Document B8gXmv3BazXvXnJQM3w5vepbJ

02/13/2003 THU 10:46 FAX 312 996 1899 UIC LHS CHICAGO @008 132 IION.SETt ST AL. Vol. 25 usually seen at postmortem examination. The peripheral cancers in this series may, therefore, represent a stage prior to hilar involvement. Two tumors were pleural in distribution, 1 disseminating and 1 not. Both were adenocarcinomas, the former having spindle-cell areas. Attention must also be drawn to the 4 peritoneal cancers, 1 in a male and 3 in females. This is a very high number in such a email series of cases. All these tumors were anaplastic carcinomas, the primary site not being found in any organ. The possibility of an origin from the sequestrated bronchial epithelium present in the diaphragmatic areas of hyaloserositis is suggested, but without any clear proof. No adequate comparable postmortem material from persons working under factory conditions and not exposed to asbestos dust is available with which to compare the incidence of lung cancer in asbestos workers. The incidence here cited is very high and by comparison with the incidence in iron-ore miners muat be highly significant. The occurrence uf occupational lung cancer in the exposed female is noteworthy. In connection with this particular form of industrial hazard, it must be em phasized that since the introduction of regulations for the control of asbestos dust in 1031, the amount of exposure of the workers to dust has been enormously reduced and we shall therefore expect to sec a disappearance of those severe degrees of pulmonary fibrosis that have been described heretofore and possibly a disappearance of associated cancer. All the present cases that had asbestosis aud cancer had been exposed prior to 1931. S. Cancer of the Lung in [ron-Orr. Miners One of the authors (JSF) has had a unique opportunity to study this disease (Stewart and Foulds, 1934) .l* Ho has personally conducted postmortem exami nations on 192 Cumberland hematite miners during the last 20 years and in addition has performed postmortem examinations on 2378 Cumberland males above tho age of 20 years, unselected in regard to cancer or lung disease. The dif ference in incidenoe of lung cancer in these 2 groups is statistically significant (Table 5). The age of onset is not significantly delayed, moat of the miners having entered the mines under the age of 30 years- AH the miners' lungs contained much silica and iron at death, but there was no significant, difference in the content of either mineral in the lungs with and without cancer. There was, however, an interesting difference in the degree of fibrosis (Table 6) and this has greater significance when a similar occurrence in relation to asbestosis is remembered. All the tumors were classified as oat-cell or squamous cancers. TABLE S Cancer of the Luno )N Iron-Ore Miners Nuobtx IQns Cancers Iron-ore miners Cumberland males over 20 years 102 2378 17 a Ptrctntage Incident* 8.8$ 2 1-8S 2 Feb. 1966 Mineral Bronchial carci Fibrosis alone Fibrosis and tr Ho fibrosis &ni Figures io I available- The oomm it is suggest* silicic aoid) c uant process which cance: lationship b than in silic examined th available ev. the lung is u asbestos or chemical act nature of th The vain cancer in th 2 aspects, any popula tional cauw More de' In regard t. involved ar latter, the > textile wor scribed. 1. Bonseb, cause 2. Bowses. propei amine