> Emerging Areas in Estimating Risk and Risk Reduction
Risk assessment and risk reduction are active areas of research. Some studies are looking at new and better ways of knowing which women are at higher risk of breast cancer. Other studies focus on methods of reducing their risk, such as risk-lowering drugs.
Using breast cells to assess risk
Methods to assess breast cancer risk currently under study include [285-291]:
These procedures remove cells from the breast. A pathologist looks at the cells under a microscope. Abnormal (atypical) cells are linked to an increased risk of breast cancer.
The procedures differ in how the cells are removed from the breast.
Ductal lavage uses a small tube to flush out fluid from the nipple. This fluid contains breast cells. The procedure causes some discomfort .
Ductal lavage is becoming more common in the U.S. and many breast centers now offer it to women at higher risk. However, more research is needed to learn how to use the findings from this test.
Nipple aspiration (nipple aspirate fluid cytology)
Nipple aspiration (such as the HALO test) uses a breast pump (and sometimes massage) to remove fluid from the nipple.
Nipple aspiration is becoming more common in the U.S. and many breast centers now offer it to women at higher risk. However, more data are needed to learn how to use the findings from this test.
Random periareolar fine needle aspiration (RPFNA)
RPFNA uses a thin needle to remove cells from about 10 areas near the areola. This procedure is more invasive and causes more discomfort than ductal lavage, nipple aspiration or fine needle aspiration done for diagnosis. RPFNA is offered mainly in clinical studies.
Ductal lavage, nipple aspiration or RPFNA and risk assessment
At this time, finding abnormal cells from ductal lavage, nipple aspiration or RPFNA should not affect a woman's decision to take tamoxifen or raloxifene or to join a risk reduction clinical trial. More research is needed to learn how to best use the findings from these tests to estimate risk for use in recommendations for breast cancer screening or other risk reduction options.
If you are interested in one of these tests, talk to your health care provider. He/she may be able to give you a referral to a breast center with expertise in risk assessment and risk reduction.
Ductal lavage, nipple aspiration and RPFNA are under study for risk assessment. Risk assessment should not be confused with breast cancer screening (tests to find cancer early). In 2013, the U.S. Food and Drug Administration issued an alert warning people that tests such as nipple aspiration should never be used as a substitute for mammography and other breast cancer screening tools .
Risk-lowering drugs (chemoprevention)
Some drugs used to treat breast cancer are under study for their use in prevention. New risk-lowering drugs are also being developed.
Learn about FDA-approved drugs for lowering the risk of breast cancer.
Aromatase inhibitors are hormone drugs that are used to treat estrogen receptor-positive breast cancer in postmenopausal women (learn more). There are three aromatase inhibitors that are FDA-approved for the treatment of breast cancer in the U.S.: anastrozole (Arimidex), letrozole (Femara) and exemestane (Aromasin). They appear to be equally effective in treating breast cancer.
Exemestane (Aromasin) and anastrozole (Arimidex)
Findings from randomized controlled trials of cancer-free postmenopausal women at high risk have shown that the aromatase inhibitors exemestane (Aromasin) and anastrozole (Arimidex) may lower the risk of breast cancer by about half [152,525].
Unlike tamoxifen and raloxifene, exemestane and anastrozole do not appear to increase the risk of blood clots [152,525]. However, exemestane, anastrozole and other aromatase inhibitors can cause menopausal symptoms, a loss of bone density and other side effects (learn more) [278-281].
The American Society for Clinical Oncology (ASCO) and the National Comprehensive Cancer Network (NCCN) now recommend exemestane as a risk-lowering drug option for postmenopausal women at higher risk of breast cancer. (These recommendations were made before the findings on anastrozole were published.) However, exemestane and anastrozole do not yet have FDA-approval for use in the chemoprevention setting. These drugs are only FDA-approved for use in breast cancer treatment.
Learn about exemestane, anastrozole and breast cancer treatment.
Learn about the side effects of aromatase inhibitors.
Other aromatase inhibitors
The aromatase inhibitor drug letrozole is also being studied to see whether it may lower risk in postmenopausal women at high risk of breast cancer.
Learn about aromatase inhibitors and breast cancer treatment.
Bisphosphonates are a group of drugs used to help strengthen bones. Bisphosphonates are used to treat and lower the risk of osteoporosis. These drugs also play a role in the treatment of early and metastatic breast cancer. Women taking aromatase inhibitors to treat early breast cancer may use bisphosphonates to help maintain bone density. (Aromatase inhibitors can cause a loss of bone mineral density.) And, people with metastatic breast cancer may use these drugs to lower the risk of bone metastases.
Early study results have found bisphosphonates may also lower the risk of breast cancer in women at risk of osteoporosis . More data are needed to confirm these findings and to learn how they relate to other women. The women in the study were at risk for osteoporosis due to their low bone density, a factor linked to a lower risk of breast cancer. This makes it hard to know whether women in the study had a lower risk of breast cancer because of their use of bisphosphonates or because of their low bone density.
Learn more about bone mineral density and breast cancer risk.
Lasofoxifene is an osteoporosis drug similar to tamoxifen and raloxifene. Early findings suggest lasofoxifene may reduce the risk of estrogen receptor-positive breast cancer in women at risk for osteoporosis . More data are needed to confirm these findings.
Clinical trials of risk-lowering drugs
If you are at higher risk of breast cancer and are considering joining a clinical trial of risk-lowering drugs, discuss the potential risks and benefits with your health care provider.
BreastCancerTrials.org in collaboration with Susan G. Komen® offers a custom matching service that can help you find a clinical trial on risk reduction for healthy women and women at high risk of breast cancer.
Learn about clinical trials.