Research into the causes, prevention, and treatment of breast cancer is going on in many medical centers throughout the world.
Causes of breast cancer
Studies continue to find lifestyle factors and habits that alter breast cancer risk. Some studies are looking at the effect of exercise, weight gain or loss, and diet on breast cancer risk. We are also learning more about how genes influence breast cancer. This should happen more quickly now that the human genome has been mapped out.
A large, long-term study is now going on to help find the causes of breast cancer. It is known as the Sister Study and it will follow 50,000 women whose sisters (not they themselves) have had breast cancer. Over 10 years, information will be gathered on many factors that might 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. If you want to find out more about these studies, you can call 1-877-4-SISTER (1-877-474-7837) or visit the Web site at www.sisterstudy.org.
Chemoprevention
Studies have suggested that drugs like tamoxifen and raloxifene may lower breast cancer risk in women with certain breast cancer risk factors. But so far, many women don't want to take these drugs because they are concerned about possible side effects.
Newer studies are looking at whether aromatase inhibitors can reduce the risk of developing breast cancer in post-menopausal women. These drugs are already being used to help prevent breast cancer recurrences, but none of them are approved for reducing breast cancer risk at this time.
Fenretinide, a drug related to vitamin A, is also being studied as a way to reduce the risk of breast cancer. 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 lab tests
Gene studies
One of the problems with early stage breast cancer is that doctors cannot always tell which women have a higher risk of cancer coming back after treatment. That is why almost every woman gets some sort of adjuvant treatment after surgery. To try to better decide 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 are already available, but doctors are still trying to figure out the best way to use them. Other tests are being developed, too.
Tumor cells in the blood
Researchers have found that in many women with breast cancer, cells may break away from the tumor and enter the blood. These tumor cells can be found with sensitive lab tests. These tests are not yet ready for general use, but in the future they may be helpful in learning whether treatment like chemo is working in patients with metastatic breast cancer.
Newer imaging tests
Some newer imaging methods are being studied to see how they can be used to look at areas of change in the breast that might be cancer. You can find out more about these methods in our document, Mammograms and Other Breast Imaging Procedures.
Computer-aided detection and diagnosis (CAD) was developed to help find suspicious changes on mammograms. In this method, computers help doctors find abnormal areas on a mammogram by acting as a second set of eyes. This can be done with standard film mammograms or with digital mammograms. For standard mammograms, the film is fed into a machine which converts the image into a digital signal that is then analyzed by the computer.
The method can also be applied to a digital mammogram. The computer then displays the image on a video screen, with markers pointing to placed that should be checked closely.
Although some doctors find CAD helpful, the results of 2 large studies found that it did not find more cancers or find cancers earlier. But it did increase the number of women who needed to come back for more tests and/or have breast biopsies. Whether CAD will continue to be used in the future is not clear.
Treatment
Oncoplastic surgery
Sometimes after breast surgery the breasts can be different sizes or shapes. Some doctors are trying to address this problem by combining cancer surgery and plastic surgery. This is called oncoplastic surgery. It involves reshaping the breast at the time of the breast-conserving surgery, and may mean operating on the other breast as well to make them look more alike. This approach is still fairly new, and not all doctors are comfortable with it. The main concern is whether or not oncoplastic surgery might be more likely to leave tumor tissue behind.
Breast reconstruction surgery
Advances in re-attaching blood vessels (microvascular surgery) have led to improvements in breast reconstruction.
Research has shown that women who have breast implants used for breast reconstruction do not have any greater risk for immune system diseases than women who have not had this surgery. Also, breast implants have not been shown to increase the risk of the breast cancer coming back or of a new cancer forming. To learn more about the types of reconstructive surgery now available, see the American Cancer Society document, Breast Reconstruction After Mastectomy.
Radiation treatment
Doctors are comparing giving larger daily doses of radiation over fewer days to the standard radiation schedule. Studies have shown that giving radiation over 3 weeks seems to work about as well as the standard 5-week course. Other studies are looking at giving even larger daily doses over an even shorter time, such as a week.
For women who need radiation after lumpectomy, a method called APBI (accelerated partial breast irradiation) may offer an easier way to get it (as opposed to the standard daily radiation treatments that take many weeks to complete). There are several types of APBI now being studied. These techniques are being studied to see if they work as well as standard radiation in helping to prevent cancer from coming back.
New chemo drugs
Because advanced breast cancers are often hard to treat, researchers are looking for newer, better drugs. A drug class has been developed that targets cancers caused by BRCA mutations. This class of drugs is called PARP inhibitors and they have shown promise in clinical trials treating breast, ovarian, and prostate cancers that had spread and were resistant to other treatments. Further studies are being done to see if this drug can help patients without BRCA mutations.
Targeted therapies
Targeted therapies are a group of newer drugs that take advantage of gene changes in cells that cause cancer.
Drugs that target HER2: There are 2 drugs approved for use that target excess HER2 protein: trastuzumab (Herceptin) and lapatinib (Tykerb).Studies are being done to see which of these is best for treating early breast cancer. Other drugs that target the HER2 protein are being tested in clinical trials. Researchers are also looking at using a vaccine to target the HER2 protein.
Anti-angiogenesis drugs: In order for cancers to grow, blood vessels must be made to feed the cancer cells. Some studies have found that breast cancers with many new, small blood vessels are likely to spread more quickly. Bevacizumab (Avastin) is an example of anti-angiogenesis drug. Although bevacizumab does not seem to be very helpful in the treatment of breast cancer, clinical trials are currently testing several other anti-angiogenesis drugs.
New drugs are being made that may be useful in stopping breast cancer growth by keeping new blood vessels from forming. Some of these drugs are now being tested in clinical trials.
Drugs that target EGFR: The epidermal growth factor receptor (EGFR) is another protein found in high amounts on the surfaces of some cancer cells. Some drugs that target EGFR, such as cetuximab (Erbitux®) and erlotinib (Tarceva®), are already used to treat other types of cancers. Other anti-EGFR drugs are still considered experimental. Studies are now under way to see if these drugs might work against breast cancers.
Other targeted drugs: Everolimus (Afinitor®) is a new type of targeted therapy drug that is approved to treat kidney cancer. In one study, this drug was found to help shrink tumors before surgery when given along with the drug, letrozole. More studies using this drug for breast cancer are planned.
Many other potential targets for new breast cancer drugs have been identified in recent years. Drugs based on these targets are now being studied, but most are still in the early stages of clinical trials.
Bisphosphonates
Bisphosphonates are drugs that are used to help strengthen and reduce the risk of fractures in bones that have been weakened by metastatic breast cancer. In some studies, they seemed to help lower the chance of the cancer coming back when they were given to women with early breast cancer, but this was not seen in other studies. More studies are needed to find out if bisphosphonates should become part of standard treatment for early breast cancer.
Denosumab
Denosumab (Xgeva, Prolia) can also be used to help strengthen and reduce the risk of fractures in bones that have been weakened by metastatic breast cancer. It is being studied in early breast cancer patients to see if it can help adjuvant treatments work better.
Vitamin D
A recent study found that women with early stage breast cancer who had low levels of vitamin D were more likely to have their cancer come back in a distant part of the body and had a poorer outlook. More research is needed to confirm this finding, and it is not yet clear if taking vitamin D supplements would be helpful. Still, you may want to talk to your doctor about testing your vitamin D level to see if it is in the healthy range.
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