Stathmin as a Surrogate Marker of Phosphatidylinositol-3-Kinase Pathway Activity: Towards Precision Medicine in HPV-Negative Head & Neck Squamous Cell Carcinoma

Abstract We assessed Stathmin as an immunohistochemical (IHC) indicator of phosphatidylinositol 3-kinase (PI3K) pathway activity in HPV-negative head \u0026 neck squamous cell carcinoma (HNSCC). We compared Stathmin IHC to expression of other pathway components. We also evaluated the relationship between Stathmin IHC and the mutational status of four key pathway genes. Finally, we ascertained whether Stathmin IHC correlates with tumor grade or primary site. We detected correlation between high Stathmin expression and high pAKT1 expression, indicating a role for Stathmin IHC as a marker of pathway activity. Our analysis did not show correlation between Stathmin IHC and mutation of the four genes evaluated. We also observed an association between high Stathmin expression and oropharyngeal primary site. Our results suggest utility of Stathmin IHC as an indicator of PI3K pathway activity, and therebydemonstrate potential relevance of Stathmin IHC in the context of HNSCC.