Amplification of FGFR1 has been reported in less than 5% of cases of pancreatic adenocarcinoma. Sequence analysis has demonstrated an activating KRAS mutation (exon 2) in all FGFR1-amplified cases according to one study. In vitro studies suggest that proliferation of a cell line with FGFR1 amplification may be inhibited using the FGFR1 inhibitor BGJ398. In the proper clinical context, FGFR1 may represent a potential new therapeutic target in a subset of patients harbouring FGFR1-amplified tumours, however, further study is required.

Amplification of FGFR1 has been reported in approximately 10% of breast cancer and may be associated with adverse outcome according to some reports. It has been reported to be associated with increased expression of FGFR1 and increased activity of downstream growth signaling pathways. Some reports suggest FGFR1 may have a role in regulating response to endocrine therapy. FGFR1 amplification may be a targetable alteration in some clinical settings (PubMed IDs: 20179196, 25400686).

FGFR1 activating mutations may be associated with response to the multitargeted tyrosine kinase inhibitor pazopanib.

FGFR1 amplification is associated with poor survival in patients with resected squamous cell lung cancer. FGRF1 amplification may be associated with sensitivity to the multitargeted tyrosine kinase inhibitor pazopanib.

FGFR1 amplification may be associated with sensitivity to the multitargeted tyrosine kinase inhibitor pazopanib in some tumor types.

The FGFR1 copy number gain is part of a large partial chrom 8 gain. The role of FGFR1 in prostate cancer is under study. FGRF1 amplification may be associated with sensitivity to pazopanib in some tumor types.

This gene is a known cancer gene.

This gene is a known cancer gene.

FGFR1 is a receptor tyrosine kinase activated upon binding of the FGF ligand, which activates RAS-MAPK and PI3K-AKT pathways. Altered function of FGFR1 in cancer may lead to increased cell proliferation and decreased apoptosis. The most common alteration of FGFR1 in lung adenocarcinoma is amplification and point mutations are rare (1% of cases). FGFR1 T141R does not lie within any known functional domains of the FGFR1 protein. T141R has been identified in sequencing studies, but has not been biochemically characterized and therefore, its effect on protein function is unknown. T141R has been reported as a somatic mutation in one case of lung adenocarcinoma in the literature. The clinicopathologic significance of FGFR1 T141R remains to be further elucidated.