Snippet from the article:
Prostate cancer might be a sexually transmitted disease caused by a common infection, according to a study. Experts say the research has limitations and is not proof, though.
Scientists at the University of California found evidence of a link between prostate cancer and the STD trichomoniasis, in which a common parasite is passed on during unprotected sexual contact.
The parasite is believed to infect around 275 million people worldwide. Furthermore, over three-quarters of men harboring it have no symptoms and may not seek treatment, resulting in chronic inflammation of the prostate.

Read the rest — Prostate Cancer ‘Could Be Transmitted Sexually’
The prostate cancer/STD link isn’t confirmed and the article points out that this research was done in a lab setting (not in actual patients). As always, more research is needed.
