Policy on Breast Cancer Screening and “Early Detection”
See BCA’s Factsheet: Mammography Screening and New Technologies
Since the early 1980s, the United States’ public campaign to eradicate breast cancer has focused largely on efforts that promote mammography screening. Since the early 1990s, Breast Cancer Action (BCA) has raised concerns about the effectiveness of mammography screening, and the dangers of misleading the public about the benefits of “breast cancer early detection.” Throughout our history, BCA has encouraged women to make informed decisions for themselves about whether to take advantage of the technology.
In recent years, mammography screening—mammograms given to healthy women with no symptoms of any breast problem—has been the subject of considerable debate within the medical community, particularly with respect to its use among premenopausal women, and, increasingly, with respect to its effectiveness as a screening tool for women of any age. BCA believes that the widespread use of mammography and the controversy over its uses dictate that women of all ages be fully informed about the risks and benefits of mammograms.
BCA also believes that once women are fully informed about mammograms, each woman should make her own decision about whether or not to make use of the technology. Informed consent, in this case, presents women with difficult choices. Those who choose to have screening mammograms should have ready access to the best available technology, with the expense covered by their health insurance or the government.
Many breast cancer awareness and education campaigns are focused on the idea that “early detection is your best protection.” They also carry the assurance that “breast cancer found early is almost 100 percent curable.” But the promotion of mammography screening actually masks the real issue in breast cancer diagnosis: the value of "early" detection. While 98 percent of women diagnosed at a localized stage are alive five years after diagnosis, this does not mean that these women have been cured of breast cancer.1
Being cancer-free for five years following diagnosis is accurately considered a cure for some cancers. But breast cancer is an exception: it can and does recur at any time, though the likelihood of recurrence is highest in the first two years following treatment, and declines over time.Many breast cancer awareness campaigns urging women to have yearly mammograms are based on the premise that breast cancer found early can always be effectively treated. But the complex biology of breast cancer means that women diagnosed with “early” breast cancer fall into one of three groups.
- One group has very aggressive disease that, no matter how small it is when it is found, cannot be effectively treated with the therapies that are currently available. These women will die of breast cancer eventually, no matter what treatment they are given, unless they die of something else first.
- Another group of women diagnosed with breast cancer has a type of either non-aggressive invasive disease or some presentations of DCIS (ductal carcinoma in situ) that will never be life-threatening.
- The third group has a type of breast cancer that responds to currently available treatments. Finding breast cancer earlier does increase the likelihood that treatment will work for women in this group.
We do not know how many women historically have fallen into each of these three groups. And, while these divisions and the treatments currently available mean that “early detection” only matters for women in the third group, we cannot determine at the time of diagnosis the type of tumor a woman has. The result is that we mistreat or over-treat many women diagnosed with breast cancer.
It is in this framework that we need to examine the three methods of screening that are currently used or recommended for breast cancer detection in the United States: mammography, breast self-exam (BSE), and clinical breast exam (CBE). Thermography—the use of heat sensors to detect breast changes—has not been thoroughly evaluated as a breast cancer screening technology, and is therefore not generally accepted in this country as a screening method.
Mammograms use low-dose X-rays to examine the breast. (X-rays are ionizing radiation, a known carcinogen which has a cumulative effect on the body. The greater the radiation exposure/dosage over a lifetime, the greater the risk of radiation-induced cancer. This risk is highest in tissue in which cells are rapidly changing, such as the breast tissue of adolescent females.)
Breast self exams involve women using their own hands and visual inspection on a regular basis to look for changes in their breasts.
Clinical breast exams are also a manual exam, done by health care professionals who periodically examine a woman’s breasts for any palpable masses.
Annual clinical breast exams by trained health professionals and breast self exams are essential aspects of breast cancer screening, and should begin with a woman’s first gynecological exam or no later than at age 20. While there is controversy over whether BSE saves lives, there is clear evidence that women who do monthly breast self exams detect many breast changes. BCA encourages women to know their own bodies and to see a medical provider if they find any changes in their breasts.
Because mammograms are the only technology medically accepted for breast cancer screening, and because the federal government and many cancer charities promote their use for breast cancer screening, they are in widespread use. But mammograms, BSE and CBE do not always detect breast cancer and are not always accurate. Mammograms, self-exams and clinical breast exams do not always detect breast cancer—causing “false negative” results (when a detection method fails to find a breast cancer that is present). In day-to-day practice, mammograms can miss more than a quarter of all tumors.2
All screening methods also result in “false positive” findings, leading to unnecessary biopsies with increased stress and anxiety, as well as physical scarring. One-third of women screened over a decade will experience at least one false-positive mammogram result.3
Resources should be focused on training health care providers in effective clinical breast exam techniques, developing better treatments for the kinds of breast cancer that we are currently unable to treat effectively, and developing techniques for distinguishing those who can be helped by treatments from those who either don’t need treatment or cannot currently be effectively treated.
Breast Cancer Action is a national grassroots organization whose mission is to inspire and compel the changes necessary to end the breast cancer epidemic. We recognize that fundamental social changes are necessary to accomplish our mission, and we are dedicated to organizing people to work toward those changes. As a matter of policy, BCA does not accept funding from any company that is profiting in any way from cancer, including pharmaceutical and other health care corporations.
Revised policy: Adopted October 2006
1 American Cancer Society, Cancer Facts & Figures 2006. Five-Year Survival Rates by Stage at Diagnosis, 1995-2001.
2 Yankaskas B et al., “Association of recall rates with sensitivity and positive predictive values of screening mammography,” American Journal of Roentgen Ray Society, 2001 Sep; 177[3]:543-9.
3 J.G. Elmore, et al., "Ten Year Risk of False Positive Screening Mammograms and Clinical Breast Examinations," The New England Journal of Medicine 338(16), April 1998, pp. 1089-1096.