[1114] Role of ProEx C and MiB-1 in Evaluation of Salivary Gland Neoplasms

S Arya, D Sundararajan, L Haydt, B Burke, C Andry, A De Las Morenas. Boston University Medical Center, Boston, MA; Boston University School of Dental Medicine, Boston, MA

Background: Salivary gland neoplasms often present diagnostic challenges with overlapping histopathologic features. The aim of this study is to differentiate various salivary gland neoplasms using cell proliferation and aberrant S-phase cell cycle induction immunohistochemical markers.
Design: Five types of salivary gland neoplasms were selected, namely Pleomorphic Adenoma (PA), Myoeipthelioma (ME), Polymorphous Low Grade Adenocarcinoma (PLGA), Adenoid Cystic Carcinoma (ACC) and Adenocarcinoma not otherwise specified (AdCa NOS). Each tumor group included biopsy tissue samples from five patients. Each patient sample was stained with two immunohistochemical markers, ProEx C and MiB-1.

ProEx C is a cocktail of two monoclonal antibodies that target MCM2 - Mini Chromosome Maintenance Proteins and TOP2A - Topoisomerase II-alpha, which are proteins over expressed in aberrant S-phase induction. Number of positively stained tumor nuclei and total number of tumor cells were determined by computer assisted morphometric analysis.

Proportions of positively stained tumor nuclei were compared amongst various tumor groups, using Poisson regression models.
Results: There was statistically significant higher proportion of positively stained tumor nuclei for MiB-1 marker, in ACC as compared to PA, 95% confindence interval (CI) 1.34 to 8.15, p value 0.009, and in AdCa NOS as compared to PA, 95% CI 1.33 to 8.13, p value 0.009. No statistically significant difference in ProEx C staining pattern was identified among the various tumor groups, p value = 0.09.
Conclusions: MiB-1 proved useful in distinguishing ACC from PA and AdCa NOS from PA, but it did not aid in the differential diagnosis of malignant salivary gland neoplasms. ProEx C did not contribute in the evaluation of salivary gland neoplasms.
Category: Head & Neck

Monday, March 9, 2009 1:00 PM

Poster Session II # 157, Monday Afternoon