There's no link between a common type of herpes virus and aggressive brain cancers, according to a new study that refutes earlier reports.
Never completely eradicated
Johns Hopkins researchers analysed tumour tissue from 125 patients with aggressive brain cancers called gliomas. Ninety-nine of the samples were from adults. Twenty-six were from children.
Other laboratories have also found no evidence of CMV in glioma tumours.
A Health24 article explains that in a healthy person who is infected with CMV, the immune system prevents the virus from replicating and causing disease. Although never completely eradicated from the body, the virus lies dormant. It is only when the immune system is severely weakened that CMV results in significant disease.
Little likelihood of connection
Further studies are needed to rule out any role for CMV in these brain cancers. But the new findings suggest little likelihood of any connection, the researchers said.
"We have found no evidence of CMV in these tissues, and if there is no virus, targeting that virus to affect cancer using antiviral drugs or tailored vaccines doesn't make biological sense," said Dr Angelo De Marzo, a professor of pathology, oncology and urology at Johns Hopkins Kimmel Cancer Center in Baltimore.
CMV is a very common virus. It infects more than half of all adults by age 40, according to the US Centers for Disease Control and Prevention.
Several earlier studies reported finding CMV in tumour cells from patients with aggressive glioma brain cancers. This led to speculation that therapies targeting CMV could improve outcomes for people with gliomas.
"Significant resources have already gone into this field of study, making it very important to definitively answer the question of whether there's an association between CMV and gliomas or not," Dr Matthias Holdhoff said in a Hopkins news release. He's an associate professor of oncology and neurosurgery at the Kimmel Cancer Center.
As researchers and a number of laboratories have to date found no evidence of cytomegalovirus (CMV) in glioma tumour tissue, it can reasonably be assumed that any connection is unlikely.
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