Metastatic breast cancer, also known as stage IV breast cancer, is an advanced form of the disease in which cancer has spread beyond the breast to distant organs such as the bones, liver, lungs, or brain. Unlike early-stage breast cancer, metastatic breast cancer is not considered curable, but advancements in treatment have allowed many patients to live longer and maintain a good quality of life.

Living with metastatic breast cancer comes with physical, emotional, and psychological challenges. However, with the right treatment plan, support system, and mindset, patients can find ways to navigate their journey with hope.

Understanding Metastatic Breast Cancer

Metastatic breast cancer is a condition where cancer cells break away from the original tumour in the breast and travel to other parts of the body through the bloodstream or lymphatic system. The most common sites of metastasis include:

• Bones – The spine, ribs, pelvis, and long bones
• Liver – Causing liver dysfunction and jaundice
• Lungs – Leading to breathing difficulties
• Brain – Affecting cognitive functions and coordination

While this is an advanced stage of breast cancer, it is important to know that many treatments can help manage the disease, slow its progression, and improve overall well-being.

What Are the First Signs of Metastatic Breast Cancer?

Metastatic cancer symptoms vary depending on where the cancer has spread in the body. The most common early signs depend on the affected organs.

1. Bone Metastasis (Most Common Site of Spread)

When breast cancer spreads to the bones, it can cause:

• Persistent, unexplained bone pain (often in the back, hips, or ribs)
• Increased risk of fractures (bones become weak and may break easily)
• Swelling or tenderness in certain areas
• Spinal cord compression (if cancer affects the spine, leading to numbness or difficulty walking)

2. Liver Metastasis

If cancer spreads to the liver, early signs may include:

• Unexplained weight loss and loss of appetite
• Abdominal pain or swelling (ascites)
• Jaundice (yellowing of the skin and eyes due to liver dysfunction)
• Fatigue and nausea

3. Lung Metastasis

Cancer in the lungs may not cause symptoms immediately, but as it progresses, you may experience:

• Chronic cough or wheezing
• Shortness of breath (dyspnea)
• Chest pain
• Frequent lung infections, such as pneumonia

4. Brain Metastasis

Breast cancer that spreads to the brain may present with neurological symptoms, including:

• Persistent headaches (often worsening over time)
• Dizziness or balance problems
• Vision disturbances (blurry vision, double vision)
• Seizures
• Memory loss or confusion

5. General Symptoms of Metastatic Breast Cancer

Some people with metastatic breast cancer experience more generalised symptoms, such as:

• Extreme fatigue that does not improve with rest
• Frequent infections due to a weakened immune system
• Unexplained weight loss
• Swelling in the arms or legs (lymphedema)

Diagnosis of Metastatic Breast Cancer: Step-by-Step Guide

Metastatic breast cancer is diagnosed through a combination of imaging tests, biopsies, and lab work to determine the extent to which the cancer has spread. Let’s take a look at the diagnostic process:

1. Clinical Evaluation & Medical History

Doctors assess symptoms such as persistent bone pain, shortness of breath, or unexplained weight loss. A detailed medical history is taken, including previous breast cancer diagnosis, treatments, and family history.

2. Imaging Tests to Detect Metastases

Various imaging scans help locate the spread of cancer to different organs:

a) PET-CT Scan (Positron Emission Tomography-Computed Tomography)

• CT and PET scans are combined to detect cancer by using a radioactive glucose tracer to highlight fast-growing cancer cells in the body.

b) CT Scan (Computed Tomography)

• This technology gives clear pictures of organs such as the lungs, liver, and brain, and is commonly used to track how tumours change and grow over time.

c) Bone Scan

• This method uses a radioactive tracer to find bone metastases in places where there is high uptake of the tracer, which may indicate bone cell activity and potential bone involvement.

d) MRI (Magnetic Resonance Imaging)

• This imaging technique is great for finding brain metastases and spinal cord involvement, as well as for producing detailed images of soft tissues.

e) X-rays

• This test is used to check for bone or lung metastases and identify fractures caused by bone metastasis.

3. Biopsy & Pathology Tests

To confirm metastasis, doctors take a sample of the suspected tumour.

a) Tissue Biopsy

• A needle biopsy is done on potential areas where the cancer might have spread to determine the type of cancer, hormone receptor status, and HER2 status. It also checks if the cancer has changed since the original diagnosis.

b) Liquid Biopsy (Circulating Tumour DNA Test)

• This technology can find cancer DNA in the blood and monitor changes in the DNA to see if the cancer is becoming resistant to treatment.

4. Blood Tests & Tumour Markers

Blood work helps assess overall health and cancer progression.

a) Tumour Marker Tests

• CA 15-3 and CA 27-29 levels are often high in some cases of metastatic breast cancer. CEA (Carcinoembryonic Antigen) levels may also be elevated in advanced cancer.

b) Liver & Kidney Function Tests

• Monitors organ function before starting treatments such as chemotherapy.

c) Complete Blood Count (CBC)

• Check for low red blood cells (anaemia) or low white blood cells (infection risk).

5. Genetic & Molecular Testing

Some metastatic breast cancer cases require genetic profiling for targeted treatments.

• BRCA1 & BRCA2 Testing: Determines if PARP inhibitors may be effective.
• PIK3CA Mutation Testing: Helps decide if PI3K inhibitors like Alpelisib (Piqray) can be used.
• PD-L1 Testing: Determines eligibility for immunotherapy in triple-negative MBC.

6. Staging & Treatment Planning

After completing all tests, the oncologist will determine the extent to which the cancer has spread and customise a treatment plan based on the type of tumour (HR+, HER2+, TNBC), where it has spread (bones, liver, lungs, brain), genetic mutations, and the patient’s overall health.

Treatment Options for Metastatic Breast Cancer

Treatment options depend on the type of cancer, HR and HER2 status, location of metastases, previous treatments, and overall health.

1. Hormone Therapy (For HR-Positive Breast Cancer)

Hormone receptor-positive (HR+) cancer relies on oestrogen or progesterone to grow. Drugs such as Tamoxifen, Aromatase Inhibitors, Fulvestrant, and Ovarian Suppression can block or lower hormone levels, slowing cancer growth by blocking oestrogen from binding to cancer cells or destroying oestrogen receptors. Hormone therapy can slow cancer progression for months or years in patients with HR+ metastatic cancer

2. Targeted Therapy (For HER2-Positive and HR+ MBC)

Targeted therapy drugs block specific proteins or pathways that help cancer cells grow. For HER2-positive cancer, drugs such as Trastuzumab and Pertuzumab target the HER2 protein. For HR-positive, and HER2-negative cancer, drugs such as CDK4/6 inhibitors can help block cancer cell division. Targeted therapy is often used in combination with other treatments for metastatic cancer.

3. Chemotherapy (For Advanced and Triple-Negative Breast Cancer)

Chemotherapy is a standard treatment for metastatic cancer that is resistant to hormones or targeted therapies. It kills fast-growing cancer cells and is given in cycles to allow the body to recover. Common drugs used for metastatic cancer include Capecitabine, Paclitaxel, Doxorubicin, Eribulin, Carboplatin, and Cisplatin, and it is frequently used for triple-negative or hormone-resistant cancers.

4. Immunotherapy (For Triple-Negative Metastatic Breast Cancer)

Immunotherapy boosts the immune system to attack cancer cells, particularly effective for triple-negative cancer lacking hormone and HER2 receptors. Atezolizumab and pembrolizumab are FDA-approved immunotherapy drugs used with chemotherapy for PD-L1-positive TNBC patients. They are commonly used for those with metastatic TNBC who test positive for the PD-L1 protein.

5. Radiation Therapy (For Symptom Control and Pain Relief)

Radiation therapy is used in metastatic cancer to help ease symptoms such as bone pain, breathing difficulties, and neurological symptoms. It is not a cure for the disease but can effectively manage pain and improve the quality of life for patients.

6. Surgery

Surgery for metastatic cancer is not common, but it can be helpful in certain situations such as removing isolated tumours, preventing complications such as bleeding or infections, and relieving pain from bone metastases. It is typically only considered when the cancer is limited to a few areas or when it improves comfort for the patient.

7. Clinical Trials (Exploring New Treatments)

Clinical trials offer access to new, experimental treatments such as PARP inhibitors, immunotherapies, and antibody-drug conjugates for specific cancers. They are especially useful for patients who have exhausted standard treatment options or want to try innovative therapies.

8. Palliative Care (For Comfort and Quality of Life)

Palliative care provides support for managing symptoms, and improving comfort, and emotional well-being for those living with cancer. It can be used alongside active treatment or in later stages for comfort care. Patients receive help with pain, nausea, fatigue, counselling, and end-of-life options like hospice care, benefiting anyone with metastatic cancer.

Coping with Metastatic Breast Cancer

A metastatic breast cancer diagnosis can be overwhelming and bring in a mix of emotions such as fear, sadness, anxiety, and anger. Taking care of your mental health is just as important as physical treatment. Connecting with support groups, obtaining therapy, and talking openly with loved ones are important ways for individuals facing metastatic breast cancer to find comfort, develop coping strategies, and build a strong support network.

Practising mindfulness and meditation, engaging in creative activities, and limiting exposure to negative information can help reduce anxiety and help express emotions in a healthy manner while dealing with cancer.

Living with this condition often involves grieving for the future you had planned. Acknowledging these feelings and focusing on what you can control, such as daily self-care, relationships, and meaningful experiences, can help find peace.

Living Well with Metastatic Breast Cancer

Even with a metastatic breast cancer diagnosis, many people find ways to live fulfilling lives by focusing on their well-being. Focus on these aspects:

1. Nutrition and Diet: Eat a balanced diet rich in whole foods such as fruits, vegetables, lean protein, and whole grains to manage side effects, boost energy, and maintain good health. Stay hydrated to reduce fatigue and improve digestion. Consult a nutritionist for personalised dietary advice.

2. Physical Activity: Exercise has many benefits such as improving energy levels, reducing stress, and strengthening muscles weakened by treatment. Gentle activities such as walking, stretching, or yoga can be beneficial. It is important to listen to your body and avoid overexertion while exercising.

3. Managing Treatment Side Effects: Common side effects of metastatic breast cancer treatment include fatigue, nausea, hair loss, and pain. To manage fatigue, prioritise rest and seek help when needed. Nausea can be alleviated with small, frequent meals and anti-nausea medication. Pain management options include medications, acupuncture, and massage therapy.

4. Maintaining Relationships: Cancer affects not just the individual but also their family and friends. Open conversations about needs, fears, and hopes can strengthen relationships and provide emotional support.

5. Planning for the Future: People with metastatic breast cancer find comfort in making plans for the future by organising personal and financial affairs, documenting healthcare wishes, and creating special moments with loved ones.

Sources:

• https://my.clevelandclinic.org/health/diseases/21497-metastatic-breast-cancer
• https://www.breastcancer.org/types/metastatic
• https://www.nationalbreastcancer.org/metastatic-breast-cancer/
• https://www.hopkinsmedicine.org/health/conditions-and-diseases/breast-cancer/metastatic-breast-cancer
• https://www.cancer.org/cancer/types/breast-cancer/treatment/treatment-of-breast-cancer-by-stage/treatment-of-stage-iv-advanced-breast-cancer.html
• https://www.komen.org/breast-cancer/facts-statistics/what-is-breast-cancer/metastatic-breast-cancer/
• https://www.healthline.com/health/breast-cancer/metastatic-prognosis#5-year-survival
• https://nbcf.org.au/about-breast-cancer/diagnosis/stage-4-advanced-or-metastatic-breast-cancer/
• https://www.mayoclinic.org/diseases-conditions/breast-cancer/diagnosis-treatment/drc-20352475
• https://www.cancercenter.com/cancer-types/breast-cancer/types/rare-breast-cancer-types/metastatic-breast-cancer