OBJECTIVES: Radon is carcinogenic, but more studies are needed to understand relationships with lung cancer and extrathoracic cancers at low exposures. There are few studies evaluating associations with cancer incidence or assessing the modifying effects of smoking. METHODS: We conducted a case-cohort study with 16 434 underground uranium miners in the Czech Republic with cancer incidence follow-up 1977-1996. Associations between radon exposure and lung cancer, and extrathoracic cancer, were estimated with linear excess relative rate (ERR) models. We examined potential modifying effects of smoking, time since exposure and exposure rate. RESULTS: Under a simple ERR model, assuming a 5-year exposure lag, the estimated ERR of lung cancer per 100 working level months (WLM) was 0.54 (95% CI 0.33 to 0.83) and the estimated ERR of extrathoracic cancer per 100 WLM was 0.07 (95% CI -0.17 to 0.72). Most lung cancer cases were observed among smokers (82%), and the estimated ERR of lung cancer per 100 WLM was larger among smokers (ERR/100 WLM=1.35; 95% CI 0.84 to 2.15) than among never smokers (ERR/100 WLM=0.12; 95% CI -0.05 to 0.49). Among smokers, the estimated ERR of lung cancer per 100 WLM decreased with time since exposure from 3.07 (95% CI -0.04 to 10.32) in the period 5-14 years after exposure to 1.05 (95% CI 0.49 to 1.87) in the period 25+ years after exposure. CONCLUSIONS: We observed positive associations between cumulative radon exposure and lung cancer, consistent with prior studies. We observed a positive association between cumulative radon exposure and extrathoracic cancers, although the estimates were small. There was evidence that the association between radon and lung cancer was modified by smoking in a multiplicative or super-multiplicative fashion.

• MeSH
• Radon Daughters adverse effects   MeSH
• Adult MeSH
• Miners statistics & numerical data   MeSH
• Incidence MeSH
• Cohort Studies MeSH
• Smoking adverse effects   MeSH
• Middle Aged MeSH
• Humans MeSH
• Lung Neoplasms epidemiology   MeSH
• Neoplasms, Radiation-Induced epidemiology   MeSH
• Neoplasms epidemiology   MeSH
• Occupational Exposure adverse effects   MeSH
• Radon adverse effects   MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Uranium MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Publication type
• Journal Article MeSH
• Research Support, N.I.H., Intramural MeSH
• Research Support, U.S. Gov't, P.H.S. MeSH
• Geographicals
• Czech Republic MeSH

BACKGROUND: Cancer risk (especially as regards lung cancer) in black-coal miners is mainly analyzed on the basis of mortality. The risk calculated based on mortality may differ from the values based on incidence. The aim of the study was to compare cancer risk in black-coal miners with and without coal workers' pneumoconiosis (CWP), based on data on mortality and the incidence of lung cancer in the Czech Republic in 1992-2013. MATERIAL AND METHODS: The cohort without CWP was composed of 6687 miners, and the cohort with CWP of 3476 miners. Information on the incidence of lung cancer was obtained from the Czech National Oncological Register (NOR), and information on mortality from the National Population Register. The risk of lung cancer incidence was compared with the general male population in the Czech Republic using the standardized incidence ratio (SIR), and the risk of lung cancer mortality using the standardized mortality ratio (SMR), with the 95% CI. RESULTS: In miners with CWP, a lower SMR value was found, SMR = 1.70 (95% CI: 1.41-2.04), compared with the SIR value, SIR = 2.01 (95% CI: 1.70-2.36). In miners without CWP, this was opposite, the value of SIR = 0.81 (95% CI: 0.69-0.94) was lower than the value of SMR = 0.83 (95% CI: 0.70-0.98). In miners without CWP, 17 cases of lung cancer (out of 176 cases in total) were not registered in NOR. In miners with CWP, the share of not registered cases was significantly lower (p = 0.018), and it was represented by 3% of not registered lung cancer cases, out of 156 cases with the diagnosis of lung cancer. CONCLUSIONS: In spite of the difference between SIR and SMR, the results of both indicators were consistent with the resulting relationship between the lung cancer risk and CWP. Med Pr. 2020;71(5):513-8.

• MeSH
• Anthracosis epidemiology   mortality   MeSH
• Adult MeSH
• Miners statistics & numerical data   MeSH
• Incidence MeSH
• Causality MeSH
• Cohort Studies MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Lung Neoplasms epidemiology   mortality   MeSH
• Occupational Diseases epidemiology   mortality   MeSH
• Prevalence MeSH
• Risk Factors MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Czech Republic MeSH