Lung cancer patients who quit smoking double their survival chances.

January 23, 2010 -

PAPER: Influence of smoking cessation after diagnosis of early stage lung cancer on prognosis: systematic review of observational studies with meta-analysis, A Parsons (a.c.parsons@bham.ac.uk), A Daley, R Begh, P Aveyard, BMJ 2010;340:b5569, ABSTRACT, FULL TEXT.

Associated Editorial: Smoking cessation It is never too late for people to stop, even when they have lung cancer Tom Treasure and Janet Treasure, BMJ 2010;340:b5630, first 150 words of the full text. The editorial says this study adds more to the evidence that it is never too late for people to stop, even when they have lung cancer.

"We used meta-analysis to summarize the findings," said 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. "Quitting smoking was associated with around double the chance of surviving at any time point compared to people who continued to smoke." Researchers at the University of Birmingham analysed the results of 10 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 to minimise bias.

Only 29 to 33 percent of early stage lung cancer patients who kept smoking survived for five years, while 63 to 70 percent of patients who quit survived that long, Parsons stated.

The survival seemed to come from a lower likelihood of tumor recurrence, not from heart/lung improvements, the researchers said.

This is the first review of studies to measure the effects of continued smoking after diagnosis of lung cancer and suggests that it may be worthwhile to offer smoking cessation treatment to patients with early stage lung cancer.

Worldwide, lung cancer is the most commonly diagnosed form of cancer. In the UK, it is second only to breast cancer, accounting for around 39,000 new cancer diagnoses annually.

Smoking increases the risk of developing a primary lung cancer; lifelong smokers have a 20-fold increased risk compared with non-smokers. But it is not known whether quitting after a diagnosis of lung cancer has any benefit.

Data suggested that most of the increased risk of death was due to cancer progression.

These findings support the theory that continued smoking affects the behaviour of a lung tumour, say the authors. They also provide a strong case for offering smoking cessation treatment to patients with early stage lung cancer.

It is concluded that further trials are needed to examine these questions.

Reference: Quitting Smoking Doubles Survival in Early Stage Lung Cancer, St. John Healt System, 1/21/2020; Lung cancer patients who quit smoking double their survival chances, EurekAlert, 1/21/2010.