October 12, 2012
Quitters Show Higher Survival Rate From Lung Cancer Than Smokers
Connie K. Ho for redOrbit.com — Your Universe Online
Researchers recently discovered that, for young people diagnosed with advanced stage of lung cancer, quitting a year or more before the diagnosis would allow them to live longer than those patients who continued the habit.
For the study, the researchers were interested in finding out survival rates among individuals who were diagnosed with non-small-cell lung cancer (NSCLC) but who had also been either current smokers, former smokers, or people who had never smoked before. The participants were part of the National Comprehensive Cancer Network´s (NCCN) NSCLC Database Project; data was compared to the overall survival rate with the use of Cox regression models. The findings were compiled in the American Cancer Society's journal Cancer.
The scientists looked at data from around 4,200 patients who were treated at eight different cancer centers throughout the United States. In the group, 618 had never smoked, 1,483 were current smokers, 380 were past smokers who had quit between one to 12 months before the cancer diagnosis, and 1,719 were former smokers who had quit over 12 months before the cancer diagnosis.
When looking at patients who were either at stage one, two, or three of the disease, only patients who had never smoked before had better survival than current smokers. For patients in stage one or two of lung cancer, 93 percent of non-smokers survived a minimum of two years as opposed to 72 percent of current smokers and 76 percent of former smokers. For patients in stage four of lung cancer, age had an impact on survival rate.
According to the Reuters report, 40 percent of non-smokers who were diagnosed at stage four survived two years, as compared to only 15 percent of smokers and 20 percent of past smokers. For younger patients, there was a 12-month increase of survival for non-smokers compared to former smokers. For patients who were 85 years of age and older, smoking status did not have a significant influence on overall survival rate.
Based on the findings, the team of investigators concluded that patients who were smoking during the period of diagnosis had a weaker survival rate compared to people who had never smoked. For younger patients who were diagnosed with stage IV disease, current smokers had a weaker survival rate than smokers who had quit less than 12 months before the diagnosis. The researchers proposed that tumor biology could affect the results for survival.
Overall, the study showed it was important for all smokers to quit the habit if they were diagnosed with the disease and it was never too late to quit smoking.
According to the National Cancer Institute, tobacco smoke includes chemicals that are harmful for smokers and nonsmokers. Out of 250 harmful chemicals in tobacco smoke, 69 chemicals are known to cause cancer. As such, smoking affects almost every organ of the body.
"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," concluded Ferketich. "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."