Metastatic breast cancer to the brain is breast cancer that spreads outside of the breast tissue to the brain. Doctors may refer to it as secondary breast cancer in the brain or brain metastases.

Once cancer spreads to the brain, a person’s life expectancy reduces considerably. But treatment can prolong a person’s life, as well as improve their quality of life while living with cancer.

Although metastatic breast cancer in the brain currently has no cure, treatment can help to control the cancer and help people live longer after diagnosis.

In this article, we look at the outlook and life expectancy for people with metastatic breast cancer to the brain, as well as at managing symptoms and finding support.

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Metastatic breast cancer is breast cancer that spreads outside of the breast tissue. About 10–30% of people diagnosed with breast cancer will develop metastatic breast cancer to the brain.

Metastatic breast cancer to the brain is a type of stage four cancer. Doctors refer to breast cancer that has spread to parts of the body away from the breasts as distant cancer.

According to the American Cancer Society, people with cancer that has metastasized to distant locations, including but not limited to the brain, have a 5-year survival rate of 28%.

Breast cancer has relatively high survival rates, but the survival rate once breast cancer metastasizes to the brain is lower.

In most cases, it is possible to treat but not cure this type of breast cancer. Average survival rates without treatment range from 227 months.

A person’s chances of survival, as well as the length of time they may survive, depend on several factors:

  • the type of breast cancer a person has
  • how well cancer responds to treatment
  • whether it is possible to operate on the cancer
  • overall health and age

According to a 2018 study, triple-negative breast cancer has the lowest overall survival rate, as well as a high rate of spread to the brain.

People with the BRCA1 gene mutation that increases the risk of breast cancer are more likely to develop this type of cancer.

According to the 2018 study, overall survival rates were 41% at one year and 22% at 2 years.

Survival rates also depend on treatment. Even when cancer is not curable, treatment can prolong a person’s life.

Doctors may use the graded prognostic assessment to estimate how long a person might survive. This figure takes into account age, overall health, and the subtype of breast cancer a person has.

The lower the score, the shorter the estimated survival. Scores of 0 to 1 suggest survival of about 3 months, and scores of 3.5 to 4 predict a median survival of about 25 months.

Breast cancer metastasizes when it travels to the lymph fluid or the bloodstream, allowing it to spread to other organs.

While any type of breast cancer can metastasize if left untreated long enough, certain risk factors make metastasis more likely:

Type of cancer

Triple-negative and HER2-positive breast cancers are more likely to metastasize to the brain.

Time of diagnosis

A 2017 study using the SEER database of the National Cancer Institute found that 0.41% of people with aggressive breast cancer had cancer in the brain at the time of diagnosis.

This suggests that the cancer spreads to the brain over time, so delayed diagnosis might increase the risk of finding cancer in the brain.

How aggressive the cancer is

Faster growing cancers may be more likely to travel outside of the breasts.

A doctor may suspect a person has breast cancer in the brain based on symptoms or because a person has a very aggressive breast cancer.

While not all people with breast cancer to the brain have symptoms, some experience neurological issues such as:

  • seizure
  • headache
  • trouble concentrating or thinking clearly
  • memory issues
  • trouble seeing or hearing

Breast cancer that has spread to the brain is not usually curable. Treatment for metastatic breast cancer focuses on controlling the cancer while maintaining the best quality of life possible.

This means that a person has to weigh the benefits of treatment, which aims to prolong life, against the risks, which may include unpleasant side effects and a lower quality of life.

Some treatment options include:

  • Chemotherapy: Chemotherapy targets cancer cells. A person may get chemotherapy treatment in a hospital or take certain chemotherapy drugs.
  • Targeted therapy: Targeted therapies aim to shrink tumors by targeting receptors on the tumor, especially hormone receptors.
  • Surgery: Surgery may remove or reduce the size of a tumor, prolonging a person’s life or reducing the severity of their symptoms.
  • Whole-brain radiation: Whole-brain radiation uses radiation to shrink cancer cells, but it can also damage healthy cells.

Treatment may also include strategies to support a person living with cancer. This may include:

  • therapy
  • counseling about the disease
  • education about end-of-life care options
  • support groups

At the end of a person’s life, some people find that hospice or palliative care relieves some pain and gives them a sense of control over their treatment.

Metastatic cancer in the brain can cause a range of symptoms, including neurological issues.

Treatment can also cause unpleasant symptoms such as nausea, vomiting, hair loss, or feeling sick. Some options for managing symptoms include:

Medication

Doctors may be able to prescribe medications to help with cancer-related pain and to ease symptoms related to treatment, such as nausea. People can also ask their doctor about dietary changes that may help with nausea.

Social support

Support groups and education about metastatic breast cancer may help a person better understand their options and advocate for themselves.

Therapy

Some people may find a cancer diagnosis overwhelming. A therapist can help a person confront their concerns, identify their needs, and plan for the future.

Lifestyle changes

Some people find relief from lifestyle changes. Exercise may help, as can a modified work schedule or accommodations at work or school.

Every person’s needs are different. Some people may find their diagnosis daunting or have concerns about the daily realities of living with breast cancer.

The right support can help a person better understand their own needs, advocate for themselves, and live as well as possible. Options for support can include:

  • Find a support group: People can ask their doctor for a referral to a patient support group. Some hospitals also have support groups.
  • Consider finding support online: Virtual support groups can offer help without the need to travel to another location or rely on a provider to give a referral.
  • Meet with a lawyer to discuss end-of-life needs: Regardless of a person’s financial situation, making a will can help protect their wishes. A living will helps to identify their needs and desires for end-of-life care.
  • Talk with loved ones about end-of-life considerations: Consider whether a person wants to prioritize comfort or aggressive treatment, time at home or in hospital, and how a person feels about hospice care.

Talking with loved ones can empower them to make decisions on behalf of the person living with cancer if necessary.

Breast cancer that metastasizes is not usually curable, but treatments can help to prolong and improve quality of life.

People may find it easier to gather information about their condition gradually, rather than trying to plan for everything at once.

With the right care, a person can live longer and more comfortably. People may find it helpful to have a support group to talk with.

People can also discuss any concerns, including about comfort and quality of life, with healthcare professionals.