Older patients and those with earlier stages of cancer, however, do not have this advantage.
Until recently it was only known that people who have never smoked are more likely to survive the disease, but whether former smokers fared better than continuing with the habit is unclear.
According to Amy Ferketich the University of Ohio, the study confirms that quitting smoking also brings health benefits. Her research group studies the medical records of 4,200 patients at eight medical centers in the U.S..
Patients who never smoked and have less advanced lung cancer in stage 1, 2 or 3 experienced disease more often than ex-smokers. Of smokers with cancer in the first or second stage, 72% experienced two or more years after diagnosis, while the figure is 93% for non-smokers and 76% former smokers.
15% of smokers with stage IV cancer survive two years, while non-smokers and ex-smokers the figure is 40 and 20%, respectively.
After adjusting for differences in age, race and radiotherapy, the researchers concluded that there is equal probability of death for former and current smokers with early-stage cancer. In advanced malignancies, however, patients under 85 years of age who had stopped smoking more than a year before diagnosis, are more likely to live longer than those who continue to use tobacco. For a 45-year ex-smoker, for example, the probability of death was 30% lower than the current one.
Researchers believe that continued exposure to tobacco smoke accelerates the progression of the disease. Furthermore, it is possible to influence smoking and biochemistry of the tumor, because current and former smokers develop cancers other than those of full teetotalers.
However, it is never too late to quit ...