It's Never Too Late to Quit Smoking, Even After Lung Cancer Diagnosis

By Megan Brooks

January 11, 2022

NEW YORK (Reuters Health) - Quitting smoking after a lung-cancer diagnosis confers a significant survival benefit, according to results of a meta-analysis.

"Doctors should tell patients that it is never too late to quit smoking, and even if they are diagnosed with lung cancer, they can raise their (chance of surviving) quite a lot by quitting smoking as soon as possible," Dr. Saverio Caini of the Institute for Cancer Research, Prevention and Clinical Network in Florence, Italy, told Reuters Health by email.

"Smoking-cessation programs must become fully integrated into multidisciplinary cancer care; providing lung-cancer patients with information and all the necessary support should be a non-optional part of the management of these patients," Dr. Caini said.

The meta-analysis included 21 studies that looked at the effect of smoking cessation after lung-cancer diagnosis in more than 10,000 patients.

Quitting smoking at or around diagnosis was significantly associated with improved overall survival (summary relative risk, 0.80; 95% CI, 0.73 to 0.96), Dr. Caini and his colleagues report in the Journal of Thoracic Oncology.

This benefit was consistent among patients with non-small-cell lung cancer (SRR, 0.79; 95% CI, 0.67 to 0.93), small-cell-lung cancer (SRR, 0.75; 95% CI: 0.57 to 0.99), or lung cancer of both or unspecified histological type (SRR, 0.81; 95% CI, 0.68 to 0.96).

"Lung cancer has on average a bad prognosis (worse than cancers at many other body sites), despite the recent advances in systemic therapy (e.g. immune therapy), so there is really a need to understand what could raise the chance of surviving for these patients," Dr. Caini told Reuters Health.

"Everyone knows that smoking is a risk factor for lung cancer, and many lung-cancer patients are diagnosed when they are still active smokers. Despite this, there was no certainty on whether (and how much) stopping smoking after diagnosis could improve survival," the researcher added.

"We were surprised by the magnitude of the effect that we observed - a 20% to 30% reduction in the risk of dying for those who quit post-diagnosis compared to those who continue, which is huge because it falls in the range of the survival benefit that chemotherapy and immunotherapy bring to cancer patients," Dr. Caini said.

The study had no commercial funding and the authors have no relevant disclosures.

SOURCE: Journal of Thoracic Oncology, online January 4, 2022.