Respiratory Function as a Prognostic Factor for Lung Cancer in Screening and General Populations.

Rationale: Despite advancements in screening, lung cancer remains the leading cause of cancer-related mortality globally.

Objectives: To investigate respiratory function as a prognostic factor for survival in the UK Biobank, a population-based cohort of over 500,000 participants, and the National Lung Screening Trial (NLST), a high-risk screening population of over 50,000 screenees.

Methods: Participants with an incident lung cancer diagnosis and spirometry-assessed lung function were included. Lung cancer was measured as the ratio of forced expiratory volume in 1-second (FEV1) and forced vital capacity and percentage of predicted FEV1. Multivariable Cox proportional hazards models were fitted to estimate the impact of lung function on 5-year overall survival in populations with different baseline lung cancer risks.

Measurements and main results: 2,690 and 609 patients were included in the analysis from the UK Biobank and the NLST, respectively. In the UK Biobank, a higher percentage of predicted FEV1 and ratio were associated with better survival after lung cancer diagnosis with hazard ratios of 0.97 (95% CI: 0.95 - 1.00, per 10% increase) and 0.95 (95% CI: 0.90 - 1.00, per 10% increase), respectively. No statistically significant results were found when assessing the data from the NLST study.

Conclusions: Impaired lung function was associated with poorer survival for lung cancer patients in the general population, although this was less clear in a high risk, screening eligible population. This highlights the potential clinical importance of respiratory function as a prognostic factor in lung cancer in the general population and presents a possibility for personalized cancer management.