It is never late to quit smoking, especially after researchers have found that if a patient who has been diagnosed with early stages of lung cancer drops smoking then chances of a patient living another five years doubles according to a new study.

Dr Tom Treasure, a cardiothoracic surgeon at University College London, and psychiatrist Janet Treasure, also from University College, wrote that the new review demonstrated that the impact of continued smoking is so large that both patients and "those caring for them should be given this information because the potential benefit is great."

It was noted that if cancer is detected an at early stage lung then the cure rate can be 50 per cent to 60 per cent. But the catch is that a very few lung cancers are diagnosed at this early stage.

An accompanying journal editorial states that less than one-third of all patients who are diagnosed with lung cancer live just one year after diagnosis.

To reach to a conclusion the British researchers studied data from 10 studies conducted earlier. 

Study lead author, Amanda Parsons, a Ph.D. candidate at the U.K. Centre for Tobacco Control Studies at the University of Birmingham College of Medicine and Dentistry, said that meta-analysis to summarize their findings was used. 

About 29 to 33 per cent cancer patients whose cancer was diagnosed at early stages survived for five years after carrying on with smoking, while 63 to 70 per cent of patients who quit survived that long.