Significance of re-biopsy of histological tumor samples in advanced non-small-cell lung cancer in clinical practice.

The significance of evaluating oncogenes, including EGFR mutations, ALK abnormalities, and PD-L1 expression has become broadly recognized with recent advances in molecular biology. It is now extremely important to investigate tumor oncogene status in each patient at the initial diagnosis. By contrast, the significance of conducting a re-biopsy in the salvage setting has not been systematically reviewed. This review reports that the significance of a re-biopsy varies depending on the clinical situation.