Pleural plaques in lung cancer screening by low-dose computed tomography: prevalence, association with lung cancer and mortality

Abstract

BackgroundTo report the prevalence of pleural plaques in a lung cancer screening trial by low-dose computed tomography (LDCT) and to test the association with incidence of lung cancer and mortality.MethodsThe LDCT of 2303 screenees were retrospectively reviewed with the specific aim of describing the prevalence and features of pleural plaques. Self-administered questionnaire was used to assess asbestos exposure. Frequency of lung cancer, lung cancer mortality, and overall mortality were detailed according to presence of pleural findings. Statistical analyses included comparison of mean or median, contingency tables, and Cox model for calculation of hazard ratio (HR) and its 95% confidence interval (CI).ResultsAmong male screenees, 31/1570 (2%) showed pleural abnormalities, 128/1570 (8.2%) disclosed asbestos exposure, 23/31 (74.2%) subjects with pleural plaques consistently denied exposure to asbestos. There was a trend for higher frequency of lung cancer among subjects with pleural plaques (9.7% vs 4.2%). Lung cancer in subjects with pleural plaques was always diagnosed in advanced stage. Subjects with pleural plaques showed HR 5.48 (95% CI 1.61–18.70) for mortality from lung cancer.ConclusionsPleural plaques are a risk factor for lung cancer mortality that can be detected in lung cancer screening by LDCT, also in subjects that are not aware of asbestos exposure.Trial registration NCT02837809 - Retrospectively registered July 1, 2016 - Enrolment of first participant September 2005.

Low-dose computed tomography screening for lung cancer in people with workplace exposure to asbestos

“…LDCT was able to detect pleural plaques in 10% of asbestos-exposed participants, which is in agreement with previous studies [20,47,48]. This relatively low frequency may be attributable to the fact that participants to the COSMOS screening were asymptomatic heavy smokers, not selected for their exposure to asbestos.…”

“…All 34 studies were assessed for inclusion in the meta-analysis. Ten were excluded for absence of original data and 9 were excluded after further review: 3 for small or undefined proportions of asbestos-exposed patients [22][23][24], 2 for failure to state number of lung cancers diagnosed at baseline LDCT screening [20,25], and 4 because original findings were inextricably mixed with data from other studies [26][27][28][29] (Supplementary Table 1). Summary data from the 15 studies that satisfied our eligibility criteria are shown in Table 4 [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44].…”

“…Most lung cancer risk models factor in asbestos exposure when estimating risk [17][18][19]. Although primary prevention is desirable, extending secondary prevention (LDCT screening) to persons at high risk for occupational exposure to asbestos may be an effective way reducing lung cancer mortality, particularly since pleural plaques (asbestos-related radiological signs) seem to be a risk factor for lung cancer mortality and can be detected by LDCT [20].…”

The radiologist’s role in lung cancer screening

“…Silva et al investigated the presence of pleural plaques in LCS participants and relationship with lung cancer and mortality. They showed that male screenees with pleural plaques showed a trend for higher risk of lung cancer and significant increase of lung cancer mortality compared to male screenees without pleural plaques with a hazard radio of 5.48 (95% CI: 1.61-18.70) for mortality of lung cancer in subjects with pleural plaques (78).…”

Asbestos, Pleural Plaques, and Lung Cancer: Untangling the Relationships

“…Many workers may be unaware of prior exposure or may have forgotten owing to the long latency. In a study of male LDCT participants selected for smoking rather than asbestos exposure, most with plaques were unaware of prior exposure (11).…”