Restricting cancer gene testing to people who meet the NHS eligibility criteria misses up to half of people at increased risk from inherited genetic changes linked to cancer, warns a new report.
Research by a team at The Institute of Cancer Research, London, found that applying NHS guidelines for gene testing would have excluded many people who had ‘actionable’ genetic alterations that could raise their risk of cancer.
They assessed patients who were tested in the private sector to see who would have been eligible for the same genetic test under the NHS.
Their research, published in Scientific Reports, means people with an increased risk of developing cancer missed out on the potential for monitoring, screening or preventive treatment.
Some cancers, such as breast, ovarian and colorectal and prostate, are linked to inherited genetic changes and eligibility guidelines for genetic testing are based on a combination of factors, including family history, and are intended to ensure that NHS care is cost-effective.
However, this study suggests the criteria for testing are too tight and are excluding patients who could benefit.
Professor Ros Eeles, professor of oncogenetics at The Institute of Cancer Research, London, said: "Our study shows that restricting cancer gene testing to people who meet the NHS eligibility criteria misses as many as half of people at increased risk.
“We provide evidence that providing wider access to gene testing on the NHS would pick up significant numbers of people with high-risk cancer mutations, who could benefit from screening, monitoring or preventive treatment.
"We feel there is a strong case to widen access to cancer gene testing on the NHS. There is however also a trade-off to doing so, through an increased chance of ambiguous findings which need follow-up and can worry patients unnecessarily.
“We need larger studies to work out exactly where the revised NHS threshold for testing should be, to maximise the benefit in people at high risk of cancer, while minimising the burden on patients and the NHS of follow-up investigations.”
The team studied 152 patients who were referred for multi-gene cancer panels in the private sector between 2014 and 2016.
Panel tests look for variants of multiple genes that can increase people’s risk of developing cancer. Each was compared with current eligibility criteria.
The study detected harmful or probably harmful gene alterations linked to personal or family history of cancer in 15 out of the group of 152.
About seven out of the 15 were found to carry a harmful or probably harmful variant. This, say the researchers, means 4.6% of the group who were tested would not have been eligible under NHS guidelines.
Detecting ‘actionable’ mutations that were harmful or probably harmful should trigger a change in the way patients and their family are managed by clinicians, with an offer of monitoring, screening, preventive treatment or other measures to prevent cancer from developing.
However, they study found that testing patients outside of the eligibility criteria had some negative consequences by picking up more patients with ‘variants of unknown significance’, for which there is no clear course of action.
The study picked up these variants in 34% of participants, which raised the possibility that wider testing could increase pressures on the NHS through the need for follow-up checks and cause unnecessary anxiety among patients.
Professor Kristian Helin, chief executive of The Institute of Cancer Research, London, said: “Over the last 20 years, we have gained a far greater understanding of the inherited genetic changes which can increase a person’s risk of developing cancer. That increasingly opens up the possibility of genetic testing to identify those people at the highest cancer risk, and to support them with strategies for cancer prevention or early detection.
“Unfortunately, accessing genetic testing on the NHS can be complicated and tends to be restricted to those people with a strong family history.
“Our new research shows that we are missing people who could benefit from genetic testing. I hope the findings will ultimately help improve national testing guidelines so that we can help more people at high risk of cancer.”
Andoni T, Wiggins J, Robinson R et al. Half of germline pathogenic and likely pathogenic variants found on panel tests do not fulfil NHS testing criteria. Scientific Reports 21 February 2022
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