Expression of Aldehyde Dehydrogenase Is Associated with High-Grade Histology and Poor Survival in Patients with Primary Small Bowel Adenocarcinomas
ML Othman, A Rashid, JL Abbruzzese, RA Wolff, H Wang. M.D. Anderson Cancer Center, Houston, TX; M.D.Anderson Cancer Center, Houston, TX
Background: Aldehyde dehydrogenase (ALDH) has been identified as highly expressed in embryonal tissue as well as in adult stem cells isolated from bone marrow, brain, breast and other tissues. Recent studies have shown that ALDH is also overexpressed in cancer stem cells and ALDH activity has been used as a marker for cancer stem cells. However the expression of ALDH in primary small bowel adenocarcinoma has not been examined.
Design: To determine the significance of ALDH as a stem cell marker in primary small bowel adenocarcinoma, a tissue microarray (TMA) consisted of 50 cases of small bowel adenocarcinoma were utilized with appropriate controls. ALDH expression were analyzed by immunohistochemistry and the staining results were graded as positive or negative using strong positive staining in more than 5% of the tumor cells as a cut off. Clinical information and follow-up were obtained from reviewing patients' medical records. The ALDH expression was correlated with tumor site, grade, and overall survival. Comparisons were performed by chi-square and overall survival was analyzed by log-rank method.
Results: Twenty-one of 50 tumors had cytoplasm staining for ALDH. The expression of ALDH correlated significantly with high-grade histology and poor survival. 9 of 11 (82%) poorly differentiated adenocarcinomas was positive for ALDH compared to 12/39 (31%) positive cases seen in well to moderately differentiated carcinoma group (p=0.004). The mean survival of patients whose tumors were positive for ALDH was 50.5 ± 12.9 months compared to 104.3 ± 14.4 months for patients whose tumors were negative for ALDH (p= 0.03).
Conclusions: Our study showed that ALDH is expressed in 42% of primary small bowel adenocarcinomas. ALDH expression in small bowel Adenocarcinomas correlates with high-grade histology and poor survival. ALDH may be a prognostic marker for primary small bowel adenocarcinomas.
Tuesday, March 23, 2010 1:00 PM
Poster Session IV # 66, Tuesday Afternoon