Prognostic implications of FGFR3high/Ki-67high in oral squamous cell carcinoma

Objective

Fibroblast growth factor receptor 3 (FGFR3) is a member of the fibroblast growth factor receptor tyrosine kinase family. The prognosis and management stratification of oral squamous cell carcinoma (OSCC) are based on histology and other factors; however, immunohistochemical (IHC) markers that can detect OSCC that are more malignant and with a worse prognosis have not been adequately investigated. OSCC expresses activated FGFR3 signaling, which is not associated with prognosis. Currently, we explored the association between FGFR3 overexpression or the proliferation and histopathological hierarchy and stratum of risk.

Methods

A total of 62 patients who had been diagnosed with OSCC at our department between January 2008 and December 2013 were included. The IHC expression of FGFR3 and Ki67 was analyzed in 45 (n = 37 tongue, 7 floor of mouth, 3 buccal mucosa) cases of OSCC. JMP14.2 was used for statistical analysis.

Results

A combined analysis of FGFR3^high/Ki67^high positivity resulted in a reduced mean overall survival (OS) of 67.3 months when comparing with all other combinations. In the multivariate analysis (MVA), high clinical stage (p = 0.036) and FGFR3^high/Ki67^high (p = 0.031) were significant independent risk factors for OS.

Conclusions

We identified FGFR3^high/Ki67^high OSCC as a subgroup that has a weak prognosis and OS. OSCC grading should probably be augmented by IHC staining, and tumors classified as having a worse prognosis require appropriate clinical surveillance.