Carsten Schroeder

MD, PhD

Georgia Regents University

Resident Surgery

NLST (Learn more about this study)

NLST-63

Mar 12, 2014

Uneven Distribution of Cancer Histology in the National Lung Screening Trial

The National Lung Screening Trial (NLST), published in 2011, studied the utility of low dose computed tomography (LDCT) as a screening test for lung cancer in a large US population and reported a 20% reduction of mortality due to lung cancer in the patients screened with LDCT compared to plain chest radiography (XRAY). We sought to compare the proportion of tumor histologic types in the NLST between the LDCT and XRAY screened populations. A total of 1993 cases of tissue diagnosed lung cancer were reported in the NLST, 1054 for the LDCT group and 939 for the XRAY group, excluding carcinoid tumor cases. The proportion of squamous cell carcinomas, adenocarcinomas and large cell carcinomas did not differ between groups. Broncho-alveolar cell carcinomas were more prevalent in the LDCT group (10.4 versus 3.7%). Two tissue types were more prevalent in the XRAY group: small cell carcinomas (16.9 versus 13%) and other non-small cell (ONSC) tissue types (16.8 versus 12.4%). The uneven distribution of adverse tissue types in these two groups could have contributed in part to the worse outcome observed in the XRAY group in the NLST.