A trial comparing different ways of checking lymph nodes in the chest for non small cell lung cancer (ASTER)

Cancer type:

Lung cancer
Non small cell lung cancer




Phase 3

The aim of this trial was to see if internal ultrasound scans were as good as surgery for checking lymph nodes in the chest for lung cancer.

Doctors use a number of different tests to find out the stage of lung cancer. This helps them to decide on the best treatment.

One of these tests is a biopsy of the lymph nodes Open a glossary item in the middle of your chest (mediastinum Open a glossary item). You usually have this done under general anaesthetic Open a glossary item. But doctors thought that internal ultrasound scans may be useful. You have this done with a sedative Open a glossary item and a local anaesthetic.

To have this test a small ultrasound probe is put into your food pipe and stomach (an endoscopic ultrasound Open a glossary item, or EUS). And another is put into your wind pipe and lungs (an endobronchial ultrasound Open a glossary item, or EBUS). Using ultrasound, doctors can see the lymph nodes in your chest. If they see any abnormal areas, they will take a sample of tissue (a biopsy).

Some hospitals already use ultrasound scans to look at lymph nodes. But doctors were not sure if they were as good as having surgery.

The aim of this trial was to find out if using ultrasound scans is as good as taking surgical biopsies to assess lymph nodes.

Summary of results

The trial team found that using ultrasound scans worked just as well as taking biopsies to assess lymph nodes.

This phase 3 trial recruited 241 people. It was a randomised trial. Those taking part were put into 1 of 2 groups

  • 118 had surgical biopsies taken of the lymph nodes
  • 123 had endoscopic ultrasound (EUS) and endobronchial ultrasound (EBUS) followed by a surgical biopsy if the ultrasounds did not find any of the lymph nodes to be abnormal

The researchers then compared how accurate the 2 different ways of assessing the lymph nodes were. They found it worked

  • 79 out of every 100 times (79%) for surgical biopsies
  • 94 out of every 100 times (94%) for EUS and EBUS

They found no difference in the number of complications between surgery and ultrasound.

The trial team concluded that EUS and EBUS worked  just as well  as taking surgical biopsies  to assess lymph nodes.

We have based this summary on information from the team who ran the trial. 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. We have not analysed the data ourselves.

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

Dr Robert Rintoul

Supported by

Health Technology Assessment Unit of the Department of Health
National Institute for Health Research Cancer Research Network (NCRN)

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Freephone 0808 800 4040

Last review date

CRUK internal database number:

Oracle 2130

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Around 1 in 5 people take part in clinical trials

3 phases of trials

Around 1 in 5 people diagnosed with cancer in the UK take part in a clinical trial.

Last reviewed:

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