New Breast Cancer Guidelines: Screen Later, Less Often

CNN/ Newswire | 10/20/2015, 1:33 p.m.
In a move sure to befuddle women -- and anger some breast cancer survivors -- the American Cancer Society has ...

By Elizabeth Cohen

Senior Medical Correspondent

(CNN) -- In a move sure to befuddle women -- and anger some breast cancer survivors -- the American Cancer Society has issued new guidelines saying less screening for breast cancer is better than more.

The venerated cancer organization says women should start getting mammograms at 45 instead of 40, and that everyone can skip the routine manual breast checks by doctors.

An exhaustive review of the medical literature shows these measures just aren't very effective, according to the group. "The chance that you're going to find a cancer and save a life is actually very small," said Dr. Otis Brawley, the society's chief medical officer.

Now three key groups -- the American College of Obstetricians and Gynecologists, the American Cancer Society, and the U.S. Preventive Services Task Force -- recommend different ages for starting regular mammograms: 40, 45 and 50 respectively.

While mammograms save lives, they can also cause harm, and each group does a different job of balancing the pros and cons.

Earlier testing is not necessarily better

The problem with mammogram is that they have a relatively high false positive rate, which means women sometimes have to undergo painful and time-consuming tests only to find out they never had cancer in the first place.

The chances of false positives are especially high for women under 45, as they have denser breasts and tumors are harder to spot on an image.

"If she starts screening at age 40, she increases the risk that she'll need a breast cancer biopsy that turns out with the doctor saying 'You don't have cancer, so sorry we put you through all this,'" Brawley said.

He said he knows women who've had false positives year after year. "False positives are a huge deal," he said. "These women are so frightened and inconvenienced they swear off mammography for the rest of their lives."

Six years ago, the federal government's Preventive Services Task Force caused a furor when it declared that women in their 40s didn't need to get routine mammograms. Younger women whose breast cancers were caught by mammograms angrily responded that they would have been dead if they'd followed that guideline.

They said they'd gladly risk a false positive, with all the inconvenient and sometimes painful followup, for the chance of finding a cancer.

Learning from that experience, the American Cancer Society has sought to soften its message, emphasizing that women in their early 40s should still be able to get mammograms if they want them, as long as they understand the risks.

There's the risk of a false positive, plus the risk that a mammogram could catch a very small breast cancer that will go away on its own, or never progress to the point that it hurts a woman. In other words, a mammogram could catch a tumor that isn't really worth catching.

But since doctors can't reliably discern the harmful from the harmless cancers, they treat them all. This means some women are getting potentially harmful treatments, such as radiation, chemotherapy and surgery, when their tumor would never have caused a problem, Brawley says.