A blood test analysing proteins in blood could one day be used to test for common cancers, new research suggests.
Early trials of a new test found it could pick up 18 early-stage cancers, representing all major organs in the human body.
Its developers say it takes them a step closer to developing a new generation of cancer screening tests that can be used across the population.
They suggest it outperforms others relying on circulating tumour DNA in the blood while having ‘a sensitivity much greater’ than the Galleri test currently being trialled in the NHS.
Early trials of a new test found it could pick up 18 early-stage cancers, representing all major organs in the human body
But other scientists cautioned that the findings are ‘very preliminary’, adding that much further research is needed before deciding if such tests could ever be used in a real-world setting.
Proteomics is the study of proteins and helps experts learn how cancer develops and spreads, speeding up diagnosis and leading to better treatment.
US biotech firm Novelna said that by looking at proteins in blood plasma, they were able to differentiate cancer samples from normal ones, even distinguishing between different types of cancers ‘with high accuracy’.
The research also found evidence that cancer protein signals were likely to be sex-specific, meaning different tests could potentially be developed for men and women.
For the study, blood plasma samples were collected from 440 people diagnosed with 18 different types of cancer, and from 44 healthy blood donors.
The team then identified proteins which showed early-stage cancers and where they originated in the body.
The team wrote: ‘At stage I (the earliest cancer stage) and at the specificity of 99 per cent, our panels were able to identify 93 per cent of cancers among males and 84 per cent of cancers among females.
‘Our sex-specific localisation panels consisted of 150 proteins and were able to identify the tissue of origin of most cancers in more than 80 per cent of cases.’
Analysis of the plasma protein amounts also showed that almost all of them were present at very low levels.
This shows the importance of low-level proteins to pick up pre-cancerous and early stage disease before a tumour has had time to cause substantial damage, they said.
However, the team said their relatively small sample size meant further studies were needed in bigger groups of people.
Writing in the journal BMJ Oncology, the researchers said: ‘This finding is the foundation for a multi-cancer screening test for the early detection of 18 solid tumours that cover all major human organs of origin for such cancers at the earliest stage of their development with high accuracy.
While the level of progress for cancer survival for some forms of the disease has been rapid, such as for breast and prostate cancers, others, like those for lung and pancreas have only improved at a snail’s pace
‘It is important to diagnose cancer at very early stages where curative treatments are achievable with surgery and available treatments.
‘Additionally, for the first time to our knowledge, we found compelling evidence that the cancer protein signatures are most likely sex-specific for all cancers.’
The researchers said their test outperforms existing technologies, providing a more efficient approach for early cancer detection.
This could re-shape screening guidelines, making this plasma test a standard part of routine check-ups, they suggest.
Dr Anguraj Sadanandam, director of the centre for global oncology at the Institute of Cancer Research, London, said: ‘This research could pave the way to a prosperous and efficient way to identify cancers earlier, when they are easier to treat.
‘Several tests looking to spot early cancers via a blood test are currently in development, with most detecting fragments of tumour DNA in the blood.
‘This study showed that early cancers may also be detected by looking for the presence of sex-specific protein signatures in the blood.’
He acknowledged it was an early study and more research, including large clinical trials, would be needed before this could be developed and approved as a diagnostic test.
Dr Mangesh Thorat, honorary senior lecturer at the Centre for Cancer Prevention at the Wolfson Institute of Preventive Medicine, said questions remain and further studies are needed.
He said: ‘The interesting aspects of this assay are a much higher sensitivity for stage I cancers than other similar assays in development and gender-specific performance differences which are biologically and clinically relevant.
‘If the assay performance in future well-designed sequential studies is anywhere close to what this preliminary study suggests, then it could really be a game-changer.’
But Paul Pharoah, professor of cancer epidemiology at the Cedars-Sinai Medical Centre, said the ‘holy grail’ for early detection was still some distance away.
He said: ‘Many such tests have been developed or are in development. This paper reports on the initial results of the development of one such test.
‘While the results show some promise, it is far too soon to be confident that this test will turn out to be useful for early cancer detection.’
