Gene-expression profiling in lung cancer: Still early days

In summary, the infancy status in gene-expresion profiling in lung cancer is the result of multiple factors. A concert of efforts is needed to move the field forward. As a high-throughput tool at the molecular level, gene-expression profiling has a clear edge over traditional histological tumor assessment. However, the day of its clinical applications has yet to come. With consideration of the histological complexity of lung cancer, molecular classification for tumor subtypes needs to focus on cases that challenge routine pathological examination or classify tumors based on genes in pathways relevant to clinical outcomes. Tumor substaging alone has little clinical value if no impact is associated with treatment options and outcomes. A gene signature or panel that does not provide improved prediction independent from well-known predictors will lies likely be adopted clinically.