Is Prostate Cancer Caused by Virus?

The causes of prostate cancer are still mysterious, but researchers are now looking at a virus to see whether infection might be a contributing factor. Investigators found evidence of a virus called XMRV in almost a third of the prostate cancers they studied. Doctors have had difficulty understanding why some prostate cancers grow so slowly they do not threaten the man’s life while other move quickly and are lethal.
One in six American men develops prostate cancer at some point during his lifetime, but many don’t need treatment because the tumor is slow-growing. The XMRV virus is strongly associated with more dangerous tumors. Cause and effect has not been determined, but if this link holds up, it might open the door to a vaccine against prostate cancer or to a way to identify more dangerous prostate tumors that require prompt and aggressive treatment.

[Proceedings of the National Academy of Sciences, online Sept. 8, 2009]