Dylan Stoll | Health Editor
Featured Image: There is still hope for those long-term smokers looking to “butt out” for good. | Courtesy of Pixabay
If there’s one phrase that’s most common among heavy, long-term smokers it’s “the damage is done.” But what if that damage was reversible?
Research conducted in the UK as part of a larger, $26-million endeavour involving the Wellcome Sanger Institute and the University College London (UCL), referred to as the Mutographs of Cancer project: a Cancer Research UK Grand Challenge initiative, found that in relation to current smokers, former long-term smokers have more genetically healthy lung cells which are much less likely to develop into cancerous cells.
This finding essentially shows that smokers, even those who have been smoking for 30 to 40 years, still have the ability to rejuvenate the inner cellular lining of their airways.
Joint senior author of the study, Dr. Peter Campbell from the Wellcome Sanger Institute, explained the significance of their team’s research.
“What is so exciting about our study is that it shows that it’s never too late to quit — some of the people in our study had smoked more than 15,000 packs of cigarettes over their life, but within a few years of quitting, many of the cells lining their airways showed no evidence of damage from tobacco.”
Their analysis of 16 lung biopsies belonging to smokers, former smokers, non-smokers and children determined that 90 per cent of the lung cells of those who smoked contained an average of 10,000 mutations. Of the 632 non-cancerous cells analyzed from each biopsy, more than a quarter contained what are known as cancer-driver mutations — genetic changes that are understood to increase the risk of the host cell becoming cancerous.
Dr. Kate Gowers, joint first author from UCL, clarified that even though these are non-cancerous cells, they “can be thought of as mini time-bombs waiting for the next hit that causes them to progress to cancer.”
However, in former smokers it was found that a significant amount of lung cells had avoided the damage — approximately 40 per cent. In comparison to a smoker, this amounted to four times more cells that are just as healthy as a non-smoker’s lung cells.
“Our study has an important public health message and shows that it really is worth quitting smoking to reduce the risk of lung cancer. Stopping smoking at any age does not just slow the accumulation of further damage, but could reawaken cells unharmed by past lifestyle choices,” said Professor Sam Janes, joint senior author from UCL.
“Further research into this process could help to understand how these cells protect against cancer, and could potentially lead to new avenues of research into anti-cancer therapeutics.”
