What Causes Prostate Cancer?

We don't know what causes prostate cancer, but a study from Harvard School of Public Health shows an association between the common sexually transmitted infection, Trichomonas vaginalis, and risk of the type of prostate cancer that kills (Journal of the National Cancer Institute, September 9, 2009). Researchers analyzed blood samples collected in 1982 from 673 men who were diagnosed with prostate cancer more than ten years later. Trichomonas vaginalis infection was associated with a more than triple risk for the type of prostate cancer that kills.

Trichomonas vaginalis infects about 174 million people each year and is the most common non-viral sexually transmitted infection. Up to three-quarters of men infected with Trichomonas vaginalis may have no symptoms at all. Trichomanes can usually be cured just by having all sexual contacts take metronidazole for five to ten days.

Several other cancers are caused by bacterial infections. For example, the bacterium Helicobacter pylori is the most common cause of stomach cancer. Bacteroides fragilis, a bacterium that causes diarrhea, has been associated with colon cancer (Nature Medicine, September, 2009). Chronic infections activate your immune system to cause inflammation, which can block apoptosis to cause cancer.

More than 90 percent of prostate cancers probably should not be treated because they cause no harm. A study in the Journal of the American Medical Association (September 15, 2009) followed men with early stage prostate cancer who were cared for without surgery or radiation. Ten years later, only six percent had died from prostate cancer. The average time from diagnosis to death for untreated prostate cancer is more than 22 years. However, five percent of prostate cancers may need immediate treatment as they grow rapidly and can kill. A reliable test that tells which prostate cancers are likely to kill would save anxiety, potency and continence for a lot of men. Such a test is not available at this time. The authors of this study recommend that doctors and patients reconsider the watch and wait option. More on prostate cancer