October is National Breast Cancer Awareness Month. Each year, over 250,000 women in the United States get breast cancer, and nearly 20% die from this disease. Catching breast cancer early before it has the chance to spread to other parts of your body is essential for successful treatment and improving survival rates. Getting regular mammograms is the best way to detect breast cancer early.
Breast cancer treatment has consisted of chemotherapy, hormone therapy, radiation, surgery, and targeted therapy. Research is ongoing to find new treatments and treatment combinations.
Types of Breast Cancer
Breast cancer is classified into subtypes based on receptors and proteins present on the cancer cells. Each type of breast cancer responds differently to different kinds of treatments.
Three main types of breast cancer have been identified.
Hormone Receptor (HR)-Positive:
These types of breast cancer have an estrogen receptor (ER) or a progesterone receptor (PR) on the cells. Some may have both. HR-positive cancer cell growth is fueled by estrogen or progesterone, so it tends to respond to hormone therapy that blocks the effects of estrogen or androgen.
Human Epidermal Growth Factor Receptor 2 (HER2)-Positive
HER2-positive cancer cells contain too much HER2 protein, which promotes cell growth. They respond to HER2-targeted therapy.
Triple-Negative Breast Cancer
Triple–negative breast cancer cells do not have ER or PR and have little HER2 protein (hence the name triple-negative). This is the most difficult breast cancer to treat because it does not respond to either hormone therapy or targeted therapy.
New HR-Positive Breast Cancer Treatment
HR-positive breast cancers are typically treated with hormone therapy that works against estrogen or progesterone. Targeted therapies are drugs that target cancer cells while minimizing damage to healthy cells.
New research is looking at adding targeted therapy to hormone therapy for patients with advanced HR-positive breast cancer or HR-positive cancer that has spread to other areas. New drugs approved to treat HR-positive breast cancer include:
New HER2-Positive Breast Cancer Treatment
HER2-positive cancer that spreads to other parts of the body has a higher chance of spreading to the brain than any other type of breast cancer. Medicines that can cross the blood-brain barrier (meaning they can penetrate the brain) are essential in preventing and treating breast cancer that spreads to the brain.
In April 2020, the FDA approved Tukysa (tucatinib) in combination with Herceptin (trastuzumab) and Xeloda (capecitabine) to treat HER2-positive breast cancer that cannot be removed by surgery or has spread to other parts of the body, including the brain.
Tukysa crosses the blood-brain barrier, and it works by blocking the signals that tell the cancer cells to grow.
Other targeted therapies approved by the FDA for HER2-positive breast cancer include:
New Triple-Negative Breast Cancer Treatment
Because triple-negative breast cancers generally do not respond to hormone therapy or targeted therapy, chemotherapy has been the standard treatment for this type of cancer.
In April 2020, the FDA approved Trodelvy (sacituzumab govitecan-hziy) to treat triple-negative breast cancer that has spread to other parts of the body and does not respond to other treatments. Trodelvy is a targeted therapy that helps deliver chemotherapy drugs directly to the cancer cells, preventing them from growing and spreading. Because Trodelvy can cross into the brain, it can help chemotherapy drugs work in the brain.
Other therapies approved to treat triple-negative breast cancer include:
Advancements in Breast Imaging Tests
Early detection and screening continue to be the cornerstone of effective breast cancer treatment. Researchers are looking for ways to improve current screening tests. Some advances in breast cancer screening and imaging tests include:
- 3-D mammography (breast tomosynthesis): This test uses images taken from different angles of the breast to create a 3-D image.
- Molecular breast imaging (MBI): A radioactive chemical and a camera are used to look into the breast.
- Positron emission mammography (PEM): This test is similar to a PET scan. It helps to detect smalls clusters of cancer cells in the breast.
- Electrical impedance imaging (EIT): This test is done without using radiation or compressing the breast. It can be used to classify breast cancer tumors.
- Elastography: This test helps determine if a tumor is cancerous or benign (noncancerous).
- Optical imaging tests: This test does not use radiation or breast compression. Current research is studying how to use this test in combination with 3-D mammography, ultrasound, or MRI tests.
Breast cancer is one of the few cancers with effective screening tools. Let's use them! Talk to your healthcare provider about a mammogram. Remember, early detection is key to successful treatment.
Rosanna Sutherby is a freelance medical writer who has been a practicing pharmacist in her community for close to 20 years. She obtained her Doctor of Pharmacy from Nova Southeastern University in Ft. Lauderdale, FL. She utilizes her clinical training in the pharmacy, where she helps patients manage disease states such as asthma, diabetes, heart disease, hypertension, and many others. Dr. Sutherby reviews and recommends drug regimens based on patients' concurrent conditions and potential drug interactions.