Ravages in a lung cancer genome – one mutation for 15 cigarettes smoked every day
Research teams led by the British scientists from Wellcome Trust Sanger Institute announced the first comprehensive analyses of lung cancer genomes and melanoma genome.
The lung cancer genome contained more than 23,000 mutations. The lung cancer patients, on average, smoke 18,000 packs of cigarettes in their lifetime hence smoke 1 pack of cigarettes daily in 50 years. A typical smoker would acquire one mutation for every 15 cigarettes smoked.
The mutations range from single-letter changes in the code to deletions or rearrangements of hundreds of thousand of letters. Most are 'passenger' mutations, previously defined by the team as mutations that do not influence the development of the cancer, but are a consequence of the highly mutagenic environment in many cancer cells. Even current smokers substantially reduce their risk by giving up now. The rates of lung cancer fall to around normal some 15 years after quitting smoking. The lung cells containing mutations are replaced by new cells derived from lung stem cells that are clear of mutation.
Lung Cancer is the most common cancer in Hong Kong with over 4,000 new registered cases and 3,600 deaths every year.