Each extra year of life adds 22 mutations in healthy lung cells genome, but tobacco smoke adds on average 5,300 more point mutations per healthy lung cell. Moreover, smoker’s genome accumulates other types of alteration too, such as insertions or deletions. This mutational potency was confirmed by a study published on Nature by a team of researchers lead by Sam H. Janes (University College London) and Peter J. Campbell (University of Cambridge), and lies at the base of smoking lung cancer-inducing potential.

Smoke and lung cancer

Tobacco smoke is associated with different form of cancer. In particular, smokers have a 30-fold higher risk of developing lung cancer than non-smokers.
It is well known that cancer-promoting effects of tobacco smoke lie on DNA damage induction. Also, it is well known that cancer development can take several decades, during which it is never too late to take actions against cancer development.

The new study

This new study reveals that in current smokers at least 25% of healthy lung cells carry lung cancer driver mutations (that is mutations promoting lung cancer development), and up to 6% of healthy lung cells have 2 or 3 driver mutations.

Moreover, the study highlights the benefits of quitting smoking too. In fact, Janes, Campbell and collaborators discovered that:

  • mutational burden in former smokers is lower than in current smokers (2,330 point mutation per lung cells);
  • less damaged cells (with a mutational burden equivalent to the one expected for people who never smoked) are 4-fold more frequent in former smokers than in current smokers;
  • less damaged cells in former smokers have considerably longer telomeres (the structures that protect chromosome from damage and aging).

Based on these data, study authors conclude that tobacco smoking increases mutation burden, but quitting promotes replenishment of lung epithelium from cells without tobacco smoke-induced mutations.

Is it time to run for cover?

Nowadays, both current and former smokers can discover if it is time to run for cover and take action against tobacco smoke-associated DNA damage before it induces cancer development. In fact, newest sequencing techniques allow the identification of cancer-associated mutations in DNA fragment circulating in the blood. In particular, HelixMoker is Bioscience Institute‘s lung cancer primary prevention program based on the monitoring of mutations in 11 genes and 169 hotspots directly involved in respiratory system cancers.

Working on a simple blood sample, HelixMoker is specifically designed for people at high risk of lung and other respiratory system cancers, such as smokers. Thanks to this prevention program, smokers can undergo a yearly checkup of their mutational profile to monitor for the potential onset of lung cancer.

For more informations, visit HelixMoker webpage or call us at +971 (0)4 375 7220.

References

  • Pfeifer GP. Smoke signals in the DNA of normal lung cells. Nature. 2020 Feb;578(7794):224-226. doi: 10.1038/d41586-020-00165-7
  • Yoshida K et al. Tobacco smoking and somatic mutations in human bronchial epithelium. Nature. 2020 Feb;578(7794):266-272. doi: 10.1038/s41586-020-1961-1
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