Exposure to beryllium and occurrence of lung cancer: A reexamination of findings from a nested case-control study

Objective: Our aim was to reanalyze a nested case-control study of beryllium and lung cancer because we identified analysis and study design issues that could have led to the elevated odds ratios obtained in the study. Methods: We reanalyzed the data using nontransformed exposure metrics instead of log-transformed metrics used in the publication. We identified and examined effects on estimated odds ratios of imbalances between cases and controls caused by the control selection method. Results: This reanalysis found no elevated odds ratios for any exposure variable. Conclusions: Our conclusions differ from the authors' interpretation that the findings are due to a causal relationship between beryllium exposure and lung cancer. Our alternative explanation is that they may be due to methodological problems that could have been controlled by closer matching of controls to cases. Clinical Significance: This study challenges conclusions made from a large case-control study concerning beryllium-lung cancer associations. Occupational medicine practitioners may want to integrate findings from this study into advice they give beryllium-exposed workers concerned about lung cancer.