Lung cancer: quitting smoking early is associated with longer survival

MADRID, 8 May. (EUROPA PRESS) -

Quitting smoking at an early age was associated with higher survival rates after lung cancer diagnosis. Compared with never-smokers being treated for non-small cell lung cancer (NSCLC), current smokers had a 68% higher mortality rate and ex-smokers 26% higher mortality, according to a new study led by researchers at the School of Public Health T.H. Chan from Harvard (United States) and published in the magazine 'JAMA Network Open'.

"Our participants' smoking histories varied widely: some had quit smoking a few years before diagnosis and others had quit several decades earlier," said David Christiani, lead author and Elkan Blout Professor of Environmental Genetics. fan gave us confidence in our results: that the benefit of quitting before diagnosis persists even after lung cancer is diagnosed."

While most similar research has compared mortality between current and never smokers, the majority of study participants were former smokers, allowing researchers to focus on the effects of smoking cessation.

The study followed 5,594 patients with NSCLC, representing 85% of all lung cancer cases, included in the Massachusetts General Hospital Boston Lung Cancer Survival Cohort between 1992 and 2022. Of these participants , 795 had never smoked; 3,308 were ex-smokers; and 1,491 were current smokers.

Participants filled out questionnaires about their smoking habits and other demographic and health data at the start of the study, and the researchers checked their survival every 12 to 18 months. During the study period, 3,842 participants died: 79.3% of current smokers, 66.8% of ex-smokers, and 59.6% of non-smokers.

Although never having smoked was associated with the best chance of survival after a lung cancer diagnosis, the results showed significant associations between lower mortality and having stopped smoking before diagnosis.

The longer a patient went without smoking, the more health benefits they gained: For ex-smokers, doubling the years they had quit smoking before lung cancer diagnosis was associated with significantly longer survival. In contrast, doubling the number of years without smoking was associated with decreased survival among smokers and ex-smokers diagnosed with NSCLC.

The researchers note that the relationship between survival and smoking history can vary depending on the clinical stage at which lung cancer was diagnosed, and that the study did not take into account the different types of treatment that participants received.