Prevalence, morphology, and natural history of FGFR1-amplified lung cancer, including squamous cell carcinoma, detected by FISH and SISH

Abstract

The aim of this study was to investigate the prevalence of fibroblast growth factor receptor 1 (FGFR1) amplification by fluorescence in situ hybridization (FISH) in a lung cancer patient cohort and to correlate results with morphology, silver in situ hybridization (SISH), and patient outcome. FGFR1 FISH and SISH were performed in 406 and 385 lung cancer cases, respectively, and the results were compared. High-level FGFR1 amplification was defined as the ratio of FGFR1/centromere 8 ≥2, or tumor cell percentage with ≥15 signals ≥10%, or average number of signals/tumor cell nucleus ≥6. Low-level amplification was defined as tumor cell percentage with ≥5 signals ≥50%. Of 406 tumors tested, there..