There is an accumulating body of evidence suggesting that a very common sexually transmitted disease could be contributing to the spread of prostate cancer in men.
The STD is trichomoniasis, also called trichomonas, a parasite.
What is troublesome is that half the people infected don't have any symptoms so they could be passing it on for years if they aren't using condoms.
Trichomonas is the number one STD in women. Women run a greater risk of complications during pregnancy and HIV because of the parasite.
There's a new study of the University of California which supports previous research that this STD activates several proteins including the protein PIM-1, which promotes the growth of cancer cells, particularly cancer cells in the prostate.
These researchers acknowledge that more study is needed to confirm the link.
Other studies have indicated this parasite may be responsible for 25 to 40 percent of all prostate cancer, especially the rapidly advancing type.