In 2/11 cases (1 adenosquamous and 1 large cell carcinoma), FGFR1 amplifications were present only in the brain metastasis and not in the primary tumor.
High FGFR1 gene copy number (amplification or high-level polysomy) was significantly more frequent in squamous cell carcinomas (SCC) (24.8%) and large cell carcinomas (LCC) (25%) compared to adenocarcinomas (11.3%) (p = 0.01 and p = 0.03 respectively).