Researchers suspect the connection may be the lower rate among
circumcised men of sexually transmitted diseases (STD), which raise
prostate cancer risk, but they caution that more study is needed to
confirm that theory.
“It’s still premature to say go ahead with circumcision to prevent
prostate cancer,” said lead author Marie-Elise Parent. “But, we
think it could be helpful.”
Based on interviews with more than 3,000 men, her team found that
those circumcised as infants were 14 percent less likely than
uncircumcised men to develop prostate cancer. The men who had been
circumcised as adults were 45 percent less likely to develop the
cancer than uncircumcised men.
Researchers have long known that Muslim and Jewish men have lower
rates of prostate cancer than men in the West, suggesting that
circumcision may play a role in cancer risk, the study team writes
in the British urology journal BJU International.
To investigate the connection, Parent, a cancer epidemiologist at
the University of Quebec’s INRS-Institut Armand-Frappier in
Montreal, and her colleagues recruited 3,208 men in the Montreal
area.
The participants were all between 40 and 75 years old when they were
recruited and 1,590 of them had been diagnosed with prostate cancer.
The other 1,618 men did not have prostate cancer but were otherwise
similar in health and age.
Between 2006 and 2011, all the men were interviewed at home, with
in-depth questions about their health and lifestyle, medical
history, family history of cancer and work history.
Overall, 40 percent of white men and 30 percent of black men
interviewed were circumcised.
For the entire group, researchers found an 11 percent lower risk of
having prostate cancer among circumcised men, but noted that it was
not statistically significant, meaning it could have been due to
chance.
The team did find a significant difference among circumcised black
men, who were 60 percent less likely than uncircumcised men to have
prostate cancer.
“Black men have the highest rate (of prostate cancer) on the planet
and we don’t know why,” Parent told Reuters Health. “It’s really
puzzling trying to figure out why this cancer is so common in men
that live in industrialized countries, when we understand so little
about what’s going on with it and have no way of preventing it.”
The National Cancer Institute estimates that in the U.S., almost
three million men are living with prostate cancer. It is the second
leading cause of cancer deaths among men.
About 79 percent of U.S. men born in the 1970s and 1980s were
circumcised as babies, according to Dr. Aaron Tobian of Johns
Hopkins University in Baltimore, Maryland. But the circumcision rate
has been declining, he told Reuters Health.
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Among males born in the U.S. in 1999, 62.5 percent were circumcised,
and by 2010, the rate among newborns was below 55 percent, Tobian
said.
Medicaid does not typically cover the procedure, which could lead to
exaggerated socio-economic differences in STD-related health, Tobian
added. “Insurers are also trending toward decreasing coverage for
circumcision,” he said.
Dr. Christopher Cooper, a professor and urologist at the University
of Iowa told Reuters Health that the Canadian study does not justify
promoting circumcision as prostate cancer prevention
The number of black men studied was too small for any conclusions to
be drawn, he notes. Only 103 of the participants with prostate
cancer were black men, and only 75 of the healthy men in the
comparison group were black.
“The STD mechanism is possible but quite a stretch,” Cooper said. He
also pointed out that there were certain factors the researchers
could not control in the study, such as how honest participants were
about having STDs or, among the men circumcised as adults, the
reason for their circumcision.
Parent told Reuters Health that even though the study was small, and
she and her colleagues saw only a slightly reduced risk later in
life among men who were circumcised as babies, the work is one more
thing to consider when studying prostate cancer.
“We are too early in the game to make it a public recommendation. It
could be that in the future it will be confirmed that it’s a good
thing and may have an added protection from other diseases,” she
added.
SOURCE: http://bit.ly/1mNIuIN
BJU International, online May 28, 2014.
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