One third of the 571,000 cancer deaths in 2011 are due to smoking. That is 188,744 men and women will die unnecessarily because of their smoking habits. These are avoidable deaths. Strong evidence supports the benefits of smoking cessation, not just lowering cancer deaths but also reducing deaths form heart disease and total mortality. The time for prevention to achieve a reduction in cancer incidence or mortality is quite rapid. Despite this strong scientific evidence a substantial gap in implementation of prevention strategies remains. Smoking cessation reduces lung cancer and total mortality with benefits increasing over time. See Figure. Compared to continuing smokers, those who successfully quit have a 20% reduction in lung cancer mortality within 1 to 4 years of quitting and more than a 40% reduction within 5 to 9 years . Smoking cessation also reduces total mortality by 13% in less than 5 years and by 33% in less than 10 years, due to the additional benefits of reduced risk of cardiovascular death and other smoking related cancer deaths .
New excitement has been present in the cancer control community since the results of the randomized trial of CT screening for lung cancer was published. This trial screened current smokers between age 55 and 74 who had a history of smoking 30 pack-years or more, or those who had quit within the past 15 years. This randomized controlled trial showed a 20% reduction in lung cancer mortality after an average of 6 years of follow-up, and a reduction in total mortality of 6.7% . These results are not as strong as those observed for smoking cessation and apply only to the lung cancer – screening for lung cancer does not reduce mortality from heart disease, for example. Thus, the benefits for smoking cessation are unarguable.
Within the USA, states such as Utah that have a low prevalence of current cigarette smoking, 9.8% overall by 2009. This is a huge difference from the smoking prevalence of more than 25% in Kentucky and Oklahoma . Based on the National Program of Cancer Registries, the CDC estimates that the corresponding lung cancer mortality varied from 26.4 per 100,000 in Utah to 97.7 deaths per 100,000 in Kentucky, a rate 73% lower when almost 10% of the population continues to smoke cigarettes .
Based on state level differences like these, we conservatively estimate that 75% or more of lung cancer could be prevented through elimination of cigarette smoking in the USA. We have the potential to achieve enormous improvements in our population health – the time to act is now.
1. Kenfield, S.A., et al., Smoking and smoking cessation in relation to mortality in women. Jama, 2008. 299(17): p. 2037-47.
2. Aberle, D.R., et al., Reduced lung-cancer mortality with low-dose computed tomographic screening. N Engl J Med, 2011. 365(5): p. 395-409.
3. State-specific prevalence of cigarette smoking and smokeless tobacco use among adults — United States, 2009. MMWR. Morbidity and mortality weekly report, 2010. 59(43): p. 1400-6.