What's new in breast cancer research and treatment?

What's new in breast cancer research and
treatment?
Research into the causes, prevention, and treatment of breast cancer is being done in
many medical centers throughout the world.
Causes of breast cancer
Studies continue to uncover lifestyle factors and habits that alter breast cancer risk.
Ongoing studies are looking at the effect of exercise, weight gain or loss, and diet on
breast cancer risk.
Studies on the best use of genetic testing for BRCA1 and BRCA2 mutations continue at a
rapid pace. Scientists are also exploring how common gene variations may affect breast
cancer risk. Each gene variant has only a modest effect in risk (10 to 20%), but when
taken together they may potentially have a large impact.
Potential causes of breast cancer in the environment have also received more attention in
recent years. While much of the science on this topic is still in its earliest stages, this is an
area of active research.
A large, long-term study funded by the National Institute of Environmental Health
Sciences (NIEHS) is now being done to help find the causes of breast cancer. Known as
the Sister Study, it has enrolled 50,000 women who have sisters with breast cancer. This
study will follow these women for at least 10 years and collect information about genes,
lifestyle, and environmental factors that may cause breast cancer. An offshoot of the
Sister Study, the Two Sister Study, is designed to look at possible causes of early onset
breast cancer. To find out more about these studies, call 1-877-4-SISTER (1-877-474-
7837) or visit the Sister Study Web site (www.sisterstudy.org).
Chemoprevention
Fenretinide, a retinoid, is also being studied as a way to reduce the risk of breast cancer
(retinoids are drugs related to vitamin A). In a small study, this drug reduced breast
cancer risk as much as tamoxifen. Other drugs are also being studied to reduce the risk of
breast cancer.
For more information, see our document, Medicines to Reduce Breast Cancer Risk.
New laboratory tests
Gene expression studies
One of the dilemmas with early-stage breast cancer is that doctors cannot always
accurately predict which women have a higher risk of cancer coming back after
treatment. That is why almost every woman, except for those with small tumors, receives
some sort of adjuvant treatment after surgery. To try to better pick out who will best
benefit from adjuvant therapy, researchers have looked at many aspects of breast cancers.
In recent years, scientists have been able to link certain patterns of genes with more
aggressive cancers—those that tend to come back and spread to distant sites. Some lab
tests based on these findings, such as the Oncotype DX, MammaPrint, and PAM50 tests,
are already available (see the section, "How is breast cancer diagnosed?" for more
information). Other tests are being developed as well.
Circulating tumor cells
Researchers have found that in many women with breast cancer, cells may break away
from the tumor and enter the blood. These circulating tumor cells can be detected with
sensitive lab tests. Although these tests are available for general use, it is not yet clear
how helpful they are for patients with breast cancer.
Newer imaging tests
Several newer imaging methods are now being studied for evaluating abnormalities that
may be breast cancers.
Scintimammography (molecular breast imaging)
In scintimammography, a slightly radioactive tracer called technetium sestamibi is
injected into a vein. The tracer attaches to breast cancer cells and is detected by a special
camera.
This technique is still being studied to see if it will be useful in finding breast cancers.
Some radiologists believe it may helpful in looking at suspicious areas found by regular
mammograms, but its exact role remains unclear. Current research is aimed at improving
the technology and evaluating its use in specific situations such as in the dense breasts of
younger women. Some early studies have suggested that it may be almost as accurate as
more expensive magnetic resonance imaging (MRI) scans. This test, however, will not
replace your usual screening mammogram.
Tomosynthesis (3D mammography)
This technology is basically an extension of a digital mammogram. For this test, the
breast is compressed once and a machine takes many low-dose x-rays as it moves over
the breast. The images taken can be combined into a 3-dimensional picture. Although this
uses more radiation than most standard 2 view mammograms, it may allow doctors to see
problem areas more clearly, lowering the chance that the patient will need to be called
back for more imaging tests. A breast tomosynthesis machine was approved by the Food
and Drug Administration (FDA) in 2011 for use in the US, but the role of this technology
in screening and diagnosis is still not clear.
Several other imaging methods, including thermal imaging (thermography) are discussed
in our document, Mammograms and Other Breast Imaging Procedures.
Treatment
Oncoplastic surgery
Breast-conserving surgery (lumpectomy or partial mastectomy) can often be used for
early-stage breast cancers. But in some women, it can result in breasts of different sizes
and/or shapes. For larger tumors, it might not even be possible, and a mastectomy might
be needed instead. Some doctors address this problem by combining cancer surgery and
plastic surgery techniques, known as oncoplastic surgery. This typically involves
reshaping the breast at the time of the initial surgery, and may mean operating on the
other breast as well to make them more symmetrical. This approach is still fairly new,
and not all doctors are comfortable with it.
Breast reconstruction surgery
The number of women with breast cancer choosing breast conservation therapy has been
steadily increasing, but there are some women who, for medical or personal reasons,
choose mastectomy. Some of them also choose to have reconstructive surgery to restore
the breast's appearance.
Technical advances in microvascular surgery (reattaching blood vessels) have made freeflap
procedures an option for breast reconstruction. For more information on the types of
reconstructive surgery now available, see our document, Breast Reconstruction After
Mastectomy.
For several years, concern over a possible link between breast implants and immune
system diseases has discouraged some women from choosing implants as a method of
breast reconstruction.
Recent studies have found that although implants can cause some side effects (such as
firm or hard scar tissue formation), women with implants do not have any greater risk for
immune system diseases than women who have not had this surgery. Similarly, the
concern that breast implants increase the risk of breast cancer recurrence or formation of
new cancers is not supported by current evidence.
Radiation therapy
For women who need radiation after breast-conserving surgery, newer techniques such as
hypofractionated radiation or accelerated partial breast irradiation may be as effective
while offering a more convenient way to receive it (as opposed to the standard daily
radiation treatments that take several weeks to complete). These techniques are being
studied to see if they are as effective as standard radiation in helping prevent cancer
recurrences. They are described in more detail in the section, "How is breast cancer
treated?"