Increased ALDH1 Expression in Squamous Cell Carcinoma of the Head and Neck May Be a Predictor for Lymph Node Metastases
S Muller, Z(G) Chen, S Nannapaneni, DM Shin. Emory University School of Medicine, Atlanta, GA; Winship Cancer Institute, Atlanta, GA
Background: Head and neck squamous cell carcinoma (HNSCC) affects approximately 47,000 patients a year in the U.S., and is associated with a high degree of morbidity and mortality. Over the last 30 years survival rates have gradually improved. However, mortality is often associated with both distant metastases and local recurrences that are therapy resistant. Aldehyde dehydrogenase 1 (ALDH1), is an enzyme that oxidizes aldehydes to carboxylic acid and is involved in the conversion of vitamin A to retinoic acid. High expression of ALDH1 has been reported in colorectal cancer stem cells and thought responsible for chemoresistance to cyclophosphamide (CPA). High ALDH1 expression in breast cancer correlated with a poor clinical outcome, and increased ALDH1 expression was seen in breast tissue with metastases compared to no metastases. To date, correlation of ALDH1 expression with metastasis in HNSCC has not been reported. We compared ALDH1 expression in HNSCC from patients who did not have lymph node metastases (LNM) and in patients with LNM.
Design: A total of 199 patients with HNSCC were examined; 100 cases from patients who had a primary tumor without LNM, and did not develop any LNM within a 2 year follow-up, and 99 patients who presented with LNM. In this second group, both the primary tumor and the corresponding LNM were examined. No patients received chemotherapy and/or radiation therapy prior to surgical treatment. Formalin-fixed paraffin sections were stained with goat polyclonal ALDH1A1 antibody at a dilution of 1:200 using standard procedures. The sections were analyzed by a pathologist and the sections were scored according to the following scheme: 1: <5 %; 2: 5-25%; 3: 25-50%; 4: >50% cells staining.
Results: There was a statistically significant increase in ALDH1 expression in tumors with LNM compared to tumors without LNM (2.12 vs. 1.26, p<.0003). The corresponding LNM also had higher ALDH1 expression compared to tumors without LNM (2.19 vs. 1.26, p<.0001). Although the LNM had higher ALDH1 expression than the corresponding primary tumor, the difference between these two groups was not significant (2.19 vs. 2.12).
Conclusions: Our results suggest that ALDH1 may be a potential marker for LNM in HNSCC. This finding may provide new insights into the biology of head and neck carcinogenesis. [This study is supported by Head and Neck Cancer SPORE (P50 CA128613) from National Cancer Institute.]
Category: Head & Neck
Monday, March 9, 2009 1:00 PM
Poster Session II # 173, Monday Afternoon