What happens when breast cancer metastasizes in the lungs?

metastatic breast cancer in lungs

By Jamie Eske    

by Yamini Ranchod, PhD, MS

About | Symotoms | Causes | Diagnosis | Reducing the
risk | Treatment | options | Complications | Prognosis

Metastatic breast cancer in the lungs refers
to cancer that originally developed inside the breast tissue but has spread to
the lungs.
Breast cancer can spread to various parts of
the body. This is called metastasis. The most common sites for breast cancer
metastases include the bones, brain, lungs, and liver.
This article will discuss metastatic breast
cancer in the lungs, including its symptoms, diagnosis, treatment options, and
outlook or prognosis.

What is metastatic breast cancer in the

Metastatic is a term that refers to cancer
that has spread outside of the original area to a different place in the body.
Metastatic breast cancer in the lungs refers to cancer that originally
developed inside the breast tissue but has spread to the lungs.
Breast cancer is the most common form of
cancer among women. Around 6–10 percent of initial breast cancers that a doctor
diagnoses are metastatic. This number does not include breast cancers that
progress to stage 4 after the initial diagnosis. Typically, oncologists call
metastatic breast cancer stage 4 breast cancer.
Some of these metastatic breast cancer cells
may affect the lungs. It is essential that an oncologist confirms that the
tumor in the lungs is secondary, meaning that it contains breast cancer cells.
If there are no breast cancer cells present, the tumor could be a newly
developed primary cancer.


People may not experience symptoms of
metastatic breast cancer in the lungs immediately. If symptoms do appear, they
can resemble those of a cold or flu.
Symptoms of metastatic breast cancer in the
lungs include:

  • a constant cough
  • pain in the lung
  • difficulty breathing or shortness of breath
  • wheezing
  • fatigue
  • recurring infections in the chest
  • coughing up blood
  • loss of appetite
  • unintentional weight loss


As the cancer cells divide and multiply, the
primary tumor grows larger. As the primary tumor grows, cancer cells can break
off from the primary tumor. These rogue cancer cells can then enter the
bloodstream or the lymph system. From there, the cancer cells can travel to
distant areas of the body.
In some cases, small amounts of breast cancer
cells can survive initial treatment and remain inactive in the body for some
time before growing again in primary site or spreading to another area of the
body. Doctors call this recurrent, or recurring, breast cancer.
Breast cancer cells must undergo significant
changes to survive and grow in the lungs. These cells must also change to
withstand attacks from the body’s immune system. The treatment options for the
newly formed cancer will depend on how it has altered during metastasis.
It is not unusual for cancer to metastasize
to multiple sites at once.


Diagnosing metastatic breast cancer in the
lungs begins with a physical examination and blood tests.
If a health care provider suspects lung
metastasis, they will likely order an imaging test, such as:

  • chest X-ray
  • CT scan
  • PET scan
If a doctor does find a tumor in the lung,
their next task involves confirming that the tumor is metastatic breast cancer
and not primary lung cancer. This is especially important for people who have
smoked or currently smoke.
Other diagnostic procedures that can help
confirm a metastatic breast cancer diagnosis include:

  • testing a mucus sample
  • bronchoscopy, where a doctor inserts a
    flexible camera thread through the nose and into the lungs to examine the
    respiratory structures
  • needle biopsy of the lung, where a doctor
    removes a sample of lung tissue for further testing
How to reduce the risk of metastasis

After someone has received initial treatment,
breast cancer can lay dormant in the body before spreading to other areas.
People who have received treatment in the past should monitor themselves for
any signs or symptoms that could indicate cancer recurrence.
While there is no single way to avoid
developing metastatic breast cancer entirely, there are some lifestyle changes
that can help reduce a person’s risk.
People may reduce the risk of metastases with
the following factors:

  • having regular health screenings
  • having regular breast cancer screenings
  • eating a balanced diet
  • exercising regularly
  • not smoking or quitting smoking
  • avoiding excessive alcohol intake
  • maintaining a healthy body weight
  • monitoring vitamin D levels
  • reducing stress

Treatment options for metastatic breast
cancer in the lungs

Doctors consider metastatic breast cancer to
be a stage 4 cancer. It is not curable, and treatments focus on weakening the
cancer to stop it from growing while working to improve the quality of life for
the individual.
Treatments for metastatic breast cancer in
the lungs usually involve systemic, or body-wide, medications that treat cancer
throughout the body, such as the following:

Chemotherapy. Chemotherapy is a drug therapy
that destroys all fast-growing cells in the body, both cancerous and healthy.
Hormonal therapy. Hormonal therapy is a
cancer treatment that controls cancer cell growth by lowering the levels of
certain hormones the cancer needs to grow. Hormone receptor-positive breast
cancers respond well to this treatment.
Targeted therapy. This form of cancer
treatment attempts to treat cancer with more precision than chemotherapy. These
treatments target specific receptors, proteins, or molecules on cancer cells
that either make it easier for the body’s immune system to identify and destroy
cancerous cells or reduce their growth.
Radiation. In the case of metastatic breast
cancer, doctors often use radiation therapy to reduce symptoms and control the
cancer’s growth. Radiation therapy can help reduce pain and lower the risk of
broken bones weakened due to cancer.


Metastatic breast cancer in the lungs can
cause other health complications that impact a person’s overall health and

Fluid in the chest

Breast cancer cells can form in the region
between the outside of the lungs and the chest wall, also known as the pleural
space. This can cause a build-up of excess fluid, a condition known as a
malignant pleural effusion.
Malignant pleural effusions can worsen some
of the symptoms of cancer in the lungs, including:

  • a worsening cough
  • shortness of breath or wheezing
  • pain in the chest
Doctors treat malignant pleural effusions by
either draining the excess fluid or by carrying out a procedure known as
pleurodesis. This involves closing the space between the lungs and the chest
wall, which prevents fluid from building up between the two linings.

Toxicity due to treatment

Cancer treatments can cause significant side
effects that impact a person’s overall health and quality of life. Chemotherapy
and other systemic cancer treatments can cause a wide range of symptoms, such

  • a lowered immune system function
  • infection
  • fatigue
  • loss of appetite
  • nausea
  • vomiting
  • constipation
Psychological impact

Receiving a diagnosis of stage 4 cancer can
leave lasting psychological impacts. People can experience depression, anxiety,
and stress as a result of their condition.
People who are struggling with negative
psychological symptoms might want to consider joining a support group or
seeking professional counseling to help them cope with their situation.
Reaching out to friends or loved ones can make a significant difference.


Metastatic breast cancer is the most advanced
form. Metastatic breast cancer is not curable, so treatment options focus on
weakening the tumor and preventing further growth. While some may view this as
a less aggressive approach, controlling the cancer is still a positive outcome.
According to the World Health Organization,
breast cancer affects an estimated 2.1 million women each year and accounted
for 15 percent of all cancer deaths among women in 2018.
Experts calculate cancer prognoses using a
5-year survival rate, which is the percentage of people who survive for at
least 5 years after diagnosis. These are estimates, and actual survival varies
depending on a person’s characteristics.
The 5-year survival rates for women with
breast cancer depends on the stage:

  • stage 0 and 1 is close to 100 percent
  • stage 2, about 93 percent
  • stage 3, about 72 percent, and treatment is
    often successful
  • stage 4, or metastatic breast cancer, about
    22 percent
These statistics do not predict what will
happen for any individual, and there are many treatment options for people with
metastatic breast cancer.
The long-term outlook for people who have
metastatic breast cancer in the lungs depends on many variables. These include:

  • age
  • overall health status
  • how the tumor responds to treatment
  • the size of the primary and secondary tumors
  • whether or not the primary cancer has
    metastasized to multiple sites within the body

Kayode Ojo
Kayode Emmanuel Ojo is the Co-Founder and Managing Director at SHEFFA Limited. He is presently studying Computer Science at the National Open University, Victoria Island, Lagos.