Scientists develop affordable spit test for prostate cancer detection

Researchers have introduced a groundbreaking saliva test that promises to revolutionize prostate cancer detection by identifying high-risk individuals early and reducing unnecessary treatments.

Prostate cancer diagnoses are expected to double to 2.9 million annually by 2040, with deaths rising by 85%. Currently, it is the most common cancer among men in over 100 countries.

Early detection is critical, but the existing PSA blood tests often miss cancer cases and lead to unnecessary treatments.

A collaborative effort between the Institute of Cancer Research, London (ICR) and the Royal Marsden NHS Foundation Trust has yielded a more accurate and less invasive alternative. Their new saliva-based DNA test can collect a sample in seconds and is being presented at the American Society of Clinical Oncology (ASCO) meeting in Chicago.

Professor Ros Eeles, an oncogenetics expert at the ICR, emphasized the significance of this development. “Our simple, inexpensive spit test can identify men at higher genetic risk, potentially turning the tide on prostate cancer by enabling earlier detection,” she said.

The test was developed after extensive research into the genetic markers associated with prostate cancer. It examines genetic signals in saliva that indicate an increased risk of the disease. The Barcode 1 trial, involving over 6,000 European men aged 55 to 69, demonstrated the test’s effectiveness. Participants’ saliva samples were used to calculate their polygenic risk score (PRS) based on 130 genetic variations linked to prostate cancer.

The new test proved superior to the PSA test, returning fewer false positives and identifying aggressive cancers that the PSA test and even MRI scans missed.

Dheeresh Turnbull, a 71-year-old participant from Brighton, discovered he had prostate cancer through the spit test, despite having no symptoms. Following robotic surgery to remove part of his prostate, Turnbull is recovering well. The test also led to the early diagnosis of an aggressive tumor in his younger brother, highlighting its life-saving potential.

Eeles cautioned that further research is needed before the test can be widely implemented. “Our next step is to validate these genetic markers across diverse populations to ensure the test benefits all men,” she said.

With an aging global population and increasing life expectancy, the incidence of prostate cancer is rising. Given that primary risk factors, such as age and family history, are unavoidable, experts believe better testing and early diagnosis are crucial.

“Early detection significantly improves the likelihood of curing cancers,” said Prof. Kristian Helin, CEO of the ICR. “With prostate cancer cases set to double by 2040, an improved screening test is urgently needed. This research marks a promising advance and underscores the critical role of genetic testing in saving lives.”