Oct 12 Younger people with advanced lung cancer
who quit smoking more than a year before their diagnosis survive
longer than those who continued smoking, according to a U.S.
However, quitters who were older or who had earlier stages
of lung cancer did not have an advantage, said the researchers,
whose findings appeared in the journal Cancer.
It's known that people who never smoked are more likely to
survive the disease, but whether former smokers do 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.
Her 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, but 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.
(Reporting from New York by Kerry Grens at Reuters Health;
editing by Elaine Lies)