Thoracoscopic rebiopsy to detect the T790M mutation after postoperative recurrence.

After pulmonary resection for non-small-cell lung cancer, some patients with postoperative recurrence and mutated epidermal growth factor receptor (EGFR) subsequently receive EGFR-tyrosine kinase inhibitors (EGFR-TKIs). Osimertinib may be efficacious if those patients become resistant to the 1st-line EGFR-TKI because of the T790M mutation. We recently performed thoracoscopic rebiopsy to detect the T790M mutation in 4 patients who became resistant to the 1st-line EGFR-TKI treatment for postoperative recurrence. Our limited experience suggests that thoracoscopic biopsy is associated with limited morbidity, can help detect the T790M mutation and may improve the management of select patients with acquired resistance to the 1st-line EGFR-TKIs.