A study to see whether circulating tumour cells can affect how well treatment for neuroendocrine tumours works (CALM-NET)

Cancer type:

Neuroendocrine tumour (NET)





This study was for people with a neuroendocrine tumour in their bowel. It was done to see if having circulating tumour cells can affect how well treatment is likely to work.

The study was open for people to join between 2014 and 2016. The team published the results in 2022.

More about this trial

The neuroendocrine system is made of nerve and gland cells. It makes hormones and releases them into the bloodstream.

Neuroendocrine tumours (NETs) are rare tumours that develop in the cells of the neuroendocrine system. You might also hear them called neuroendocrine neoplasms (NENs) or neuroendocrine carcinomas (NECs). They can develop in a number of different organs of the body, including the bowel.

When this study was done, doctors often used a drug called lanreotide to treat NETs. This is a type of treatment called a somatostatin analogue.

It is possible for small parts of the tumour to break away. They can travel in the bloodstream and grow into new tumours in other parts of the body. These cells are called circulating tumour cells, or CTCs.

In this study, researchers looked for CTCs in blood samples before people had treatment. They wanted to find out if having CTCs in the blood affected how well treatment is likely to work.

The main aim of this study was to find out if having CTCs can affect how well treatment works.

Summary of results

Study design

This study was for people with neuroendocrine tumour in their small bowel that was causing diarrhoea. They were due to start treatment with lanreotide.

The research team looked for circulating tumour cells (CTCs) in blood samples. They looked at whose symptoms got better with treatment, and whether they had CTCs or not.

A total of 40 people had blood tests and completed treatment as part of this study.

The results showed that symptoms improved with lanreotide for 35 out of 40 people (87%) in total. This included:

  • 14 out of 18 people (78%) who had CTCs before they started treatment
  • 21 out of 22 people (95%) who didn’t have CTCs before they started treatment

The team also looked at other proteins (biomarkers Open a glossary item). They didn’t find a link between these proteins and whether people had CTCs or not.

The study team concluded that treatment may be more likely to work for people who don’t have circulating tumour cells. But it’s hard to draw any firm conclusions because of the small number of people in the study.

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.

Circulating tumour cells and tumour biomarkers in functional midgut neuroendocrine tumours
T Meyer and others
Journal of Neuroendocrinology, 2022. Volume 34, Issue 4.

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 Open a glossary item) 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.

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 Tim Meyer

Supported by

Experimental Cancer Medicine Centre (ECMC)
NIHR Clinical Research Network: Cancer

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.

Wendy took part in a new trial studying the possible side effect of hearing loss

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"I was delighted to take part in a clinical trial as it has the potential to really help others in the future.”

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