PI3K Overexpression and PIK3CA Mutations Are Associated with Age, Tumor Staging, and Other Clinical Characteristics in Chinese Patients with Esophageal Squamous Cell Carcinoma

Aims: The aim of this study was to investigate the association of PI3K expression and PIK3CA mutations with various clinical features in Chinese patients diagnosed with esophageal squamous cell carcinoma (ESCC). Methods: The study included 112 patients diagnosed with ESCC from Jan 2013 to Dec 2015. Immunohistochemistry was used to determine the expression of PI3K. PIK3CA mutations were determined by sequencing. Statistical analysis was done using SPSS 19.0 software. Results: PI3K protein was expressed in 81.3% (91/112) of all ESCC samples, whereas it was found in only 4.9% (5/56) of adjacent normal cells. This rate of expression of PI3K was significantly higher in ESCC tissues (p < 0.001). PI3K protein expression was highly correlated with age, lymph node metastasis, and clinical stage (p < 0.05), but not with gender, location, tobacco use, alcohol use, or degree of differentiation. PIK3CA gene mutations were highly correlated with age, tobacco use, and clinical stage (p < 0.05), but not with gender, location, alcohol use, lymph node metastasis, or degree of differentiation. PI3K protein expression was not statistically correlated with PIK3CA gene mutations. Conclusion: PI3K overexpression and PIK3CA mutations are associated with age, tumor staging, and other clinical characteristics in Chinese patients with ESCC and thus can be further exploited as biomarkers and therapeutic targets in esophageal cancer.