Study calls for population-wide genomic screening

Michelle Wisbey

9/11/2023 3:29:07 PM

Expanded testing for three genetic conditions could save lives and money, Monash University research suggests.

Woman holding a letter at her mailbox.
Researchers say around one in 75 people are at risk of one of three potentially fatal genetic conditions, but most are unaware of that risk.

Australians have become all too familiar with bowel cancer kits, Pap smears, and breast screenings, but researchers are now calling for a new at-home test to be added to healthcare’s prevention toolkit.
A new study from Monash University has found population-wide genetic screening for the BRCA1 and BRCA2 genes, familial hypercholesterolemia, and Lynch syndrome would save lives and be cost effective.
Published in The Lancet’s eClinicalMedicine journal, researchers proposed all Australian adults aged 18–40 be screened for the potentially deadly conditions through a saliva sample done at home.
The paper’s modelling used a world-first DNA Screen pilot study, which offered genomic screening to 10,000 young adults within that same age group, with around 2% of people finding a high-risk genetic result.
The study’s lead co-author, Associate Professor Paul Lacaze, told newsGP the testing would be specifically focused on adult-onset conditions.
‘When you hit a certain age, you would be able to participate in this as a public population screening program,’ he said.
‘That would need to be accompanied by all the right information and consent framework, service delivery framework, and downstream return of results, genetic counselling, and links with clinical services.
‘In order for that to be delivered and exactly how that would work still needs to be determined, and that would happen over many years in partnership with governments to figure out how all those segments need to be delivered.’
Currently, while around one in 75 people are at high genetic risk of one of these conditions, most are unaware of the potential threat.
To undertake the study, experts simulated a model of 8.3 million adults’ lifetime to age 80, assuming 50% would uptake DNA screening.
They found an estimated 4047 deaths could be averted and it could prevent 2612 cancers – including 1140 breast, 950 ovarian, 451 colorectal, and 71 endometrial – and 542 non-fatal coronary heart disease events.
The research said it would cost $200 per test to rollout the program, meaning a total government investment of $832 million would be required to screen 50% of the model population.
This would lead to an incremental cost-effectiveness ratio (ICER) of $23,926 per quality-adjusted life-year gained.
Associate Professor Lacaze said concerns about overdiagnosis had been examined through the research, but he does not believe it to be an issue.
‘We focus only on the highest-risk genes and the highest-risk conditions so that everyone who you would find with a genetic variant for one of these conditions is at very high risk of a cancer or heart disease,’ he said.
‘Therefore, once they’re identified, there’s no question about overdiagnosis or whether they need access to risk management because of the genuine high-risk category and if the screening is maintained with that goal, I don’t think there’s a risk of overdiagnosis and over detection.
‘The real problem is currently there’s a huge chronic under-diagnosis of these conditions in the system and we’re not finding these high-risk people, and they’re dying from young onset cancers and heart attacks.’
Researchers say in the future, they will lobby governments to have the testing introduced nationwide, but in the meantime future research was needed on the screening’s psychosocial impacts, ethical and societal issues, and implementation challenges.
But if it is one day rolled out, Associate Professor Lacaze said GPs would have a big role to play in population screening programs and keeping patients aware of testing opportunities.
‘I would highlight the critical role for GPs in all population screening programs in Australia, and that the education and awareness of the public screening is a good thing to do and the benefits, but also that any potential harms are understood,’ he said.
‘Once a program is developed to try and make it successful, and implemented, and increase uptake, GPs play a key role there.
‘GPs play a very important role in the long-term management of risk for cancer and heart disease for individuals and across families, so as genetics are used more in the health system, and maybe in population screening, GPs really will play a critical role in the broader system.’
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