NEW
YORK: Younger people with advanced lung cancer who quit smoking more
than a year before their diagnosis survive longer than those who
continue smoking, according to a new study.
It's known that
people who never smoked are more likely to survive the disease than
those who light up. But whether former smokers do any better than
current ones has been less clear.
"The findings do suggest there
is some benefit to quitting smoking," said Amy Ferketich of Ohio State
University College of Public Health in Columbus, who worked on the
study.
However, quitters who were older or who had earlier stages
of lung cancer did not have an advantage over smokers, she and her
colleagues report in the journal Cancer.
Ferketich's group used
medical records from 4,200 lung cancer patients treated at eight cancer
centers around the country. Patients who never smoked were more likely
to survive the less advanced cancers - stage 1, 2 or 3 - than were
former or current smokers, the researchers found.
Among smokers
with stage 1 or 2 lung cancer, for instance, 72 percent survived at
least two years, compared to 93 percent of the never-smokers and 76
percent of people who'd kicked the habit a year or more before
diagnosis.
Only 15 percent of smokers with stage 4 disease
survived two years, while 40 percent of never-smokers and 20 percent of
former smokers did.
After adjusting the numbers for factors such
as age, race and radiation treatment, the researchers determined that
quitters were just as likely to die from the early-stage cancers as were
current smokers.
But for advanced cancers, people under 85 who
had stopped smoking more than a year before their diagnosis survived
longer than smokers. Forty-five-year-old former smokers, for instance,
were 30 percent less likely to die from stage 4 lung cancer within two
years than were current smokers.
Smoking is the number one risk
factor for developing lung cancer, and studies have shown that people
who quit are less likely to get it than current smokers.
It's not clear why smokers already diagnosed with lung cancer fare worse than non-smokers, Ferketich said.
"In
general, never smokers are healthier individuals, so they tend to, in a
lot of trials, have better outcomes with disease than people who
continue to smoke," she said. "Just the continued exposure to tobacco
might make the disease progress more quickly in smokers compared to
never-smokers who don't have that exposure."
Ferketich said it's
also possible that smoking could influence the biology of the cancer,
and perhaps smokers get tumors that never-smokers are less likely to
develop. She added that it's never too late to quit.
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