A study looking at testing all Ashkenazi Jewish people for a cancer gene (GCaPPS)

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Cancer type:

Breast cancer
Ovarian cancer
Prostate cancer





This study looked at the possibility of offering gene testing to all Ashkenazi Jewish people in London. The aim of the GCaPPS research study was to find the best method of screening for risk of inherited (familial) cancer. It compared the current system of testing only those with a strong family history of cancer with the new option of testing everyone (population testing).

Genes are coded messages inside the cell that tell it how to behave. If the gene is lost, or changed due to damage, this changes the code. We know from research that alterations in the BRCA 1 Open a glossary item and BRCA 2 Open a glossary item genes can increase the risk of developing breast, ovarian and prostate cancer. But there are many different changes that can happen in these genes.

Inherited changes in these genes are more common in Ashkenazi Jewish people than in the rest of the population. The only people currently offered testing for these gene changes are those with a strong family history of cancer. However, many people are not aware of their family history or its significance and do not seek advice. This could miss a number of people who do not have a strong family history but carry an alteration in this gene. And so have an increased risk of getting cancer or of passing these gene changes on to their children.

In this study, the researchers wanted to find out

  • Whether population screening (compared to a family history based approach) finds more people with BRCA gene alterations
  • If it is acceptable to people
  • About possible differences in psychological impact and quality of life Open a glossary item
  • About the cost effectiveness of both methods

Summary of results

The study team found that testing everyone with an Ashkenazi Jewish background helped to identify more people with a BRCA gene change than only testing those with a strong family history.

1,034 Ashkenazi Jewish people took part in this randomised study. They were put into 1 of 2 groups by a computer. Neither the person taking part nor the researchers could decide which group they were in. Everyone was offered detailed individual genetic counselling.

In group 1, everyone had their blood tested for the BRCA gene alterations (genetic testing). Researchers call this the population screening group.

In group 2, only people who had a strong family history of cancer had their blood tested for the BRCA gene changes. Researchers call this the family history group.

When the researchers looked at the results they found that

  • In group 1 there were 13 people with BRCA gene changes
  • In group 2 there were 9 people with BRCA gene changes

The researchers also looked at how people rated their quality of life and the emotional impact that genetic testing had. But they found there was no difference between the 2 groups in either of these.

The study team followed up the people who took part for 3 years. They found that 210 people in group 2 who didn’t have a strong family history and so didn’t have their blood tested in the study, decided to have the genetic test later on.  When the researchers looked that these results, they found 5 more people with a BRCA gene change.

In this study, the researchers found that 15 out of 27 (56%) or over half the people  carrying a BRCA gene alteration (mutation) would not have been identified or detected using family history based testing.

The researchers also looked at the cost effectiveness of testing all Ashkenazi Jewish women aged 30 years or older for changes in the BRCA1 or BRCA2 genes. The study team worked out the number of cancers and possible treatment costs for them if they were diagnosed with breast or ovarian cancer in the future. They compared the outcomes and treatment costs of population screening with the current practice of family history based screening. They found that population screening (compared to family history screening) cost a lot less.

The researchers concluded that population screening for people with an Ashkenazi Jewish background was useful, acceptable to people and helped to identify more people with a BRCA gene change. Population screening for this group of people could save the NHS money, prevent cancers and save lives in the long term.

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

Professor Ian Jacobs
Dr Ranjit Manchanda

Supported by

The Eve Appeal
Academic Study Group on Israel & the Middle East
Agudas Israel Housing Association
Institute for Womens Health University College London (UCL)
Jewish Care
Liberal Judaism
Reform Judaism

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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.

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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