Quit smoking after cancer diagnosis to survive

The findings demonstrate that it's not too late to stop smoking after being diagnosed with cancer, researchers say.

They used data from a study conducted in China among men aged 45 to 64, starting between 1986 and 1989. Researchers determined that more than 1,600 among them had developed cancer by 2010.

Of those men, 340 were non-smokers, 545 had quit smoking before their cancer diagnosis and 747 were smokers at the time they were diagnosed.

Higher risk of death

Among the smokers, 214 quit after diagnosis, 336 continued to smoke occasionally and 197 continued to smoke regularly.

Compared to men who did not smoke after a cancer diagnosis, those who smoked after diagnosis had a 59% higher risk of death from all causes. Researchers accounted for factors including age, cancer site and treatment type.

Among men who were smokers at diagnosis, those who continued smoking after diagnosis had a 76% increased risk of death from all causes compared to those who quit, according to the study published in the journal Cancer Epidemiology, Biomarkers & Prevention.

Compared to men who quit smoking after cancer diagnosis, the higher risk of death among those who continued smoking varied with different types of cancer: 2.95-fold for bladder cancer, 2.36-fold for lung cancer and 2.31-fold for colorectal cancer.

Worthwhile quitting

"Many cancer patients and their health care providers assume that it is not worth the effort to stop smoking at a time when the damage from smoking has already been done, considering these patients have been diagnosed with cancer," study author Dr Li Tao, an epidemiologist at the Cancer Prevention Institute of California, said in a journal news release.

But the study contradicts that assumption and instead suggests that efforts to quit are indeed worthwhile.

"As far as we know, only a fraction of cancer patients who are smokers at diagnosis receive formal smoking cessation counselling from their physicians or health care providers at the time of diagnosis and treatment, and less than half of these patients eventually quit smoking after the diagnosis," Tao said. "Therefore, there is considerable room for improvement with regard to tobacco control [after diagnosis] for the growing population of cancer survivors."

Although the study found a higher death risk among men with cancer who keep smoking, it did not prove a cause-and-effect relationship.

More information

The American Cancer Society offers a guide to quitting smoking.