Prostate cancer could be a sexually transmitted disease caused by a common infection passed on during intercourse, scientists say. Trichomoniasis is currently tested for in adult performers.

Research by the University of California found a sex infection called trichomoniasis supported cancer growth when a team of scientists tested human prostate cells in a laboratory.

Trichomoniasis is the most common non-viral sexually transmitted infection and is understood to have infected an estimated 275 million people around the world.

Testing for Trichomoniasis is included in PASS adult performer testing protocols.

Infected men can experience pain during urination and thin white discharge from the penis. In women, the infection may trigger soreness and itching around the vagina and a change in discharge, although half of all men and women show no symptoms at all.

The study, published in the Proceedings of the National Academy of Sciences (PNAS), discusses how the STI could make men more vulnerable to cancer. However, Cancer Research UK has said it is too early to add prostate cancer to a list of other cancers caused by infections.

This research follows a study conducted by the Harvard School of Public Health in 2009, which found a quarter of men with prostate cancer showed signs of trichomoniasis and were more likely to have advanced tumors.

Cancer Growth

Working in the laboratory, the researchers found that the parasite makes a protein similar to a human protein needed by the immune system. The human protein has also been shown to be involved in the growth of cancers, as it causes inflammation.

The scientists conclude that infection with the parasite, along with other factors, might trigger inflammation that could lead to cancer growth.

More research is needed though, they say.

‘No Clear Link’

Commenting in a statement, Nicola Smith, health information officer at Cancer Research UK, says: “This study suggests a possible way the parasite Trichomonas vaginalis could encourage prostate cancer cells to grow and develop more quickly. But the research was only done in the lab, and previous evidence in patients failed to show a clear link between prostate cancer and this common sexually transmitted infection.

“There’s been a lot of research into prostate cancer risk, and we’re working hard to piece together the puzzle. But there are still no lifestyle factors that seem to affect the risk of developing the disease – and no convincing evidence for a link with infection. The risk of prostate cancer is known to increase with age.”

WebMD/Fox23 / The Independent