Validation of a Model of Lung Cancer Risk Prediction Among Smokers

Cornell University, Итак, New York, United States
Journal of the National Cancer Institute (Impact Factor: 12.58). 06/2006; 98(9):637-40. DOI: 10.1093/jnci/djj163
Source: PubMed


The Bach model was developed to predict the absolute 10-year risk of developing lung cancer among smokers by use of participants
in the Carotene and Retinol Efficacy Trial of lung cancer prevention. We assessed the validity of the Bach model among 6239
smokers from the placebo arm of the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study. The expected numbers of
lung cancer cases and deaths without lung cancer were calculated from the Bach model and compared with the observed numbers
of corresponding events over 10 years. We found that the risk model slightly underestimated the observed lung cancer risk
(number of lung cancers expected/number observed = 0.89, 95% confidence interval [CI] = 0.80 to 0.99) over 10 years. The competing
risk portion of the model substantially underestimated risk of non-lung cancer mortality (number of non-lung cancer deaths
expected/number observed = 0.61, 95% CI = 0.57 to 0.64) over 10 years. The age-specific concordance indices for 10-year predictions
were 0.77 (95% CI = 0.70 to 0.84), 0.59 (95% CI = 0.53 to 0.65), 0.62 (95% CI = 0.57 to 0.67), and 0.57 (95% CI = 0.49 to
0.67) for the age groups 50–54, 55–59, 60–64, and 65–69 years, respectively. Periodic radiographic screening in the ATBC Study
may explain why slightly more cancers were observed than expected from the Bach model.

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