The research, published in the BMJ, suggests there is a strong case for offering smoking cessation treatment to patients with early stage lung cancer.
To date, it has not been confirmed whether quitting after diagnosis of lung cancer has any benefit but this review supports the theory that continued smoking affects the behaviour of a lung tumour.
The review, conducted by researchers at the University of Birmingham, analysed 10 studies measuring the effect on prognosis of quitting smoking after diagnosis of lung cancer.
Compared with those who gave up smoking post-diagnosis, patients who continued to smoke had a substantially higher risk of death due to cancer progression, and of the tumour returning.
Analysis showed a 5-year survival rate of 63-70% amongst quitters versus 29-33% amongst those who continued to smoke.