Australische asbestwerkers hebben meer risico op longkanker ondanks stoppen met roken

Voormalige Australische asbest-werkers hebben een extra risico op het krijgen van longkanker tot 20 jaar na het stoppen met roken. De extra kans op longkanker van iemand die én heeft gerookt én asbestvezels heeft ingeademd is minder dan het product van de verhoging bij alleen roken en die bij alleen asbestblootstelling. Dit concludeerde Reid et al. na een onderzoek onder bijna 3000 ex-werknemers van de asbestmijnen in het Australische Wittenoom. In Wittenoom werd tussen 1943 en 1966 het meest gevaarlijke blauwe asbest (crocidoliet) gewonnen. Reid A., et al. (2006). The risk of lung cancer with increasing time since ceasing exposure to asbestos and quitting smoking. Occupational Environmental Medicine, Aug.63(8):509-12.
Reid A, de Klerk NH, Ambrosini GL, Berry G, Musk AW., (2006). The risk of lung cancer with increasing time since ceasing exposure to asbestos and quitting smoking. Occupational Environmental Medicine, Aug.63(8):509-12.

OBJECTIVES: To examine if the risk of lung cancer declines with increasing time since ceasing exposure to asbestos and quitting smoking, and to determine the relative asbestos effect between non-smokers and current smokers. METHODS: A cohort study of 2935 former workers of the crocidolite mine and mill at Wittenoom, who responded to a questionnaire on smoking first issued in 1979 and on whom quantitative estimates of asbestos exposure are known. Conditional logistic regression was used to relate asbestos exposure, smoking category, and risk of lung cancer. RESULTS: Eighteen per cent of the cohort reported never smoking. 66% of cases and 50% of non-cases were current smokers. Past smokers who ceased smoking within six years of the survey (OR = 22.1, 95% CI 5.6 to 87.0), those who ceased smoking 20 or more years before the survey (OR = 1.9, 95% CI 0.50 to 7.2), and current smokers (<20 cigarettes per day (OR = 6.8, 95% CI 2.0 to 22.7) or >20 cigarettes per day (OR = 13.2, 95% CI 4.1 to 42.5)) had higher risks of lung cancer compared to never smokers after adjusting for asbestos exposure and age. The asbestos effect between non-smokers and current smokers was 1.23 (95% CI 0.35 to 4.32). CONCLUSION: Persons exposed to asbestos and tobacco but who subsequently quit, remain at an increased risk for lung cancer up to 20 years after smoking cessation, compared to never smokers. Although the relative risk of lung cancer appears higher in never and ex-smokers than in current smokers, those who both smoke and have been exposed to asbestos have the highest risk. this study emphasises the importance of smoking prevention and smoking cessation programmes within this high risk cohort.