Quitting smoking - male hand crushing cigarette

Results from a study by Rafael Meza, Ph.D. from the University of Michigan and colleagues, published in the Journal of Thoracic Oncology, a publication of the International Association for the Study of Lung Cancer, suggest that the combination of smoking cessation and existing lung cancer screening efforts can reduce lung cancer mortality by 14% and increase life-years gained by 81% compared to screening alone.

The study was funded by the International Association for the Study of Lung Cancer (IASLC), a global organization dedicated solely to the study of lung cancer and other thoracic malignancies.

Modeling the history of cancer plays an important role in shaping cancer prevention and control policies. In the United States, the National Cancer Institute (NCI) Cancer Intervention and Surveillance Modeling Network (CISNET) consortium developed models and a modeling infrastructure designed to support the development of guidelines and policies for cancer screening and tobacco control.

Screening
Annual lung cancer screening with low-dose computed tomography (LDCT) is recommended for adults aged 55-80 with a greater than 30 pack-year smoking history who currently smoke or quit within the previous 15 years. About 50% of these screen-eligible individuals are still current smokers. And while information about the short- and long-term effects of joint screening and cessation interventions is limited, cessation interventions at the point of screening are recommended.

Rafael Meza, Ph.D., is Associate Chair and Associate Professor, Epidemiology, Associate Professor of Global Public Health and Co-Leader, Cancer Epidemiology and Prevention Program, UM Rogel Cancer Center. Photo Courtesy: 2020 – The Regents of the University of Michigan.

Meza, who is Associate Chair and Associate Professor, Epidemiology and Associate Professor of Global Public Health, and his colleagues from the University of Michigan and Georgetown University used an established lung cancer simulation model to project the impact of cessation interventions within the screening context on lung cancer and overall mortality for the 1950 and 1960 US birth-cohorts.

As part of the simulation, two million individual smoking and life histories were generated per cohort. Simulated individuals were screened annually according to current guidelines and different assumptions of screening uptake rates. Meza’s team then simulated a cessation intervention at the time of the first screen, under a range of efficacy assumptions.

Delay death
Point-of-screening cessation interventions would greatly reduce lung cancer mortality and delay overall deaths compared to screening alone. For example, under a 30% screening uptake scenario, adding a cessation intervention at the time of the first screen with a 10% success probability for the 1950 birth-cohort would further reduce lung cancer deaths by 14% and increase life-years gained by 81% compared with screening alone.

The authors of the study confirm that the actual gains are highly sensitive to the variation in screening uptake and cessation probability. Meza said that even mildly effective cessation interventions could greatly enhance the impact of LDCT screening programs because cessation not only reduces the risk of lung cancer.

In addition to lung cancer, LDCT would also be beneficial in the prevention of other tobacco-related diseases, including chronic obstructive pulmonary disease (COPD) and cardiovascular disease.

Pianpian Cao, MPH, a doctoral student at the University of Michigan, and the study’s first author noted that most of these benefits won’t be realized unless lung screening uptake is improved. “So more work is needed to promote lung cancer screening and facilitate access, particularly for those at the highest risk,” Cao observed.

Based on the outcomes of the study, the researchers concluded that further evaluation of specific cessation interventions within lung screening, including costs and feasibility of implementation and dissemination, are needed to determine the best possible strategies and realize the full promise of lung cancer screening.