Advancements in Treating & Preventing Recurrence For Common Breast Cancer Subtypes
- Florida's First Lady Casey DeSantis, 43, is nearing two years since she was first diagnosed with breast cancer. She’s since been declared "cancer-free" thanks to effective treatments. Advancements in breast cancer treatments are not only helping patients beat cancer but reducing their risk of it coming back.
- Men and women with common breast cancer subtype HR+, HER2- that have a high or medium risk of returning after surgery may have hope thanks to a newer class of cancer drugs called CDK4/6 inhibitors.
- Ribociclib (brand name Kisqali) is a CDK4/6 inhibitor and according to a new study when it's used alongside endocrine therapy after surgery the chances of tumor recurrence drop by 25%.
- Despite the benefits of the new treatments, they come with side effects. Dr. Eleonora Teplinsky, Head of Breast Medical Oncology at Valley Health System, told SurvivorNet that it's important for patients to sit down with their doctors about the side effects of CDK4/6 inhibitors like Ribociclib to determine if it's worth the potential benefit.
Florida's First Lady Casey DeSantis, 43, is nearing two years since she was first diagnosed with breast cancer. She’s since been declared "cancer-free" thanks to effective treatments. Advancements in breast cancer treatments are not only helping patients beat cancer but reducing their risk of it coming back, which is, of course, a huge concern for survivors.
DeSantis revealed her breast cancer diagnosis in October 2021. It came about after she started experiencing symptoms often associated with breast cancer which may include a new breast lump or swelling in the breast. Rather than wait around for her symptoms to progress, she sought her doctor. Although her doctors initially reassured her that nothing was wrong, she remained unconvinced and pushed for a mammogram. A mammogram is a breast cancer screening method that examines breast tissues for any abnormalities. Her instincts proved correct, as test results confirmed she had breast cancer.
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Understanding the Breast Cancer Subtypes
Again, we don't know the specifics of Casey DeSantis' breast cancer type, but the most common types of breast cancer include HR+ (positive)/HER2- (negative), HR- (negative)/HER2- (negative), HR+ (positive)/HER2+ (positive), HR- (negative)/HER2+ (positive).Hormone receptors are proteins found on breast cells that pick up either estrogen or progesterone signals and promote cell growth. If the cancer has one of those receptors, meaning it is hormone receptor-positive (HR+), the hormones help the cancer to grow.
Breast tumors may be positive for estrogen receptors (ER+), progesterone receptors (PR+), or both (ER/PR+). About 80% of all HR+ breast cancers are ER+ or ER/PR+, according to Penn Medicine.
HER2 stands for human epidermal growth factor receptor 2. It's a protein that can be found on the surface of breast cancer cells and make them grow quickly.
Tumors can be HER-negative, meaning they show minimal or no expression of the protein.
Tumors can also be HER2-low or HER2-positive, depending on the level of the protein present. They respond well to treatments that target the HER2 protein, such as Enhrtu (trastuzumab deruxtecan) or Herceptin (trastuzumab).
Advancements In Treatment
People with early-stage HR+, HER2- breast cancer that has a high or medium risk of returning after surgery have added hope thanks to the new cancer drug ribociclib (brand name Kisqali) that prevents recurrence.
Ribociclib is a CDK4/6 inhibitor, which helps slow down the growth of cancer in women with HR+, HER2- breast cancer.
CDK4/CDK6 inhibitors are targeted therapies that attack proteins known as cyclin-dependent kinases 4 and 6 (CDK4/CDK6).
These proteins control how quickly cells divide and multiply, and for women with breast cancer, these proteins can cause cancer cells to grow uncontrollably. That's where CDK4/CDK6 inhibitors come in they slow down or stop the proteins from multiplying.
WATCH: CDK4/6 Inhibitors for Breast Cancer, Explained
Three drugs within this class are approved:
- Abemaciclib (brand name Verzenio), approved for HR+, HER2- breast cancer that is advanced or metastatic, or that is early stage and is node-positive with a high risk of recurrence
- Palbociclib (brand name Ibrance), approved for HR+, HER2- breast cancer that is advanced or metastatic
- Ribociclib (Kisqali)
Breast cancer patients tend to tolerate these drug treatments well however they do come with side effects.
Dr. Eleonora Teplinsky, head of Breast Medical Oncology at Valley Health System says common side effects may include:
- Low white blood cell counts, such as neutropenia (which can cause fever, chills, cough, and more)
- Nausea
- Vomiting
- Diarrhea
- Constipation
- Fatigue
- Hair thinning
"The side effects look different in every single person," Dr. Teplinsky said. "So it's sometimes hard to know how someone will tolerate the medication until we put them on it."
She indicated that it's important for patients to understand that they could be on Kisqali for years, which means they could experience a symptom like diarrhea for an extended period. Dr. Teplinsky said patients should talk with their doctor when deciding together if the drug's benefits outweigh the risks.
"So I think it's really important to say, look, we have this new medication, here are the benefits, here are the side effects and then work with each patient [to decide] whether it's something that is going to be right for them," Dr. Teplinksy said.
A study on the effectiveness of ribociclib in combination with endocrine therapy after surgery reduced the risk of invasive tumor recurrence by 25% in patients with early-stage breast cancer that was hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) and had a high or intermediate risk of recurrence.
"I expect that these trial results will change practice," said Dr. Rita Nanda, director of the Breast Oncology Program and an associate professor of medicine at the University of Chicago Medicine, indicating this could change the way doctors make treatment plans for these patients.
More on Breast Cancer Treatment
- Acupuncture Promising for Pain Relief from Some Breast Cancer Treatment
- Advances in Metastatic Breast Cancer Treatments Over the Last Year Offer New Hope for Those Fighting
- An Overview of Breast Cancer Treatment
- FDA Warning: Robotically-Assisted Surgical (RAS) Devices Have Not Been Authorized for Breast Cancer Treatment or Prevention
- Do You Have HER2-Positive Metastatic Breast Cancer? Here’s A Breakdown Of Some Of Your Treatment Options
How the New Drug Treatment Works? By Interrupting Cancer Cells from Growing
Kisqali is part of a class of drugs called CDK4/6 inhibitors, which work to interrupt the growth of cancer cells. It's currently only approved for HR+, HER2- metastatic breast cancer (has spread). It is effective for patients whose cancer hadn't even spread to the lymph nodes yet. The drug cut the risk of recurrence by 37% in this subgroup. However, it's important to note that the showing wasn't statistically significant.
"While a number of patients are still on treatment, given the statistically significant and clinically meaningful improvement in disease-free survival, along with the trend in overall survival, the results have implications to change practice," Dr. Aditya Bardia, director of the breast cancer research program at Mass General Cancer Center, told SurvivorNet.
After early-stage HR+, HER2- patients have their cancer surgically removed, they may be eager to move on from treatment and get back to normal life. However, if there is a high or medium risk of the cancer returning, it may be beneficial for these patients to talk with their doctor about what options are available to prevent that from happening.
Questions to Ask Your Doctor
If you or a loved one was recently diagnosed with breast cancer and are interested in exploring some of these newer treatments, consider asking your doctor some questions.
- Does my breast cancer have a higher chance of returning?
- Would a CDK4/6 inhibitor help prevent it from coming back?
- Am I eligible to receive Kisqali?
- How do I know my hormone receptor or HER2 status?
- How will I feel during treatment?
- What are the most common side effects of Kisqali?
- Are there ways to manage the side effects?
- What will my treatment cost? Will my treatment be covered by my medical insurance company?
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