The study of cancer patients who smoke found that those using
e-cigarettes as well as tobacco cigarettes were more nicotine
dependent and equally or less likely to have quit than those who
didn't use e-cigarettes.
The scientists behind the research, which was published online in
Cancer, the journal of the American Cancer Society, said their
results raised doubts about whether e-cigarettes had any benefit in
helping cancer patients to give up smoking.
But that conclusion was questioned by other tobacco and addiction
researchers, who said the selection of patients for the study had
given it an inherent bias.
The uptake of e-cigarettes, which use battery-powered cartridges to
produce a nicotine-laced vapor for the "smoker" to inhale, has
rocketed in the past two years, but there is fierce debate about
their potential risks and benefits.
Because they are new, there is a lack of long-term scientific
evidence on their safety. Some experts fear they could lead to
nicotine addiction and be a gateway to tobacco smoking, while others
say they have enormous potential to help millions of smokers around
the world to quit.
What few studies there are give a mixed picture, with some
concluding that e-cigarettes can help people give up a deadly
tobacco habit, while others suggest they may carry health risks of
A World Health Organization (WHO) report last month called for stiff
regulation of e-cigarettes as well as bans on indoor use,
advertising and sales to minors.
But that report itself was also criticized by experts who said it
contained errors, misinterpretations and misrepresentations.
For the Cancer journal study, researchers led by Jamie Ostroff of
the Memorial Sloan Kettering Cancer Center in New York City studied
1,074 cancer patients who smoked and who were enrolled between 2012
and 2013 in a tobacco treatment program at a cancer center.
They found a three-fold increase in e-cigarette use from 2012 to
2013 - rising from 10.6 percent to 38.5 percent.
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At enrolment onto the program, the researchers' analysis found, the
e-cigarette users were more nicotine dependent than non-users, had
more prior quit attempts, and were more likely to be diagnosed with
lung or head and neck cancers.
By the end of the study period, the researchers said, e-cigarette
users were just as likely as non-users of e-cigarettes to be
But Robert West, director of tobacco research at University College
London, said the study was not able to assess whether or not for
cancer patients who smoke using an e-cigarette to try and quit is
beneficial "because the sample could consist of e-cigarette users
who had already failed in a quit attempt, so all those who would
have succeeded already would be ruled out".
Peter Hajek, director of the Tobacco Dependence Research Unit at
Queen Mary, University of London, agreed that the study's data did
not justify the conclusions.
"The authors followed up smokers who tried e-cigarettes but did not
stop smoking, and excluded smokers who tried e-cigarettes and
stopped smoking," he said.
"Like smokers who fail with any method, these were highly dependent
smokers who found quitting difficult. The authors concluded that
e-cigarette (use) was not helpful, but that would be true for any
treatment however effective if only treatment failures were
(Editing by Mark Potter)
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