And proponents have used the most misleading screening statistic there is: survival rates. A recent Komen foundation campaign typifies the approach: “Early detection saves lives. The five-year survival rate for breast cancer when caught early is 98 percent. When it’s not? It decreases to 23 percent.”

Survival rates always go up with early diagnosis: people who get a diagnosis earlier in life will live longer with their diagnosis, even if it doesn’t change their time of death by one iota. And diagnosing cancer in people whose “cancer” was never destined to kill them will inflate survival rates — even if the number of deaths stays exactly the same. In short, tell everyone they have cancer, and survival will skyrocket.

Screening proponents have also encouraged the public to believe two things that are patently untrue. First, that every woman who has a cancer diagnosed by mammography has had her life saved (consider those “Mammograms save lives. I’m the proof” T-shirts for breast cancer survivors). The truth is, those survivors are much more likely to have been victims of overdiagnosis. Second, that a woman who died from breast cancer “could have been saved” had her cancer been detected early. The truth is, a few breast cancers are destined to kill no matter what we do.

What motivates proponents to use these tactics? Largely, it’s sincere faith in the virtue of early diagnosis, the belief that screening must be good for women. And 30 years ago, when we started down this road, they may have been right. In light of what we know now, it is wrong to continue down it. Let’s offer the proponents amnesty and move forward.

What should be done? First and foremost, tell the truth: woman really do have a choice. While no one can dismiss the possibility that screening may help a tiny number of women, there’s no doubt that it leads many, many more to be treated for breast cancer unnecessarily. Women have to decide for themselves about the benefit and harms.