Journal Article

Airflow Limitation and Histology Shift in the National Lung Screening Trial. The NLST-ACRIN Cohort Substudy

Aberle, Denise, Greco, Erin M., Chiles, Caroline, Hopkins, Raewyn J., Gatsonis, Constantine, Young, Robert P., Duan, Fenghai, Gamble, Greg D.

2015

Overview

Abstract Rationale Annual computed tomography (CT) is now widely recommended for lung cancer screening in the United States, although concerns remain regarding the potential harms, including those from overdiagnosis. Objectives To examine the effect of airflow limitation on overdiagnosis by comparing lung cancer incidence, histology, and stage shift in a subgroup of the National Lung Screening Trial (NLST). Methods In an NLST subgroup (n = 18,714), screening participants were randomized to annual computed tomography (CT, n = 9,357) or chest radiograph (n = 9,357) screening and monitored for a mean of 6.1 years. After baseline prebronchodilator spirometry, to identify the presence of airflow limitation, 18,475 subjects (99%) were assigned as having chronic obstructive pulmonary disease (COPD) or no COPD. Lung cancer prevalence, incidence, histology, and stage shift were compared after stratification by COPD. Measurements and Main Results For screening participants with spirometric COPD (n = 6,436), there was a twofold increase in lung cancer incidence (incident rate ratio, 2.15; P < 0.001) and, when compared according to screening arm, no excess lung cancers and comparable histology. Compared with chest radiography, there was also a trend favoring reduced late-stage and increased early-stage cancers in the CT arm (P = 0.054). For those with normal baseline spirometry (n = 12,039), we found an excess of lung cancers during screening in the CT arm, almost exclusively early-stage adenocarcinoma-related cancers (histology shift and overdiagnosis). After correction for these excess cancers, stage shift was marginal (P = 0.077). Conclusions In the CT arm of the NLST-ACRIN (American College of Radiology Imaging Network) cohort, COPD status was associated with a doubling of lung cancer incidence, no apparent overdiagnosis, and a more favorable stage shift.

• Publisher: Oxford University Press,American Thoracic Society
• Subject: Chronic obstructive pulmonary disease / Cohort Studies / Female / Histology / Humans / Lung - diagnostic imaging / Lung - physiopathology / Lung cancer / Lung Neoplasms - epidemiology / Male / Mass Screening - methods / Mass Screening - statistics & numerical data / Medical screening / Middle Aged / Original / Spirometry / Tomography / Tomography, X-Ray Computed / United States - epidemiology