The task force concluded that the risks associated with mammograms for women in their forties outweigh the benefits.
A mammogram is an X-ray study of the breasts used to diagnose breast cancer in its earliest stages, before it can be felt on clinical exam. It has long been considered the gold standard for early detection of breast cancer (and the perception of a greater chance of cure). Fear of breast cancer is many women’s number one fear. A 1995 Gallup poll found that 40 percent of women believe they will die of breast cancer, even though the actual risk of death from the disease is less than 4 percent. So women and doctors historically have clung to mammograms and early detection as though they were lifelines.
But in November 2009, the United States Preventive Services Task Force (an influential government-appointed group giving guidance to doctors, insurance companies, and policy makers) made headlines when it reversed its long-standing advice and released new guidelines recommending that most women start regular breast cancer screening at age fifty (instead of forty, as previously suggested). US1 The guidelines also recommended that women between the ages of fifty and seventy-four have mammograms only every two years. The guidelines did not recommend routine screening for women older than seventy-four at this time because the risks and benefits remain unknown. (These new guidelines did not apply to women at high risk for breast cancer because of a gene mutation that makes breast cancer more likely or because of previous extensive exposure to radiation.)
The task force concluded that the risks associated with mammograms for women in their forties (including a 60 percent greater chance of getting a false-positive result thanks to denser breast tissue, even though they are less likely to have breast cancer) outweigh the benefits (a 15 percent reduction in breast cancer mortality). Mandelblatt2 These risks have long been reported in the literature. For example, as far back as 2000 and 2001, Danish researchers Ole Olsen and Peter Gotzsche published two studies in the Lancet of their reviews of seven randomized controlled studies on the benefits of mammography in reducing mortality from breast cancer. They found that five of the seven studies were so flawed they couldn’t even be reviewed. In the remaining two, they also found major design flaws and limitations. They concluded that mammograms had no effect on deaths attributed to breast cancer. The studies also showed that mammograms often led to needless treatments and were linked to a 20 percent increase in mastectomies, many of which were unnecessary. Gotzsche3
Almost all cancer screening modalities (except functional ones such as thermography) identify the slow-growing lesions that women would die “with,” not “from.” In other words, they would never become life-threatening if left alone. An intriguing and important study published in the November 2008 edition of Archives of Internal Medicine suggests that some breast cancers will indeed go into remission without any treatment. Zahl4 This study followed more than 200,000 Norwegian women between the ages of fifty and sixty-four over two consecutive six-year periods. Half of the women received regular, periodic breast exams or regular mammograms; the rest had no regular breast cancer screenings. Researchers found that the women who received regular screenings had 22 percent more incidents of breast cancer. The researchers concluded that the women who didn’t have regular breast cancer screenings probably had the same number of occurrences of breast cancer, but that their bodies had somehow naturally resolved those abnormalities without intervention. Other doctors unrelated to the study analyzed the data and concurred that this conclusion makes sense.
Still, for the moment, major medical organizations such as the American Cancer Society and the American College of Obstetricians and Gynecologists continue to support the regular use of mammography for women starting in their forties. The American College of Radiology was so opposed to the change that it even went so far as to ask the task force to reverse its recommendation. Some medical groups, however, including the National Cancer Institute, announced they would reevaluate their guidelines. This dichotomy isn’t difficult to understand. Both inside and outside medicine, we as a culture have come to rely on screening to save us. And even though the evidence doesn’t support it, individual women and their doctors often feel safer if they perceive that they’ve “covered all the bases.”
One helpful way to assess your risk for breast cancer—which in turn can help you decide how often you want to have mammograms—is to use the National Cancer Institute’s Breast Cancer Risk Assessment Tool, available online at www.cancer.gov/bcrisktool. After you answer seven simple questions, it calculates both your risk of getting invasive breast cancer in the next five years as well as your lifetime risk, and it compares each to the risk for the average U.S. woman of the same age and race or ethnicity.
A number of other negative studies on mammography have appeared in the medical literature over the years—and these are finally getting the press they deserve. In 2000, the Journal of the National Cancer Institute pointed out that the cumulative risk of having false positive mammograms is quite significant in many women. And in 2002, a National Cancer Institute advisory panel concluded that the benefits of mammography are uncertain, in part because of the substantial chance of receiving a false positive result. While this is possible in any age group, it is most common in women in their forties because they tend to have denser and more fibrous breasts that get read as false positives on mammograms and then require biopsy. Andrew Wolf, M.D., an associate professor at the University of Virginia School of Medicine, supports these findings. In an August 2003 review article on breast cancer screening in Consultant, Dr. Wolf states, “If a woman begins getting regular mammograms at age 40, there is virtually a 100 percent chance that some kind of abnormality will show up that will warrant at least a follow-up mammogram, an ultrasound scan, or a call from the physician recommending a six-month follow-up examination. It is also likely that over the course of a lifetime, she will undergo an unnecessary breast biopsy.” Wolf5
For me, the biggest concern about mammography is that it doesn’t appear to reduce mortality from breast cancer any better than simple breast exam (which also doesn’t decrease mortality). According to a 2000 study from the Journal of the National Cancer Institute, after following nearly forty thousand women between the ages of fifty and fifty-nine, researchers found that annual mammograms were no more effective than standard breast exams in reducing breast cancer mortality. Miller6 Another study published in the Journal of the American Medical Association found that women age seventy and older benefited very little from mammography. Kerlikowske7 The cancers detected at this age never would have killed them. Then there are those researchers who doubt the safety of mammography because of radiation exposure. A 1994 study published in the Lancet addressed another concern that many women have brought up with me—that the breast compression that occurs during a mammogram may cause small, in-situ tumors to rupture, thereby spreading cancer cells into surrounding tissues and potentially leading to more invasive cancers and metastases. Vannetten8
Cornelia Baines, M.D., professor emerita at the University of Toronto and former deputy director of the Canadian National Breast Screening Study, put it succinctly when she said, “I remain convinced that the current enthusiasm for screening is based more on fear, false hope and greed than on evidence.” Baines9 I agree with Dr. Baines completely.
The bottom line is this: When it comes to mammograms, things are not as cut-and-dried as they seem. There’s a lot we simply don’t know. After discussing their options with a knowledgeable health care practitioner, all women will need to follow their own inner guidance on this issue, taking full responsibility for their choices. Intelligent, informed women can be trusted to do what’s right for them, including forgoing mammograms—and I support them wholeheartedly.
The Limits of Conventional Early Detection
Doing breast self-exams and getting mammograms (or sonograms) regularly is not the same as prevention. In other words, it is not the same as brushing and flossing the teeth, which actually prevents cavities and periodontal disease. As one of my colleagues said of breast cancer, “We identify the risks, but we don’t know what to do until they manifest as disease.” Our culture uses mammograms as a fix but doesn’t encourage women to change their diets, exercise, stop smoking, and learn how to be in relationships that nurture them. These are preventive changes that favor healthy breasts. But as one researcher has said, it’s difficult to put together a constituency for prevention. It is treatment that gets our attention. If your sister or mother dies of breast cancer, you usually give money to programs that do research to produce better treatments; you don’t start a whole-food restaurant in your neighborhood or advocate teaching eighth-grade girls how to appreciate their breasts and make sure they have optimal levels of vitamin D. Our culture is crisis-oriented, acting only once the horse is out of the barn.
There is a third option, however. You can use thermography, mammography, and other disease screening as an external guidance system. And if any abnormality appears, you then have the opportunity to ask the abnormal cells what they need that they’re not getting. The earlier in the disease process you make adjustments to your diet, beliefs, and lifestyle, the easier it is to transform your cells.
Make sure to read my Program to Promote Healthy Breast Tissue in Women’s Bodies, Women’s Wisdom (Bantam, revised 2010).
- U.S. Preventive Services Task Force, “Screening for Breast Cancer: U.S. Preventive Services Task Force Recommendation Statement,” Annals of Internal Medicine, vol. 151, no. 10 (November 17, 2009), pp. 716–26; also available online at http://www.annals.org/content/151/10/716.full.
- J. S. Mandelblatt et al., “Effects of Mammography Screening Under Different Screening Schedules: Model Estimates of Potential Benefits and Harms,” Annals of Internal Medicine, vol. 151, no. 10 (November 17, 2009), pp. 738–47; also available online at http://www.annals.org/content/151/10/738.full.
- P. C. Gotzsche and O. Olsen, “Is Screening for Breast Cancer with Mammography Justifiable?” The Lancet, vol. 355, no. 9198 (Jan. 8, 2000), pp. 129–34; P. C. Gotzsche and O. Olsen, “Cochrane Review on Screening for Breast Cancer with Mammography,” The Lancet, vol. 358, no. 9290 (Oct. 20, 2001), pp. 1340–42.
- P. Zahl, J. Maehlen, and H. G. Welch, “The Natural History of Invasive Breast Cancers Detected by Screening Mammography,” Archives of Internal Medicine, vol. 168, no. 21 (November 2008), pp. 2311–6.
- Andrew M. D. Wolf, “Share the Burden of Uncertainty with Patients,” Consultant, vol. 43, no. 9 (August 2003), pp. 1102–3.