Prostate cancer is the most common cancer amongst men in this country. At autopsy, 60% of men aged 60 were found to have the disease in their prostate tissue. And aside from skin cancer (which is the leading cause of death from cancer amongst American men), prostate cancer is the second most fatal cancer affecting males in the US. For the most part, it is diagnosed in men over the age of 65, but often begins far earlier in life. Digital Rectal Examination is used by MDs during physicals for early detection, especially in men over fifty years of age. Prostate cancer easily metastasizes to lymph, lungs, bones and brain.
But what causes this epidemic of prostate cancer? Recent research strongly suggests an infectious agent is involved, and that this micro-organism is sexually transmitted. Simply put, prostate cancer may be the late, end result of an STD. This would not be entirely surprising, as 20% of all visceral cancers, such as cervical cancer, are now proven to be caused by infectious agents. At this point, research is not conclusive linking prostate cancer to a sexually transmitted virus, however further studies are ongoing.
The principal suspect is a gamma retrovirus, XMRV (xenotropic murine leukemia related virus.) Researchers at Columbia University and the University of Utah found the virus in more than a quarter of some 300 prostate cancer tissue samples, especially in malignant cells. In July of this year, Researchers at the Cleveland Clinic in Ohio reported that both human semen and one of its major components, acid phosphatase, increase XMRV infectivity for prostate cells 100-fold. They also found the virus in prostatic secretions of men with prostate cancer. If a man with viral particles in his lower genital tract has intercourse and deposits semen in his partner, acid phosphatase in the semen could increase the virus’s ability to infect prostate tissue of the partner’s subsequent partners.
Eric Klein at the Cleveland Clinic explains a “domino effect” in sexually transmitted prostate cancer: If a man with viral particles in his lower genital tract has intercourse and deposits semen in his partner, acid phosphatase in the semen could increase the virus’s ability to infect prostate tissue of the partner’s subsequent partners.
The research team at the Cleveland Clinic have shown that XMRV integrates into host DNA. In other words, the virus inserts itself close by a gene that signals cell growth. Hence, epithelial proliferation will occur, giving rise to tumor growth.
If the STD hypothesis turns out to be correct, prevention and treatment of prostate and other visceral cancers will involve ) Protection from infection 2) Strengthening the immune system to kill off the virus early on.