Expression of CD44 and CD133 stem cell markers in squamous cell carcinoma of esophagus

Context: Role of cancer stem cells in the esophageal carcinogenesis is not clear. Aim: To assess the expression of CD44 and CD133 cancer stem cell markers in esophageal squamous cell carcinoma (ESCC) and its predisposing lesions by immunohistochemistry. Setting and Design: Prospective study as a part of an intramural research project. Materials and Methods: Tissues samples were obtained with endoscopic biopsy and from surgically resected esophageal specimens. Fifty cases each of histopathologically diagnosed cases of esophageal squamous cell carcinoma and its predisposing lesions (mild, moderate, and severe dysplasia and esophagitis) were evaluated for stem cell marker CD44 and C133 by immunohistochemistry using a scoring system. Statistical Analysis: Chi-square test, analysis of variance (ANOVA), post-hoc tests (Tukey-HSD) were used as appropriate for data analysis. Two sided P < 0.05 was considered as significant. Results: CD44 expression was significantly higher in ESCC as compared to dysplasia and esophagitis (mean IS 7.92 +/- 1.45 vs. 6.34 +/- 0.80 vs 5.15 +/- 0.86 respectively, P < 0.001). CD133 expression was also significantly higher in ESCC as compared to dysplasia (mean IS 6.82 +/- 1.57 vs. 1.00 +/- 0.00 respectively, P < 0.001) while esophagitis showed no expression. CD44 and CD133 expressions were significantly higher in poorly differentiated ESCC than moderately differentiated and well differentiated lesions (CD44 mean IS 6.94 +/- 1.44 vs 8.17 +/- 1.38 vs. 8.63 +/- 1.02 respectively, P < 0.001 and CD 133 mean IRS 5.63 +/- 0.81 vs 6.00 +/- 00 vs. 9.0 +/- 00 respectively, P <0.001). Conclusion: Significantly higher expression of CD44 and CD133 cancer stem cell markers in ESCC as compared to its predisposing lesions (esophagitis and dysplasia) suggests its role in esophageal carcinogenesis.