When to Start Routine Mammograms: Breast Cancer Organizations Discuss Safety and Concerns

It’s not as well known as October’s National Breast Cancer Awareness Month, but May is Mammography Month. In its honor, we thought we’d take a closer look at the debate over routine mammograms for premenopausal women in their 40s.

When a woman turns 40, her doctor will likely suggest she schedule a screening mammogram, with a repeat screening every year or two. Mainstream organizations such as the American Cancer Society, and government institutions like the National Cancer Institute, recommend beginning routine mammograms at this age (women younger than 40 who have a higher than average risk of breast cancer are urged to discuss with their doctors whether they should get screened sooner).

Yet despite these recommendations, the value of routine mammograms for premenopausal women age 40 and over is hotly debated, with some women’s health organizations and researchers raising questions about the risks.

Why the break with conventional wisdom? For starters, mammograms are an imperfect cancer detection method, and some studies show that routine mammography may do more harm than good — especially for premenopausal women, who statistically have a lower risk of breast cancer.

These concerns, however, are routinely drowned out by public health campaigns that maintain mammograms are the best available tool for early detection. It’s been up to breast cancer activists to address the limitations of current screening practices and call attention to the risks of unnecessary biopsies and treatments.

To be clear, the safety controversy focuses on the value of screening mammograms, not diagnostic mammograms, which are given to women who have a breast lump or other symptoms that require further investigation.

After analyzing a number of studies in the 1990s, the National Breast Cancer Coalition in 2002 changed its policy and no longer advises annual mammograms for healthy women, even those over age 50. The NBCC says that based on scientific reviews, “the benefits of screening mammography in reducing mortality are modest and there are harms associated with screening.”

Last year, in a newsletter to members, Cynthia Pearson, executive director of the National Women’s Health Network, explained the history behind bringing the mammography controversy to light:

What we discovered in the 1990s was disheartening. In the aftermath of mammography screening’s first trial, several other trials were undertaken, without impressive results. Screening’s life-saving benefit was not found in all trials. It certainly wasn’t found in the one trial designed to show the benefit of beginning mammography at age 40. NWHN went public with this information, and in 1993, issued a position paper recommending against screening mammography for pre-menopausal women — a very controversial position. The breast cancer advocacy movement was just getting started back then, and many organizations had a hard time accepting the idea that screening mammography might not really be very effective.

We also found that many people were shocked at the very idea that screening could, in fact, be harmful. Here’s why: screening leads to diagnosis, which leads to treatment. There is no treatment without risks. Treatment is often worth the risk when a condition is causing symptoms or is dangerous. But early cancer found through screening, when no symptoms are present, doesn’t always progress to life-threatening, advanced cancer. We wanted to be sure that treating everyone found to have early cancer would actually help save women’s lives. It was these considerations that led NWHN to tell women we believe that breast cancer screening should not be recommended for pre-menopausal women until it’s been well-proven to do more good than harm.

“Times have changed but, unfortunately, the complicated nature of mammography screening hasn’t,” Pearson adds.

The main risks most often cited include the high incidence of both false-negative and false-positive results (and the problems that result from each), along with the potential risk of radiation.

About half of all premenopausal women, and one-third of postmenopausal women, have dense breasts, which makes their mammograms more difficult to read. In fact, women under age 50 have a false-positive rate 12 times higher than women age 50 and older. When a positive reading occurs, women are likely to experience psychological stress while waiting for a biopsy and the results (here’s a recent study).

Biopsies are also problematic — though the surgery is relatively simple, they can cause distress, scarring and, more rarely, medical complications. The NBCC notes that in the United States, it has been estimated that a woman’s cumulative risk for a false-positive result after 10 mammograms is almost 50 percent, while the risk for undergoing an unnecessary biopsy is almost 20 percent.

Barbara Brenner, executive director of Breast Cancer Action, said research indicates that having more biopsies increases the risk of breast cancer, though the reason is unclear.

Another problem is that women are constantly being told “early detection saves lives,” yet we know some breast cancers, by the time they’re found, cannot be treated. Other cancers will never be life-threatening, and some will respond to currently available treatments. Unfortunately, the type of cancer cannot be determined at the time of diagnosis, which means the treatment can end up causing more harm than the cancer.

“Sometimes the side effects are deadly,” said Brenner. “Some of the chemotherapy treatments increase the risk of heart disease or other cancers. Radiation treatment also increases the risk of other cancers.”

So what’s the bottom-line advice for a woman who just turned 40? According to Brenner, she should talk to her doctor to determine her individual risks and benefits.

“If screening mammography is less effective for a premenopausal woman, she’ll need to decide with her doctor whether the risk posed by additional exposure to radiation is worth it,” said Brenner. “This is a highly individual decision that requires knowing all the options — including clinical breast exams and breast self exams, which are appropriate for women at all ages.”

Plus: For further reading …

* Breast Cancer Action has more analysis of the benefits and shortcomings of breast cancer screenings and information on new breast cancer screening technologies.

* Maryann Napoli, associate director of the Center for Medical Consumers, argues in this article that women are not receiving honest information about mammography’s harms.

* And the Oct. 15, 2003 issue of the Journal of the National Cancer Institute includes point and counterpoint articles on whether women have enough information to give true informed consent for mammograms.

Next month — minus any national awareness campaign — we’ll look at related health care disparities concerning screening costs and access to the best and safest technologies.