Prostate cancer, say scientists, may actually be a sexually transmitted disease passed on during sex.
Researchers at the University of California who worked with Professor Johnson's research group at UCLA and Professor Pier Luigi Fiori's group at The University of Sassari looked at human prostate cells and found that a sexually infection, trichomoniasis actually helps cancer growth.
"Trichomoniasis," reports The Independent, "is the most common non-viral sexually transmitted infection and is understood to have infected an estimated 275 million people around the world."
The NHS says: "Trichomoniasis is a sexually transmitted infection (STI) caused by a tiny parasite called Trichomonas vaginalis (TV). Symptoms of trichomoniasis usually develop within a month of infection, although up to half of all infected men and women have no symptoms.
"Infected men may experience pain during urination and a thin white discharge from the penis."
However, although some cancers can be caused by infections - for instance cervical cancer - Cancer Research UK says more work needs to be done before prostate cancer is added to the list.
The BBC reported Nicola Smith from the charity as saying: "There are still no known lifestyle factors that seem to affect the risk of developing the disease - and no convincing evidence for a link with infection.”
However, this is something the researchers agree with. The team, led by Professor Patricia Johnson "found the parasite responsible for causing trichomoniasis, Trichomonas vaginalis, produces a protein that in turn promotes the growth and progression of benign and cancerous prostate cells."
The authors agree more research is needed as the cause of prostate cancer is still unknown and their study does not prove an absolute link between the STI and cancer of the prostate.
Their research appeared in the journal Proceedings of the National Academy of Sciences (PNAS).