ALDH1 Expression and Its Significance in Adenoid Cystic Carcinoma of Salivary Glands
Jane H Zhou, Ehab Y Hanna, Dianna Roberts, Randal S Weber, Diana Bell. MD Anderson Cancer Center, Houston
Background: ALDH1 has been used as a marker for normal as well as cancer stem cells in several tissue types. Several investigators have also found it to be a prognostic/predictive marker for carcinomas of the breast, lung, pancreas, bladder and etc. A recent study of adenoid cystic carcinoma (AdCC) using Aldeflour assay showed that cells with high level ALDH1 had higher tumorigenic, invasive and metastatic abilities. Currently there has been no report on immunohistochemical expression of ALDH1 in adenoid cystic carcinoma. In this study we examine the expression of ALDH1 in 216 adenoid cystic carcinomas using tissue micro-array and immunohistochemistry and its correlation with survival in a 12 year follow up cohort.
Design: Archival paraffin blocks of adenoid cystic carcinomas at the University of Texas, MD Anderson Cancer Center between 1988 and 2006 were used for this study with the approval of IRB. The tissue microarray was constructed using two 1.0 mm diameter cores of spatially different areas of representative tumor from each paraffin block. Normal salivary gland and splenic tissue was used as control. Immunohistochemical expression of ALDH1 was analyzed using mouse monoclonal ALDH1 antibody (BD Biosciences, San Jose, CA). Correlations between ALDH1 expression and clinical and histological parameters were assessed by Pearson's Chi-square and M-L Chi-square tests. Survival curves were generated using the Kaplan-Meier method and statistical differences by log rank test.
Results: Majority of the tumors (116, 63%) showed stromal staining only, 21 (11%) tumors showed both epithelial and stromal expression, 47 (26%) tumors did not show either epithelial or stromal staining. The normal salivary gland showed epithelial expression only. Statistical analyses did not show any correlation between tumor pattern, tumor size, the presence of perineural invasion and the patterns of ALDH1 expression. The survival analysis using Kaplan-Meier method and log rank test did not show any significant differences among the three patterns of ALDH1 expression with survival.
Conclusions: Other unknown factors, besides cancer stem cells, may play important roles in tumorigenesis, cell differentiation and tumor progression.
Category: Head & Neck
Tuesday, March 20, 2012 1:00 PM
Poster Session IV # 160, Tuesday Afternoon