A study looking at personalised treatment for early HER2 positive breast cancer (HER2-RADiCAL)

Cancer type:

Breast cancer





This study is looking at a personalised treatment plan. It is for people with HER2 Open a glossary item positive early breast cancer Open a glossary item

It is open to people who have:

  • had surgery to remove the cancer 
  • a low risk of their cancer coming back after surgery 

More about this trial

Doctors use a combination of chemotherapy and a targeted drug Open a glossary item to lower the risk of the cancer coming back. 

They usually start this treatment before surgery. This is to see how well this works for your cancer. So after surgery they can personalise your treatment. The aim is to not give you any more treatment than you need. 

One of the targeted drugs you might have if you have HER2 positive breast cancer is trastuzumab. This is a monoclonal antibody. It works by attaching to the HER2 receptor on the surface of the cancer cell. This stops the cancer from growing. 

In this study researchers are looking at continuing trastuzumab after surgery for a shorter time than the standard time. It is only for people who have a low risk of their cancer coming back.  

The aims of the study are to find out:

  • how safe it is to give less treatment 
  • how acceptable this is 

Who can enter

The following bullet points are a summary of the entry conditions for this study. Talk to your doctor or the study team if you are unsure about any of these. They will be able to advise you. 

Who can take part

You may be able to join this study if all of the following apply.

  • You have invasive breast cancer that is HER2 positive Open a glossary item.
  • You had chemotherapy with trastuzumab and pertuzumab before surgery. 
  • You had a scan before having chemotherapy that showed your cancer was 20mm or less in size. The scan showed cancer in 1 or more lymph nodes Open a glossary item in the lower or middle part of the armpit only. Or your cancer was between 21mm and 50mm in size and there is no cancer in any lymph nodes or there is cancer in 1 or more lymph nodes in the lower or middle part of the armpit. 
  • Your surgery has removed all of the cancer. 
  • A sample of tissue (biopsy Open a glossary item) taken before any treatment is available for the study team to access. 
  • You must be able to continue with trastuzumab after surgery.
  • You are willing to use reliable contraception during treatment and for a time after. This is if there is any chance you or your partner could become pregnant.
  • You are at least 16 years old.

Who can’t take part

You cannot join this study if any of these apply.

  • You have had invasive breast cancer before.
  • You have had surgery to remove the area of cancer in the breast (breast conserving surgery). And you are not planned to have radiotherapy to the breast for example you don't want radiotherapy.
  • There are signs that your cancer may have spread to another part of the body since your diagnosis. 
  • There is still some cancer left at surgery after having your chemotherapy. 
  • You plan to have more surgery to remove cancer for example surgery to remove the lymph nodes in the armpit. 
  • At diagnosis your cancer was stage 3 or stage 4.
  • Your sentinel lymph node Open a glossary item biopsy before having chemotherapy had cancer cells in it.
  • There is scarring in 4 or more lymph nodes in the armpit. 
  • You had more than 9 cycles of trastuzumab. 
  • You had chemotherapy after surgery. 
  • You have had another cancer in the last 5 years. This is apart from successfully treated non melanoma skin cancer Open a glossary item and abnormal cells on the surface of the cervix (CIN Open a glossary item). 
  • You had a heart attack, unstable chest pain (angina) or any other major heart problem Open a glossary item within the year before starting trastuzumab. 
  • You have in the past had inflammation of the lungs. 
  • You are not able to have trastuzumab. 
  • You are pregnant or breastfeeding.
  • You have any other medical condition or mental health problem that could affect you taking part. 

Trial design

The trial team need 720 people to join. 

You have trastuzumab for a total of 9 cycles of treatment Open a glossary item. This is about 6 months of treatment. This includes the cycles you had before surgery. For example if you had 3 cycles of trastuzumab before surgery you have another 6 cycles after surgery. 

You can have trastuzumab as a drip into a vein or an injection under the skin. You continue having it the same way as you did before. 

You can have other standard treatment. This includes radiotherapy, bisphosphonates or hormone therapy.  

During the study if your cancer comes back your doctor will talk to you about your treatment options. 

Research samples
The team ask for a piece of the tissue sample (biopsy) from before you started chemotherapy. As well as a piece of the tissue sample from surgery after you had chemotherapy. 

If your cancer comes back and you have a biopsy to confirm this the team will ask for a piece of this sample.  

Hospital visits

There are no extra hospital visits if you take part. 

Side effects

The study team monitor you during treatment and afterwards. Contact your advice line or tell your doctor or nurse if any side effects are bad or not getting better. 
We have information about the side effects of trastuzumab


Barrow in Furness
Kings Lynn
Weston Super Mare

Recruitment start:

Recruitment end:

How to join a clinical trial

Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Chief Investigator

Professor Iain Macpherson

Supported by

Institute of Cancer Research (ICR)
NIHR Health Technology Assessment (HTA) programme

If you have questions about the trial please contact our cancer information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:


Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Deborah wanted to help other breast cancer patients in the future

A picture of Deborah

“Deborah agreed to take part in a trial as she was keen to help other cancer patients in the future. "If taking part in a trial means others might be helped then I’m very happy with that."

Last reviewed:

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