Quantitation of asbestos and asbestos-like fibers in human lung tissue by hot and wet ashing, and the significance of their presence for survival of lung carcinoma and mesothelioma patients.
Technical standardization on randomly chosen samples of tissue specimen is essential for the validity of interpretations derived from measurements on the presence of asbestos fibers in lung in combination with further features of the patients. Fixed non-tumorous lung tissue (2-3 g) of 150 patients after surgery for various lung diseases were either digested in 45 ml of 13% solution with sodium hypochlorite (NaClO; wet ashing) or heated in an oven at 600 degrees C for 15 min (hot ashing). After tissue disintegration asbestos and asbestos-like fibers were counted by visual inspection, and the fiber concentration in the lung parenchyma was computed. In addition, the patients' survival, and the occupational and social history were analyzed. As a result, the mean concentrations of fibers were found to be 55 f/g (fibers/gram, hot ashing) and 46 f/g (wet ashing). The difference is statistically not significant. Mesotheliomas contributed 49% (73 patients), non-small cell lung carcinomas 32% (59 patients) to the entire cohort. Eighteen patients had a non-malignant lung disease. Analysis of living habits revealed that 73 (49%) patients were heavy smokers, and 99 (66%) patients had a history of occupational asbestos exposure which lasted for 18 years on average. A statistically significant difference of the asbestos fiber concentration between the group with professional exposure and that without detectable asbestos exposure could be obtained in mesothelioma patients and non-malignant lung diseases only, and a tendency for elevated fiber presence was seen in non-small cell lung carcinoma patients. In tissue specimen of patients with non-malignant lung diseases the highest fiber concentration was measured (median 104 f/g) followed by mesothelioma patients (77 f/g), and lung carcinoma patients (62 f/g wet tissue). The difference in the fiber concentration between smokers and ex-smokers versus non-smokers was particularly high in patients with non-malignant lung diseases (103 f/g in smokers versus 33 f/g in non-smokers), still statistically significant in mesothelioma patients (100 f/g smokers versus 61 f/g non smokers), and negligible in lung carcinoma patients (58 f/g smokers versus 62 f/g non-smokers). Only 5/70 mesothelioma patients were not exposed to asbestos at work, and nearly half of the patients (36) were non-smokers. The median survival of mesothelioma patients was significantly shortened for patients with a high intrapulmonal fiber concentration greater than 70 f/g (35 weeks versus 60 weeks). This correlation was also true for lung carcinoma patients (110 weeks versus 230 weeks).
Kayser
K
K
Abteilung für Pathologie, Thoraxklinik, Heidelberg, Germany. klkayser@lung.de
Becker
C
C
Seeberg
N
N
Gabius
H J
HJ
D001194:Asbestos / Q000032:analysis*; D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality*; D005260:Female; D006801:Humans; D008168:Lung / Q000737:chemistry*; D008171:Lung Diseases / Q000401:mortality; D008175:Lung Neoplasms / Q000401:mortality*; D008297:Male; D008654:Mesothelioma / Q000401:mortality*; D008875:Middle Aged; D019016:Mineral Fibers / Q000032:analysis*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012907:Smoking; D015996:Survival Rate
D019016:Mineral Fibers; D001194:Asbestos