> Emerging Areas in Chemotherapy, Hormone Therapy and Targeted Therapy
This section discusses emerging areas of research in the treatment of early breast cancer, including some tools for tailoring treatment.
Learn about promising, new treatments for metastatic breast cancer.
Improving chemotherapy, hormone therapy and targeted therapy
Research is ongoing to improve chemotherapy, hormone therapy and targeted therapy for breast cancer. New therapies are under study in clinical trials. The results of these studies will decide whether these therapies become part of standard care. After discussing the benefits and risks with your health care provider, we encourage you to consider joining clinical trials of new therapies.
BreastCancerTrials.org in collaboration with Susan G. Komen® offers a custom matching service that can help you find a clinical trial that fits your health needs. Learn more about this program.
Learn more about joining a clinical trial.
Gene expression profiling
Gene expression profiling is a promising tool to help guide breast cancer treatment. These tests do not show genetic information about a person, but rather information about the genes in a tumor. The gene profiles of some tumors may help predict whether the cancer is more likely to recur (when cancer comes back) and metastasize (when cancer spreads to other organs) . Tumors with gene profiles showing a high risk of recurrence or metastasis may be more likely to respond to chemotherapy than tumors with gene profiles showing a low risk.
At this time, Oncotype Dx® is the only gene expression profiling tool widely used in the United States. Oncotype Dx can be used to help make chemotherapy treatment decisions in some people with estrogen receptor-positive (ER+) cancers who are going to have hormone therapy [43-44]. Other gene profiling tools (such as MammaPrint®) and their use in guiding treatment plans are still under study .
Learn more about Oncotype Dx.
Subtypes of breast cancer
Molecular and genetic differences in breast cancers may be useful in guiding the development of new targeted therapies. One area of study divides breast cancers into four molecular subtypes: luminal A, luminal B, triple negative/basal-like and HER2 type. Although mainly used in research setting, these subtypes may be useful in tailoring treatment in the future.
Learn more about subtypes of breast cancer.
Bone-strengthening therapy using bisphosphonates is a standard treatment for women with bone metastases (more) . Bisphosphonates are also used to help prevent bone loss (osteoporosis) in breast cancer survivors and cancer-free women .
Early findings from a randomized clinical trial showed the bisphosphonate zoledronate (Zometa) increased disease-free survival among some premenopausal women . However, a more recent, larger study found no survival benefit . This study also showed bisphosphonate use increased the risk of osteonecrosis of the jaw, a serious jawbone disorder . Bisphosphonate use among breast cancer survivors is still under active study.
Because bisphosphonates may increase the risk of osteonecrosis of the jaw, it is important to have a dental exam before starting treatment with bisphosphonates .
Poly(ADP-ribose) polymerase (PARP) inhibitors are a class of drugs under study for many types of cancer, including breast cancer. PARP is an enzyme involved in DNA repair. Some chemotherapy drugs damage DNA. Adding a PARP inhibitor to some chemotherapy plans may lower the chances that the cancer cells will become resistant to the chemotherapy. This is most often a problem for those with metastatic breast cancer.
PARP inhibitors are under study for the treatment of breast cancers related to BRCA1 and BRCA2 gene mutations .
At this time, data on PARP inhibitors and breast cancer are limited and are not conclusive. Although some results look promising, these drugs are in the early stages of study and are only available in clinical trials.
Read comments on the potential uses of PARP inhibitors from our Chief Scientific Advisor, Dr. Eric Winer.
Other drugs, including capecitabine (Xeloda), are under study for the treatment of early breast cancer. Capecitabine is a chemotherapy drug used to treat metastatic breast cancer. It is now under study for use in the treatment of early breast cancer in both the neoadjuvant and adjuvant setting [51-52]. Results to date have not shown a survival benefit with capecitabine .
CYP2D6 and tamoxifen
CYP2D6 is an enzyme that affects how the body metabolizes (breaks down and uses) certain medications. For this reason, researchers were interested in whether certain forms of the gene related to CYP2D6 function affected the hormone therapy tamoxifen. The largest studies to date have found no difference in the risk of breast cancer recurrence in women with gene variations related to less CYP2D6 function compared to risk in women with genes related to normal or high CYP2D6 function [53-54]. There is no role for routine testing of CYP2D6 in women taking tamoxifen.
Certain medications can interfere with CYP2D6 function and probably should be avoided while taking tamoxifen . For example, some antidepressants, such as fluoxetine (Prozac), buproprion (Wellbutrin) and paroxetine (Paxil), can interact with CYP2D6 and may affect how tamoxifen works in the body . If you are considering taking tamoxifen, talk to your health care provider about potential drug interactions.
Learn more about tamoxifen.
High-dose chemotherapy/bone marrow transplant
High-dose chemotherapy (sometimes called bone marrow transplant) was an experimental therapy that used high doses of drugs to try and kill a large number of cancer cells. It was thought this more intense chemotherapy might kill cancer cells better than standard chemotherapy.
Despite early hopes for this approach, randomized clinical trials in the 1990s showed high-dose chemotherapy was no more effective than standard dose chemotherapy [56-58]. High-dose chemotherapy also had more serious side effects, such as liver, lung and bone marrow problems and was found to be fatal in about six percent of people . It is no longer used to treat metastatic breast cancer, but is still under study in some ongoing clinical trials of treatment for non-metastatic breast cancer.
Our commitment to research
At Susan G. Komen®, we are committed to ending breast cancer forever by energizing science to find the cures and ensuring quality care for all people, everywhere. Our global research grants and scientific programs are essential driving forces for achieving this mission. Many of the world’s leaders in breast cancer research have been supported by Komen’s Research and Scientific Programs – including three Nobel Laureates. Komen’s funding has supported research that has resulted in a better understanding of breast cancer; earlier detection; personalized, less invasive treatments for what was once a “one-treatment-fits-all” disease; and improved survival rates. Learn more about the exciting research we are funding.
*Please note, the information provided within Komen Perspectives articles is only current as of the date of posting. Therefore, some information may be out of date at this time.