Abstract
Lung cancer causes >1·6 million deaths annually, with early diagnosis being paramount to effective treatment. Here we present a validated risk assessment model for lung cancer screening.
The prospective HUNT2 population study in Norway examined 65,237 people aged >20years in 1995–97. After a median of 15·2years, 583 lung cancer cases had been diagnosed; 552 (94·7%) ever-smokers and 31 (5·3%) never-smokers. We performed multivariable analyses of 36 candidate risk predictors, using multiple imputation of missing data and backwards feature selection with Cox regression. The resulting model was validated in an independent Norwegian prospective dataset of 45,341 ever-smokers, in which 675 lung cancers had been diagnosed after a median follow-up of 11·6years.
Our final HUNT Lung Cancer Model included age, pack-years, smoking intensity, years since smoking cessation, body mass index, daily cough, and hours of daily indoors exposure to smoke. External validation showed a 0·879 concordance index (95% CI [0·866–0·891]) with an area under the curve of 0·87 (95% CI [0·85–0·89]) within 6years. Only 22% of ever-smokers would need screening to identify 81·85% of all lung cancers within 6years.
Our model of seven variables is simple, accurate, and useful for screening selection.
•Applying this risk model in adults, screening 22% of ever-smokers would identify 81·85% of all lung cancers within 6years.•Two novel highly significant factors were identified, periodical daily cough, and hours of daily indoors exposure to smoke.•The HUNT Lung Cancer Model is an accurate risk predictor useful in prospective screening studies for lung cancer.
The National Lung Screening Trial used selection criteria that failed to include three quarters of people who went on to develop lung cancer because they only screened heavy smokers of a certain age group (55-74). In a European Union position statement recently published in Lancet Oncology, risk stratification was identified as one of the keys to ensuring the successful implementation of future low-dose CT screening programmes in Europe. The current study has developed a new, simple and accurate model, named HUNT Lung Cancer Model, including seven clinical variables that can pick the high-risk population even among the young and the light smokers.