Acquired MET amplification in non-small cell lung cancer is highly associated with the exposure of EGFR inhibitors and may not affect patients' outcome.

MET amplification has been associated with shorter survival in cancer patients and thought to represent one of two major mechanisms for developing resistance to therapy with EGFR inhibitors. We retrospectively studied 99 patients who had non-small cell lung cancer (NSCLC) and had at least two FISH analyses for MET/CEP7 at different time points during the course of disease. Four (4%) patients showed MET amplification in the initial diagnostic biopsy, and 16 (16%) patients acquired MET amplification in the follow-up biopsy specimens. Acquired MET amplification was highly associated with EGFR inhibitor treatment. Except for EGFR and TP53 mutations, other gene mutations were rare in the patients with MET amplification. Patients with acquired MET amplification showed no significant survival difference comparing to the patients who did not show MET amplification.