A saliva test may enhance prostate cancer screening by identifying individuals at higher risk based on genotype.
Researchers at the American Society of Clinical Oncology found the test shows promise in supporting prostate cancer diagnosis in those missed by other screening methods. Currently, researchers are comparing the saliva test to fast MRI scans and prostate-specific antigen (PSA) blood tests to determine the most effective approach.
Genome-wide association studies have pinpointed variants associated with prostate cancer.
DNA test analysis
Building on these studies, researchers at The Institute of Cancer Research, London, and The Royal Marsden NHS Foundation Trust developed a DNA test analysing 130 genetic variants linked to prostate cancer to calculate a polygenic risk score (PRS).
They invited more than 40,000 men aged 55 to 69 in the UK to participate, with about one-fifth showing interest. PRS scores were then generated for around 6,100 participants.
The 745 men with the highest 10% risk scores were invited for further testing, resulting in 187 cancer diagnoses. More than half were indeterminate or high-risk cancers, with about one-third requiring treatment such as surgery or radiotherapy.
The study suggests the saliva test may outperform existing methods, identifying 55.1% aggressive cancers compared to 35.5% by PSA tests. Additionally, MRI failed to detect prostate cancer in 119 high-risk men identified by the PRS test.
Notably, nearly 78% of patients diagnosed had "normal" PSA levels. The saliva test generated fewer false positives than PSA testing.
Researchers are now validating these findings in a larger study involving around 12,500 participants, with plans to expand to 300,000 men.