CD44 and Snail1 Expression Predicts Poor Prognosis of Oral Squamous Cell Carcinoma.

Oral squamous cell carcinoma (OSCC) remains a challenging malignancy with poor 5-year survival rates due to diagnosis at an advanced stage and a high likelihood of recurrence and metastasis. These aggressive traits may be influenced by cancer stem cells (CSC) and epithelial-mesenchymal transition (EMT). This study investigated the prognostic significance of the CSC marker CD44 and EMT-related proteins (Snail1, Snail2, E-cadherin, N-cadherin) in 132 OSCCs using immunohistochemistry. The comprehensive survival analysis included univariate and multivariate (stepwise method) Cox regression for disease-specific survival (DSS) and disease-free survival (DFS), Kaplan-Meier curves based on log-rank testing, and receiver operating characteristic (ROC) analysis to assess the predictive accuracy of the markers. High CD44 expression independently predicted worse DSS (HR = 2.74, 95% CI 1.44-5.23, p = 0.003) and DFS (HR = 2.22, 95% CI 1.16-4.23, p = 0.01), and Snail1 was significantly associated with poor DSS (HR = 2.62, 95% CI 1.37-5.03, p = 0.004). The combined expression of CD44 and Snail1 improved the discrimination of worse outcomes compared to markers individually. The presence of lymphovascular invasion (HR = 8.68, 95% CI 3.81-19.75, p < 0.0001) and a positive surgical margin (< 5 mm; HR = 4.45, 95% CI 1.99-9.96, p = 0.0003) were also independently associated with DSS. The results of this study highlight the prognostic significance of CD44 and Snail1 in OSCC, emphasizing their potential interplay in tumor aggressiveness.