People diagnosed with early-stage lung cancer can double their chances of survival over five years if they stop smoking compared with those who continue to smoke, a new review has found.
Researchers at the University of Birmingham analysed results of ten studies that measured the effect of quitting smoking after diagnosis of lung cancer on prognosis. Differences in study design and quality were taken into account.
They found people who continued to smoke after diagnosis of early-stage lung cancer had a substantially higher risk of death and a greater risk of the tumour returning compared with those who stopped at that time. Data suggested that most of the increased risk of death was due to cancer progression.
Further analysis found a five-year survival rate of 63-70 per cent among quitters compared with 29-33 per cent among those who continued to smoke.
These findings support the theory that continued smoking affects the behaviour of a lung tumour, say the authors.