Meta-analysis: Quitting smoking after diagnosis of early stage lung cancer improved survival

Patients who continued to smoke after diagnosis of early stage lung cancer had a higher risk for recurrence, second primary tumor and all cause mortality, according to findings from a meta-analysis.

To examine whether smoking cessation after diagnosis of a lung tumor could improve survival, researchers searched CINAHL, Embase, Medline, Web of Science and CENTRAL for randomized, controlled trials or observational studies that measured the effect of quitting smoking after diagnosis, and reviewed ten.

In adjusted analysis among patients with early stage non–small-cell lung cancer, there was almost a threefold increase in risk for all-cause mortality for those who continued smoking (HR=2.94; 95% CI, 1.15-7.54). Additionally, the risk for recurrence increased by twofold (HR=1.86; 95% CI, 1.01-3.41) among those who continued smoking.

Results were similar among patients with small cell lung cancer. Those patients who continued smoking had an increased risk for all cause mortality (HR=1.86; 95% CI, 1.33-2.59), development of a secondary primary tumor (HR=4.31; 95% CI, 1.09-16.98) and recurrence (HR=1.26; 95% CI, 1.06-1.50).

In analysis based on data from these studies, the five-year survival rate for a patient with NSCLC who continued to smoke was 33% vs. 70% for one who quit. The rates for small cell lung cancer were 29% for those who continued to smoke vs. 63% for those who quit.

“As for all treatments, expertise, a knowledge base, skills and strategies are important,” Tom Treasure, MD, and Janet Treasure, PhD, wrote in an accompanying editorial.

Tom Treasure is professor of cardiothoracic surgery at the Clinical Operational Research Unit UCL, London. Janet Treasure is professor of psychiatry at the Institute of Psychiatry and King’s College London.

“Even better than getting smokers to stop would be to stop them starting,” they wrote.

Parsons A. BMJ. 2010;doi:10.1136/bmj.b5569.