NHS gene testing misses people at risk of cancer

Stringent NHS genetic testing guidelines may mean that nearly 50 percent of those at risk of cancer are going unchecked, recent evidence suggests.

Researchers from the Institute of Cancer Research, (ICR), considered whether patients who had undergone genetic testing for cancer in the private sector would meet eligibility for NHS genetic testing and what the consequences would be of not being eligible. Up until recently, such tests were only available for those presenting with a family history of cancer and with a GP referral. This may potentially result in people with an increased risk of developing cancer being overlooked for cancer screening, monitoring, or prevention.

'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.' explained Professor Kristian Helin, chief executive of the ICR. 'Unfortunately, accessing genetic testing on the NHS can be complicated and tends to be restricted to those people with a strong family history.'

The team, who published their results in Scientific Reports, looked at 152 patients who underwent genetic 'panel tests' in the private sector between 2014 and 2016. Panel tests look for mutations that can increase people's risk of developing cancer. Every panel test conducted was compared with current eligibility criteria. Only 37 percent of those who underwent private sector testing fulfilled the NHS testing criteria.

Cancer, whilst not typically inherited, may run in families. Indeed, some types, such as breast cancer, are linked to inherited mutations in certain genes, such as BRCA1 and BRCA2. Current NHS eligibility guidelines for genetic testing are based on various factors, including family history, and are intended to ensure cost-effectiveness. However recent evidence suggests the criteria for testing are too tight and excluding patients who could benefit from it.

The study found harmful or potentially harmful mutations linked to personal or family history of cancer in 15 people, approximately ten percent of the study sample. Seven of these people, or 4.6 percent of all those tested, would not have been eligible for genetic testing under NHS guidelines. Further investigation found a pathogenic variant in two of these cases.

The authors also report that 34 percent of participants had genes classified as 'variants of unknown significance', which are gene variants with an unclear impact on potential cancer risk due to limited research. This high incidence may increase pressure on the NHS for further testing.

The researchers noted some potentially negative consequences of more widespread genetic testing. Predictive genetic tests for cancer risk may give increased anxiety to people who after a positive result feel they are waiting for an inevitable cancer diagnosis.

Professor Rosalind Eeles, an expert in oncogenetics at the ICR, concluded that '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.'