subject: Is There An Alternative To Mammograms? [print this page] When the U.SWhen the U.S. Preventive Services Task Force (USPSTF) in 2009 came out against routine mammography for women in their 40s, their study results shined a glaring and not necessarily positive light on the role of mammography. The Task Force's findings not only questioned the value of early screening for younger women, the research also suggested that the use of mammograms may lead to unintended harm.
For more than 35 years, mammography has been the screening tool of choice. Mammography makes 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 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 and 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. These recommendations were based on several findings:
The false positive rate in the U.S. is twice as high as in Canada and ten times higher than the Netherlands because doctors are probably quicker to label a finding abnormal and, unlike most other countries, the U.S. routinely screens women under age 50.
Mortality from breast cancer varies by country and does not seem to directly correlate with screening practices, probably because there are so many other variables such as diet, environment and access to medical care.
There is no specific evidence to show that earlier screening creates significant benefit. In fact, the USPSTF found that the risks associated with over diagnosis were significant compared to the benefits of earlier screening.
Women who undergo additional testing and find that they have no cancer report high levels of stress and anxiety. Since it can be difficult to determine which cancers should not be treated, treatment almost always occurs. This approach results in significant additional problems for women including pain, fatigue, nausea, loss of hair, threats to heart/lungs/kidneys and income loss.
Many of the breast cancers that are diagnosed and then treated may not need to be treated. Some are inconsequential.
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. A 2004 review of scientific literature showed that about 5% of breast cancers were found by clinical breast examination. Other studies suggest a success rate of up to 15%.
These revelations have led many people to wonder if there are safer or more accurate alternatives to mammography for detecting breast cancer. 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.
(1) Breast Ultrasound 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.
(2) Magnetic Resonance Imaging (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.
(3) Positron Emission Mammography(PEM)scanners can show the location as well as the metabolic phase of a potential cancer. 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. Studies indicate that PEM has a higher rate of success in eliminating false positives, compared to MRI.
(4) Thermography - 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. 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 it is not recommended as a substitute for mammography.
(5) HALO Breast Pap Test 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 developig breast cancer over her lifetime. 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. 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.
(6) Molecular Breast Imaging (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. MBI is three times more effective than mammography at finding tumors in dense breast tissue. In MBI, a radioisotope (Tc-99m) is injected beforehand. Breast-tumor cells absorb this tracer, and appear as bright spots. While more expensive than mammography, MBI is about one-fifth of the cost of breast MRI. The FDA approved MBI in early 2010; its availability should expand this year.
(7) CT Laser Mammography images the human breast without using radiation, only laser light, to create a 3D image. 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 CTLM is currently in clinical trials and is not approved in the United States, but is available internationally. However, the company that makes the CTLM is also testing a modified version utilizing dye injection similar to MBI. If this optical scanning technique proves successful, CTLM promises to be a possible non-compressing substitute for mammography.
(8) Breast Tomosynthesis - 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 is available commercially in Europe and Canada but not yet approved for use in the United States.
In summary, most cancer authorities still recommend the continuing use of mammogram as a screening tool for women aged 40 to 50, whereas the 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. 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.
The message here is clear - get screened to protect your health. And, 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.
Someday this controversy will disappear when the imperfect 'gold standard' mammogram is replaced by a less invasive screening tool. Hopefully soon!
