Expression of aldehyde dehydrogenase 1A1 in oral squamous cell carcinoma and its correlation with clinicopathological parameters

BACKGROUND: Aldehyde dehydrogenase 1A1 (ALDH1A1) is a key aldehyde dehydrogenase (ALDH) isozyme, related to the cancer stem cells which are responsible for initiating tumor growth, progression, and recurrence. High expression of ALDH1A1 has been reported in several tumor types in humans and its expression is associated with poor prognosis. The aim of this study was to assess the expression of the ALDH1A1 in oral squamous cell carcinoma (SCC) and its correlation with various clinicopathological parameters. MATERIALS AND METHODS: ALDH1A1 expression was analyzed by using immunohistochemistry on paraffin blocks of 112 cases of primary oral SCC and their corresponding 68 lymph nodes with metastatic deposits. ALDH1A1 expression was also correlated with various clinicopathological parameters. Statistical analysis was done with statistical analysis software, the Statistical Package for the Social Sciences version 21.0. RESULTS: High ALDH1A1 expression was observed in 31.2% of cases of primary oral SCC as compared to 73.5% in lymph node metastasis. A statistically significant difference (P = 0.04) was observed in high TNM stages (68.6%) of the tumor as compared to low TNM stages (31.4%). However, histopathological grades of tumor showed nonsignificant correlation with ALDH1A1 expression (P = 0.093). 40.2% of patients were expired at the end of the study, and the rate of mortality was significantly higher (P = 0.01) in patients with high ALDH1A1 expression as compared to low expression (60.0% vs. 31.2%). CONCLUSION: High ALDH1A1 expression was associated with higher TNM tumor stage and high nodal stage. It was also associated with high mortality rate which validates it as a marker of invasiveness and poor prognosis in oral SCC.