A common virus that most people catch as children, with symptoms akin to a cold, has been identified as a potential trigger for bladder cancer in later life, according to new British research.
From Flu-Like Symptoms to a Cancer Diagnosis
The findings are brought into sharp focus by the experience of Tim Tavender, a 51-year-old man from Southampton. In 2015, following a kidney transplant, Mr Tavender became ill with the BK virus, also known as polyomavirus. Six years later, in 2021, he noticed significant blood in his urine and received a devastating diagnosis of bladder cancer. Doctors now believe his cancer was likely linked to that earlier BK infection.
"It was a terrifying experience," Mr Tavender said. "BK virus made me feel sub-par, like constantly having the flu, and lowering my immunosuppressants to fight it left me walking a medical tightrope." He described the moment he discovered his symptom: "It wasn't just a little bit, it was claret. That visit to the doctor probably saved my life."
The 'Friendly Fire' That Damages DNA
The groundbreaking study, published in the journal Science Advances, was conducted by researchers including Dr Simon Baker from the University of York. The team exposed human urinary tract tissue to the BK virus to understand its long-term effects.
They discovered that in the body's fight against the virus, enzymes meant to attack it cause collateral "friendly fire" damage to the DNA of the body's own cells. Crucially, this damage occurs not only in infected cells but also in nearby 'bystander cells'.
"This is important because it might explain why most bladder cancers have no sign of the virus in them when they are diagnosed many years later," explained Dr Baker. The virus usually lies dormant in the kidneys but can reactivate in transplant patients on immunosuppressants, potentially damaging the kidneys and bladder.
New Hope for Prevention and Future Treatment
Mr Tavender, who underwent a 13-hour surgery to remove his bladder, believes this research could be "life-changing" for others. With around 10,000 new bladder cancer cases diagnosed in the UK each year, the study opens a new avenue for prevention beyond known risks like smoking.
"We can now see how BK virus may contribute to bladder cancer, in transplant recipients and the general population," said Dr Baker. "It gives us motivation to seek prevention strategies for both bladder cancer and the kidney damage caused by BK virus." His lab, supported by Kidney Research UK and York Against Cancer, is now developing new ways to control the virus.
Dr David Crosby, chief research officer at Kidney Research UK, emphasised the potential impact: "These findings move us closer to understanding why some people develop bladder cancer and show how tackling BK virus early could one day stop these cancers from developing at all."
