Guidelines for treating prostate cancer called further into question.
A new study reinforces the wait-and-see approach for some prostate cancer diagnoses. The research found that in a group of deceased men over 60 – none of whom died of prostate cancer – almost half harbored the disease. The men studied had lived in either Russia or Japan. Had these men been subject to North American cancer screening guidelines, they would have been subjected, on doctors' recommendations, to (ultimately) unnecessary and unpleasant treatments. "The study concludes that it is probably worth re-examining our current definitions of clinically unimportant and clinically significant prostate cancer," said lead author Dr. Alexandre Zlotta, director of uro-oncology at Mount Sinai Hospital in Toronto, Canada.
In total, 220 men from Russia and 100 in Japan had their prostate glands examined post-autopsy. The Caucasian population was selected for environmental cancer risk profiles similar to North Americans, such as reduced sun exposure and high-fat diets, said Zlotta. A second reason for studying these men is the lack of widespread prostate specific antigen (PSA) testing in Russia, as in the United States and Canada. PSA testing, the increasingly controversial standard for monitoring prostate health, casts a wide net; 17 percent of North American men get a prostate cancer diagnosis in their lifetimes, but only around 3 percent die from the malady, says Zlotta.
In those aged 60-plus, more than 40 percent of prostate glands showed signs of cancer, and nearly 60 percent did for the over-80 crowd. Importantly, about a quarter of the Caucasian group and half of the Asian group had cancers with a Gleason score of seven or greater, which would have prompted physicians in North American to recommend surgery or radiation. (The Gleason score rates prostate cancers based on how fast they might grow and spread; higher scores indicate higher risk.) Why Asian men, who have higher rates of aggressive prostate cancers compared to North American men, yet don't die from them, is unknown, Zlotta says, but could relate to their notably different lifestyles and diet.
The findings are in line with the American Urological Association's about-face in May, advocating that PSA testing should mainly be done on patients aged 55 to 69. The previous standard for testing had included men as young as 40 and on through their 70s. "Rather than detecting and treating all prostate cancers in the male population, it might make much more sense to try to further understand what are the biological differences between those cancers men die from and those they die with," says Zlotta.