A recent American meta-analysis offers a new glimmer of hope to ex-smokers. The overall mortality risk related to smoking remains high but quitting smoking could be beneficial, even as late as 2 years before lung cancer is diagnosed.*
Smoking, a scourge that has not gone away
Contrary to what may have been reported in the media concerning a potentially protective effect of nicotine against Covid-19, smoking is still very bad for the health and is the number one risk factor for lung cancer. According to the French Cardiology Federation, the Covid-19 pandemic may also have played a detrimental role in terms of addictions and, in particular, smoking.
Smoking predominantly concerns men and is generally more widespread in under-privileged populations. Worldwide, 8 million people die because of smoking every year. In France, despite a significant decrease in the number of smoking-related deaths in 2019, each year 75,000 people still die as a result of smoking. A scourge that has not gone away, therefore, despite regulatory and preventive measures.
Tobacco smoking causes a number of different cancers (esophagus, bladder, ENT, pancreas, etc.), as well as cardiovascular and respiratory diseases, and even type 2 diabetes. However, there is still little data available concerning the impact of smoking cessation on overall survival, and specifically in the case of lung cancer. A team of American researchers therefore conducted a meta-analysis to demonstrate whether or not there is a benefit of quitting smoking, even at a late stage.
Smoking cessation, even recent, is beneficial
American researchers have recently demonstrated that there is a benefit in terms of overall survival of quitting smoking, irrespective of how long people have smoked. A meta-analysis of 17 studies was presented at the 2020 American Society of Clinical Oncology virtual meeting (Asco 2020).
This meta-analysis focused on a pool of over 34,000 patients around the globe. Of the 34,649 patients included, 41% were smokers at the time of their lung cancer diagnosis, 41% were ex-smokers, and 18% had never smoked. According to the researchers, ex-smokers and never-smokers improved their overall survival compared to current smokers. They demonstrated, for example, that the all-cause mortality risk fell by 20% in former smokers having quit at least five years before their lung cancer diagnosis. In patients having quit between 2 and 5 years ago, the reduction in the risk of death is 16%, and the figure is 12% for those having stopped within two years prior to their lung cancer diagnosis.
The researchers therefore demonstrate the benefit of quitting, irrespective of how long people have smoked. According to them, even two years before a lung cancer diagnosis, quitting smoking improves patients’ overall survival.1
Aline Fusco Fares, Mei Jiang, Ping Yang, David C. Christiani, Chu Chen, Paul Brennan, Jie Zhang, Ann G. Schwartz, Maria Teresa Landi, Kouya Shiraishi, Brid M Ryan, Hongbing Shen, Matthew B. Schabath, Garcia Adonina, Sanjay Shete, Loic Le Marchand, Angela Cox, Rayjean Hung, Wei Xu, and Geoffrey Liu, Smoking cessation (SC) and lung cancer (LC) outcomes: A survival benefit for recent-quitters? A pooled analysis of 34,649 International Lung Cancer Consortium (ILCCO) patients. Journal of Clinical Oncology 2020 38:15_suppl, 1512-1512