Khaberni - British researchers have discovered a new link between a common virus in childhood and an increased risk of bladder cancer later in life.
The study showed that the BK virus, which infects most people in childhood (usually before the age of ten) typically without clear symptoms or with mild flu-like symptoms, can cause DNA damage in bladder tissue, which may explain why there is a higher risk of cancer in kidney transplant patients, as they are more susceptible to the virus due to immune suppression caused by anti-rejection drugs.
The BK virus remains latent in the kidneys, bladder, and lining of the ureters in people with a healthy immune system, while it may be reactivated in those with weakened immunity, such as kidney transplant patients.
Dr. Simon Baker, a researcher in molecular cancer development at the University of York and the lead researcher in the study, said, “Our findings show that the bladder cells' defense response against the virus causes changes in the DNA, which may lead to cancer. This represents a significant shift in our understanding of the origins of bladder cancers.”
He added, "We can now see how the BK virus contributes to bladder cancer, whether in kidney transplant recipients or the general public, and it explains why no trace of the virus is found in tumors years after infection."
In the study, researchers analyzed human tissue from the lining of the urinary tract that had been exposed to the BK virus in the lab, and found that DNA damage was not limited to the infected cells alone, but also extended to surrounding cells. This explains why, when bladder cancer is diagnosed years after infection with the virus, the virus itself is not observed inside the tumor. In other words, the virus may have previously caused changes in the DNA that led to cancer, but it does not remain inside the cancer cells themselves when discovered after a long time.
The experience of one patient, who contracted the BK virus after a kidney transplant in 2015, shows how he noticed blood in his urine six years later, which is a sign of bladder cancer. The 51-year-old man underwent a 13-hour surgery to remove the bladder and reroute the urine flow. He said, "It was a terrifying experience, but seeing this research gives me hope, as the findings may help protect other people from the same suffering."
Symptoms of bladder cancer, in addition to the presence of blood in the urine, include frequent urination, pain, unexplained weight loss, fatigue, urinary incontinence, and abdominal pain.
The study was published in the journal Science Advances.
