DNA screenings of adults could save the lives of many Australians without breaking the bank, a new study argues.
The research, published in the Lancet, targeted three genetic conditions – two with links to cancer and one to heart disease. Study co-author Associate Professor Paul Lacaze says the research “forms a critical pillar of evidence” supporting a national expansion of DNA screening.
“We can now say with confidence, based on our rigorous modelling analysis, that offering population-wide preventive DNA screening to young adults in Australia would not only save lives but also be cost-effective,” said Assoc. Prof. Lacaze from the Monash University school of public health and preventive medicine.
DNA screening – the state of play
States and territories already offer a number of DNA screening services. However, the majority have a prenatal or newborn focus. One example of this is a screen for Down syndrome in the first trimester of pregnancy.
Other screenings can be performed even before pregnancy. For instance, parental screening can test whether either or both parents carry the genetic change associated with cystic fibrosis. If both parents are carriers, their children are at a higher risk of inheriting that condition. (This is true even if neither parent has the condition themselves.)
Newborns are screened for cystic fibrosis as a matter of course, as well as for phenylketonuria (PKU) and hypothyroidism.
How can screening adults be useful?
DNA screening of adults can assess the outlook for any potential children, but also for later life risk for the adults themselves. And that is where the new Monash University research comes in.
The study used health economic evaluation to model combined DNA screening for all adults in Australia aged 18-40. The evaluation identifies risk of three genetic conditions:
- hereditary breast and ovarian cancer (caused by the BRCA1 and BRCA2 genes)
- a type of genetic high cholesterol called familial hypercholesterolemia
- Lynch syndrome, a genetic condition that increases the risk of colorectal and other cancers.
All three conditions can be treated or prevented – if detected early. The problem is, most sufferers are unaware they have the condition, and are therefore not accessing available life-saving interventions.
And we are not talking about miniscule population numbers here. Around one in 75 people are at high genetic risk of one of these conditions. In a population closing in on 26.5 million, that translates to more than 350,000 Aussies at risk.
The study’s module simulates 8.3 million adult lifetimes to age 80. It assumes a 50 per cent uptake of DNA screening, from which it estimates 4047 deaths could be averted. It would also prevent 2612 cancers and 542 non-fatal coronary heart disease events.
When lined up against current practice, the study concludes, this is equal to preventing 63 cancers, 31 CHD cases and 97 deaths per 100,000 people offered DNA screening.
But is it worth it?
According to Assoc. Prof. Lacaze and the study’s co-authors, yes. At $200 per test, a total government investment of $832 million would be required to screen 50 per cent of the model population. This investment would also cover $539 per high-risk person identified, for clinical confirmation testing and genetic counselling.
That sounds rather expensive, but the study found the initial cost would be well worth it. This is based on the overall benefit to society through early detection and prevention, calculated using a range of factors.
Senior author Professor Zanfina Ademi says that combined population genomic screening for high-risk conditions in the young adult population may be cost-effective from the public healthcare perspective, compared to the current status-quo.
Prof. Ademi leads Monash University’s health economics and policy evaluation research group in the Faculty of Pharmacy and Pharmaceutical Sciences. She said a societal perspective is required, “with potential healthcare costs and costs of lost work productivity considered”.
When accounting for those factors, “combined genomic screening would save lives and money compared to the status quo,” Prof. Ademi says.
What do you think of the DNA screening proposal? Would you have consented to such a test when you were younger? Let us know via the comments section below.
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