Clinical trials are underway into multi-centre early detection, and Australian experts are mapping potential pathways for implementation if evidence thresholds are met.
Annual multi-centre early detection (MCED) testing could result in 49% fewer late-stage diagnoses than standard single-cancer screening tests, according to researchers from the University of Oxford.
Using data of 100,000 people aged 50-79, researchers applied a state-transition model to evaluate the optimal testing frequency of the cfDNA-based Galleri MCED test, which was designed to detect more than 50 different types of cancer.
They found that annual screening detected more cancers earlier and prevented more deaths than biennial screening but had a higher false positive rate than biennial screening (0.5% vs 0.25%). Biennial screening was more efficient and reduced test burden but showed a slightly lower impact on mortality.
Annual MCED testing in this model detected 370 more cancers each year per 100,000 people and reduced deaths by 21% over five years than conventional cancer screening tests. Performing MCED testing every two years was found to have 39% fewer late-stage diagnoses than non-MCED testing, detecting 292 more cancers per year per 100,000 people and reducing deaths by 17%.
Associate Professor Julia Steinberg, genomics and precision health lead at the Daffodil Centre, a joint venture between Cancer Council NSW and the University of Sydney, told TMR that MCED testing aims to improve health outcomes by detecting cancers at earlier stages, before there are any symptoms.
“The technologies for MCED tests are evolving quite rapidly, so I think there is a lot of promise in their future potential,” she said.
She said a large clinical trial of MCED testing is underway in the UK and another one is planned in the US but, as there is no data from trials yet, studies like this explore potential benefits of MCED tests under different scenarios and help design future trials.
“Given the immense efforts needed to run a sufficiently large cancer screening trial, refinement for optimal outcomes is very valuable,” she said. “This modelling study is helping to advance the understanding of what the potential benefits of MCED tests might be, while the outcomes of clinical trials are still pending.”
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Her team started a large collaborative program of work to evaluate the potential of MCED tests in Australia in March this year. Their aim is to establish an evidence-based roadmap with recommended next steps for MCED testing for more effective early detection of cancers in Australia.
“Evidence from these trials will need to be interpreted for the Australian context, considering how it would apply to Australian current and future cancer burden, clinical pathways, and community preferences and needs,” she said.
“Over the next five years, we will be mapping potential clinical pathways, identifying relevant needs and preferences of health professionals (including GPs) and consumers.”
Another area that will need to be addressed is the false positive rate.
Professor Steinberg said that MCED tests generally have a low false-positive rate by design, but when aggregated across the population, false positive still lead to considerable burden to the individual and health systems.
“Ultimately, an accurate assessment of benefits and harms from potential screening using MCED tests will very much require clinical trials and real-world data to confirm long-term reductions in late-stage cancer diagnoses and improvements in health outcomes (which could include survival but also important patient-reported outcomes), and harms including the costs of diagnostic follow-up,” she said.
Study authors note that MCED testing should be complementary to standard single-cancer screening tests, not a replacement, and are likely to expand categories of screenable cancers without significantly increasing the overall rate of false positives that are already seen with current cancer screenings.
