|
 Researchers examined data from previous studies with a total of
22,549 men with prostate cancer that hadn't spread to other parts of
the body. The cancers were treated with either surgery or radiation.
Overall, nearly one in five were current smokers. The rest were
either former smokers or had never smoked.
The researchers tracked half the men for at least six years. During
follow-up, compared to men who never smoked, current smokers were 40
percent more likely to have tumors return after treatment and more
than twice as likely to have cancer spread beyond the prostate.
Smokers were also 89 percent more likely to die from cancer.
"Prostate cancer diagnosis, even when it is not associated with
tobacco smoking, is a teachable moment for patients to quit
smoking," said senior study author Dr. Shahrokh Shariat of the
Medical University of Vienna in Austria.
"Former smoking was associated with higher risk of relapse, but not
with spread or cancer-specific death, which underlines the
importance of smoking cessation in improving disease outcome,"
Shariat said by email. In fact, he added, men who had stopped
smoking more than 10 years earlier "were not significantly different
than patients who had never smoked."
Not all men with localized prostate tumors get aggressive treatment
with surgery or radiation. Often, men with these types of tumors
will opt for more conservative alternatives, such as watchful
waiting or hormone therapy to shrink tumors without surgery or
radiation.
Smoking has long been linked to an increased risk of death from a
range of malignancies including tumors of the lung, bronchus,
trachea and larynx, stomach and kidney.
"We know that tobacco smoking produces more than 70 carcinogens,"
Shariat said.
It's not clear exactly how smoking might lead prostate cancer to
develop or make it more aggressive or more fatal. One possibility is
that smoking causes inflammation, which in turn encourages tumors to
grow, or that nicotine leads malignancies to spread, Shariat said.
[to top of second column] |
The smaller studies in the current analysis that looked at
cancer-related deaths had a total of 7,924 participants. Overall,
654 men, or about 8 percent, died by the time researchers had
followed half of them for about eight years.
The current study wasn't a controlled experiment designed to prove
whether or how smoking influences the odds of dying from prostate
cancer. Researchers also based the analysis on smoking status when
patients were in treatment, and it's possible some patients might
have stopped or started smoking after that.
Smokers also might be less compliant with treatment than nonsmokers,
said Dr. Stephen Freedland, author of an accompanying editorial and
director of the Center for Integrated Research on Cancer and
Lifestyle at Cedars-Sinai Medical Center in Los Angeles.
But because the study looked at men undergoing aggressive treatment,
it's unlikely that noncompliance influenced patient outcomes,
Freedland said by email.
"Cigarettes themselves have chemicals that can cause cancer,"
Freedland said.
"This is more clear in the lung where the smoke is inhaled,"
Freedland added. "However, the fact that prostate cancer death is
linked with smoking means (these cancer causing) chemicals are not
just present in the lungs but absorbed in the body and make their
way to the prostate and, as such, they probably make their way into
every organ in our body."
SOURCE: http://bit.ly/2M2LqFg and http://bit.ly/2M0M6Ls JAMA
Oncology, online May 24, 2018.
[© 2018 Thomson Reuters. All rights
reserved.] Copyright 2018 Reuters. All rights reserved. This material may not be published,
broadcast, rewritten or redistributed.
Thompson Reuters is solely responsible for this content. |
