Study shows survival benefits of smoking cessation after lung cancer diagnosis
Current smokers with early-stage lung cancer who quit smoking after their diagnosis had improved overall and progression-free survival rates, according to a prospective cohort study.
To date, studies that investigated whether smoking cessation after a cancer diagnosis might improve patients’ chances of survival have only measured smoking status at the time of diagnosis or treatment without follow-up, or had a limited number of smokers and short follow-up, Mahdi Sheikh, MD, PhD, a physician and cancer epidemiologist at WHO's International Agency for Research on Cancer, and colleagues wrote in Annals of Internal Medicine.
“Furthermore, it is not clear whether any effects of smoking cessation differ between mild to moderate smokers and heavy smokers or among those with earlier- versus later-stage tumors,” the researchers wrote.
Sheikh and colleagues followed 517 current smokers — most of them men — with a mean age of about 61 years who had non–small cell lung cancer and tumor stage between IA and IIIA. The study participants were recruited between 2007 and 2016 and followed annually through 2020. During the study, 297 patients told the researchers they quit smoking.
During an average follow-up of 7 years, 325 patients died; 271 died from cancer. The researchers documented 172 cases of tumor progression — either a local recurrence or metastasis. The adjusted median overall survival time was 21.6 months longer among patients who quit smoking compared with those who continued to smoke (6.6 vs. 4.8 years, P = .001). The 5-year overall survival rate (60.6% vs. 48.6%; P = .001) and the progression-free survival rate (54.4% vs. 43.8%; P = .004) were both higher in patients who quit compared with those who continued smoking. Compared with patients who continued smoking in the follow-up period, those who quit smoking had a 33% decreased risk for overall mortality and a 25% decreased risk for cancer-specific mortality.
The researchers also wrote that after adjusting for numerous factors, smoking cessation remained associated with a decreased risk for all-cause mortality (HR = 0.67; 95% CI, 0.53-0.85), cancer-specific mortality (HR = 0.75, 95% CI, 0.58-0.98) and disease progression (HR = 0.72, 95% CI, 0.56-0.92). Similar effects were seen among mild to moderate and heavy smokers and patients with earlier and later cancer stages.
“Given that at least 50% of active smokers with [non–small cell lung cancer] are thought to continue smoking after diagnosis, this provides an important opportunity to substantially improve overall and progression-free survival in this type of cancer,” Sheikh and colleagues wrote.
In 2019, the International Association for the Study of Lung Cancer recommended all physicians screen their patients with cancer for tobacco use and recommend tobacco cessation. In addition, the authors of a 2019 commentary in JAMA Network Open wrote that comprehensive cancer care should include making “effective smoking treatment an integral and essential component of cancer care for patients who smoke.”
In a related editorial, Nancy A. Rigotti, MD, founder and director of the Tobacco Research and Treatment Center at Massachusetts General Hospital, wrote the new findings “strengthen the case for making tobacco cessation treatment a standard component of routine health care for all patients with cancer.”
Regrettably, some of the efforts to ensure such treatments are provided are either “struggling to sustain viability” or not universally offered, according to Rigotti.
“It’s not too late for cigarette smokers with cancer and cancer survivors to benefit from becoming smoke-free,” she wrote. “We need to make this happen!”
IASLC. Declaration from IASLC: Tobacco cessation after cancer diagnosis. www.iaslc.org/About-IASLC/News-Detail/declaration-from-iaslc-tobacco-cessation-after-cancer-diagnosis. Accessed July 26, 2021.