A trial looking at using irinotecan beads for bowel cancer that had spread to the liver (PARAGON II)

Cancer type:

Bowel (colorectal) cancer

Colon cancer

Rectal cancer

Secondary cancers

Status:

Results

Phase:

Phase 2

This trial looked at using irinotecan beads to treat bowel cancer that had spread to the liver, before having surgery to remove it.

More about this trial

Chemotherapy is one of the usual treatments for bowel cancer that has spread to the liver. The aim of the chemotherapy is to shrink the tumours in the liver as much as possible before surgery. One of the common chemotherapy drugs is called irinotecan.

But chemotherapy that reaches the whole body (systemic treatment) Open a glossary item can cause side effects. Researchers are looking at ways to reduce these side effects. In this trial, they looked at irinotecan beads.

Irinotecan beads are very small beads with irinotecan attached to them. The doctor injects these beads into the blood vessels around the cancer in the liver. The treatment combines giving irinotecan straight to the cancer with a way of blocking the blood vessels that supply it. This is called chemoembolisation. The beads release irinotecan at the site of the tumour to help destroy the cancer cells.

The aims of this trial were to find out:

how safe treatment is
how well treatment worked
more about the side effects

Summary of results

The trial team found it was safe to have irinotecan beads before surgery to remove the tumours in the liver. And the side effects were mild.

The researchers published the results in 2016. 40 people took part in this phase 2 trial.

Treatment

Everyone had a single treatment with irinotecan beads 4 weeks before their planned surgery. They then had surgery to remove the tumours although this wasn’t possible in 2 people.

Unfortunately, 2 people died a short time after surgery but this wasn’t related to having the beads. And 1 person had cancer that started in the liver. So, the trial team had the results for 35 people.

The surgeon removed the cancer with a border (margin) of tissue from around it. They tested the cells in the surrounding tissue (margin) for cancer cells. It is called a clear margin if there are no cancer cells. In this trial:

just over 7 out of 10 (74%) samples had clear margins
just under 3 out of 10 (26%) samples had a few cancer cells in the margins

Results

Tumours samples

A specialist doctor (a pathologist Open a glossary item

) analysed all the tissue samples from the tumours that the surgeons removed. They examined 63 tumours or lesions in total. A lesion is an area of abnormal tissue that may be benign or malignant. The researchers found in:

11 samples there were no signs of cancer in the tumour (a complete pathological response)
37 samples most of the cancer had disappeared (a major pathological response)
4 samples a little bit of the cancer had disappeared (a minor pathological response)
1 sample treatment hadn’t worked at all

Scans

Everyone had a scan 1 month after having the beads and before their surgery. The trial team looked at scans to see if the tumours had shrunk. They had the results for 34 people’s scans. They found in:

1 person the cancer had gone away a little bit
22 people the cancer stayed the same
11 people the cancer got worse

The trial team think that the scan results are quite different to the tissue sample results. They think the tissue sample results are much better. The trial team say this might be because:

they scanned the tumours very early and they hadn’t had time to shrink
the beads caused a short term increase in the size of the tumour due to swelling

But the researchers are a little unclear about the tumour responses and why these differences happened.

Follow up

The trial team looked at how long people lived for after treatment. This is called overall survival. They found that on average, this was 50.9 months. These results were similar to people having chemotherapy to the whole body (systemic treatment Open a glossary item

The researchers looked at the number of people living at 5 years. This was just under 5 out of 10 people (49%).

They also looked at how long before the cancer started to grow again. They found this was just under 20 months.

Side effects

The trial team found that people coped well with having the beads and most of the side effects were mild.

Conclusion

The trial team found that it was possible and safe to have irinotecan beads before surgery. It didn’t delay planned surgery dates or impact on how well people did afterwards. They also found that the side effects were mild.

Researchers are planning further trials looking at these beads before surgery for people with bowel cancer that has spread to the liver. This will help them work out who will benefit most from this treatment.

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.