A trial looking at capecitabine and radium-223 for advanced breast cancer (CARBON)

This trial was for people with breast cancer that had spread to their bones. They were due to have chemotherapy.

The trial had 2 parts. 

In part 1 they looked for the safest dose of capecitabine and radium-223 to use. Everyone in this part had both capecitabine and radium-223.

In part 2 they looked at how well it worked as a treatment. People in this part were put into a treatment group at random. Some people had capecitabine and radium-223. And some people had capecitabine alone.

Results
A total of 34 people joined this trial:

• 23 people had capecitabine and radium-223
• 11 people had capecitabine alone

The research team found that no one in part 1 had any side effects that suggested the dose of treatment they were having was too high.

They looked at several factors to assess how well treatment was working. These included:

• the length of time before the cancer got worse
• any symptoms caused by cancer in the bones 
• levels of various proteins that show the growth and breakdown of bone cells

They found these were all similar in people who had radium-223 and capecitabine, and those who had capecitabine alone.

Side effects
Most people taking part had at least 1 side effect. Many of these were mild or didn’t last long. But some people in each group had a side effect that was more severe.

The number of people with side effects such as diarrhoea, nausea, a sore mouth or a drop in blood cells was similar in both groups.

We have more information about the side effects of capecitabine and internal radiotherapy in our Treatment for cancer section.

Conclusion
The research team concluded that having radium-223 as well as capecitabine was safe. They also concluded it wasn’t better than capecitabine alone for breast cancer that has spread to the bones. But all trial results help doctors and researchers understand more about different cancers and the best way to treat them. 

More detailed information
There is more information about this research in the reference below. 

Please note, this article is not in plain English. It has been written for health care professionals and researchers.

A phase IB and randomised phase IIA trial of CApecitabine plus
Radium-223 (Xofigo™) in breast cancer patients with BONe metastases:
CARBON trial results
M Winter and others
Journal of Bone Oncology, 2022. Volume 35, article 100442.

Where this information comes from
We have based this summary on the information in the article above. This has been reviewed by independent specialists (peer reviewed ) and published in a medical journal. We have not analysed the data ourselves. As far as we are aware, the link we list above is active and the article is free and available to view.