Influence of quartz exposure on lung cancer types in cases of lymph node–only silicosis and lung silicosis in German uranium miners

ABSTRACT

Inhaled crystalline quartz is a carcinogen. Analyses show differences in the distribution of lung cancer types depending on the status of silicosis. Using 2,524 lung tumor cases from the WISMUT autopsy repository database, silicosis was differentiated into cases without silicosis in lung parenchyma and its lymph nodes, with lymph node–only silicosis, or with lung silicosis including lymph node silicosis. The proportions of adenocarcinoma, squamous cell carcinoma, and small-cell lung carcinoma mortality for increasing quartz exposures were estimated in a multinomial logistic regression model. The relative proportions of the lung cancer subtypes in lymph node–only silicosis were more similar to lung silicosis than without any silicosis. The results support the hypothesis that quartz-related carcinogenesis in case of lymph node–only silicosis is more similar to that in lung silicosis than in without silicosis.

KEYWORDS:

• Lung cancer
• lymph node silicosis
• quartz
• silicosis
• uranium mining