Cancer survivors are about 50 percent more likely to quit smoking two years after their diagnosis than smokers without cancer, a new study found.
While the finding buttresses the theory that a cancer diagnosis can be a "teachable moment" to promote smoking cessation, the study also revealed that a such diagnosis isn't enough to get many smokers to quit.
Almost 70 percent of study participants were smoking at least two years after their diagnosis, and 57 percent were still smoking four years after being diagnosed with cancer.
"This speaks to the difficulty of quitting an addiction," said study lead author J. Lee Westmaas, director of Tobacco Control Research at the American Cancer Society's Behavioral Research Center.
"We also know there's evidence that cancer patients who have smoked are not followed up to see if they have quit smoking and are often not actively supported in quitting. Getting that support and follow-up could help many quit," he said.
The new study looked at smokers diagnosed with cancers whose effects typically don't force smokers to involuntarily stop smoking. The idea was to look at the effects of a diagnosis on smokers who wouldn't be forced to quit by their disease.
The study authors launched the research because "we know a fair amount about smoking's effect on cancer but relatively little about cancer's effect on smoking," Westmaas said. "A few previous studies had suggested that a cancer diagnosis might influence quitting, but they focused on a particular cancer, or used small samples of smokers."
The researchers examined statistics from a U.S. survey from 1992 to 2009. They then looked at quit rates at two years and four years after diagnosis. Each analysis included more than 12,000 smokers -- some with cancer, and many without.
Of nearly 800 smokers diagnosed with cancers that fit the study's inclusion criteria, 31 percent had quit at the two-year mark, compared to 19.5 percent of those who weren't diagnosed with cancer.
At the four-year mark, the researchers found 900 smokers with cancers that fit the inclusion criteria. Forty-three percent had quit smoking, compared to 34 percent of those who didn't have cancer.
Deborah Mayer, a professor at the School of Nursing and director of the Cancer Survivorship at University of North Carolina at Chapel Hill, reviewed the study findings and said "it is heartening to see that a diagnosis of cancer can increase smoking cessation."
The researchers aren't sure why smokers quit -- or didn't quit -- because the survey didn't ask.
"One possibility is that getting a diagnosis may make smokers think about all the ways they can try to be healthy so they can fight the cancer," Westmaas said. "That might include getting more exercise or changing their diet."
What can loved ones do to help smokers quit?
Mayer said they should quit themselves if they smoke.
"Many smokers live with other smokers. If loved ones are smokers, the biggest thing they can do to be helpful is to quit themselves to make it easier for the person with cancer to quit as well," she said.
Westmaas recommends against a hard-sell approach based around a message like, "You're gonna die."
"One approach," he said, "would be to express caring and concern about a loved one's smoking in a non-confrontational manner, recognize the difficulty of quitting, and offer quitting information or resources."
The study appears online April 20 in the Journal of Clinical Oncology.