Scientists may have discovered why lifelong smokers never get lung cancer. That may sound silly, especially considering that cigarettes are the number one risk factor for lung cancer. Despite the fact that tobacco products are the cause of 90 percent of deaths, lifelong smokers somehow tend to avoid lung cancer. Now, science may have finally figured out why this is.
Some smokers never get lung cancer - and this study may have found why
DNA repair genes may keep some smokers from getting lung cancer, according to new findings published in Nature Genetics. Researchers found an inherent advantage in many smokers who never developed lung cancer. They found that the cells lining the lungs were less likely to mutate over time.
Essentially, because some smokers have very active DNA repair genes in their bodies, they protect that person from forming cancer cells. This is an intriguing finding that could ultimately explain why some smokers never get lung cancer.
The researchers looked at the genetic characteristics of bronchial basal cells in 33 participants. All participants were between 11 and 86 years of age. 14 participants had never smoked, while the other 19 had a history of light, moderate and heavy smoking.
They then sequenced surface cells collected from the participants' lungs to measure mutations in their genomes.
Multiplication of mutations
The results showed that these lung cells survived for many years. And these mutations accumulate as a person ages and continues to smoke. These are also the lung cells most likely to turn into cancer, a lung expert at Albert Einstein College of Medicine noted in a statement.
But most interestingly, after smoking a pack of cigarettes a day for about 23 years, scientists found a dramatic drop in the risk and mutation rate of these cells. Thus, some lifelong smokers will never get lung cancer because the mutation rate changes so dramatically.
This is because their DNA is able to repair the body before the cell mutation develops into a tumor. Scientists say these DNA repair genes can be either inherited or acquired. And exactly what makes a person's body more adept at repairing DNA remains a mystery.
However, according to the results of this study, it may play a large role in why 80 to 90 percent of lifelong smokers never develop lung cancer.
However, even with this knowledge, the risk associated with smoking is still very high. Geneticists plan to develop new methods to measure a person's ability to repair their DNA. This could help us better understand the role that DNA repair plays in why lifelong smokers never get lung cancer. In addition, it could even help us more effectively assess a person's risk of developing lung cancer.