FGFR1 Amplification in Squamous Cell Carcinoma of The Lung

Introduction: Amplification of fibroblast growth factor receptor 1 (FGFR1) has been reported in squamous cell lung carcinoma and may be a molecular target for therapy. Little is known, however, about the clinical and demographic correlates of FGFR1 amplification. Methods: The study is an Institutional Review Board approved retrospective analysis of 226 patients with squamous cell lung cancer seen at the Massachusetts General Hospital from 2005 to 2011. Clinical and demographic characteristics of all patients were obtained, as well as treatment details including surgery, radiation, and chemotherapy, and overall survival. fluorescence in situ hybridization was performed for FGFR1 on formalin-fixed paraffin-embedded tumor tissue. Clinical genotyping results were also reviewed where available. Results: Thirty-seven of 226 patients (16%) with squamous cell lung cancer were found positive for amplification using a definition of amplification of a gene to copy number control ratio of 2.2 or higher. FGFR1 amplification status was not associated with age, sex, stage, histologic subtype within squamous cell, smoking history, or pack-years of smoking. We found no significant difference in overall survival by FGFR1 amplification status as a whole; in the advanced stage subset, our findings are inconclusive because of the small sample size. Conclusion: FGFR1 amplification was found in 16% of a clinical cohort of squamous cell lung cancer patients. The lack of any specific clinicodemographic features that correlates with FGFR1 amplification suggests that all squamous cell patients should be tested for this genomic change.