Research involving clinical researchers and patients from the University Hospitals of Leicester NHS Trust has shown that a new blood test can diagnose prostate cancer and identify what stage the disease is at with 99 per cent accuracy.
The method, developed by scientists at Nottingham Trent University, aims to reduce the use of the most common diagnostic tool, an invasive biopsy, while still accurately confirming prostate cancer.
Prostate cancer is the fourth most common cancer in the world, with 1.8 million new cases in 2018 alone. Scientists believe around 12,000 British men will die from prostate cancer in the UK this year.
This is not the first time blood tests have been used to detect prostate cancer. Current blood tests look for an elevated level of a ‘prostate specific antigen’ (PSA) and if the test is positive then a patient is sent for a biopsy.
However, this method can be flawed as not all patients have elevated PSA levels, and some men who do not have the cancer have naturally high PSA levels. This can lead to either unnecessary investigations or missed diagnoses.
The new blood test builds on previous work by Nottingham Trent scientists that found changes in the immune system can be identified in the blood of a patient. Alterations in the white blood cells are the primary signals for the cancer.
After the blood is extracted, computers analyse the sample for signs of the disease and categorise it as either low, intermediate or high-risk.
Seventy two men with no symptoms of prostate cancer participated in the study. Using the new blood test, 31 of the men were diagnosed with low risk cancer, and 41 with high risk cancer. These results were verified by a combination of rectal examinations, PSA levels and tissue sampling.
Professor Masood Khan, consultant urologist at University Hospitals Leicester NHS Trust and an honorary professor at Nottingham Trent University, said: “Improving our ability to detect men harbouring clinically significant prostate cancer is vital to save lives. MRI scans can help spot a tumour but are not accurate enough to make a conclusive diagnosis on their own. PSA blood tests can give false positives, which can cause unnecessary psychological impact through being misdiagnosed.
“If this test can be proven to work at scale, then it will not only reduce the burden on the NHS but also spare men from having unnecessary invasive procedures and help clinicians to decide whether to ‘watch’ or ‘actively manage’ patients, even when they are asymptomatic but have mildly higher PSA levels.”
The next step will be to conduct a larger study including more participants to verify these initial findings. If those findings confirm the accuracy of the blood test, it could be a game-changer for diagnosing prostate cancer.
The research, ‘Identifying prostate cancer and its clinical risk in asymptomatic men using machine learning of high dimensional peripheral blood flow cytometric natural killer cell subset phenotyping data’, is published in the journal, eLife https://elifesciences.org/articles/50936.
Rachael Dowling, head of research communications