“Low-dose computed tomography screening may increase diagnoses of T1a node-negative non-small-cell lung cancers (NSCLC). One-quarter of these patients die within 5 years. Maximizing the benefit of screening requires a reliable method to identify patients with high mortality risk,” writes Johannes R. Kratz, M.D., of the University of California, San Francisco, and colleagues. “A molecular prognostic assay has been clinically validated for nonsquamous NSCLC, but performance of the assay was not studied in small node-negative tumors.”
As reported in a Research Letter, the study included 269 patients with node-negative tumors of less than 2 cm who had undergone resection of nonsquamous NSCLC. The prognostic test measures the expression of 14 genes using quantitative polymerase chain reaction on RNA extracted from specimens, and assigns patients to low-, intermediate-, and high-risk groups based on clinically validated cutoff values for a calculated risk score. Five-year survival was the primary end point.
The average age of patients was 62 years; median (midpoint) follow-up among survivors was 74 months, and 5-year mortality was 28.6 percent. Ninety-two patients (34.2 percent) were identified as high risk by the prognostic assay; survival was significantly different among the high-risk group (52.3 percent), the intermediate-risk group (69.1 percent), and the low-risk group (83.0 percent). “… these data suggest the potential clinical utility of a new prognostic assay in the postoperative management of node-negative T1a disease. The identification of high-risk patients may further maximize the benefit of early detection of T1a node-negative tumors through low-dose computed tomography screening.”