Quantitative analysis of syndecan-1 expression in dysplasia and squamous cell carcinoma of the oral cavity

Introduction: Decreased expression of syndecan-1 has been reported in dysplasia and squamous cell carcinoma (SCCA) of the oral cavity and appears to correlate with decreasing histological differentiation and poor clinical outcome. Assays of syndecan-1 expression to date have utilized manual microscopic analysis with qualitative grading of immunohistochemical staining intensity, which may introduce observer bias. We evaluated syndecan-1 expression in dysplasia and squamous cell carcinoma (SCCA) of the oral cavity, using a novel automated cellular imaging system that incorporates both staining intensity as well as the percentage of positively stained cells to yield a quantitative value for syndecan-1 expression. Materials and Methods: We performed a quantitative immunohistochemical analysis of syndecan-1 expression using an automated cellular image analysis system. We analyzed specimens from cases of mild dysplasia (N = 55), moderate dysplasia. (N = 38), severe dysplasia. (N = 25), carcinoma in situ (CIS) (N = 43), and SCCA of the oral cavity (N = 45), using normal mucosal epithelium (N = 21) as a positive control. The SCCA specimens were further subdivided by degree of differentiation. We retrospectively reviewed patient charts to identify tumor stage at diagnosis, recurrence, and disease-specific survival. Results: Syndecan-1 expression was significantly greater in normal controls than in specimens of mild, moderate, or severe dysplasia, CIS, or invasive SCCA (P <.05). Syndecan-1 expression did not differ significantly among specimens of mild, moderate, or severe dysplasia, CIS or SCCA. There was no significant difference in syndecan-1 expression between specimens from patients with no evidence of disease at 3 years follow-up and patients with local, regional, or distant recurrence. Conclusions: Syndecan-1 expression does not appear to be useful as a marker of differentiation or as a prognostic indicator in dysplasia and SCCA of the oral cavity. The search for a suitable and reliable marker of biological aggressiveness is ongoing.