Breast cancer overdiagnosis due to mammograms may be even higher than we thought

Going overboard

“Why won’t you get a mammogram?”

I heard that question from several people after I mentioned my mammogram problem a few days ago.

Whenever I hear that question, I have a question of my own: “Where do I start?”

I could start by pointing out that compression of breasts is barbaric and may actually prompt a cancer to spread.

Or I could start with the radiation issue. (There are alternatives that don’t require radiation exposure.)

Either one of those issues would be a good starting point. But today I’m going to start in Norway.

Slow on the uptake

A new study from Norway must have radiologists fuming.

A Norwegian team reviewed nine years of data collected from nearly 80,000 women. Half of the women had invasive breast cancer.

Results revealed that as many as one in every four cases was overdiagnosed.

And here’s the catch: In Norway, routine yearly screening begins when women turn 50. In the U.S., it generally begins when we turn 40. So the rate of overdiagnosis is probably even higher here.

Add to that, another recent study found that the overdiagnosis rate might be closer to one in three.

That means that thousands of results are false positive. It also means that mammograms turn up thousands of cancers that don’t require treatment.

In a recent interview, Dr. Otis Webb Brawley, chief medical officer of the American Cancer Society, describes the problem.

He tells CNN.com that doctors still use diagnostic methods that are more than 150 years old. But when those methods are applied to today’s technology, it can pose a problem. You see, they detect many cancers that would never become dangerous.

This leads to unnecessary screenings and harsh therapies. In many cases, women go through needless worry, pain, and life-threatening side effects.

Dr. Brawley sums it up by noting that mammography has “significant limitations.”

That’s a candid statement from an ACS official. But he’s also in the medical mainstream. And that’s why (of course!) he adds that he still recommends that women begin getting a yearly mammogram, starting at age 40.

I was very disappointed to see that. Especially after he did such a great job of illustrating one of mammography’s primary limitations. And I’m certain Dr. Brawley must also be familiar with the 2009 U.S. Preventive Services Task Force recommendation.

The PSTF found that mammography saves one life out of every 10,000 mammograms conducted on women in their 40s.

That one life is important. But many of those 9,999 other mammograms prompt unnecessary biopsies, surgeries, and radiation treatments. That’s why the task force recommended that women start getting regular mammograms every year or two starting at age 50 instead of 40.

Three years ago, that recommendation was controversial. Today, it clearly does a better job of protecting women in their 40s.

Sources:
“Overdiagnosis of Invasive Breast Cancer Due to Mammography Screening: Results From the Norwegian Screening Program” Annals of Internal Medicine, Vol. 156, No. 7, 4/3/12, annals.org

“‘Overdiagnosis’ of breast cancer may be higher than thought” Dr. Otis Brawley, CNN, 4/2/12, cnn.com