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/m(3) × 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.

IL-13 Immunotoxin Accelerates Resolution of Lung Pathological Changes Triggered by Silica Particles in Mice

“…Remarkably, evidence has been shown indicating that silicotic rats treated with cortisone also showed reduction of the amount of silica particles in the lungs and a little increase of silica detected in the lymph nodes (45). It is known from patients that inhaled silica particles not only affect the lungs but also other organs, mainly mediastinal lymph nodes, although the underlying mechanism is still poorly understood (46)(47)(48). Thus, it is conceivable that IL-13-PE might exert its inhibitory effect upon pulmonary silicosis, at least in part, by increasing the lymphaticmediated drainage of silica crystals from the lungs.…”

Mediastinal Lymph Node Silicotic Nodules and Occupational Exposure to Respirable Crystalline Silica: A Controlled Study in Patients with Lung Cancer

“…It has long been known that inhaled particles are concentrated in MLN through lymphatic clearance before abnormal accumulation in the lung parenchyma (2,3,10). Parenchymal silicotic nodules were only observed in three patients, a sampling bias could be hypothesized as silicosis is an upper lobe disease, however lung specimens were mainly collected from resected upper lobes.…”

“…To the Editor, Mediastinal lymph nodes (MLN) have recently been pointed out to be key targets in interstitial lung diseases especially in association with environmental exposure (1). In the context of well-defined occupational exposures to respirable crystalline silica (RCS), occurrence of silicotic nodules in MLN without parenchymal silicosis has been clearly identified and considered as an early stage in silicosis leading some authors to coin the term lymph-node-only silicosis (2,3). The carcinogenicity of crystalline silica for lung cancer is now well established (4,5), however in some countries as France lung cancer is still considered an occupational cancer only when associated with silicosis ( https://www.inrs.fr/publications/bdd/mp/tableau.html?refINRS=RG%2025).…”