Smoking and Lung Cancer Mortality in the United States From 2015 to 2065: A Comparative Modeling Approach

Abstract

Background: Tobacco control efforts implemented in the United States since the 1960s have led to considerable reductions in smoking and smoking-related diseases, including lung cancer.

Objective: To project reductions in tobacco use and lung cancer mortality from 2015 to 2065 due to existing tobacco control efforts.

Design: Comparative modeling approach using 4 simulation models of the natural history of lung cancer that explicitly relate temporal smoking patterns to lung cancer rates.

Setting: U.S. population, 1964 to 2065.

Participants: Adults aged 30 to 84 years.

Measurements: Models were developed using U.S. data on smoking (1964 to 2015) and lung cancer mortality (1969 to 2010). Each model projected lung cancer mortality by smoking status under the assumption that current decreases in smoking would continue into the future (status quo trends). Sensitivity analyses examined optimistic and pessimistic scenarios.

Results: Under the assumption of continued decreases in smoking, age-adjusted lung cancer mortality was projected to decrease by 79% between 2015 and 2065. Concomitantly, and despite the expected growth, aging, and longer life expectancy of the U.S. population, the annual number of lung cancer deaths was projected to decrease from 135 000 to 50 000 (63% reduction). However, 4.4 million deaths from lung cancer are still projected to occur in the United States from 2015 to 2065, with about 20 million adults aged 30 to 84 years continuing to smoke in 2065.

Limitation: Projections assumed no changes to tobacco control efforts in the future and did not explicitly consider the potential effect of lung cancer screening.

Conclusion: Tobacco control efforts implemented since the 1960s will continue to reduce lung cancer rates well into the next half-century. Additional prevention and cessation efforts will be required to sustain and expand these gains to further reduce the lung cancer burden in the United States.

Primary funding source: National Cancer Institute.

Figure 1.

Smoking prevalence among US adults. (a) and (b) Smoking prevalence for US men and women aged 18–84 and 30–84, respectively. The observed smoking prevalence (points) includes current smokers and former smokers who quit smoking less than 2 years in the NHIS data. The line represents the estimates based on simulated smoking histories for the US population by the SHG. The smoking prevalence was projected up to year 2065 under the status quo scenario. (c) Life expectancy at age 40 under the status quo scenario. The line represents the estimates based on simulated smoking histories for the US population by the SHG and projected US population based on the Lee-Carter model. The points represent the corresponding life expectancy in the Human Mortality Database (HMD) data. An interactive version of the figure can be found at https://resources.cisnet.cancer.gov/projects/#shg/sbc2/tool?figure=fig_1.

Figure 2.

Age-adjusted lung cancer mortality rates per 100,000 for 1964–2065 under the status quo scenario. The line represents the mean age-adjusted lung cancer mortality rate across four CISNET-Lung models, and the shaded area shows the range of age-adjusted lung cancer mortality rates per 100,000 across four models. The points represent the observed US lung cancer mortality rates for 1969–2010. The 2000 US population was used as the standard to calculate age-adjusted rates. An interactive version of the figure can be found at https://resources.cisnet.cancer.gov/projects/#shg/sbc2/tool?figure=fig_2.

Figure 3.

Population and lung cancer deaths from the University of Michigan (UM) model. Number and percentage of US population aged 30–84 by smoking status for 1964–2065 (left panels) and number and percentage of lung cancer deaths by smoking status for 1964–2065 (right panels), under the status quo scenario. An interactive version of the figure can be found at https://resources.cisnet.cancer.gov/projects/#shg/sbc2/tool?figure=fig_3.

Figure 4.

Population attributable fraction (PAF) of lung cancer deaths due to smoking in the US for 1964–2065 under the status quo scenario. The line in the middle represents the mean PAF across four CISNET-Lung models. The shaded area shows the range of PAF estimates across four models. An interactive version of the figure can be found at https://resources.cisnet.cancer.gov/projects/#shg/sbc2/tool?figure=fig_4.