A trial looking at radiotherapy to prevent breast cancer spreading to the brain in women treated with traztuzumab (HER PCI)

Cancer type:

Breast cancer

Status:

Results

Phase:

Phase 3

This trial was trying to find out if radiotherapy to the brain can prevent breast cancer spreading to the brain (brain secondaries or metastases). It was for women who were due to have treatment with trastuzumab (Herceptin) for breast cancer that is locally advanced or had spread elsewhere in the body. This trial was supported by Cancer Research UK.

More about this trial

Doctors test breast cancer cells for certain receptors to help them decide which treatments their patients should have. Women whose breast cancer cells have a lot of HER2 protein are called HER2 positive breast cancers. Doctors can usually treat HER2 positive breast cancer with trastuzumab (also called Herceptin). Trastuzumab is a kind of a biological therapy called a monoclonal antibody. It seeks out cancer cells by looking for the HER2 proteins on the cells surface.

If breast cancer spreads, one of the places it can spread to is the brain. Women with HER2 positive breast cancer have an increased risk of this happening. Herceptin travels in the bloodstream so it can treat most of the body. But it cannot treat cancer that has spread to the brain because it cannot cross the blood brain barrier Open a glossary item .

In some cancers, radiotherapy to the brain is used to prevent cancer spreading to the brain. The use of radiotherapy in this way had not previously been looked at for women with HER2 positive disease. In this trial

About half the women had radiotherapy to the brain
The other half did not (this was the control group )
Everyone had treatment with trastuzumab.

The aims of the trial were to

Find out if radiotherapy to the brain reduced the number of women whose breast cancer spread to the brain
See if there was any difference in how long people lived in the 2 groups
Learn more about the side effects and how it affected quality of life

Summary of results

The trial team published the results of their research in 2015. They were not able to recruit enough women on to the trial and so the researchers could not draw any firm conclusions from the results.

The trial team hoped to recruit at least 390 patients over 4 years. Over 3 years, only 51 women had been recruited and so the trial team decided to stop recruitment and follow the patients that they had.

51 women had treatment with trastuzumab treatment and some women also had chemotherapy. It was a randomised trial.

25 women had radiotherapy to the brain
26 women did not have radiotherapy to the brain

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After 2 years the researchers found the following number of patients had developed brain secondaries that were causing symptoms

5 women who had radiotherapy to the brain
9 women who didn’t have brain radiotherapy

The following number of women had died

13 women who had radiotherapy to the brain
9 women who didn’t have radiotherapy to the brain

The researchers felt that the slightly larger number of deaths in the radiotherapy group was due to chance, or a combination of different reasons. Women in both groups died due to their breast cancer continuing to grow, not due to the treatments they had. They concluded that there would be no medical reason why radiotherapy to the brain would cause someone to die.

The side effects experienced by women who had radiotherapy to the brain included

Feeling or being sick
Tiredness (fatigue)

After 2 years, the researchers found that there was no difference between the 2 groups in terms of thinking and memory (cognitive function) and quality of life Open a glossary item .

We have based this summary on information from the research team. The information they sent us has been reviewed by independent specialists (peer reviewed Open a glossary item ) and published in a medical journal. The figures we quote above were provided by the trial team who did the research. We have not analysed the data ourselves.