150 Lung Cell Mutations Each Year from Cigarette Smoking

Smoking Causes Cell Mutations or Genetic Damage

Background: A cell mutation is the permanent change in the sequence, or order, of the DNA in genes within a cell. Cell mutations play a part in both cancer and the immune system (fights infection and inflammation). Mutations may be harmless, but the more there are, the greater the risk that one or more of them will wind up causing cancer.
Cigarette smoking causes 150 cell mutations each year

Cigarette smoking causes 150 cell mutations each year in the lung

Study Results: On November 3, 2016, researchers reported in the journal Science a direct link between the number of cigarettes smoked in a lifetime and the number of mutations in cells. The findings are based on a genetic analysis of 5,243 cancers, including 2,490 from smokers and 1,063 from patients who said they had never smoked tobacco cigarettes. In lung cells, there were on average 150 mutations in each cell each year with smoking a pack of cigarettes per day. Smoking did not only affect cells in the lung. On average, there were 97 mutations in each cell of the larynx (voice box), 39 mutations for the pharynx (throat), 18 for the bladder, and 6 mutations in every cell of the liver each year.
Number of cell mutations due to smoking a pack per day

Number of cell mutations due to smoking a pack per day

Conclusions: “The way tobacco smoking causes cancer is more complex than we thought,” commented study coauthor Dr. Mike Stratton, director of the Wellcome Trust Sanger Institute in England. The researchers said they think these kinds of mutations have the effect of speeding up the “clock” inside of cells. The faster a cellular clock runs, the more chances the cell’s DNA has to mutate. My Comments: This study provides clear proof that cigarette smoking causes cancer. Smoking kills 6 million people a year worldwide. If the current trend continues, the World Health Organization predicts more than 1 billion tobacco-related deaths in this century. If you smoke, ask your health care provider for help to quit. Medications are available to help people quit smoking, while numerous professional organizations offer various support services.  

Donald A. Mahler, M.D. is Emeritus Professor of Medicine at Geisel School of Medicine at Dartmouth in Hanover, New Hampshire. He works as a pulmonary physician at Valley Regional Hospital in Claremont, NH, where he is Director of Respiratory Services.