Cause specific mortality in an Italian pool of asbestos workers cohorts

BACKGROUND

Asbestos is a known human carcinogen and is causally associated with malignant mesothelioma, lung, larynx and ovarian cancers.

METHODS

Cancer risk was studied among a pool of formerly asbestos-exposed workers in Italy. Fifty-two Italian asbestos cohorts (asbestos-cement, rolling-stock, shipbuilding, and other) were pooled and their mortality follow-up was updated to 2018. Standardized mortality ratios (SMRs) were computed for major causes of death considering duration of exposure and time since first exposure (TSFE), using reference rates by region, age and calendar period.

RESULTS

The study included 63,502 subjects (57,156 men and 6346 women): 40% who were alive, 58% who died (cause known for 92%), and 2% lost to follow-up. Mortality was increased for all causes (SMR: men = 1.04, 95% confidence interval [CI] 1.03-1.05; women = 1.15, 95% CI 1.11-1.18), all malignancies (SMR: men = 1.21, 95% CI 1.18-1.23; women = 1.29, 95% CI 1.22-1.37), pleural and peritoneal malignancies (men: SMR = 10.46, 95% CI 9.86-11.09 and 4.29, 95% CI 3.66-5.00; women: SMR = 27.13, 95% CI 23.29-31.42 and 7.51, 95% CI 5.52-9.98), lung (SMR: men = 1.28, 95% CI 1.24-1.32; women = 1.26, 95% CI 1.02-1.53), and ovarian cancer (SMR = 1.42, 95% CI 1.08-1.84). Pleural cancer mortality increased during the first 40 years of TSFE (latency), reaching a plateau thereafter.

CONCLUSIONS

Analyses by time-dependent variables showed that the risk for pleural neoplasms increased with latency and no longer increases at long TSFE, consistent with with asbestos clearance from the lungs. Peritoneal neoplasm risk increased over all observation time.

Mortality for Lung Cancer among PVC Baggers Employed in the Vinyl Chloride Industry

Vinyl-chloride monomer (VCM) is classified as a known carcinogen of the liver; for lung cancer, some results suggest a potential association with polyvinyl chloride (PVC) dust. We evaluated the relationship between lung cancer mortality and exposure as PVC baggers in a cohort of workers involved in VCM production and polymerization in Porto Marghera (Venice, Italy) considering both employment status and smoking habits. The workers were studied between 1973 and 2017. A subset of them (848 over 1658) was interviewed in the 2000s to collect information about smoking habits and alcohol consumption. Missing values were imputed by the Multivariate Imputation by Chained Equations (MICE) algorithm. We calculated standardized mortality ratios (SMR) and 95% confidence intervals (95% CIs) using regional reference rates by task (never, ever, and exclusively baggers) and by smoking habits. Mortality rate ratios (MRR), adjusted for age, calendar time, time since first exposure, and smoking habits, were obtained via Poisson regression using Rubin’s rule to combine results from imputed datasets calculating the fraction of information due to non-response. Lung cancer mortality was lower than the regional reference in the whole cohort (lung cancer SMR = 0.92; 95% CI 0.75–1.11). PVC baggers showed a 50% increase in lung cancer mortality compared to regional rates (SMR = 1.48; 95% CI 0.82–2.68). In the cohort analyses, a doubled risk of lung cancer mortality among PVC baggers was confirmed after adjustment for smoking and time-dependent covariates (MRR = 1.99, 95% CI 1.04–3.81). Exposure to PVC dust resulting from activity as bagger in a polymerization PVC plant was associated with an increase in lung cancer mortality risk after adjustment for smoking habits.

[Impact of the COVID-19 epidemic in Friuli Venezia Giulia Region (Northern Italy): assessment of factors associated with the risk of death by competing risks analysis]

OBJECTIVES

to investigate the role of gender, age, province of residence, and nursing home residency on the risk of death for residents in the Friuli Venezia Giulia (FVG) Region (Northern Italy) tested positive for Covid-19, considering recovery as a competing event. The secondary objective is to describe the impact of the Covid-19 epidemic in FVG and in the Regions of Northern and Central Italy in terms of incidence and mortality compared to the national data.

DESIGN

retrospective cohort study.

SETTING AND PARTICIPANTS

resident population in FVG in the period between 29 February and 25 June 2020.

MAIN OUTCOME MEASURES

in order to describe the impact of the Covid-19 outbreak in FVG, in terms of incidence and mortality compared to the national data, the standardized incidence (SIR) and mortality (SMR) ratios and their respective 95% confidence intervals (95%CI) were calculated compared to the Italian population for the northern and central Regions of Italy and the autonomous Provinces (PA) of Trento and Bolzano. A retrospective cohort study was conducted on subjects residing in FVG to whom at least one naso-oropharyngeal swab (hereafter, named swab) resulted positive for Covid-19. For each subject included in the cohort, the observation period started with the first positive swab and ended with the first of the following events: death, recovery or censored, which means that at the end of the observation period the subject was still alive and positive. The cause of death was assigned to Covid-19 if a subject had not yet recovered at the time when the event occurred. Cohort members were considered recovered after two negative consecutive swabs. The sub-hazard ratio (SHR) was estimated by applying the regression model of competing risks by Fine and Gray, in which the event of interest was the death caused by Covid-19 and the competing event was recovery. The explanatory variables included in the multiple models are: gender, age at the beginning of the observation period, the Province of residence, and nursing home residency. The cause-specific hazard was estimated using Cox proportional hazard regression.

RESULTS

during the observation period, 3,305 cases and 345 deaths were recorded in FVG; SIR and SMR resulted, respectively, equal to 0.64 (95%CI 0.61-0.68) and 0.43 (95%CI 0.37-0.50). The FVG was the Northern Region one with the lowest incidence and mortality. The cohort consisted of 3,121 residents in FVG with at least one swab with a positive Covid-19 result during the study period. The SHR of dying for Covid-19 is equal to 16.13 (95%CI 9.73-26.74) for people with age 70-79 years and 35.58 (95%CI 21.77-58.15) with age >=80 years respect those with age <70 years. It is higher in males (SHR 1.71; 95%CI 1.34-2.17). There is no evidence that being resident in a nursing home affects the SHR (SHR 0.91 and 95%CI 0.69-1.20). As regards the province as an explanatory variable, the sub-hazard of death in the province of Trieste appears to overlap to the sub-hazard of Pordenone used as a reference; for the provinces of Udine and Gorizia the sub-hazards seem lower than the reference.

CONCLUSIONS

while other Northern Regions and autonomous Provinces show higher standardized incidence and mortality compared with Italy, FVG and Veneto do not. In FVG, male gender and age are important determinants of death while there is no evidence that the condition of guest in a nursing home increases the sub-hazard of death.

Impact of low-dose computed tomography screening on lung cancer mortality among asbestos-exposed workers

Background

We previously showed that low-dose computed tomography (LDCT) screening in asbestos-exposed workers is effective in detecting lung cancer (LC) at an early stage. Here, we evaluate whether LDCT screening could reduce mortality from LC in such a high-risk population.

Methods

Within a cohort of 2433 asbestos-exposed men enrolled in an Occupational Health surveillance programme, we compared mortality between the participants in the ATOM002 study (LDCT-P, N  =  926) and contemporary non-participants (LDCT-NP, N  =  1507). We estimated standardized mortality ratios for the LDCT-P and LDCT-NP populations using regional and national rates (SMR_FVG and SMR_ITA, respectively). We compared survival for all causes, all neoplasms, LC and malignant neoplasm of pleura (MNP) between LDCT-P and LDCT-NP using Cox proportional hazard models adjusted for age, smoking history, asbestos exposure level and comorbidities.

Results

A reduction in mortality from LC was observed in the LDCT-P group compared with regional and national figures (SMR_FVG  =  0.55, 95% confidence interval (CI) 0.24-1.09; SMR_ITA  =  0.51, 95% CI 0.22-1.01); this was not the case for the LDCT-NP group (SMR_FVG  =  2.07, 95% CI 1.53-2.73; SMR_ITA  =  1.98, 95% CI 1.47-2.61). A strong reduction in LC mortality was observed for the LDCT-P compared with the LDCT-NP [hazard ratio (HR)  =  0.41, 95% CI 0.17-0.96]. Mortality was also reduced for all causes (HR  =  0.61, 95% CI 0.44-0.84), but not for all neoplasms (HR  =  0.97, 95% CI 0.62-1.50) and MNP (HR  =  0.86, 95% CI 0.31-2.41) within the LDCT-P population.

Conclusions

In our cohort, participation in the LDCT screening study was associated with reduced mortality from LC. This finding supports the use of LDCT in surveillance programmes for asbestos-exposed workers.

Cancer incidence in a cohort of asbestos-exposed workers undergoing health surveillance

OBJECTIVES

To compare a local cohort of 2488 men occupationally exposed to asbestos and enrolled in a public health surveillance program with the 1995-2009 cancer incidence of the general population of Friuli Venezia Giulia (FVG) region, Northeast Italy, we conducted a historical cohort study.

METHODS

Standardized incidence ratios (SIRs), with 95% confidence interval (95% CI), for specific cancer sites were estimated in the cohort and in subgroups of workers employed in shipbuilding between 1974 and 1994. For internal comparisons, we calculated incidence rate ratios (IRRs) for all cancers, lung cancer and mesothelioma, by level of exposure to asbestos and sector of employment adjusted for smoking habits and age at start of follow-up.

RESULTS

Among cohort members the SIR was 8.82 (95% CI 5.95-12.61) for mesothelioma and 1.61 (95% CI 1.26-2.04) for lung cancer. In subgroup analyses, the SIR for lung cancer in subjects hired in shipbuilding between 1974 and 1984 was 2.09 (95% CI 1.32-3.13). In the overall cohort, a borderline increased incidence was also found for stomach cancer (SIR = 1.53 95% CI 0.96-2.31). Internal comparisons within the cohort show that among men with high asbestos exposure level the relative risk was almost threefold for lung cancer (IRR = 2.94 95% CI 1.01-8.57).

CONCLUSIONS

This cohort experienced an excess in the incidence of both mesothelioma and lung cancer, showing increasing incidence rates at higher level of asbestos exposure. For lung cancer, the relative incidence was highest among workers hired in shipbuilding between 1974 and 1984.

Mortality in a cohort of asbestos-exposed workers undergoing health surveillance

Background:

The coastal area of Friuli Venezia Giulia (FVG) region, north-eastern Italy, was characterized by work activities in which asbestos was used until the early 1990s, particularly in shipbuilding. A public health surveillance program (PHSP) for asbestos-exposed workers was established, although limited evidence exists about the efficacy of such programs in reducing disease occurrence and mortality.

Objectives:

To compare mortality in a cohort of 2,488 men occupationally exposed to asbestos, enrolled in a PHSP in FVG between the early 1990s and 2008, with that of the general population of FVG and Italy.

Methods:

Standardized Mortality Ratios (SMR), with 95% Confidence Interval (95% CI), for all causes, all cancers, lung (LC) and pleural cancer (PC) were estimated in the cohort and in subgroups of workers with the first hire in shipbuilding that caused asbestos exposure (<1974, 1974-1984, 1985-1994).

Results:

A strong excess in mortality for PC with reference to FVG (SMR=6.87, 95% CI 4.45-10.17) and Italian population (SMR=13.95, 95% CI 9.02-20.64) was observed. For LC, the FVG-based SMR was 1.49 (95% CI 1.17-1.89) and the Italy-based 1.43 (95% CI 1.12-1.81). Mortality among workers with the first hire in shipbuilding before 1974 was high for PC (FVG-based SMR=8.98, 95% CI 5.56-13.75; Italy-based SMR=18.41, 95% CI 11.40-28.17) and for LC (FVG-based SMR =1.60, 95% CI 1.18-2.11; Italy-based SMR=1.54, 95% CI 1.14-2.03). Further, for LC between 1974 and 1984, the FVG-based SMR was 2.45 (95% CI 1.06-4.82), and the Italy-based SMR was 2.33 (95% CI 1.01-4.60).

Conclusions:

This cohort experienced an excess mortality for pleural and lung cancer, compared with regional and national populations. For lung cancer, the excess was stronger in workers with the first hire in shipbuilding before 1985, suggesting a key role of asbestos exposure.

[Not Available]

INTRODUCTION

The incidence of mesothelioma in Italy shows wide geographical variation, with the highest incidence rates in Genoa and Friuli Venezia Giulia (FVG). For mesothelioma, national standard incidence rates are not available prior to the calendar year 2006.

OBJECTIVES

To estimate the Standardized Incidence rate Ratio (SIR) of mesothelioma in a cohort of former workers undergoing health surveillance because of previous asbestos exposure, when sex-, age-, and calendar year-specific rates of the national standard are not available and the number of expected cases calculated from the regional rates is biased by the size of the study cohort.

METHODS

We conducted a sensitivity analysis in a cohort of 2,488 men. We considered every Italian cancer registry available with complete data in the period 1995-2007 (N=14). We calculated, for each year and age group, the corresponding weighted mean rate of 10 registries of North-Italy (Mean W10), the weighted mean rate of all 14 registries available (Mean W14) and considered FVG standard rate.

RESULTS

During the period 1995-2007, we observed 25 incident cases of mesothelioma with expected cases that varied between 2.00 (Mean W14) and 2.56 (FVG standard rate), with a SIR of 12.49 (CI95% 8.08-18.48) and 9.76 (CI95% 6.32-14.45) respectively.

CONCLUSIONS

Our results show that the use of FVG rates as standard does not lead to significant distortions in the calculation of the expected cases. However, distortion is remarkable in the SIRs estimation. Using a weighted mean standard incidence rate may be a valid alternative for SIR estimate when national standard rates are not available.