Analysis: Protective lungs cells replenish in ex-smokers reducing cancer risk

Research co-led by UCL has discovered that protective cells in the airways of ex-smokers could explain why quitting smoking reduces the risk of developing lung cancer. Here senior author, Professor Sam Janes (UCL Medicine), writes about the research and explains its importance. We know that quitting smoking is an excellent way to reduce your risk of developing lung cancer. But until now, experts weren't quite sure why this was the case. Our latest research has uncovered that in people who quit smoking, the body actually replenishes the airways with normal, non-cancerous cells that help protect the lungs, in turn reducing their risk of getting cancer. Cancer develops when a single rogue cell acquires genetic changes, called mutations, that instruct that cell to ignore all the normal constraints on its growth, causing it to rapidly replicate out of control. Throughout our lives, all of our cells acquire mutations at a steady rate - around 20-50 mutations per cell per year.