Study Sheds Light on Why Most Smokers Don’t Get Lung Cancer
Smoking is a major risk factor for lung cancer. The harmful substances in cigarettes contribute to DNA mutations. However, heavy smokers do not necessarily carry more mutations than others, according to a study published in Nature Genetics. How can this be explained?

The researchers did not have the ability to sequence the entire genome of a single cell without sequencing itself producing mutations that are then difficult to distinguish from true mutations caused by cigarette smoke. The technique, which has been refined by researchers at Albert Einstein Medical School, is called SCMDA. It was used on basal bronchial cells from 33 participants between the ages of 11 and 86, with different smoking histories. “These lung cells can live for many years, even decades, and therefore can accumulate mutations with age and smoking.

It seems clear that long-term smokers accumulate more mutations, which increases the risk of cancer. But that’s not what the researchers observed. “The heaviest smokers did not have the highest number of mutations. Study data suggest that these individuals survived as long as they did, despite heavy smoking, because they were able to avoid accumulating additional mutations.”

This observation opens new avenues for investigating the efficiency of DNA repair mechanisms. It is currently difficult to assess the repair capacity of human DNA, but researchers hope to develop a test that makes this possible.