A trial of chemotherapy and bevacizumab before surgery for rectal cancer (BACCHUS)

The trial team said it was difficult to draw firm conclusions from these results as the trial had to close early. 

The team found that the treatments didn’t shrink the cancer as much as they hoped. But the side effects of treatment were manageable. 

Trial design
This was a phase 2 trial. The team had hoped to find about 60 people to take part. But only 20 people joined. This was because it was difficult to find enough people to join the trial.

They were put into 1 of 2 groups at random:

• 10 had fluorouracil (5FU), folinic acid and oxaliplatin (FOLFOX) and bevacizumab
• 10 had 5FU, folinic acid, oxaliplatin and irinotecan (FOLFOXIRI) and bevacizumab

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They had treatment once every 2 weeks for up to 12 weeks. 

17 people completed their treatment. And 18 went on to have their surgery as planned to remove their rectal cancer. They had surgery between 6 and 8 weeks after finishing treatment. 

Results
The researchers analysed the results of the people who took part. They looked at how well treatment had worked. To do this they examined the tissue removed during surgery to see whose cancer had gone away completely. A specialist doctor called a pathologist  did this analysis. 

They found that cancer had gone away completely in 2 people who had FOLFOXIRI and bevacizumab. But this didn’t happen to anyone who had FOLFOX and bevacizumab.  

At 2 years they looked at the number of people living. This is overall survival. 
They found this was:

• all of the people who had FOLFOXIRI and bevacizumab 
• most of the people (80%) who had FOLFOX and bevacizumab

They also looked at the number of people living whose cancer hadn’t started to grow again. This is progression free survival. They found this was:

• all of the people who had FOLFOXIRI and bevacizumab 
• more than half of the people (60%) who had FOLFOX and bevacizumab 

Side effects
This was a small trial.  A few people who had FOLFOX and bevacizumab had severe side effects. These included:

• heart problems
• tummy pain
• constipation or diarrhoea
• being sick
• an increased risk of infection
• kidney problems
• high blood pressure  

A few people who had FOLFOXIRI and bevacizumab had severe side effects. These included:

• a drop in the number of blood cells in the bone marrow
• tummy pain
• tiredness (fatigue)
• infection or an increased risk of infection 
• a drop in the level of salt in the blood
• high or low blood pressure

The team found that treatment didn’t increase the number of complications from surgery. Only 1 person developed a wound infection.

Conclusion
It was difficult to reach definite conclusions about treatment as the trial had to close early. This was because it was difficult to find enough people to take part. 

Despite this the researchers think that the combination of FOLFOXIRI and bevacizumab could be promising. They hope to test this combination of treatment in future trials. 

All trial results help doctors and researchers understand more about different cancers and the best way to treat them. 

Where this information comes from    
We have based this summary on information from the research team. The information they sent us has been reviewed by independent specialists (peer reviewed ) 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.