The receptor tyrosine kinase FGFR2 is one of four fibroblast growth factor receptors designated FGFR1-4 that activate FGF signalling upon trans-autophosphorylation of the receptor dimers. Some genetic alterations of FGFR2 lead to aberrant activation of FGFR2 signaling cascades due to the creation of autocrine signaling loop or the release of FGFR2 from autoinhibition. It is known that some FGFR2 gene variations including intronic polymorphisms confer a risk for breast cancer, preferentially for estrogen receptor-positive breast tumors. FGFR2 and FGF10, the main ligand of FGFR2, are both overexpressed in 5-10% of breast tumors. Somatic missense mutations have also been reported in breast cancer leading to ligand independent activation of FGFR2. In cell line and xenograft experiments, inhibition/knockdown of FGFR2 results in anti-tumour effects, suggesting the oncogenic role of FGFR2, raising the potential of FGFR2 as a target of therapy in FGFR2 driven cancers. The P253R variant in FGFR2 has also been described in some constitutional disorders including craniosynostosis syndromes (eg, Apert syndrome).

The receptor tyrosine kinase FGFR2 is one of four fibroblast growth factor receptors designated FGFR1-4 that activate FGF signalling upon trans-autophosphorylation of the receptor dimers. Some genetic alterations of FGFR2 lead to aberrant activation of FGFR2 signaling cascades due to the creation of autocrine signaling loop or the release of FGFR2 from autoinhibition. About 10-16% of primary endometrial cancers harbor activating mutations in FGFR2. These mutations are more frequent in cancers of endometrioid histological subtype compared with serous or clear-cell subtypes. Gain-of-function mutations in the kinase domain lead to ligand-independent activation of the receptor, whereas mutations in the extracellular ligand-binding domain increase the affinity for fibroblast growth factors (FGFs). Both types of mutations have been shown to be potentially oncogenic in endometrial cancer cell lines. In cell line and xenograft experiments, inhibition/knockdown of FGFR2 results in anti-tumour effects, suggesting the oncogenic role of FGFR2, raising the potential of FGFR2 as a target of therapy in FGFR2 driven cancers. Therefore, FGFR-pathway inhibition remains potentially promising in this patient population.

FGFR2 mutation in a patient with oral squamous cell carcinoma was associated with response to the multitargeted tyrosine kinase inhibitor pazopanib. The clinical significance of this finding in this tumor type is unknown.

FGFR2 mutation in a patient with oral squamous cell carcinoma was associated with response to the multitargeted tyrosine kinase inhibitor pazopanib.

Although FGFR2 mutation in a patient with oral squamous cell carcinoma was reported to be associated with response to the multitargeted tyrosine kinase inhibitor pazopanib, FGFR2 mutations in bladder cancer are very rare. The clinical significance of this finding is unknown.

Activation of FGFR protein family can lead to the activation of RAS-MAPK and PI3K-AKT pathways. Amplification of FGFR2 has been observed in lung adenocarcinoma, lung squamous cell carcinoma, endometrial carcinoma, urothelial carcinoma, germ cell tumor and breast cancers. Anti-FGFR2 agents are actively under multiple clinical trials against many types of solid tumor, including lung squamous cell carcinoma, gastric cancer, endometrial cancer, and cholangiocarcinoma. Germeline mutations in FGFR2 are also associated with multiple craniosynostosis syndromes.

This gene is a known cancer gene.

This gene is a known cancer gene.

The receptor tyrosine kinase FGFR2 is one of four fibroblast growth factor receptors designated FGFR1-4 that activate FGF signaling upon trans-autophosphorylation of the receptor dimers. Some genetic alterations of FGFR2 lead to aberrant activation of FGFR2 signaling cascades due to the creation of autocrine signaling loop or the release of FGFR2 from autoinhibition. Activating mutations, including FGFR2 N549K which lies within the protein kinase domain, have been associated with multiple types of malignancies. FGFR2 mutations are more common in tumors of hepatobiliary origin than other solid tumor locations and are found in about 7% of hepatobiliary adenocarcinomas. Treatments with pan-FGFR inhibitors and FGFR2 inhibitors have inhibited proliferation in some tumor types and are under investigation.