Abstract
The mortality of 724 subjects with silicosis, first diagnosed in 1964-70 in the Sardinia region of Italy, was followed up through to 31 December 1987. Smoking, occupational history, chest x ray films, and data on lung function were available from clinical records for each member of the cohort. The overall cohort accounted for 10,956.5 person-years. The standardised mortality ratios (SMRs) for selected causes of death (International Classification of Diseases (ICD) eighth revision) were based on the age specific regional death rates for each calendar year. An excess of deaths for all causes (SMR = 1.40) was found, mainly due to chronic obstructive lung disease, silicosis, and tuberculosis with an upward trend of the SMR with increasing severity of the International Labour Office (ILO) radiological categories. Twenty two subjects died from lung cancer (SMR = 1.29, 95% confidence interval (95% CI) = 0.8-2.0). The risk increased after a 10 and 15 year latency but the SMR never reached statistical significance. No correlation was found between lung cancer and severity of the radiological category, the type of silica (coal or metalliferous mines, quarries etc), or the degree of exposure to silica dust. A significant excess of deaths from lung cancer was found among heavy smokers (SMR = 4.11) and subjects with airflow obstruction (SMR = 2.83). A nested case-control study was planned to investigate whether the association between lung cancer and airway obstruction was due to confounding by smoking. No association was found with the ILO categories of silicosis or the estimated cumulative exposure to silica. The risk estimate for lung cancer by airflow obstruction after adjusting by cigarette consumption was 2.86 for a mild impairment and 7.23 for a severe obstruction. The results do not show any clear association between exposure to silica, severity of silicosis, and mortality from lung cancer. Other environmental or individual factors may act as confounders in the association between silicosis and lung cancer. Among them, attention should be given to chronic airways obstruction as an independent risk factor for lung cancer in patients with silicosis.
Full text
PDFSelected References
These references are in PubMed. This may not be the complete list of references from this article.
- Ames R. G. Does coal workers' pneumoconiosis predict to lung cancer? Some evidence from a case-control study. J Soc Occup Med. 1983 Jul;33(3):141–144. doi: 10.1093/occmed/33.3.141. [DOI] [PubMed] [Google Scholar]
- Anthonisen N. R. Prognosis in chronic obstructive pulmonary disease: results from multicenter clinical trials. Am Rev Respir Dis. 1989 Sep;140(3 Pt 2):S95–S99. doi: 10.1164/ajrccm/140.3_Pt_2.S95. [DOI] [PubMed] [Google Scholar]
- Beaty T. H., Cohen B. H., Newill C. A., Menkes H. A., Diamond E. L., Chen C. J. Impaired pulmonary function as a risk factor for mortality. Am J Epidemiol. 1982 Jul;116(1):102–113. doi: 10.1093/oxfordjournals.aje.a113385. [DOI] [PubMed] [Google Scholar]
- Carta P., Aru G., Barbieri M. T., Bario P., Casciu G., Cocco P. L., Casula D. Cause di morte nei silicotici della Sardegna (1964-1977). Med Lav. 1988 Nov-Dec;79(6):431–443. [PubMed] [Google Scholar]
- Cohen B. H., Ball W. C., Jr, Brashears S., Diamond E. L., Kreiss P., Levy D. A., Menkes H. A., Permutt S., Tockman M. S. Risk factors in chronic obstructive pulmonary disease (COPD). Am J Epidemiol. 1977 Mar;105(3):223–232. doi: 10.1093/oxfordjournals.aje.a112378. [DOI] [PubMed] [Google Scholar]
- Cohen B. H. Chronic obstructive pulmonary disease: a challenge in genetic epidemiology. Am J Epidemiol. 1980 Aug;112(2):274–288. doi: 10.1093/oxfordjournals.aje.a112994. [DOI] [PubMed] [Google Scholar]
- Costello J., Graham W. G. Vermont granite workers' mortality study. Am J Ind Med. 1988;13(4):483–497. doi: 10.1002/ajim.4700130408. [DOI] [PubMed] [Google Scholar]
- Davis L. K., Wegman D. H., Monson R. R., Froines J. Mortality experience of Vermont granite workers. Am J Ind Med. 1983;4(6):705–723. doi: 10.1002/ajim.4700040604. [DOI] [PubMed] [Google Scholar]
- Duggan M. J., Soilleux P. J., Strong J. C., Howell D. M. The exposure of United Kingdom miners to radon. Br J Ind Med. 1970 Apr;27(2):106–109. doi: 10.1136/oem.27.2.106. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Finkelstein M., Kusiak R., Suranyi G. Mortality among miners receiving workmen's compensation for silicosis in Ontario: 1940-1975. J Occup Med. 1982 Sep;24(9):663–667. doi: 10.1097/00043764-198209000-00012. [DOI] [PubMed] [Google Scholar]
- Finkelstein M., Liss G. M., Krammer F., Kusiak R. A. Mortality among workers receiving compensation awards for silicosis in Ontario 1940-85. Br J Ind Med. 1987 Sep;44(9):588–594. doi: 10.1136/oem.44.9.588. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Forastiere F., Lagorio S., Michelozzi P., Cavariani F., Arca' M., Borgia P., Perucci C., Axelson O. Silica, silicosis and lung cancer among ceramic workers: a case-referent study. Am J Ind Med. 1986;10(4):363–370. doi: 10.1002/ajim.4700100404. [DOI] [PubMed] [Google Scholar]
- Goldsmith D. F., Guidotti T. L., Johnston D. R. Does occupational exposure to silica cause lung cancer? Am J Ind Med. 1982;3(4):423–440. doi: 10.1002/ajim.4700030408. [DOI] [PubMed] [Google Scholar]
- Harber P., Oren A., Mohsenifar Z., Lew M. Obstructive airway disease as a risk factor for asbestos-associated malignancy. J Occup Med. 1986 Feb;28(2):82–86. [PubMed] [Google Scholar]
- Heppleston A. G. Silica, pneumoconiosis, and carcinoma of the lung. Am J Ind Med. 1985;7(4):285–294. doi: 10.1002/ajim.4700070404. [DOI] [PubMed] [Google Scholar]
- Hessel P. A., Sluis-Cremer G. K., Hnizdo E. Silica exposure, silicosis, and lung cancer: a necropsy study. Br J Ind Med. 1990 Jan;47(1):4–9. doi: 10.1136/oem.47.1.4. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jacobsen M. Lung cancer and coal workers' pneumoconiosis. Br Med J. 1979 Jul 21;2(6183):208–208. doi: 10.1136/bmj.2.6183.208-b. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Koskela R. S., Klockars M., Järvinen E., Kolari P. J., Rossi A. Cancer mortality of granite workers. Scand J Work Environ Health. 1987 Feb;13(1):26–31. doi: 10.5271/sjweh.2088. [DOI] [PubMed] [Google Scholar]
- Lubin J. H., Gail M. H. Biased selection of controls for case-control analyses of cohort studies. Biometrics. 1984 Mar;40(1):63–75. [PubMed] [Google Scholar]
- MANTEL N., HAENSZEL W. Statistical aspects of the analysis of data from retrospective studies of disease. J Natl Cancer Inst. 1959 Apr;22(4):719–748. [PubMed] [Google Scholar]
- Maillard J. M. Silicose et cancer bronchique. Poumon Coeur. 1980 Jan-Feb;36(1):41–48. [PubMed] [Google Scholar]
- Mastrangelo G., Zambon P., Simonato L., Rizzi P. A case-referent study investigating the relationship between exposure to silica dust and lung cancer. Int Arch Occup Environ Health. 1988;60(4):299–302. doi: 10.1007/BF00378477. [DOI] [PubMed] [Google Scholar]
- McDonald J. C. Silica, silicosis, and lung cancer. Br J Ind Med. 1989 May;46(5):289–291. doi: 10.1136/oem.46.5.289. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Miettinen O. Estimability and estimation in case-referent studies. Am J Epidemiol. 1976 Feb;103(2):226–235. doi: 10.1093/oxfordjournals.aje.a112220. [DOI] [PubMed] [Google Scholar]
- Miller B. G., Jacobsen M. Dust exposure, pneumoconiosis, and mortality of coalminers. Br J Ind Med. 1985 Nov;42(11):723–733. doi: 10.1136/oem.42.11.723. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rimington J. Smoking, chronic bronchitis, and lung cancer. Br Med J. 1971 May 15;2(5758):373–375. doi: 10.1136/bmj.2.5758.373. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rogan J. M., Attfield M. D., Jacobsen M., Rae S., Walker D. D., Walton W. H. Role of dust in the working environment in development of chronic bronchitis in British coal miners. Br J Ind Med. 1973 Jul;30(3):217–226. doi: 10.1136/oem.30.3.217. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rooke G. B., Ward F. G., Dempsey A. N., Dowler J. B., Whitaker C. J. Carcinoma of the lung in Lancashire coalminers. Thorax. 1979 Apr;34(2):229–233. doi: 10.1136/thx.34.2.229. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Saffiotti U. Attività cancerogena della silice e possibile ruolo patogenetico della reazione cellulare fibrogena. Med Lav. 1985 Sep-Oct;76(5):351–357. [PubMed] [Google Scholar]
- Skillrud D. M., Offord K. P., Miller R. D. Higher risk of lung cancer in chronic obstructive pulmonary disease. A prospective, matched, controlled study. Ann Intern Med. 1986 Oct;105(4):503–507. doi: 10.7326/0003-4819-105-4-503. [DOI] [PubMed] [Google Scholar]
- Steenland K., Beaumont J. A proportionate mortality study of granite cutters. Am J Ind Med. 1986;9(2):189–201. doi: 10.1002/ajim.4700090210. [DOI] [PubMed] [Google Scholar]
- Tockman M. S., Anthonisen N. R., Wright E. C., Donithan M. G. Airways obstruction and the risk for lung cancer. Ann Intern Med. 1987 Apr;106(4):512–518. doi: 10.7326/0003-4819-106-4-512. [DOI] [PubMed] [Google Scholar]
- Westerholm P. Silicosis. Observations on a case register. Scand J Work Environ Health. 1980;6 (Suppl 2):1–86. [PubMed] [Google Scholar]
- Wilson T., Scheuchenzuber W. J., Eskew M. L., Zarkower A. Comparative pathological aspects of chronic olivine and silica inhalation in mice. Environ Res. 1986 Apr;39(2):331–344. doi: 10.1016/s0013-9351(86)80059-7. [DOI] [PubMed] [Google Scholar]
- Zambon P., Simonato L., Mastrangelo G., Winkelmann R., Saia B., Crepet M. Mortality of workers compensated for silicosis during the period 1959-1963 in the Veneto region of Italy. Scand J Work Environ Health. 1987 Apr;13(2):118–123. doi: 10.5271/sjweh.2072. [DOI] [PubMed] [Google Scholar]