The difference between

Primary and secondary
breast cancer

Most cancers start in one place. The place where a cancer starts is called the primary site. For example, if you have cancer that started in the breast, you have primary breast cancer.

Cancers can spread around the body if left untreated, and in some cases, even if the patient is currently receiving a cancer treatment. This can occur in a number of ways, like when the cancer cells get into the lymphatic system and reaches the lymph nodes.

When the cancer has spread to a new location, this location is known as the secondary site. For example, if your breast cancer has spread to the lungs, you have secondary site is the lung and you have secondary breast cancer.1

The most common places primary cancer can spread to are:2

The bones, lungs, liver, skin and brain.

Catching a diagnosis early

You could improve your quality of life with early treatment

You understand your body better than anybody else, which means healthcare professionals will only know something is wrong if you let them know. This means that if you feel any difference or worsening of any symptoms, it is important that you let your doctor or nurse know as soon as you notice any change.

Read on to find out more about symptoms of secondary breast cancer in various parts of the body.

Woman consulting doctor
Doctor with iPad
What to look out for

Symptoms of SBC

These are dependent on where the cancer has spread. There are some general symptoms, which may differ from person to person and can include:3

  • feeling more tired than usual
  • loss of appetite
  • feeling generally unwell for no obvious reason

These symptoms can be also associated with a wide range of other conditions, so if you experience any of them you should let your healthcare professional know. You should always let them know if you develop any new symptoms, especially if they last more than 1 or 2 weeks.

Red flag symptoms

Take a moment to learn about the symptoms you might experience if the cancer has spread to another area in your body. If you experience these symptoms, you should contact your cancer specialist as soon as possible.


The most common symptom of secondary breast cancer in the bones is an ongoing ache in the affected bone/bones. If you are experiencing pain when you move around, or you are having difficulty sleeping because of the pain, this could be due to the cancer having spread to the bones.4

Too much calcium

If the cancer has spread to a bone, it can cause damage. If this happens, the bone can release calcium into the bloodstream. A high level of calcium in the blood is known as hypercalcaemia which can cause the following symptoms:4

  • Feeling tired, nauseous, dehydrated and/or weak
  • Passing more urine than usual
  • Constipation
  • Feeling confused

A healthcare professional can detect elevated levels of calcium in the bloodstream with a blood test before any symptoms develop.

A break in the bone

If the bone is damaged by cancer over time, it could become weaker and eventually lead to a break or a fracture. In most cases treatment will begin before the bone weakens enough to break.4

Pressure on the spinal cord

Cancer that has spread to the bones of the spine can cause pressure on the spinal cord. This is known as spinal cord compression. The symptoms can include:4

  • Unexplained pain in the back, around the chest and neck areas or down the arms and legs
  • Numbness or pins and needles in toes, fingers or buttocks
  • Unsteadiness or difficulty walking
  • Problems controlling your bladder or bowel.


Spread of breast cancer to the lung(s) (lung metastasis) can be symptomless. However, symptoms can include discomfort in the lung, shortness of breath, coughing up blood and a persistent cough. Other signs include:4,5

  • Pleural effusion – build-up of excess fluid between the layers of tissue outside the lungs, which cause pain on breathing, cough, or shortness of breath
  • Wheezing – whistling or rattling sound in the chest
  • Pain in the lung


If the cancer has spread to the liver, it is likely that you will feel some pain or discomfort around the area of the liver. The liver sits under the lower ribs on the right side of the abdomen. Other symptoms can include:4,6

  • General feelings of unwellness
  • Loss of appetite
  • Fatigue
  • Bloating
  • Jaundice

Secondary breast cancer in the liver can cause a build-up of bile in the blood. This is known as jaundice. Symptoms of jaundice can include yellowing of the skin and the whites of the eyes, and itchy skin.

Sometimes liver metastasis might be found incidentally via abnormal LFTs and the patients could be completely asymptomatic.


Secondary breast cancers can sometimes spread to the skin. Known as skin secondaries or metastases, it can develop on or just below the skin. This can happen to women who already have secondary breast cancer.

Possible symptoms of secondary cancer that has spread to the skin include:4

  • A firm painless lump on the skin
  • Many lumps of different size on the skin
  • Inflamed skin (areas of redness, swelling, or irritation)
  • Bleeding, pain or infections

Skin secondaries can appear near the area of the primary cancer, for example on the skin around a scar or around the chest. They have also been known to develop on the scalp, neck, back and upper limbs.

A variety of treatments can be used to treat skin secondaries.


The symptoms experienced with brain metastasis may be dependent on which part of the brain the cancer has spread to. The symptoms can include:4,7

  • Weakness in the muscles, numbness and feeling unsteady (ataxia)
  • Seizures or fits
  • Mood and personality changes
  • Sensory changes
  • Memory problems

The meninges

Sometimes, breast cancer cells spread to tissue that covers the brain and spinal cord (meninges). Doctors call this meningeal metastases or carcinomatous meningitis. It causes symptoms similar to a secondary cancer in the brain.4


  1. Northern Ireland Cancer Network. What is the difference between primary and secondary cancer? Available online at: [Last accessed: September 2021]
  2. Macmillan Cancer Support. Secondary Breast Cancer. Available online at: [Last accessed: September 2021]
  3. Macmillan Cancer Support. Symptoms of Secondary Breast Cancer. Available online at: [Last accessed: September 2021]
  4. Macmillan Cancer Support. Understanding secondary breast cancer. Available online at: [Last accessed: September 2021]
  5. Breast Cancer. Lung metastasis: Symptoms and Diagnosis. Available online at: [Last accessed: September 2021]
  6. Breast Cancer. Liver metastasis: Symptoms and Diagnosis. Available online at: [Last accessed: September 2021]
  7. Breast Cancer. Brain metastasis: Symptoms and Diagnosis. Available online at: [Last accessed: September 2021]

UK | SEPTEMBER 2021 | 124190

You know you best

Make your next appointment count

Your healthcare team is your best resource throughout your treatment. Talk openly and often with them about your doubts, questions and concerns. It might make you feel more in control if you take some time to plan for your appointment. Making notes before, during and after can help you retain information and make the most of your visits. We have developed a guide to support you in having these conversations with some tips to help you get the information you need.

Download your Moments That Count appointment guide

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If you get side effects with any medication you are taking, talk to your doctor, pharmacist or nurse.This includes any possible side effects not listed in the information leaflet that comes in the pack. You can report side effects via the Yellow Card Scheme at (UK). By reporting side effects, you can help provide more information on the safety of your medication.

The Moments That Count campaign has been developed and funded by Novartis Pharmaceuticals UK Limited, with insights from breast cancer patients.

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