Clinicopathological and Survival Analysis of Japanese Patients with Resected Non-Small-Cell Lung Cancer Harboring NKX2-1, SETDB1, MET, HER2, SOX2, FGFR1, or PIK3CA Gene Amplification. 
Gene amplification is an important genetic change in cancer cells.  We investigated the prevalence, clinicopathological characteristics, and prognostic value of NKX2-1 (also known as TTF-1), SETDB1, MET, HER2, SOX2, FGFR1, and PIK3CA amplification in Japanese patients with non-small-cell lung cancer (NSCLC).  The copy numbers of the seven above-mentioned genes were assessed using fluorescence in situ hybridization in a tissue microarray containing 282 surgically resected NSCLC specimens (164 adenocarcinoma [AC], 99 squamous cell carcinoma [SCC], and 19 others).  Clinicopathological information were obtained from the medical records.  NKX2-1, SETDB1, MET, HER2, SOX2, FGFR1, and PIK3CA gene amplification were observed in 30 of 277 (10.8%), 16 of 280 (5.7%), 38 of 278 (13.7%), 8 of 270 (3.0%), 34 of 278 (12.2%), 18 of 282 (6.4%), and 53 of 278 (19.1%) cases, respectively.  Coamplification was detected in 16 of 156 (10.3%) AC patients and 35 of 93 (37.6%) SCC patients (p < 0.0001).  NKX2-1 amplification was significantly related to an AC histology (p = 0.004), whereas SOX2, FGFR1, and PIK3CA amplifications were related to a SCC histology (p < 0.0001).  Within the ACs, NKX2-1 and SETDB1 amplifications were markers of a shorter survival period.  A multivariate Cox proportional hazards model revealed that NKX2-1 amplification was an independent predictor of poor survival (hazard ratio, 2.938; 95% confidence interval, 1.434-6.022; p = 0.003).  Coamplification had impact on patient outcome in AC but not in entire NSCLC and SCC.  The amplification status differed among the histological types of NSCLC.  NKX2-1 amplification was an independent and the most practically important predictor of a poor prognosis among Japanese patients with AC.