Phosphorylated signal transducer and activator of transcription-1 immunohistochemical expression is associated with improved survival in patients with oral squamous cell carcinoma.

Purpose To estimate whether the immunohistochemical (IHC) expression patterns of the tumor suppressor gene signal transducer and activator of transcription-1 ( STAT1 ) and its active phosphorylated form ( PSTAT1 ) serve as potential prognostic and predictive markers in patients with oral squamous cell carcinoma (OSCC). Materials and Methods STAT1 and PSTAT1 protein expressions were examined immunohistochemically in OSCC tumor tissues and adjacent normal mucosa from 49 patients who underwent primary surgery. The IHC scores were correlated with all available clinicopathologic parameters that were obtained from a maximum of 7 years of follow-up, including survival and response to adjuvant therapy treatment. Results There was a shift toward lower percentages of cells with STAT1 ( P P P  = .008). Conclusions This is the first study to concurrently evaluate STAT1 and PSTAT1 IHC expression patterns and their prognostic significance in patients with OSCC, highlighting the potential role of PSTAT1 as a biomarker in therapeutic decision making. Large prospective studies are needed to verify these findings.