Treatment for HR+/HER2- metastatic breast cancer (mBC) usually involves drugs that affect the entire body. And while these treatments can often control the disease and ease symptoms for months or years, they can also trigger complications that may require their own treatment and lifestyle adjustments.
Research suggests that almost half of all women treated for breast cancer develop at least one medical condition after treatment. Unlike cancer treatment side effects such as short-term bouts of nausea and fatigue, complications are long-term health issues that may resolve over time or may require attention for the rest of your life.
HR+/HER2- mBC treatment complications can include chronic conditions such as neuropathy and lymphedema, which can be particularly challenging when you’re also dealing with the physical and psychological effects of the cancer itself.
Of the four main subtypes of female breast cancer, HR+/HER2- is the most common.
HR+/HER2- mBC Treatment Complications
Metastatic breast cancer is usually treated with systemic therapies that go throughout your body. Each type of treatment can trigger its own set of complications, though some HR+/HER2- mBC treatment complications are common to more than one therapy.
Bone loss, osteoporosis, fractures
Because HR+/HER2- mBC is fueled by hormones such as estrogen, one often-used treatment involves drugs that lower estrogen levels. These include aromatase inhibitors (AIs), such as anastrozole (Arimidex), exemestane (Aromasin), and letrozole (Femara).
Because AIs cause a significant drop in estrogen levels, women who have this type of therapy may experience bone thinning. This can lead to osteoporosis and a higher risk of bone fractures. An estimated 10% to 20% of women taking hormone therapy for breast cancer experience a fracture after five years.
If you take AIs, your doctor may suggest that you have bone density checked regularly and take medications to help keep your bones strong. These medications include denosumab (Prolia, Xgeva) and bisphosphonates, such as zoledronic acid (Zometa).
Talk with your health care team about getting a bone density scan before you start treatment. This gives you a baseline you and your doctor can use to keep an eye on your bone health through treatment and beyond.
Other strategies to lower your risk of fractures include getting enough vitamin D (1,000 to 2,000 IU) and calcium (1,000 to 1,200 milligrams) daily. Check with your doctor to see which dosages are right for you. Quitting smoking and limiting alcohol can help, too. Weight-bearing exercises — such as walking and climbing stairs — also support bone health.
Peripheral neuropathy
Peripheral neuropathy is damage to nerves beyond those in the brain and spinal cord. It can lead to pain, numbness, tingling, or weakness, often in the hands and feet. Digestion and urination, as well as other functions, may also be affected.
Chemotherapy for metastatic breast cancer can lead to peripheral neuropathy. The risk of neuropathy may be high if a type of chemo called a taxane is used. Women who already have neuropathy also may face greater risks of it getting worse after chemotherapy. Being older and being overweight also increase the chances of post-chemo peripheral neuropathy.
If you are scheduled for chemotherapy, talk with your doctor about what drugs are being used and about your personal risk for peripheral neuropathy or other complications.
If you are dealing with peripheral neuropathy, you may find some relief with over-the-counter pain relievers or prescription anti-seizure medications such as gabapentin (Gralise, Neurontin) or pregabalin (Lyrica). Topical treatments like lidocaine — either in creams or patches — may be helpful. Certain antidepressants can help with pain management, too.
You should also talk with your doctor about other potential treatments, such as physical therapy or neurostimulation — the use of low-level electrical pulses to block pain signals from reaching the brain.
Lymphedema
When breast cancer spreads, it often goes into lymph nodes. If the lymph nodes are removed surgically or treated with radiation, it can mess up the healthy flow of lymph, a watery fluid that delivers white blood cells to areas fighting infection, carries unwanted substances to the lymph nodes to be filtered out, regulates fluid levels in the body, and performs other important tasks.
When the lymphatic system — made up of lymph nodes, vessels, and organs — is not working efficiently because of cancer and cancer treatment, fluid can build up in the body. The result is lymphedema, and it can cause swelling and stiffness throughout the body as well as skin changes and other symptoms.
It’s important to work with your doctor in managing lymphedema. It’s a chronic condition with no cure, but you may be able to reduce symptoms. Some strategies that might help include:
- Exercise, which supports lymph drainage
- Compression bandages or stockings to help move lymph through the body
- Careful skin care that reduces the risk of infections and keeps skin moisturized and healthy
Cardiovascular problems
Metastatic breast cancer treatments including chemotherapy, hormone therapy (also known as endocrine therapy), radiation therapy, and targeted therapy (a treatment that tries to destroy cancer cells while preserving healthy ones) all can cause cardiotoxicity — damage to the heart caused by cancer treatment.
Potential heart problems caused by cancer treatment include:
- Left ventricular dysfunction (LVD, problems with the heart’s main pumping chamber)
- High blood pressure
- Pericardial disease (inflammation of the thin membrane that surrounds the heart)
- Thromboembolic disease (a blood clot that forms in a blood vessel and travels to another part of the body, blocking circulation)
- Myocardial ischemia (reduction in blood flow to the heart muscle)
- Arrhythmia (abnormal heart rhythm)
If a serious heart problem develops, you should work with a cardiologist. While a general cardiologist may help you manage your blood pressure, you may need to see a specialist if you get an arrhythmia or LVD, which can lead to heart failure.
Following a heart-healthy lifestyle that includes regular exercise, a balanced diet, no smoking, getting enough sleep, stress management, and little or no alcohol consumption can complement whatever heart treatment you need.
Build a Winning Health Care Team
As you navigate HR+/HER2- mBC treatment complications, as well as the cancer treatment itself, remember to surround yourself with health care professionals to help you all along the way. Your primary care doctor may be best suited to be the captain of your health care team, managing your overall care and staying up to speed with the treatments and recommendations of your oncologist (cancer doctor) and other specialists.
Work with your primary care doctor to make sure all of your health care providers know the medications you’re taking and at which doses, as well as your medical history, current symptoms, recent blood work, and planned imaging, procedures, and treatments.
It’s important that you feel comfortable sharing information and asking questions of the people on your care team. To make the most of your appointments, write down questions ahead of time, and find out how best to communicate with your doctors’ offices in between appointments. Phone calls may be best, but you may also be able to communicate through patient portals.
Consider Talk Therapy
You may need to take medications, participate in physical therapy, and see several specialists to manage the physical impacts of HR+/HER2- mBC treatment complications. But you shouldn’t ignore the emotional and psychological challenges that can come along with a chronic health condition. People with chronic disease are at a higher risk of mental health disorders such as depression.
Even if you aren’t having depression symptoms, you may find it helpful to establish a relationship with a mental health professional to learn strategies in anticipation of possible troubling times ahead. It will be important to share information about any medications you’re already taking in case your mental health care provider suggests antidepressants or other medications.
Show Sources
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SOURCES:
Breast Cancer Research and Treatment: “Long-term risk of medical conditions associated with breast cancer treatment.”
Journal of Clinical Medicine: “Long-Term Effects of Breast Cancer Therapy and Care: Calm after the Storm?”
National Cancer Institute: “Cancer Stat Facts: Female Breast Cancer Subtypes,” “Long-Term Nerve Damage Possible after Chemotherapy for Breast Cancer.”
Cleveland Clinic: “HER2-Negative Breast Cancer.”
Penn Medicine: “Metastatic (stage 4) breast cancer.”
American Cancer Society: “Hormone Therapy for Breast Cancer.”
Endocrine Society: “Breast Cancer and Bone Loss.”
Mayo Clinic: “Peripheral neuropathy: Overview,” “Peripheral neuropathy: Diagnosis and Treatment.”
National Institute of Mental Health: “Understanding the Link Between Chronic Disease and Depression.”
Johns Hopkins Medicine: “Breast Cancer: Lymphedema After Treatment.”
Indian Journal of Medical Research: “Cardiac morbidity & mortality in patients with breast cancer: A review.”
