Blood test could predict prostate cancer more than 15 years before diagnosis

Blood proteins may help identify men at risk of prostate cancer more than 15 years before diagnosis, according to new research.

Scientists found biological differences between men who later developed the disease and those who did not, including proteins associated with aggressive prostate cancer.

The findings suggest blood-based markers could eventually help identify men at greater risk of developing life-threatening forms of the disease.

Dr Zhe Huang, first author of the study and a postdoctoral epidemiologist at Oxford Population Health, said: “Prostate cancer is not one disease.

“Many prostate cancers grow slowly and may never cause harm, while others are aggressive and can be life-threatening.

“Ultimately, we hope this will help us understand the biology of aggressive prostate cancer and identify markers that could improve how we assess risk in the future.”

Researchers at Oxford University analysed blood samples from 982 men who subsequently developed prostate cancer, alongside 1,573 men randomly selected from the European Prospective Investigation into Cancer and Nutrition.

The study measured more than 6,000 proteins in participants’ blood, with follow-up lasting approximately 16 years.

Researchers identified 12 proteins associated with prostate cancer diagnosed more than 15 years after the samples were collected.

One was GZMK, a protein produced by immune cells involved in recognising and destroying abnormal cells.

The researchers suggested this could indicate a role for the immune system in keeping prostate cancer in check long before diagnosis.

Seven proteins were linked to aggressive forms of the disease, including ANKRD1, which was associated with cancers that spread or caused early death.

Other associations involved blood levels of proteins produced by genes already known to be important in prostate cancer, including ERBB3, KRAS and NRAS.

These were linked to aggressive cancers diagnosed approximately a decade after the blood samples were collected.

The study also provided insights into how cancer cells interact with surrounding tissue and how new blood vessels develop.

The researchers stressed that finding these proteins in blood years before diagnosis does not mean cancer was already present when the samples were collected.

Instead, the associations may offer clues about biological processes linked to the later development of the disease.

Professor Karl Smith-Byrne, a senior author of the study, said: “Finding proteins linked to known prostate cancer driver genes in blood collected years before diagnosis gives us new insights into the earliest stages of the disease.

“Together with existing and future genetic evidence, these findings may help us identify biological pathways that could be targeted to prevent aggressive prostate cancer.”