Lung cancer screening an asbestos exposed population: Existing lung cancer risk criteria are not sufficient

Abstract

Background and Objective Asbestos is a major risk factor for lung cancer, with or without tobacco smoke exposure. Low dose computed tomography (LDCT) screening for early lung cancer is effective but only when targeting high risk populations. This study aimed to analyse the effectiveness of LDCT screening in an asbestos exposed population and to compare lung cancer screening program (LCSP) eligibility criteria. Methods Participants in an asbestos health surveillance program, the Western Australia Asbestos Review Program, underwent at least one LDCT scan and lung function assessment as part of annual review between 2012 and 2017. Lung cancer cases were confirmed through linkage to the WA cancer registry. Theoretical eligibility for different screening programs was calculated. Results Five thousand seven hundred and two LDCT scans were performed on 1743 individuals. The median age was 69.8 years, 1481 (85.0%) were male and 1147 (65.8%) were ever‐smokers (median pack‐year exposure of 20.0). Overall, 26 lung cancers were detected (1.5% of the population; 3.5 cases per 1000 person‐years of observation). Lung cancer was early stage in 86.4% and four (15.4%) cases were never smokers. Based on current lung screening program criteria, 1299 (74.5%) of this population, including the majority (17, 65.4%) of lung cancer cases, would not have been eligible for any LCSP. Conclusion This population is at raised risk despite modest tobacco exposure. LDCT screening is effective at identifying early‐stage lung cancer in this population and existing lung cancer risk criteria do not capture this population adequately.

Occupational lung cancer screening: A Collegium Ramazzini statement

“…Nine nonrandomized studies of asbestos-exposed populations with ≥150 participants reported results of LDCT screening for lung cancer between 2002 and 2019. [65][66][67][68][69][70][71][72][73][74] Age, smoking history, and asbestos exposure were principal or exclusive eligibility criteria with frequent use of broader age and smoking ranges than those used in NLST or NELSON. These studies were included in a published systematic review and meta-analyses by Ollier et al 75 and Maisonneuve et al 73 None of these studies used risk prediction models, NLST, or NELSON eligibility criteria to determine eligibility.…”

“…Brims and colleagues conclude that existing lung cancer screening criteria do not adequately account for occupational exposures. 74…”

“…Nine nonrandomized studies of asbestos‐exposed populations with ≥150 participants reported results of LDCT screening for lung cancer between 2002 and 2019 65–74 . Age, smoking history, and asbestos exposure were principal or exclusive eligibility criteria with frequent use of broader age and smoking ranges than those used in NLST or NELSON.…”

“…Consequently, no more than 35% of the 26 lung cancers detected by the program would have been detected by application of these alternative eligibility criteria. Brims and colleagues conclude that existing lung cancer screening criteria do not adequately account for occupational exposures 74 …”

Lung cancer: Removing toxic dust from our environment

“…The recent publication in Respirology by Brims et al 11 shows again that screening criteria based on age and pack‐years fail to optimally capture individuals at risk. Data from 1743 participants in the Western Australia Asbestos Review Program were collected including a description of occupation and residency.…”