In November 2009 the U.S. Preventive Services Task Force (USPSTF) recommended that routine mammography screening for breast cancer start at age 50, as opposed to age 40. And in 2011 the Canadian Task Force on Preventive Care followed suit. As expected it caused quite an uproar both in Canada and the United States.1,2
The Task Force's findings shined a glaring and not necessarily positive light on the role of mammography in women's healthcare. The results not only questioned the value of early screening for younger women but the research also suggested that the use of mammograms may lead to unintended harm to women. In fact, the harm primarily comes from the consequences of the false positives produced by the test.
For close to forty years, mammography has been the screening tool of choice for early detection of breast cancer making it possible to see tiny cancers that may measure as little as half a centimeter (about one-fifth of an inch). A lump would have to be at least twice that size to be felt during breast manual examination.
The resulting X-ray shows the structures of the breast in varying degrees of black and white: white areas are typically milk ducts, grey and black areas are fat tissue; suspicious features show up as light or white spots. Depending on the shape and distribution of the spots, the mammogram may be read as abnormal. (Suspicious spots may look star-like, vary in size and shape or be lined up in a row.) Researchers are also beginning to report a reduction in false-positives by the use of three dimensional mammography, a technique that is not yet fully approved for use and not yet approved for insurance reimbursement.3
For years breast cancer screening guidelines in the U.S. agreed on by all major cancer detection authorities such as USPSTF, the American Cancer Society and the American College of Radiology have consisted of yearly mammograms starting at age 40 and continuing for as long as a woman is in good health as well as a clinical breast exam (CBE) about every 3 years for women in their 20s and 30s and every year for women 40 and over.4
The USPSTF determined that the risk of over diagnosis of benign lesions and the resulting, sometimes harmful treatments was greater than the value of detecting disease earlier in women under 50. They recommended that women under 50 talk with their doctors first, rather than simply undergoing mammography screening. They further suggested that mammograms could take place every two or three years instead of annually.
The USPSTF also couldn’t give a clear answer about the effectiveness of clinical breast examination. Two major studies, one from China and another from Russia, found no evidence that breast self-examinations reduced deaths from breast cancer, but instead the practice can lead to additional screening and biopsies.5 Research has shown that the effectiveness of breast examination by a healthcare provider depends greatly on the skill of the practitioner. A 2004 review of scientific literature showed that about 5% of breast cancers were found by clinical breast examination.6 Other studies suggest a success rate of up to 15%.
Many people, including most of the breast cancer organizations, reacted with shock and outrage at the reversal in clinical guidance. They accused USPSTF of conducting a cost/benefit analysis and concluding that the value of saving lives wasn’t worth the cost of screening for disease. Pretty tough stuff, especially against a backdrop of hysteria around “death panels” and other deliberate falsehoods about the U.S. President’s healthcare legislation. Fortunately, these “sound bite” interpretations of the USPSTF findings (and about the healthcare legislation) simply aren’t true.
So, why would the USPSTF turn the status quo upside down?
As a result of their findings, USPSTF recommends that earlier screening for women with no known risk factors should be a matter of discussion between women and their doctors. The choice boils down to the question of your comfort level with a higher likelihood of undergoing cancer treatment unnecessarily versus a much lower likelihood of earlier cancer detection, which dramatically improves survival rate.
So, is overtesting and extra stress enough reason to reduce the possibility that a 40 year old woman’s life could be saved?
As always, it’s a bit more complicated than that. Many of the breast cancers that are diagnosed and then treated may not need to be treated. According to a 2009 study conducted in Europe not all breast cancers are potential killers, some are inconsequential. If they were not picked up, women would not know they had them. But because they are detected through breast cancer screening, women usually undergo surgery and chemotherapy which are traumatic and potentially harmful.9
And, on top of this some critics continue to believe that the mammogram itself is harmful because of the level of radiation breast cells receive as well as the concern that breast compression may spread cancer cells. However, these concerns have not been supported conclusivly by evidence in the scientific literature.10
These revelations have also led many people to wonder if there are safer or more accurate alternatives.
Frankly, there aren’t very good alternatives at this point in time. However we’ve taken a look at most of the diagnostic tools currently available to give you a good sense of the options and the state of the art.
An imaging test that uses painless high-frequency sound waves to evaluate whether a density that appears on a mammogram is a fluid-filled cyst, a solid mass, or a variation of normal breast tissue. A cyst is generally benign. A solid mass may be either benign or malignant. Ultrasound isn't used for routine screening because it only visualizes small areas accurately and it doesn’t show as much small detail as a mammogram does. It is, however, very useful for focusing in on an abnormality found by mammogram.
A newer ultrasound method, the Warm Bath Ultrasound system by TechniScan, is designed to capture three-dimensional images of the breast as a woman lies prone on a table and state-of-the-art ultrasound technology is used in a warm water tank to image the breast anatomy.This new method of imaging produces information and whole breast images that are not available with traditional reflection ultrasound or whole breast ultrasound systems. Clinical testing is underway.
MRI is a diagnostic technique that is already well proven for many uses. MRI, which generates images by using magnetic fields, is extremely useful in confirming a breast cancer diagnosis, establishing the exact location of the disease and finding small areas of cancer elsewhere in the same or other breast. However, MRI is not considered to be an appropriate tool for primary diagnosis of breast cancer because the procedure falsely detects breast cancer in five out of every six positive scans according to a 2008 study from the Netherlands and corroborated by other studies as well. This technique is recommended to be used in follow up to a mammogram.11
PEM scanners are high-resolution breast positron emission systems that can show the location as well as the metabolic phase of a potential cancer, i.e. how much growth has occurred. This information is critical in determining whether an abnormality is malignant and influences the course of treatment. Other imaging systems, such as mammography and ultrasound, show only the location, not the metabolic phase. This new diagnostic tool, available commercially only since 2007, is seen as an alternative to MRI as a follow up diagnostic tool after mammogram. Studies indicate that PEM has a higher rate of success in eliminating false positives, compared to MRI.
Cancer cells create new blood vessels to feed its higher rate of growth. That activity creates heat which can be detected by breast thermography. Thermography uses an infrared camera to detect heat within the breast. There is no physical contact needed. Thermography proponents suggest that their technique finds cancer cells years before they can be detected by mammogram. They allege that mammography manufacturers have effectively squelched use of this relatively inexpensive technology to maintain market share.
However, research has shown that while thermography may be a useful adjunct technique, especially for women with dense breasts (typically younger women), its usefulness is limited because temperature changes in the breast can also be caused by infection or inflammation. A more recent study credits thermography with more diagnostic capability but continues to place it in a support role for mammography. It is not recommended as a substitute for mammography.12,13
A recently FDA approved diagnostic test, is also not a substitute for mammography. Instead, the HALO is a risk assessment test that screens for a condition called atypia or atypical ductal hyperplasia, an early indicator of a predisposition towards cancer. If a woman has atypia, she has a 400-500% increased risk of developing breast cancer over her lifetime. This is useful because in some cases, changes such as stopping smoking, losing weight, better eating habits, cutting back on drinking, can actually reverse atypia and help to inhibit the cancer. The screening age range is lower, 25-55, because of the density of a woman’s breast.
The HALO® machine itself is about the size of a laser printer and there are two cups that go over the end of the breasts. The cups compress the end of the breast to help express fluid, which is then suctioned out. The procedure takes about five minutes. If a woman does not produce fluid, she is considered to be at normal risk. If she produces fluid and does not have atypia, she has approximately double the normal risk of developing breast cancer over her lifetime. If she produces fluid with atypia, her risk of developing breast cancer in her lifetime is up to 500% greater. Women rate the level of pain associated with the HALO procedure as 3-4 on a pain scale of 1 to 10, versus a rating of 8 given to the pain of a mammogram.
MBI is the most promising available alternative at this point. MBI overcomes a major shortcoming of mammography, its inability to differentiate between tumors and dense breast tissue. On a mammogram, they both appear white. Researchers at the Mayo Clinic have discovered that MBI is three times more effective than mammography at finding tumors in dense breast tissue. MBI has also demonstrated fewer false positives.
The MBI procedure is similar to a mammogram. The breast is compressed, although with two-thirds less pressure than a mammogram and two images are taken of each breast. However, in MBI, a radioisotope (Tc-99m) is injected in the patient’s arm beforehand. Breast-tumor cells absorb this tracer, and appear as bright spots on MBI films. The patient is seated during the 40-minute procedure. While more expensive than mammography, MBI is about one-fifth of the cost of breast MRI (magnetic resonance imaging). Although it’s both invasive (includes an injection) and time consuming, the improved diagnostic capability makes it worth it. The FDA approved MBI in early 2010; its availability should expand this year.
CTLM images the human breast without using radiation—only laser light—to create a 3D image. Unlike x-ray mammo, the CTLM never compresses or even touches the breast. The patient lies face down on the scanning table with one breast hanging into a specially designed scanning chamber. The laser beam sweeps 360 degrees around the breast starting from the chest wall moving forward until the entire breast is scanned. The data is reconstructed to create three-dimensional cross sectional images of the breast. The CTLM is currently in clinical trials and is not approved in the United States, but is available internationally.
At this time, CTLM is seen as an adjunct to mammography rather than as a substitute. However, the company that makes the CTLM is also testing a modified version of this technology that can detect fluorescent dye injected into the body. Following dye injection, the scanner produces 3D images of the localized concentration of the dye. These images will show increased accumulation of the dye in malignant tissue. If this optical scanning technique proves as successful as expected, CTLM promises to be a possible non-compressing substitute for mammography.
One of the biggest problems in breast cancer detection is the overlap of breast structures that hide cancers when viewed through two dimensional techniques such as mammography. The overlap creates shadows which can be read as false positives. A new technique for three dimensional imaging eliminates the overlap problem.
Breast tomosynthesis differs from standard mammography in the way a CT scan differs from a standard X-ray procedure. The breast is held in the same compressed way, but in tomosynthesis the X-ray tube moves in a 50-degree arc around the breast while 11 low-dose images are taken during a 7-second examination. A computer then assembles the information to provide high-resolution cross-section and three-dimensional images that can be reviewed by the radiologist at a computer workstation. Breast tomosynthesis is available commercially in Europe and Canada but not yet approved for use in the United States. Clinical trials are underway.
We would be remiss if we didn't talk about BRCA testing which assesses risk.
BRCA1 and BRCA2 are human genes that belong to a class of genes known as tumor suppressors. Mutation of these genes has been linked to the development of hereditary breast and ovarian cancer. Women who inherit a mutation of BRCA1 or BRCA2 have an increased risk of developing breast and/or ovarian cancer at an early age and often have multiple, close family members who have been diagnosed with these diseases. However, not every woman who has a harmful BRCA1 or BRCA2 mutation will develop breast and/or ovarian cancer. Several blood tests are available to test for BRCA1 and BRCA2 mutations.
Currently, there are no standard criteria for recommending or referring someone for BRCA1 or BRCA2 mutation testing. In a family with a history of breast and/or ovarian cancer, it makes sense to first test a family member who has breast cancer. If that person is found to have a harmful BRCA1 or BRCA2 mutation, then other family members can be tested to see if they also have the mutation. Women who appear to be at increased risk of breast and/or ovarian cancer because of their family history should consider genetic counseling to learn more about their potential risks and about BRCA1 and BRCA2 genetic tests.14
The Final Word (or words)
At this point in time, the mammogram remains the best screening tool for breast cancer detection. Most cancer authorities recommend the continuing use of mammogram as a screening tool for women aged 40 to 50. USPSTF recommends that women in this age group discuss the issue with their doctors and make individual decisions. What should you do? It depends.
If you’re under age 50, you have to weigh your options. If you choose to have routine mammograms, recognize that there’s a higher false positive rate for your age group. That means that if an abnormality is found, you will want to be sure that you have an in-depth follow up, possibly using one of these new techniques, to know as much as possible about a potential cancer so you can make an informed decision about treatment.
If you are 50 or older, you should be receiving a screening mammogram either annually as the current guidelines suggest, or at least every two to three years, as USPSTF suggests. In 2005, just 71.8 percent of women between the ages of 50 and 64 and 72.5 percent of women ages 65 to 74 had received a mammogram within the previous two years, according to government figures.15
The Bottom Line
Someday this controversy will disappear when the imperfect 'gold standard' mammogram is replaced by a less invasive screening tool. In the meantime the message here is clear – still get screened to protect your health and earlier screening for women with no known risk factors should be a matter of discussion between women and their doctors.
While breast self examination, like every other diagnostic tool, may lead to some unnecessary testing and treatment, it is a safe, painless and no cost way for a woman to take responsibility for her healthcare. On that basis alone, breast self examination makes sense.
Mammograms can be inherently lousy. Now is an opportune time to replace this outmoded screening tool but there is one problem - there is nothing on the horizon, yet, but hopefully soon. Women deserve better!
Published August 9, 2010, updated May 30, 2012
Susan M. Brissette brings 30 years of experience in healthcare, ranging from positions as Chief Executive Officer and Chief Operating Officer in the acute care hospital setting to Senior Executive for a major national healthcare management company. Ms. Brissette holds a BS in Biology from Northeastern University and an MS in Health Policy & Management from the Harvard School of Public Health. She has lectured on healthcare management at the University of Massachusetts, developed a healthcare delivery system for a mining company in Cajamarca, Peru, and recently led the Afghanistan Public Health Redevelopment Task Force for the Washington Harvard Alumni Group. She has consulted on healthcare projects in Poland, Romania, Israel, Kuwait, Peru, Canada, and Mexico. She now owns and operates SB Cass Associates, a healthcare consulting firm located in upstate New York. Ms. Brissette’s consulting practice handles client projects ranging from business plan development for clinics, assisted living facilities, and clinical research groups to the development of market research reports for the pharmaceutical and biotechnology industries. She has written dozens of healthcare articles published on the internet and in national professional and consumer journals. She has also authored or edited online courses on HIPAA compliance, corporate security, childhood obesity, and business ethics.
Susan Brissette can be reached at SB Cass Associates firstname.lastname@example.org