Response

Abstract

To foster understanding and facilitate implementation, we were able to include remarks with each recommendation or statement of the updated CHEST lung cancer screening guidelines.1Mazzone P.J. Silvestri G.A. Patel S. et al.Screening for lung cancer: CHEST Guideline and Expert Panel Report.Chest. 2018; 153: 954-985Abstract Full Text Full Text PDF PubMed Scopus (191) Google Scholar The intention of our remarks under the recommendation against routinely screening a cohort of high-risk individuals who do not meet our core eligibility criteria was to allow thoughtful clinicians to make informed judgments about whether an individual at high risk for developing lung cancer should be offered low-dose CT screening. Assessing occupational and environmental exposures as risk factors in addition to those used in the core eligibility criteria fits squarely with this remark. There are challenges to consider before including occupational and environmental exposure histories in the selection of individuals or cohorts to screen. These include how to identify and quantify the exposure, translate the combination of exposure history and other risk factors into a total risk, and determine whether the exposure has led to competing risks that diminish the benefit of lung cancer screening. Unfortunately, the strength of evidence to address these challenges remains weak. The French workgroup described many assumptions when estimating exposure related risk. It did not recommend screening this cohort, but instead to study screening in this group.2Delva F. Margery J. Laurent F. et al.Medical follow-up of workers exposed to lung carcinogens: French evidence-based and pragmatic recommendations.BMC Public Health. 2017; 17: 191Crossref PubMed Scopus (14) Google Scholar The systematic review in CHEST assessed the prevalence of lung cancer in seven heterogeneous cohort studies. Most of the cancers identified were in smokers, and pack-years of smoking was not described.3Ollier M. Chamoux A. Naughton G. Pereira B. Dutheil F. Chest CT scan screening for lung cancer in asbestos occupational exposure: a systematic review and meta-analysis.Chest. 2014; 145: 1339-1346Abstract Full Text Full Text PDF PubMed Scopus (62) Google Scholar The National Comprehensive Cancer Network guidelines do not specify how to quantify exposures.4Wood D.E. Kazerooni E.A. Baum S.L. et al.Lung cancer screening, version 3.2018, NCCN Clinical Practice Guidelines in Oncology.J Natl Compr Canc Netw. 2018; 16: 412-441Crossref PubMed Scopus (310) Google Scholar In the Bach risk prediction model,5Bach P.B. Kattan M.W. Thornquist M.D. et al.Variations in lung cancer risk among smokers.J Natl Cancer Inst. 2003; 95: 470-478Crossref PubMed Scopus (485) Google Scholar to be classified as having a history of asbestos exposure, the first exposure had to occur ≥ 15 years ago and there had to be a minimum duration of 5 years spent in a trade at high risk of occupational exposure. Using this model, a 52-year-old man who smoked a pack of cigarettes per day for 25 years, quit smoking 5 years ago, and had asbestos exposure would be estimated to have a 0.33% 6-year probability of a lung cancer diagnosis, with a number needed to screen to avert a lung cancer death of 1,521. This is far lower than the 1.51% estimated 6-year probability of lung cancer suggested as a high-risk threshold in our guideline remarks. We thank Drs de la Hoz and Weissman for their letter and hope that it serves as a reminder about the importance of occupational and environmental exposures and the need for a thoughtful assessment of the evidence when determining screening policy. Consideration of Occupational and Environmental Lung Carcinogen Exposures for Lung Cancer Screening Using Low-Dose Chest CTCHESTVol. 154Issue 4PreviewWe read with great interest the American College of Chest Physicians’ guidelines for lung cancer screening1 and the excellent Point and Counterpoint editorials by Drs Wood and Mazzone2-5 in CHEST (June 2018) addressing the important issue of how to approach persons at high risk for lung cancer who don’t meet the guidelines’ core criteria for lung cancer screening. In his final rebuttal, Dr Mazzone5 states that the guidelines “…recommend that the cohort that does not meet our core eligibility criteria, but is at elevated risk for lung cancer based on risk calculators, should not be ‘routinely’ screened. Full-Text PDF Screening for Lung Cancer: CHEST Guideline and Expert Panel ReportCHESTVol. 153Issue 4PreviewLow-dose chest CT screening for lung cancer has become a standard of care in the United States in the past few years, in large part due to the results of the National Lung Screening Trial. The benefit and harms of low-dose chest CT screening differ in both frequency and magnitude. The translation of a favorable balance of benefit and harms into practice can be difficult. Here, we update the evidence base for the benefit, harms, and implementation of low radiation dose chest CT screening. We use the updated evidence base to provide recommendations where the evidence allows, and statements based on experience and expert consensus where it does not. Full-Text PDF