Prostate cancer could be sexually transmitted

New research has suggested that a common, sexually-transmitted infection could lead to the development of prostate cancer, though a leading charity has said it is too early to make the claim.

A study conducted by a team at the University of California has indicated that prostate cancer could be caused by an infection passed on during intercourse. However, Cancer Research UK has said there is not enough evidence to add the disease to the list of cancers caused by infections.

The researchers tested human prostate cells in the lab and found that a sex infection called trichomoniasis helped cancer to grow. Around 275 million people are thought to be infected with trichomoniasis, making it the most common non-viral, sexually-transmitted infection.

Published in the journal Proceedings of the National Academy of Sciences (PNAS), the team cited that more research would be needed to confirm the link. The study suggests that the infection could make men more vulnerable to prostate cancer, though there is not enough evidence to prove this yet.

The study, led by Professor Patricia Johnson, found the parasite that causes trichomoniasis - trichomonas vaginalis - secretes a protein, which causes inflammation and the increased growth of benign and cancerous prostate cells.

This is not the first time that a link has been made between infections and prostate cancer. In 2009, the Harvard School of Public Health conducted research showing that a quarter of men with prostate cancer showed signs of trichomoniasis, making them more likely to have advanced tumours.

More research is needed to pursue the finding as scientists are still unaware of what causes prostate cancer.

Nicola Smith, health information officer at Cancer Research UK, told the BBC: "This study suggests a possible way the parasite trichomonas vaginalis could encourage prostate cancer cells to grow and develop more quickly."

However, she added that research was only conducted in the lab and more evidence is necessary to establish a link between prostate cancer and the common sexually-transmitted infection.