Metastatic breast cancer side effects

We know that a metastatic breast cancer diagnosis can feel like a shock. It can be equally overwhelming to manage the side effects of metastatic breast cancer as a part of your daily life. Talking with your healthcare team can help you work together to recognize and manage the side effects of metastatic breast cancer, so it’s easier to focus on the things that mean the most to you.

Although people with all stages of breast cancer experience treatment side effects, metastatic breast cancer typically means ongoing treatment for long periods of time. But metastatic breast cancer treatment plans are usually designed to keep side effects to a minimum while providing the most effective treatment to control the cancer. This is different than treatment for early breast cancer, which can often mean a more intense level of side effects. When treatment is ongoing, having a good quality of life is one of the top priorities.

It can sometimes be hard to tell the difference between the side effects of treatment and symptoms of metastatic breast cancer itself:

• A side effect is an unwanted reaction to a treatment.
• A symptom is caused by the growth and activity of breast cancer cells in different parts of the body.

Some side effects and symptoms can feel similar, such as fatigue or pain. If you’re experiencing a new or unusual feeling in your body and are unsure of the cause, talk to your care team about whether it’s more likely a treatment side effect or cancer symptom.

It’s important to remember that not everyone experiences every side effect. Any side effects you experience will depend on a few things:

• The specific treatments you’re getting
• How long and how often you’re getting them
• The dose of medicine
• How your individual body reacts to a medicine

Side effects can range from mild to severe, and they may last for a short period of time — until your body adjusts to a treatment — or persist during or after a treatment. There may be times when side effects have a major impact on your day-to-day life, and other times when they fade into the background or aren’t really bothersome.

No matter what kinds of side effects you might experience, we’re here for you. On this page, we’ll talk about some of the most common side effects that can happen with metastatic breast cancer treatments. We’ll also share tips on how to talk with your care team about ways to prevent, reduce, or manage side effects — so you can keep doing things you enjoy.

Talk to your team

It’s important to communicate regularly with your healthcare team about side effects. While side effects can be upsetting, there are many ways to manage them and reduce their impact on your life. Having some strategies in place up front can bring a sense of control.

Here are some tips for keeping your care team informed:

• Always be open with your care team about any side effects you’re experiencing. If you’re having trouble, let them know what you’re feeling so they can support you. Sometimes this can mean switching a medicine or adjusting a dose so you can feel better and get back to doing things you enjoy.
• After talking with your team about any side effects you’re experiencing, it can help to keep a journal to track when a side effect happens, what strategies you use to manage it, and whether it’s helping. This can make it easier to let your care team know exactly what’s happening.
• Ask a friend or loved one to be available to call your care team if a side effect is especially difficult.

Here are some questions you can ask your doctor when you’re starting a new treatment:

• What side effects can I expect with this treatment?
• How can I reduce or manage these side effects?
• Which care team member should I call in between appointments if a side effect is interfering with my daily life?
• Are there any side effects that require emergency attention?
• How will we know if I need to try a different treatment to see if it has fewer side effects?

Most treatments have recommendations built in to either lower the dose or change the timing of the medicine if side effects are especially difficult to tolerate. Even if the dose is lowered or the schedule is changed, the treatment will still work against the cancer. Another option may be to try a different treatment.

Although one goal of treatment is to keep the cancer under control for as long as possible, a second equally important goal is to allow you to have a good quality of life. Remember, your needs are an important part of your treatment plan. If you’re experiencing difficult side effects, you and your care team will decide together whether continuing with a certain treatment is right for you — or if trying a new one might be a better option. This will be an ongoing conversation about a treatment plan that evolves as needs change: a plan that works for your diagnosis and supports your quality of life at the same time.

Visit Questions to ask an oncologist to learn more about talking with your care team.

Common metastatic breast cancer side effects

On this page, you can learn about these common metastatic breast cancer treatment side effects and ways to manage them:

Heart health

In some people with metastatic breast cancer, certain medicines can lead to heart problems. Although these side effects are rare, they may include:

• Swelling of the heart muscle
• Congestive heart failure, which means the heart doesn’t pump blood as well as it should
• Heart disease, which is a general term for damage or disease affecting the vessels of other structures of the heart

Treatments that have been associated with a higher risk of heart problems include:

• High doses of certain chemotherapy medicines. These can weaken the left ventricle, the heart’s main pumping chamber, which can lead to heart failure. If chemotherapy is part of your treatment plan, talk with your doctor about any potential risk to your heart health and ways to monitor and protect your heart.
• Targeted therapies used to treat HER2-positive, metastatic breast cancer. These medicines carry a higher risk for congestive heart failure. But with close monitoring, usually every 3 months, risks to the heart can be controlled or reversed by pausing treatment and/or starting treatment with medicines that control heart rhythm and reduce high blood pressure.
• Some hormonal therapies, such as aromatase inhibitors, have also been associated with heart problems. Talk with your doctor about your heart health history so you can choose an effective treatment and protect your heart at the same time.

With ongoing treatment to keep metastatic breast cancer under control, you and your care team can talk about how best to protect your heart. Here are some important things to discuss about keeping your heart healthy:

• Before starting a new treatment, share any past history of heart problems or heart-related risk factors.
• Let your doctor know if anyone in your family has had heart problems.
• Ask how your heart will be monitored before, during, and after treatment, and what symptoms of heart problems you should watch out for.
• Healthy eating and regular exercise also can help keep your heart stronger.

If you have heart-related side effects such as shortness of breath, irregular heart rate, or chest pain, call your doctor, or the doctor on call at your oncologist’s office if it’s after hours. If symptoms are very intense, go to the nearest emergency room.

If you do experience heart-related side effects, your doctor may prescribe medicine that can help protect your heart. Depending on the type of cancer treatment, your doctor may be able to lower the dose or delay a scheduled treatment so that side effects can resolve.

For more information, visit Heart health.

Hair loss

Whether metastatic breast cancer is your first diagnosis, or you’ve been treated in the past for early-stage breast cancer, it’s completely normal to be concerned about hair loss. It can feel traumatic to lose what feels like a part of your physical identity. If you experienced hair loss from previous treatment, going through it again can bring up some of the same emotions you felt the first time, but new ones too. And not everyone feels the same way about treatment-related hair loss. For some people, it’s more of a minor annoyance. No matter how you feel, there are things you can do to make it easier, including being able to keep some or all of your hair.

Chemotherapy is the main cause of breast cancer treatment-related hair loss, but not all chemotherapy medicines cause hair loss. If chemotherapy is part of your treatment plan, ask your doctor if the recommended type of chemo causes hair loss. If it does, talk with your doctor about whether there are other treatments with less of a risk for hair loss that could work just as well against the cancer.

If not, there are many options, including:

• Wearing a wig
• Wearing hats
• Wearing head scarves
• Wearing nothing at all
• Scalp cooling, which has allowed many people to keep some or all of their hair during chemo

People having ongoing chemotherapy often decide that wearing hats, scarves, or a bald look is easier than the steps involved in scalp cooling.

With some chemotherapies, your hair may get thinner but not fall out completely. There are some strategies you can follow to be gentler with your remaining hair:

• Shampoo less often, and use a mild shampoo.
• Use soft-bristle hair brushes and brush gently and sparingly.
• Avoid pulling your hair with too much blow drying, hair rollers, or styling into tight braids or ponytails.
• If you do blow dry, use a low-power, cool setting.
• Avoid curling irons and flat irons, as well as harsh treatments such as hair dyes and perms.
• Consider using a satin pillowcase when you’re sleeping. The smooth fabric can help reduce the risk of hair coming out in clumps.

To learn more, visit Hair loss.

Hand-foot syndrome

Hand-foot syndrome, also known as palmar-plantar erythrodysesthesia, causes redness, swelling, tenderness, and sometimes peeling on the palms of the hands and the soles of the feet. Hand-foot syndrome is caused by some chemotherapy medicines, such as capecitabine (Xeloda). Targeted therapies, such as lapatinib (Tykerb), can also cause it.

If you’re taking a medicine that causes hand-foot syndrome, it’s important to protect your hands and feet from extremes such as hot temperatures, harsh chemicals and soaps, rough surfaces, and high-impact sports and exercises. Gentle moisturizers and soft gloves and socks can help protect your hands and feet. Using cold packs wrapped in a towel might also help if you’re experiencing pain and tenderness.

For persistent pain and inflammation that make daily activities difficult, your care team also may:

• Recommend an over-the-counter or prescription medicine or topical cream to reduce pain and inflammation
• Lower the dose of your treatment so that you’re able to do everyday activities, such as walking and grasping objects, with less pain
• Add extra time in between treatments to lessen your symptoms
• Give you a break from treatment or switch you to a different medicine

For more detailed information and tips, visit Hand-foot syndrome.

Mouth sores

Some treatments for metastatic breast cancer can cause mouth sores. Often these appear as ulcers on the lips, inside the mouth (on the inner cheeks or gums), or at the back of the throat. Some chemotherapy medicines and targeted therapies can cause mouth sores; however, not everyone taking these medicines gets them, and they can vary widely in how severe they are. Staying on a treatment for long periods of time can increase the risk of mouth sores becoming a problem.

If you develop mouth sores, these strategies can help:

• Brushing your teeth regularly with a soft toothbrush
• Rinsing your mouth with a mixture of water and salt or baking soda
• Drinking plenty of water
• Avoiding spicy or salty foods that might aggravate soreness
• Eating soft, chilled foods
• Drinking through a straw

If you develop multiple mouth sores that cause pain, talk to your care team. They might recommend:

• Applying medicine directly to the sores to reduce pain, or using a pain-relieving mouthwash (sometimes referred to as magic mouthwash)
• Taking pain medications to reduce discomfort
• Lowering the dose of your treatment
• Increasing the time between treatments, or even stopping for a time
• Switching to a different medicine to see if the side effect is reduced

For more information, visit our section on Mouth sores.

Pain

Pain is sometimes caused by metastatic breast cancer itself, especially if it is present in the bones or spine. But pain can also be a side effect of some breast cancer treatments. Anticipating pain as a result of treatment can trigger worry and anxiety, but there are many strategies for controlling and lessening pain.

If you’re concerned about the possibility of painful side effects, talk to your care team about a plan for managing pain. You should not have to live with pain that keeps you from engaging in normal everyday activities and enjoying family and friends. Controlling this side effect up front, before it becomes too intense, is a better strategy than toughing it out.

Different treatments can trigger different kinds of pain.

• Chemotherapy medicines can lead to painful conditions such as:
  • Mouth sores
  • Hand-foot syndrome
  • Neuropathy
• Hormonal therapies, such as aromatase inhibitors and tamoxifen, can cause bone, joint, and muscle pain.
• Some targeted therapies can lead to joint, muscle, or bone pain.

Still, each person’s body can react differently to the same medicines. If you develop pain that interferes with your daily routines, you and your care team have a number of strategies for alleviating it, such as:

• Over-the-counter or prescription oral medications
• Topical lotions, creams, our mouthwashes that dull the pain at its source
• Physical therapy or gentle exercise
• Complementary approaches such as acupuncture, meditation, relaxation, or guided imagery

If pain becomes severe despite these strategies, your care team can consider changing your treatment schedule or trying a new medicine. Some people with cancer are using medical marijuana to address pain symptoms. If you’re interested in seeing if this is an option, talk with your doctor.

Always let your care team know about any pain you’re experiencing so that you can continue the daily activities you enjoy. To learn more about management strategies, visit our section on pain.

Bone pain

People who have metastatic breast cancer affecting the bones sometimes experience bone pain as a symptom of the disease itself. When bones weaken, they are more prone to fractures, which can be painful.

However, bone and joint pain can also be a side effect of some treatments for metastatic breast cancer:

• Certain chemotherapy medicines can cause aches and pains in joints and bones. So can hormonal therapies, including tamoxifen and aromatase inhibitors.
• Aches and pains also may result from medicines taken to treat side effects of cancer treatments, such as bisphosphonates to manage bone thinning.
• It’s common to feel joint pain from growth factors given for neutropenia (low white blood cells) such as filgrastim (Neupogen) and pegfilgrastim (Neulasta).

Talk to your care team about whether your treatment plan includes any medicines that cause bone or joint pain. Over-the-counter treatments such as naproxen (Aleve) and ibuprofen (Tylenol, Advil) can help — but always check with your doctor to make sure these medicines are safe for you to take, and if so, what dosage is right for you. Prescription medicines such as opioids, steroids, antidepressants, or anti-seizure medicines, such as gabapentin (Neurontin) also may be options, depending on the nature and severity of the pain.

Self-care strategies for pain include:

• Hot or cold packs placed directly on the arms, legs, back, or neck
• Gentle, low-impact exercises such as walking, stretching, yoga, or swimming — but always talk with your doctor about what’s safe for you before starting a new exercise
• Eating nutritious food and maintaining a healthy weight to reduce stress on joints
• Acupuncture, an ancient complementary therapy that has been shown to be effective at managing bone pain from aromatase inhibitors

For more information, visit Bone pain.

Nail and skin changes

Some chemotherapies for metastatic breast cancer can lead to changes in the nails and skin. These can include fingernails or toenails darkening or becoming more brittle, and nail cuticles that are tender. They can also include dry or itchy skin, redness, peeling, or a rash. Some types of targeted therapy can cause dry skin, a rash, and nail problems as well.

Ask your care team what to expect and what you should do if you experience nail and skin changes. Many can be managed with self-care strategies, such as:

• Using mild soaps and skin products (ask for guidance on good choices)
• Moisturizing the skin and nails with a gentle lotion
• Protecting skin from the sun and wearing soft fabrics
• Taking short, lukewarm showers or baths; ask your doctor or nurse about adding colloidal oatmeal to bath water to reduce itching
• Keeping nails clean and cut short
• Wearing gloves while cleaning or doing other household chores or yardwork
• Wearing soft socks and comfortable-fitting shoes

Ask your care team what skin and nail changes would require a medicated ointment (over-the-counter or prescription) or an oral prescription medication, such as an antibiotic or steroid. To learn more, visit our Nail and skin changes page.

Insomnia and fatigue

Insomnia  (not being able to sleep) and fatigue (feeling tired even with adequate rest) can happen as a result of metastatic breast cancer treatment, for a range of reasons. These side effects can be caused by:

• Medicines such as hormonal and targeted therapies
• Chemotherapy medicines that cause anemia (very low red blood cell count), which can make you feel tired
• Pain and discomfort from treatment side effects, such as neuropathy, bone pain, and menopausal symptoms such as hot flashes, which can make it difficult to sleep
• Nausea, vomiting, and/or difficulty eating, all of which can lead to low energy
• The emotional stress of living with uncertainty — worrying about what’s going to happen can keep you up at night and drag you down in the daytime
• Anxiety and depression caused by stress or certain medicines

Feeling exhausted and not being able to sleep can be very difficult when you know you’ll be in treatment for long periods of time. If you have these side effects, work with your doctor to figure out what is likely causing them, especially if they last for 3-4 weeks or longer. Together you can come up with a plan that may include strategies such as:

• An exercise plan that is safe for you
• A healthy eating plan, developed in collaboration with a dietitian
• Complementary therapies such as massage, yoga, mindfulness-based stress reduction
• Working with a professional licensed counselor or therapist to address anxiety that may cause fatigue and poor sleep

If lifestyle changes aren’t enough, there are prescription medicines that can help with insomnia and fatigue. Your care team also may consider changing your treatment plan if these side effects are causing major disruptions in your day-to-day life over long periods of time. Adjusting the dosage and timing of treatment or switching to a new medicine may provide some relief. For more information, visit the Insomnia and fatigue page.

Neutropenia

Many chemotherapy medicines can cause neutropenia, a condition caused by lower than normal amounts of neutrophils, a type of white blood cell. Neutrophils fight infection by killing harmful bacteria in the blood. Neutropenia can also happen when breast cancer has moved into the bones and crowds out healthy bone marrow cells, because the marrow is an important source of white blood cells.

If a specific treatment you’re on has a high risk of causing neutropenia, your doctor may prescribe a medicine called a growth factor to lower that risk. Growth factors may also be given to increase white blood cell counts after they have already dropped. These may include:

• Filgrastim (Neupogen), or a biosimilar, a medicine designed to be very similar to filgrastim and work the same way in the body, given as an injection under the skin
• Pegfilgrastim (Neulasta), or a biosimilar for pegfilgrastim, given by as an injection under the skin

If you experience neutropenia and your white blood cell counts remain too low after trying a growth factor, your doctor may decide to lower the dose of your treatment or allow more time in between treatments. You also may need to switch to a different medicine.

There are some steps you can take to protect yourself against infection in your daily life: washing your hands often and well; avoiding crowds and sick people; wearing a mask if you need to be in a group setting; cleaning and bandaging any cuts or scrapes; and washing and cooking foods thoroughly.

Call your doctor right away if you develop a temperature of 100.5 degrees Fahrenheit or higher during chemotherapy treatment, or if you have any shaking chills, a sore throat, diarrhea, ear pain, headache or sinus pain, skin rash, painful urination, or other potential signs of infection.

For more information, visit our Neutropenia page.

Bone health

If metastatic breast cancer moves into the bones, it can weaken them and increase the risk of fracture. At the same time, certain cancer treatments can also affect the bones by decreasing bone density, which makes bones thinner and more prone to fracture:

• Chemotherapy medicines can have a direct impact on the bones. For premenopausal women, chemotherapy can sometimes lead to early menopause or symptoms of menopause. That can mean lowered estrogen in the body and decreasing bone density.
• Hormonal therapies, such as aromatase inhibitors and ovary suppressing medicines, can also lower the amount of estrogen in the body and lead to decreased bone density.

Besides breast cancer treatment, other factors can play a role in bone health, such as:

• Age, because bones lose density as we age
• Being postmenopausal
• Having a thin body frame
• Whether or not you exercise
• Ethnic background
• Family and personal medical history

To reduce the risk of metastatic breast cancer side effects to the bones, your care team may recommend medicines such as:

• Bisphosphonates such as zoledronic acid (Zometa) and pamidronate (Aredia), which can strengthen and protect the bones and treat bone pain, or both
• Targeted therapies such as denosumab (Xgeva), a type of medicine called a RANK ligand inhibitor; these medicines work to prevent bone-related problems in people with bone metastasis by treating bone pain and lowering the risk of breaks and fractures

These medicines protect the bones from the effects of the cancer itself, rather than the impact of treatment side effects on the bones.

There are also other ways to support bone health:

• Weight-bearing exercises, such as walking and low-impact aerobics, and strength training with light weights and resistance bands can help strengthen bones. Always consult with your care team before trying any exercise.
• Eating foods rich in vitamin D and calcium can also support bone strength. You care team can refer you to a dietitian and consult with you about whether supplements may be right for your situation.

To learn more, visit out page on Bone health.

Nausea and vomiting

Nausea and vomiting can result from some chemotherapy medicines. These side effects can also be caused by certain types of targeted therapy, immunotherapy, and aromatase inhibitors. Some pain medications and bisphosphonates (bone-strengthening medications) also can trigger nausea and vomiting.

If nausea and vomiting are known side effects of your treatment, your care team may prescribe an antinausea medicine. Some antinausea medicines can be given right before chemotherapy treatments as part of an infusion. Others can be taken as-needed in pill form.

It can be helpful to record any episodes of nausea and/or vomiting over time so that your care team knows how these side effects are impacting your daily life. Let your care team know what you’re experiencing, because frequent nausea and vomiting can keep you from getting the nutrition you need and can lead to dehydration. Other tips that may help include:

• Eating small amounts throughout the day or whenever you feel up to it
• Choosing plain foods such as toast, cereal, pasta, soups, and broths
• Avoiding rich, greasy, and strong-smelling foods
• Having someone else cook the family meals, if you're accustomed to doing it
• Taking slow sips of water, tea, ginger ale, and other clear liquids

To learn more, visit our Nausea and vomiting page

Neuropathy

Neuropathy is the medical term for pain or discomfort caused by damage to the body’s peripheral nervous system. The peripheral nervous system includes the nerves that control movement and sensations in the arms and legs. Chemotherapy is most commonly associated with neuropathy, but surgeries and radiation therapy for metastatic breast cancer can also sometimes cause this side effect, as well as certain targeted therapies.

Treatment-related neuropathy can vary from person to person, but symptoms often include numbness, pain, tingling, burning, or loss of feeling in the hands or feet. Your care team can help you understand if any treatment you’re taking is likely to cause neuropathy, and whether you have other contributing risk factors such as diabetes, autoimmune disease, or excessive alcohol use.

There are medicines that help relieve neuropathy, such as gabapentin (Neurontin) and pregabalin (Lyrica), steroids, numbing creams, and either over-the-counter or prescription pain medicines. It can also help to take good care of your hands and feet and keep floors clear of things that are easy to trip over. Some people benefit from physical therapy and gentle forms of exercise. If a specific treatment causes severe neuropathy, your care team can consider a change in dose or treatment schedule, or even switching to a new medicine entirely.

For more information and management strategies, visit our Neuropathy page

Menopausal symptoms

For women who are premenopausal or not quite all the way through menopause, some metastatic breast cancer treatments can cause menopausal symptoms. Chemotherapy can affect the ovaries, damaging eggs and disrupting the menstrual cycle. Other therapies that lower amounts of estrogen in the body — such as hormonal therapies (tamoxifen and aromatase inhibitors), ovary-suppressing medicines, and surgery to remove the ovaries — can also lead to menopausal symptoms. These may include:

• Vaginal dryness
• Loss of sexual desire, or libido
• Thinning bones and possibly bone pain
• Weight gain
• Hot flashes
• Depression and mood swings
• Changes in memory and thinking
• Fatigue
• Trouble sleeping

Depending on what you’re experiencing, there are many different ways to manage menopausal symptoms. Be open with your care team so they can recommend strategies that can help. Regular exercise, healthy eating, and resting when you need to are good starting points. There also medicines that can help with depression, mood changes, hot flashes, trouble sleeping, and bone loss. You can work with your care team to figure out options.

For more information, visit Menopausal symptoms.

Chemobrain

Chemobrain is the term used to describe changes in thinking and memory that affect some people during and after breast cancer treatment. Although everyone experiences it differently, people may have trouble concentrating on a task, remembering words or directions, doing several things at once, or recalling names, dates, or phone numbers.

Although this side effect is most closely associated with chemotherapy, some women who have other forms of treatment, such as hormonal therapies, also report experiencing chemobrain. Other contributing factors may be related to the experience of cancer itself, such as:

• Poor sleep
• Fatigue
• Chronic stress or chronic loneliness
• Under-treatment or over-treatment of pain
• Depression and anxiety
• Lack of exercise or activity
• Poor nutrition
• Side effects of medicines for other conditions, including some nausea and sleep medicines

Some people find that regular exercise, healthy eating, and getting professional help for stress and depression can improve the effects of chemobrain. Many people use handwritten lists or smartphone reminders as cues for remembering key tasks or information. Keeping spaces organized and learning to tackle one task at a time can also help with staying on track.

If chemobrain feels very intrusive, ask your doctor to refer you to a speech therapist or a neuropsychologist, a doctor with special training in the connections between the brain and behavior.

In some situations, your doctor may consider using certain medicines, such as methylphenidate (Ritalin) or modafinil (Provigil), to try to improve your concentration.

Sexual side effects

Being diagnosed and treated for metastatic breast cancer can affect people’s ability and desire to have sex or be intimate with a partner. The physical side effects of cancer treatments, including surgery, radiation therapy, chemotherapy, hormonal therapies, and targeted therapies, can make sex uncomfortable for some people. Treatments can also change the way you feel about your body. Medicines for pain, nausea, depression, diarrhea, and a range of other treatment side effects can interfere with sex drive and the sexual response. Stress and anxiety about a difficult diagnosis can also move sex to the bottom of anyone’s priority list.

Still, if and when you feel ready to be intimate with a partner, there is support available for you. Talk to your care team about any concerns you may have, and ask if there is a licensed, professional sexual health specialist, social worker, or counselor who can help. Your care team can refer you to professionals who can help with emotional issues, such as fear and anxiety, or concern about hair loss or surgical scars that can dampen sexual feelings and motivation.

Your gynecologist also may be able to help you address physical issues, such as vaginal dryness, pain, or fatigue.

Our Sex & intimacy page offers information about body image, self-care, treatments that can help with sexual function, and how to communicate effectively with intimate partners as well as your care team. Sexual side effects are common in metastatic breast cancer, but there is help available.

Other side effects

Here are some other side effects that can sometimes occur with treatment for metastatic breast cancer. On these pages, you can learn about management strategies and treatments that can help.

• Anemia
• Anxiety
• Depression
• Diarrhea
• Fear of breast cancer recurrence
• Fertility issues
• High cholesterol
• Lymphedema
• Secondary cancers
• Weight gain
• Weight loss