Association Between Lymph Node Silicosis and Lung Silicosis in 4,384 German Uranium Miners With Lung Cancer

ABSTRACT

This study investigates the association between lymph node–only and lung silicosis in uranium miners with lung cancer and exposure to quartz dust. Tissue slides of 4,384 German uranium miners with lung cancer were retrieved from an autopsy archive and reviewed by 3 pathologists regarding silicosis in the lungs and lymph nodes. Cumulative exposure to quartz dust was assessed with a quantitative job-exposure matrix. The occurrence of silicosis by site was investigated with regression models for exposure to quartz dust. Miners with lung silicosis had highest cumulative quartz exposure, followed by lymph node–only silicosis and no silicosis. At a cumulative quartz exposure of 40 mg/m³ × years, the probability of lung silicosis was above 90% and the likelihood of lymph node–only silicosis and no silicosis do not differ anymore. The results support that lymph node silicosis can precede lung silicosis, at least in a proportion of subjects developing silicosis, and that lung silicosis strongly depends on the cumulative quartz dose.

KEYWORDS:

• lung cancer
• lymph nodes
• quartz
• silicosis
• uranium mining

Acknowledgments

The authors gratefully acknowledge the Bundesanstalt für Arbeitsschutz und Arbeitsmedizin (BAuA; German Federal Institute for Occupational Safety and Health) for access to the Health Data Archive of the WISMUT corporation; the Deutsche Gesetzliche Unfallversicherung (DGUV; German Social Accident Insurance) for access to the job-exposure matrix for ionizing radiation, quartz dust, arsenic exposure, and job history of WISMUT miners; and the Deutsches Krebsforschungszentrum (DKFZ) for the database developed for the Archive.

Notes

*Odds ratios are for an increase of 10 years in age at death, an increase of 10 mg/m³ × years of cumulative exposure, an increase of 10 years for duration of exposure, and an increase of 10 years for time since last exposure.