Smoking cessation after lung cancer diagnosis linked to nearly 30% improvement in survival
Quitting smoking at or around time of diagnosis conferred a significant survival benefit for patients with lung cancer, according to results of a meta-analysis published in Journal of Thoracic Oncology.
Treating physicians should educate these patients on the benefits of smoking cessation even after diagnosis and provide them with necessary support, researchers wrote.
“It is really never too late to quit. Critically, this is a message for the patients, and for the doctors, as well,” Saverio Caini, MD, PhD, senior medical epidemiologist at Institute for Cancer Research, Prevention and Clinical Network (ISPRO) in Italy, told Healio. “Even if they are diagnosed with lung cancer, they can raise their chance to survive quite a lot by quitting smoking as soon as possible. Actually, we recommend that smoking cessation programs become fully integrated into multidisciplinary cancer care.”
Caini and colleagues pursued avenues to increase the chances of survival for patients with lung cancer because, despite advances in immunotherapy, lung cancer on average is associated with a worse prognosis than many other cancers.
“Everyone knows that smoking is a risk factor for lung cancer, and many [patients with lung cancer] are diagnosed when they are still active smokers,” Caini said. “Despite this, there was no certainty on whether (and how much) stopping smoking after diagnosis could improve survival.”
The meta-analysis included 21 articles published between 1980 and October 2021 on the effect of smoking cessation at or around the time of diagnosis among a total of 10,938 patients with lung cancer.
“We were surprised by the small number of studies that could be included, only 21, which is a tiny number compared to the number of studies that examine, for instance, the association between smoking and the risk [for] developing cancer,” Caini said.
Caini and colleagues used random effect meta-analysis models to pool study-specific data into summary relative risk [SRR] and corresponding confidence intervals.
Results showed patients who quit smoking after diagnosis had a 29% improvement in OS compared with patients who continued to smoke after their diagnosis (SRR = 0.71; 95% CI, 0.64-0.8).
Researchers found benefits of quitting smoking regardless of histologic subtype, with SRRs for OS between quitters and continued smokers of 0.77 (95% CI, 0.66-0.9) among patients with non-small cell lung cancer based on eight studies, 0.75 (95% CI, 0.57-0.99) among patients with small cell lung cancer based on four studies, and 0.81 (95% CI, 0.68-0.96) among patients with lung cancer of both or unspecified histologic type based on six studies.
Caini and colleagues were surprised by the magnitude of the effect.
“A 20% to 30% reduction in the risk of dying for those who quit post-diagnosis to those who continue is huge because it falls in the range of the survival benefit that chemotherapy and immunotherapy bring to [patients with cancer],” Caini said. “We believe that not all doctors and health professionals are aware that smoking cessation — an intervention tolerable by everyone, with practically no adverse effects and costless — can produce such a big benefit for people with a disease as severe as lung cancer.”
Based on the findings, oncologists and health care systems should educate, encourage and put systems in place to help patients quit smoking at time of diagnosis, even with the challenges it presents to many patients.
“It’s difficult because [patients with lung cancer} may be disheartened and discouraged and feel too depressed to engage themselves in smoking cessation, especially considering that they may have been smoking for decades, which makes quitting even more complicated,” Caini said. “Patients must be made aware that smoking cessation can be nearly as effective (for improving the chance of surviving) as chemotherapy, immune therapy, radiation therapy, etc., and that there is plenty of support for them if they decide to attempt to stop.”
For more information:
Saverio Caini, MD, PhD, can be reached at Institute for Cancer Research, Prevention and Clinical Network (ISPRO), Cancer Risk Factors and Lifestyle Epidemiology Unit, Via Cosimo il Vecchio 2, 50141, Florence, Italy; email: email@example.com.