Mammogram guidelines: Breast cancer detection confusion and controversy
Are the revised breast screening guidelines boggling your brain? Join the club. The controversy that started last year has many of us scratching our heads. The jury’s still out on the advantages of the old versus new recommendations and experts from all sides are hotly debating the issue. In the meantime, here are the old and new guidelines, along with the buzz over breast cancer screening.
Breast screening mammography recommendations
According to a report published in 2009, an estimated 193,370 women in the United States will develop invasive breast cancer, and about 40,170 of them will die of the disease.
Two decades ago, in response to the alarming rise in breast cancer, The American Cancer Society (ACS) created breast screening guidelines to promote prevention awareness among health care providers and women. Doctors stressed to women the importance of monthly breast self-exams, annual mammograms starting at age 40, advanced screenings and genetic testing for those at risk, and key lifestyle changes shown to decrease the incidence of breast cancer.
The ACS recommends:
- Women receive an annual mammogram beginning at age 40.
- Women in their 20s and 30s get a breast exam about every three years.
- Women at higher risk of breast cancer because of family history or other factors talk to their doctor about when to start screening and what other tests they may need.
- Women continue with mammography every year if they are healthy.
- Women, starting in their 20s, learn how to conduct a breast self-exam (BSE) and conduct a BSE every month.
Some health care providers suggest women get a baseline mammogram at age 35. Medical groups have backed off promoting breast self-exams in recent years because there's insufficient evidence to support their benefit, but many continue to adhere to the existing ACS mammogram guidelines.
New breast screening recommendations
In November 2009, the U.S. Preventive Services Task Force radically revised the ACS' breast screening guidelines, bringing them in line with the European Guidelines, which screen women age 50 to 69 every two years.
The panel gathered data from around the world and created statistical models to see what would happen if women were screened at different ages and time intervals. Findings revealed that annual mammograms before age 50 and breast self-exams have increased the number of false positives, unnecessary mammograms and invasive biopsies. The panel concluded that current guidelines cause women to endure unwarranted medical procedures, added expense and enormous stress without substantially increasing their odds of surviving breast cancer. "The benefits are less and the harms are greater when screening starts in the 40s," says Dr Diana Petitti, vice chair of the panel.
As a result the panel recommended the following new guidelines:
- Women receive their first mammogram starting at age 50.
- Women receive a mammogram every two years.
- Women stop mammograms after age 74.
- Women not conduct breast self-exams because there isn't enough evidence to suggest they provide a preventive benefit.
The guidelines are for the general population, not for women at high risk of breast cancer because of family history or gene mutations that would justify having mammograms sooner or more often.
"Biennial [every two years] screening achieves most of the benefit of annual screening with less harm. Decisions about the best strategy depend on program and individual objectives and the weight placed on benefits, harms and resource considerations," writes the task force in their report.
Mammogram guidelines controversy
The American Cancer Society, however, joins a notable list of organizations including The American College of Radiology, the American College of Obstetrics and Gynecology, the Society for Breast Imaging and prestigious hospitals like the Mayo Clinic and M.D. Anderson that disagree with the new guidelines.
"This is one screening test I recommend unequivocally, and would recommend to any woman 40 and over," says ACS chief medical officer Dr Otis Brawley in response to the new guidelines.
Dr Len Lichtenfeld, ACS deputy chief medical officer, worries that women may opt out altogether, reversing decades of tremendous effort to increase breast cancer screening compliance. "Our concern is that as a result of that confusion, women may elect not to get screened at all. And that, to me, would be a serious problem."
Mammograms do save lives
The task force maintains, however, that physicians have to screen 1,900 women in the 40 to 49 age range to find one with cancer, compared to only 1,000 women over age 50. The data projects that starting mammograms at age 40 prevents one additional death but also leads to 470 false alarms for every 1,000 women screened. Continuing mammograms through age 79 prevents three additional deaths but increases the number of women treated for breast cancers that wouldn't threaten their lives.
"You save more lives because breast cancer is more common, but you diagnose tumors in women who were destined to die of something else. The over-diagnosis increases in older women," says Georgetown University researcher Dr Jeanne Mandelblatt.
The findings and their implications don't resonate well with some. "That stance is essentially telling women that mammography at age 40 to 49 saves lives, just not enough of them," says Dr Brawley.
Proponents of the revised guidelines argue that because most breast tumors are slow-growing, there's little risk to women by extending the time between mammograms. Even for the minority of women with aggressive, fast-growing tumors, annual screening makes little difference in survival odds, they insist.
Review Breast Screening Options Before Deciding
Barbara Brenner, executive director of San Francisco-based Breast Cancer Action, says the group was "thrilled" with the revisions. The advocacy group doesn't support screening before menopause, and is changing its suggested interval from yearly to every two years. "Mammograms, like all medical interventions, have risks and benefits," says Brenner.
What's the bottom line?
For women caught in the middle of all the confusion and controversy, what's the right choice?
The effects of screening for breast cancer with thermography, ultrasound or magnetic resonance imaging (MRI) are unknown and it's not clear whether annual screening (after age 40) with mammography does more good than harm.
Unfortunately, because science often presents these kinds of conundrums, women ultimately have to become their own judge and jury, enlisting input from their trusted healthcare provider. "Women are entitled to know what [the guidelines] are and to make their best decisions," says Brenner. "These guidelines will help that conversation."
More advice on preventing breast cancer
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