In a new paper, researchers from the U.S. National Cancer Institute and other U.S. institutions predict mortality from lung cancer will plunge through 2065, largely due to the success of smoking-control efforts. Lung cancer screening may also help reinforce this trend, according to the article, published online October 8 in the Annals of Internal Medicine.
By 2065, nearly 85,000 fewer Americans will die of lung cancer annually compared with the number who died in 2015, predicted first author Jihyoun Jeon, PhD, from the University of Michigan, and colleagues. The decline parallels the decline in smoking prevalence.
Smoking-cessation and tobacco-control programs and policies have played a major role in the declining rate of lung cancer mortality in the U.S. since the 1990s. These measures are likely to continue driving this tendency toward ever-lower mortality rates from smoking.
To determine how this pattern might look in the next several decades, the group used four simulation models developed by the Cancer Intervention and Surveillance Modeling Network (CISNET) to project the effect of smoking-control efforts on lung cancer mortality rates in the U.S.
The researchers calibrated the models to match actual lung cancer mortality rates from 1969 to 2010, adjusting for age-related variations in cancer risk. Next, they applied each distinct model to smoking histories generated from the National Health Interview Survey, the Cancer Prevention Study I and II, and the Human Mortality Database. This process enabled the models to estimate lung cancer mortality from 2015 to 2065, with the assumption that current trends in smoking habits would persist.
All four of the models predicted that lung cancer mortality rates in U.S. smokers would decline in the designated 50-year period -- starting with a sharp decrease until 2040, followed by a more moderate decrease until 2065.
| Projected effect of smoking-cessation efforts on U.S. lung cancer mortality | ||
| 2015 | 2065 | |
| Lung cancer mortality rate per 100,000 people | 65 | 13.9 |
| Total lung cancer deaths | 135,000 | 50,300 |
Overall, this represents a hypothetical reduction in the lung cancer mortality rate by 79% and in lung cancer deaths by 63%. These decreases coincided with projected reductions in smoking prevalence.
The researchers also measured the proportion of lung cancer deaths credited to smoking. The average population-attributable fraction was 88% for men and 79% for women in 2015, which fell to 58% for men and 44% for women in 2065.
Despite these projected reductions in smoking prevalence and lung cancer mortality, the models estimated that there will still be approximately 4.4 million deaths from lung cancer from 2015 to 2065 in the U.S., with around 20 million smokers ages 30 to 84 years in 2065.
These statistics highlight the "need for additional efforts, such as lung cancer screening, to further reduce the burden of lung cancer," the authors wrote.
"Although lung cancer screening is now being slowly adopted, changes to it could not only reduce lung cancer deaths but could also increase smoking cessation rates," they added.
For now, Jeon and colleagues believe their findings can serve as a reference point for evaluating future trends in smoking and lung cancer mortality, which may involve the expansion of tobacco-control policies and other prevention strategies in the U.S.
