About Secondary Breast Cancer

Secondary (metastatic) breast cancer is cancer that has started in the breast and spread to other parts of the body. This diagram shows common places where it may spread.

Click here for more information about sites of secondary breast cancer.


  1. What is secondary breast cancer?

  2. Signs and Symptoms 

  3. Diagnosis 

  4. Treatments 

  5. Living with secondary breast cancer

What is secondary breast cancer?

Secondary breast cancer can also be known as: 

  • metastatic breast cancer 

  • advanced breast cancer

  • stage 4 breast cancer

The breast cancer cells can spread to other parts of the body through the bloodstream or lymphatic system. This process of spread is called metastasis and involves the following steps:


  1. The cancer cells break away from the primary tumour site and invade the nearby normal tissue. 
  2. The cancer cells enter the blood or lymphatic system.  
  3. The cancer cells travel through the blood or lymphatic vessels until they reach the target site, such as the bones, lungs, liver, brain etc. 
  4. Once at the target site, the cancer cells leave the blood or lymphatic vessels and start to grow, forming secondary tumours.

Secondary breast cancer can be treated but it cannot be cured. Treatments aim to control and and slow the spread of the cancer for as long as possible, whilst giving the patient the highest quality of life.

Secondary breast cancer may be diagnosed years after primary breast cancer. Nearly 30% of women diagnosed with early-stage breast cancer will see their disease spread to other organs and develop secondary breast cancer. However, at first diagnosis some people can already have secondary breast cancer. This is classified as being diagnosed ‘de novo’.

recent research estimate from NHS England data estimates that the number of patients living with secondary breast cancer in England was over 57,000 in 2021. The findings of this study showed that estimates for the number of secondary breast cancer patients have increased steadily and risen from 38,350 patients in 2016-2017. 

These are estimates because cases of secondary breast cancer are not currently counted separately to primary breast cancer in the UK until death. Hopefully this will change as people living with secondary breast cancer are being counted for the first time, with national audits underway in England, Wales and Northern Ireland, with calls for Scotland to follow suit

Signs and symptoms

The signs and symptoms of secondary breast cancer will vary in each individual. Usually, the signs and symptoms will depend on where the cancer has spread to in the body. It is important that you consult a doctor or your local breast cancer clinic if you have any signs or symptoms that:

  • Are new or unusual for you

  • Do not go away

  • Do not have an obvious cause (e.g. a recent injury or illness)

    To find out more information about common signs and symptoms, visit the signs and symptoms page on our website.


How is secondary breast cancer diagnosed?

A secondary breast cancer diagnosis can have lots of medical terms that you might not be familiar with and can be difficult to understand at first.

The main way secondary breast cancer is diagnosed is via the use of imaging and/or biopsies. 

There are different subtypes of secondary breast cancer and understanding these classifications is important because they determine what treatment options will be available to you.

The main subtypes are based on the presence or absence of the hormone receptors (HR) oestrogen (ER) and progesterone (PR) and human epidermal growth factor receptor 2 (HER2). If none of these receptors are present your subtype would be known as Triple Negative breast cancer (TNBC).

For more information on how a secondary breast cancer diagnosis is made and to learn more about these different subtypes, visit this page


There are many different treatment options for secondary breast cancer. The aim is to relieve symptoms and control/slow down the spread of cancer for as long as possible. This will hopefully allow people with secondary breast cancer the best quality of life. Treatment lines are determined by the oncology team with consideration of: 

  • The type of breast cancer you have

  • How far it has spread and which part of the body it has spread to

  • What treatments you have had so far

  • How quickly your cancer is growing

  • Your general health

Treatment can include and can be a combination of:

  • Hormone therapy

  • Radiotherapy

  • Chemotherapy

  • Targeted biological therapies

For more information about types of treatment visit the treatments page.

Clinical trials may offer early access to new and improved treatments for secondary breast cancer. If you are interested to find out more about the options available through clinical trials, our dedicated team of nurses will be happy to support you.

See our Patient Trials Advocate Service and our clinical trials page for more information. 

Living with secondary breast cancer

Getting a secondary breast cancer diagnosis can be mentally and physically gruelling for patients and those closest to them. In this section we have gathered together some resources to support you. 

Having conversations with friends and family can be difficult. Here is a guide your loved ones may find helpful. 


Patient Stories

There are many people living with secondary breast cancer who have shared their stories. These can be found on our Truth Be Told Page and the SBC and Me page. By reading about other people's stories, you may find similarities between other people's experiences and yours, this may put you at ease or grow a sense of community around you.

Life Expectancy

Life expectancy is difficult to predict as there are so many factors which can affect it. It can be dependent on subtype, how far the cancer has spread and the location(s) of spread.

However, with more research into new treatments, more people are living longer with a secondary breast cancer diagnosis. 

Some people find it helpful to talk to their clinician for individual information about life expectancy. However, some prefer to not look at statistics or not to know. 

It is important to know that there is no right way to live with secondary breast cancer and it’s ok to make your own path. 

Support Available and Where to Find It
Make 2nds Count offers online support groups, virtual meet ups and classes: see the 2nds Together Facebook Group and Wellbeing Classes to find out more.

Our Tea & A Chat service offers a safe space for patients to meet and get peer to peer support in times of uncertainty. We also have a collection of online resources which may be helpful. To find groups and services available in your local area visit the 2nds Support Hub.