Mesothelioma Mortality among German Asbestos-exposed

Mesothelioma Mortality among German Asbestos-exposed

Mesothelioma Mortality
among German Asbestos-exposed Workers
Pesch, B.1, Taeger, D.1, Johnen, G.1, Gross, I.M.1, Weber, D.G.1, Gube, M.2 , Brüning, T.1 , Kraus, T.2
1
2
BGFA – Research Institute of Occupational Medicine of the German Social Accident Insurance, University of Bochum, Germany
Institute for Occupational and Social Medicine, RWTH Aachen University, Germany
OBJECTIVES
z To
examine the mesothelioma risk of asbestos exposure of
German workers enrolled in the national surveillance program
z To evaluate the cancer risks after final asbestos ban in 1993
z To assess the role of fibrotic changes of the pleura in cancer
development
Table 1. Observed and expected deaths between 1993 and 2007
and age-standardised mortality ratios (SMR) among 576 asbestosexposed workers
Cause of death
ICD-9
Mortality follow-up (Table 1)
z 128 deceased workers (all causes)
SMR 0.59 (95% CI 0.49-0.70)
z 58 workers died from cancer of all sites
SMR 0.82 (95% CI 0.63-1.07)
z 15 workers died from pleural mesothelioma
SMR 28.10 (95% CI 15.73-46.36)
Mesothelioma risks (Table 2)
z Increased risk of workers with recognized occupational
asbestos disease at baseline RR 6.0 (95% CI 2.4-14.7)
z Decreased risk of workers with increasing time since
cessation of exposure RR 0.1 (95% CI 0.0-0.6)
for ≥ 30 vs. < 30 years
217.1
0.59
0.49 – 0.70
All cancer
140-208
58
70.4
0.82
0.63 – 1.07
Digestive organs without peritoneum
150-157, 159
17
22.8
0.74
0.43 – 1.19
Respiratory and intrathoracic organs
160-165
23
21.9
1.05
0.67 – 1.58
Trachea or bronchus or lung
162
8
20.4
0.39
0.17 – 0.77
Pleura
163
15
0.53
28.1
15.73 – 46.36
Urogenital system
185-189
9
12.0
0.75
0.34 – 1.42
Brain
191
2
1.4
1.42
0.17 – 5.13
Ill-defined site
195-199
3
3.8
0.79
0.16 – 2.32
Lymphatic & haematopoietic system
200-208
4
5.1
0.78
0.21 – 2.01
500-508
2
1.0
1.93
0.23 – 6.98
Cancer sites
Pneumoconioses and other lung
diseases due to external agents
* Expected cases derived from the male German population
#
Unknown cause of death for 15 workers
Table 2. Relative risks (RR) and 95 % confidence intervals (CI) of
deaths from pleural mesothelioma among 573 asbestos-exposed
workers for exposure, fibrotic pleural alterations, and smoking
exposure was associated with a very high mesothelioma risk
z In the long-term, cessation of asbestos exposure resulted in a
risk reduction
z Fibrotic changes detected by HRCT and recognized as occupational disease were a predictor for subsequent mesothelioma
z Participants comprised a lower fraction of active smokers than
non-responders
Mesothelioma
Covariate
PY
RR
95% CI
4436
8
1.0
65 years
2206
7
1.6
Never smoker
1747
3
1.0
Ever smoker
4896
12
1.2
< 25 fibre years
3282
7
1.0
25 - 50 fibre years
1442
4
1.0
0.5 – 2.7
> 50 fibre years
1918
4
0.8
0.4 – 1.8
< 20 years
3132
7
1.0
20 years
3511
8
0.1
< 30 years
2542
8
1.0
30 years
4101
7
0.1
Smoking
Asbestos exposure
Obs
< 65 years
Age at baseline
Duration of asbestos exposure
Time since last exposure
Pleural thickenings*
Recognized asbestos disease*
No
2407
3
1.0
Yes
4236
12
2.1
No
3143
2
1.0
Yes
3500
13
6.0
0.8 – 3.3
0.5 – 2.8
0.0 – 0.6
0.0 – 0.6
0.9 – 4.9
2.4 – 14.7
* The risks of pleural thickenings and of recognized asbestos disease were assessed with separate Poisson regression models
DISCUSSION
z Asbestos
95% CI
128
Cancer sites
Study population
z High age at baseline (53-70 years)
z High fraction of ex-smokers (60%)
z HRCT investigations revealed 363 males (63%) with pleural
plaques or thickenings
z HRCT findings resulted in recognition as occupational
disease in 53% of the workers
SMR
000-999
z 576 males selected as highly exposed among 110,000 German
RESULTS
Exp*
All causes#
MATERIAL AND METHODS
asbestos workers
z Extended health surveillance program with high-resolution computer tomography (HRCT) in 1993-1997
z Mortality follow-up until 4/2007
z SMR using German mortality rates based on death certificates
z Internal comparisons with Poisson regression using additional
information from the National Mesothelioma Register
Obs
CONCLUSIONS
►
Large surveillance programs are a valuable resource for cancer
research
Acknowledgement
The study was supported by the German Social Accident Insurance.