Can a National Lung Cancer Screening Program in Combination with Smoking Cessation Policies Cause an Early Decrease in Tobacco Deaths in Italy?

A compartmental model for smoking dynamics in Italy: a pipeline for inference, validation, and forecasting under hypothetical scenarios

We propose a compartmental model for investigating smoking dynamics in an Italian region (Tuscany). Calibrating the model on local data from 1993 to 2019, we estimate the probabilities of starting and quitting smoking and the probability of smoking relapse. Then, we forecast the evolution of smoking prevalence until 2043 and assess the impact on mortality in terms of attributable deaths. We introduce elements of novelty with respect to previous studies in this field, including a formal definition of the equations governing the model dynamics and a flexible modelling of smoking probabilities based on cubic regression splines. We estimate model parameters by defining a two-step procedure and quantify the sampling variability via a parametric bootstrap. We propose the implementation of cross-validation on a rolling basis and variance-based Global Sensitivity Analysis to check the robustness of the results and support our findings. Our results suggest a decrease in smoking prevalence among males and stability among females, over the next two decades. We estimate that, in 2023, 18% of deaths among males and 8% among females are due to smoking. We test the use of the model in assessing the impact on smoking prevalence and mortality of different tobacco control policies, including the tobacco-free generation ban recently introduced in New Zealand.

Intergroupe francophone de cancérologie thoracique, Société de pneumologie de langue française, and Société d'imagerie thoracique statement paper on lung cancer screening

Following the American National Lung Screening Trial results in 2011 a consortium of French experts met to edit a statement. Recent results of other randomized trials gave the opportunity for our group to meet again in order to edit updated guidelines. After literature review, we provide here a new update on lung cancer screening in France. Notably, in accordance with all international guidelines, the experts renew their recommendation in favor of individual screening for lung cancer in France as per the conditions laid out in this document. In addition, the experts recommend the very rapid organization and funding of prospective studies, which, if conclusive, will enable the deployment of lung cancer screening organized at the national level.

Smoking Cessation in the ITALUNG Lung Cancer Screening: What Does “Teachable Moment” Mean?

Background

Changes in smoking habits and predictors of smoking cessation were examined in the randomized ITALUNG lung cancer screening trial.

Methods

In three centers, eligible smokers or ex-smokers (55–69 years, ≥20 pack-years in the last 10 years) were randomized to receive annual invitation for low-dose computed tomography for 4 years or usual care. At invitation, subjects received written information for a free smoking cessation program. Quitting outcome was assessed at year 4.

Results

Among participants who completed baseline assessments and year 4 screening, higher quitting (20.8% vs. 16.7%, p = .029) and lower relapse (6.41% vs. 7.56%, p = .50) rates were observed in the active screening group as compared to the usual-care control group. Corresponding figures in the intention-to-treat analysis were as follows: 16.04% versus 14.64% (p = .059) and 4.88% versus 6.43% (p = .26). Quitting smoking was significantly associated to male gender, lower pack-years, and having pulmonary nodules at baseline. Center-specific analyses showed a threefold statistically significant higher probability to quit associated with participating in the smoking cessation program. A subsample of smokers of the scan group from one center showed higher quitting rates over 12-month follow-up as compared to matched controls from the general population who underwent the same smoking cessation program.

Conclusions

Consistently with previous reports, in the ITALUNG trial, screened subjects showed significantly higher quit rates than controls, and higher quit rates were associated with both the presence of pulmonary nodules and participating in a smoking cessation program. Maximal effect on quitting outcome was observed with the participation in the smoking cessation program.

Implications

Participating in lung cancer screening promotes smoking cessation. An effective “teachable moment” may be achieved when the smoking cessation intervention is structured as integral part of the screening clinical visits and conducted by a dedicated team of health care professionals. Standardized guidelines for smoking cessation interventions in lung cancer screening are needed.

All-cause mortality versus cancer-specific mortality as outcome in cancer screening trials: A review and modeling study

BACKGROUND

All-cause mortality has been suggested as an end-point in cancer screening trials in order to avoid biases in attributing the cause of death. The aim of this study was to investigate which sample size and follow-up is needed to find a significant reduction in all-cause mortality.

METHODS

A literature review was conducted to identify previous studies that modeled the effect of screening on all-cause mortality. Microsimulation modeling was used to simulate breast cancer, lung cancer, and colorectal cancer screening trials. Model outputs were: cancer-specific deaths, all-cause deaths, and life-years gained per year of follow-up.

RESULTS

There were large differences between the evaluated cancers. For lung cancer, when 40 000 high-risk people are randomized to each arm, a significant reduction in all-cause mortality could be expected between 11 and 13 years of follow-up. For breast cancer, a significant reduction could be found between 16 and 26 years of follow-up for a sample size of over 300 000 women in each arm. For colorectal cancer, 600 000 persons in each arm were required to be followed for 15-20 years. Our systematic literature review identified seven papers, which showed highly similar results to our estimates.

CONCLUSION

Cancer screening trials are able to demonstrate a significant reduction in all-cause mortality due to screening, but require very large sample sizes. Depending on the cancer, 40 000-600 000 participants per arm are needed to demonstrate a significant reduction. The reduction in all-cause mortality can only be detected between specific years of follow-up, more limited than the timeframe to detect a reduction in cancer-specific mortality.

Mathematical Modeling in Tobacco Control Research: Initial Results From a Systematic Review

OBJECTIVES

The US Food and Drug Administration has expressed interest in using mathematical models to evaluate potential tobacco policies. The goal of this systematic review was to synthesize data from tobacco control studies that employ mathematical models.

METHODS

We searched five electronic databases on July 1, 2013 to identify published studies that used a mathematical model to project a tobacco-related outcome and developed a data extraction form based on the ISPOR-SMDM Modeling Good Research Practices. We developed an organizational framework to categorize these studies and identify models employed across multiple papers. We synthesized results qualitatively, providing a descriptive synthesis of included studies.

RESULTS

The 263 studies in this review were heterogeneous with regard to their methodologies and aims. We used the organizational framework to categorize each study according to its objective and map the objective to a model outcome. We identified two types of study objectives (trend and policy/intervention) and three types of model outcomes (change in tobacco use behavior, change in tobacco-related morbidity or mortality, and economic impact). Eighteen models were used across 118 studies.

CONCLUSIONS

This paper extends conventional systematic review methods to characterize a body of literature on mathematical modeling in tobacco control. The findings of this synthesis can inform the development of new models and the improvement of existing models, strengthening the ability of researchers to accurately project future tobacco-related trends and evaluate potential tobacco control policies and interventions. These findings can also help decision-makers to identify and become oriented with models relevant to their work.