It’s NEVER Too Late –

Jan. 29, 2020 – The overwhelming majority of cells taken from a smoker’s airways had been mutated by tobacco, with cells containing up to 10,000 genetic alterations. 

“These can be thought of as mini time bombs, waiting for the next hit that causes them to progress to cancer,” said Dr Kate Gowers, one of the researchers at UCL.

But a small proportion of cells went unscathed.

Exactly how they avoid the genetic devastation caused by smoking is unclear, but the researchers said they appeared to “exist in a nuclear bunker”.

However, after someone quits smoking, it is these cells that grow and replace the damaged cells in the lungs. 

Motivation to quit

The researchers still need to assess how much of the lungs are repaired. The study focused on the major airways rather than the small structures called alveoli, where oxygen crosses from the air we breathe into our lungs.

There are about 47,000 cases of lung cancer in the UK each year. Nearly three-quarters of them are caused by smoking.

Studies have already shown that people cut their risk of lung cancer almost from the day they quit.

The assumption had been that this was simply because any further mutations caused by smoking were avoided.