I read with interest the latest Canadian Cancer Statistics: A 2020 special report on lung cancer. The report has new results from the ComPARe study showing the population attributable risk (PAR) for known risk factors for lung cancer in 2020. We see the impact of physical inactivity, residential radon and air pollution, which respectively account for 11%, 7% and 6% of lung cancer cases. Tobacco use, the most commonly known risk factor, accounts for 74%. Yes, that means about 3 in 4 of all lung cancer cases are due to smoking tobacco. Living smoke-free is still by far the best thing people can do to prevent lung cancer.
Canadians have dramatically reduced the prevalence of smoking over the last few decades. This has led to dramatic reductions in lung cancer. But more can be done. Lung cancer has the highest incidence and death rates of all cancers in Canada, yet three-quarters of lung cancer cases could be prevented by eliminating tobacco use.
The report features new statistics on the percentage of lung cancer deaths due to modifiable risk factors. Previously, only the PAR for incidence has been reported. When combined, modifiable risk factors account for 86% of the lung cancer deaths expected in 2020. This number is expected to drop to 81% in 2047, assuming smoking and lung cancer rates continue to decline. Again, the majority of the preventable cancer deaths are related to tobacco, namely 75% in 2020 and 70% in 2047.
In the last several years, there has been concern among health care professionals that smoking rates may increase as e-cigarettes gain popularity among youth and cannabis has been legalized. The direct effects of e-cigarettes and cannabis on lung cancer are not known. But they may cause smoking to be “re-normalized,” and the gains made in smoking cessation could be lost. This is not a situation in which we can afford to “slip up.” We need to re-emphasize the ongoing public health efforts to reduce smoking, including smoking cessation programs like Smokers’ Helpline and eliminating smoking in public spaces.
The cancer control community has raised concerns regarding the stigma of lung cancer and the effect of smoking cessation efforts in helping to create that stigma. The success of public health intervention and education has shown the public the importance of smoking cessation. With the success of anti-smoking campaigns, people falsely assume that smoking is easy to stop and that it is the person with lung cancer’s fault if they get the disease. We need to address the stigma of lung cancer in smoking cessation efforts and incorporate ways to reduce it.
The impact of smoking on lung cancer represents both a challenge and an opportunity. The majority of lung cancer cases can be prevented by eliminating tobacco. Public health efforts have been successful in reducing tobacco use but the job is not done. Currently 1 in 7 adults smoke tobacco. Although this is much better than the 1 in 3 from the 1980s, it’s still a huge number of people who are at significant risk for lung cancer and 15 other types of cancer associated with tobacco smoking. Collective public health efforts aimed at reducing tobacco use must persist. 1 in 7 is still too many.
Alex Mathieson, MD, FRCSC
General Surgery and Surgical Oncology
Associate Professor of Surgery
Developed in association with Dr Leah Smith