Although changing smoking behaviors have had a major impact on lung cancer mortality in the U.S., the numbers of lung cancer deaths averted are only a small fraction of deaths that could have been avoided had all smoking ceased following the 1964 Surgeon General’s Report. Further efforts to control tobacco use are needed to decrease the impact of the disease, according to a study published in the Journal of the National Cancer Institute.

The restrictions on smoking in public places, escalations in cigarette taxes, reduced access to cigarettes, and an increased public awareness on the health issues related to smoking have all helped steadily decrease the number of smokers in the U.S. since the mid 1950’s; however, little measurable information exists in regards to the amount lung cancer deaths have diminished in association with the decline in smoking.

In order to determine the effect that reduced tobacco smoking has had on lung cancer mortality in the U.S., Suresh H. Moolgavkar, M.D., Ph.D., of the Program in Biostatistics and Biomathematics at the Fred Hutchinson Cancer Research Center in Seattle, Washington and colleagues built independent models based on cohort, case-control, or registry data and adjusted to overall mortality to estimate the number of lung cancer deaths prevented between 1975-2000.

The data were distinguished by sex and birth decade (1890-1970), and the prevalence of smoking and lung cancer deaths were considered based on actual tobacco control (ATC), historical changes in smoking rates, no tobacco control (NTC), predicted smoking rates had there been no tobacco control, and complete tobacco control (CTC), which estimates the effects of what may have happened if all smoking had stopped in 1965.

The researchers found that between 1975 and 2000, there were 2,067,775 lung cancer deaths among men and 1,051,978 lung cancer deaths among women. The models predicted that 550,000 lung cancer deaths among men and 240,000 among women were averted by tobacco control efforts. “The results of this article show the dramatic impact of the reduction in smoking associated with tobacco control efforts in the second half of the 20th century on lung cancer mortality during the period 1975-2000,” the researchers write.

The researchers note the limitations of the study, namely that the numbers don’t reflect the effects of non-cigarette forms of tobacco use. Despite this, they feel that, “continued implementation of evidence-based tobacco control policies, programs, and services remains the most promising approach to reducing the burden of lung cancer.”

In an accompanying editorial, Thomas J. Glynn, Ph.D., Director of Cancer Science and Trends and International Cancer Control at the American Cancer Society, writes that we may be dawning on a new era for tobacco control, citing the Affordable Care Act and the Family Smoking Prevention and Tobacco Control Act as major components of the avoidance of lung cancer deaths. “Tobacco taxes have been raised substantially at the federal, state, and local level,” he writes.

Glynn also notes that smoke-free laws and regulations have protected millions against secondhand smoke at workplaces, public spaces, and even at home, not to mention new treatments developed to combat the smoking habit. Still, he feels that the tobacco industry is aggressive in combatting the tobacco control laws, saying that many state governments have lowered their support for tobacco control.

However, he writes that, “We should use all of the tools at our disposal to rein in the rogue tobacco industry, and assiduously apply all of our political, research, advocacy, public health, and clinical skills to end tobacco’s century of death, disease, and disability.”

Source: JNCI