Enriching the molecular definition of the airway "field of cancerization:" establishing new paradigms for the patient at risk for lung cancer.

The "field of cancerization" refers to histologically normal-appearing tissue adjacent to neoplastic tissue that displays molecular abnormalities, some of which are the same as those of the tumor. Improving our understanding of these molecular events is likely to increase our understanding of carcinogenesis. Kadara and colleagues attempt to characterize the molecular events occurring temporally and spatially within the field of cancerization of patients with early-stage non-small cell lung cancer (NSCLC) following definitive surgery. They followed patients with bronchoscopies annually after tumor resection and extracted RNA from the serial brushings from different endobronchial sites. They then conducted microarray analysis to identify gene expression differences over time and in different sites in the airway. Candidate genes were found that may have biologic relevance to the field of cancerization. For example, expression of phosphorylated AKT and ERK1/2 was found to increase in the airway epithelium with time. Although there are limitations in the study design, this investigation demonstrates the utility of identifying molecular changes in histologically normal airway epithelium in lung cancer. In addition to increasing our understanding of lung cancer biology, studying the field of cancerization has the potential to identify biomarkers from samples obtained in a minimally invasive manner. ©2013 AACR.