Gain of copy number and amplification of the RET gene in lung cancer.

RET rearrangement represents a unique molecular subset of lung cancer. The identification of specific clinicopathologic characteristics and RET gene status would provide critical information on targeted therapeutics. In this study, we investigated the patterns of RET gene in a series of lung carcinomas. Of one hundred and sixteen tumors, a low frequency (1.7%) of RET translocation was identified. Only two specimens of lung adenocarcinomas displayed the rearrangement of RET in 54% and 78% of tumor cells respectively. A high incidence of gain of copy number (3-4 copies) and amplification (≥ 5 copies) of the RET gene was observed in 52% and 12% of all 116 samples. An association between increased copy number of RET and EGFR mutation was statistically significant (p < 0.05) in these lung carcinomas. This study sheds light on the unique molecular characteristics of the RET gene in lung carcinomas.