[Bronchial cancer in anthracosilicosis and silicosis. Study of workers in coal fields in Wallonia]

This study was carried out between 1973 and 1982 on the proportional mortality by lung cancer of a group of workers living either in Brussells or in Wallonia and receiving compensation for silicosis or anthrasilicosis. The majority of patients suffered from anthrasilicosis (more than 96%) and had been exposed to the risk of pneumoconiosis in one of the four coal fields in Wallonia. If, in 13,822 deaths studied the proportional mortality from lung cancer had grown by 0.56% per year reaching 3.7% in 1973 and 9.3% in 1982, it remained below that for a similar Belgian population matched for age and sex. No correlation could be found between the occurrence of this tumour and one or other radiological category as defined by the international classification of pneumoconiosis in 1980. In addition the severity of pneumoconiosis, either from a radiological or functional view, hardly had any influence on the genesis of lung cancer. Finally, the localisation of the tumour and the different histological types do not differ from that reported in the literature among the general population. On the other hand a significant rise in proportional mortality from lung cancer between 1973 and 1982 (p less than 0.001) seemed to be related to two factors, smoking habitis (89.1% of subjects dying from lung cancer were smokers at the moment of death against 68.5% of smokers among other causes of death), and above all the progressive aging of the population of pneumoconioties receiving compensation, the cross section 50-69 rose from 53.17% in 1973 to 73.8% in 1982.