Abstract A70: Mast cells in prostate cancer race disparities: Are the minutemen of the microenvironment the key?

The goal of the current study is to establish the mechanism by which mast cells may serve as a prognostic factor in and possibly explain the racial disparity associated with prostate cancer. There is increasing evidence for a strong association between chronic inflammation and prostate cancer, and the role of mast cells in prostate cancer are of particular interest as they have been suggested to influence cancer progression and immune modulation. It is well established that prostate cancer presents with significant racial disparities, with African American (AA) men being 65% more likely to be diagnosed with prostate cancer than Caucasian American (CA) men and more than two times as likely to die as a result of prostate cancer. In addition, studies have shown AA men to be significantly more likely to present with inflammation in prostate biopsy samples negative for prostate cancer, while microarray data has suggested that inflammatory pathways are highly represented in the differentially expressed mRNA in the tumors of AA vs CA men. Complicating these results, it is probable that inflammatory cells play varied and multiple roles in different regions and grades within the same cancer. With this in mind, we are currently using immunohistochemistry (IHC) and in-situ hybridization techniques to directly visualize and localize mast cells in the prostate microenvironment. These studies are aided by novel digital image analysis using a software framework integrating whole slide imaging, virtual microscopy, and ImageJ based analysis algorithms. Our preliminary results in a 10 case tissue microarray (TMA) are consistent with other reports in the literature indicating that there are higher mast cell densities in better differentiated cancers; however, we are examining this further in a larger full slide cohort in relation to Gleason grade and stage. We are currently utilizing this image analysis technology on a TMA cohort designed to explore differences in mast cell density in AA vs CA men. Furthermore, we aim to examine differences in mast cell subtypes between benign and malignant regions of the prostate and between AA and CA men. Our goal is to establish the mechanism by which mast cells may serve as a prognostic factor in prostate cancer and may help to explain prostate cancer racial disparities.

Citation Format: Heidi A. Hempel, Ibrahim Kulac, Nathan S. Cuka, Toby C. Cornish, Angelo M. De Marzo, Karen S. Sfanos. Mast cells in prostate cancer race disparities: Are the minutemen of the microenvironment the key? [abstract]. In: Proceedings of the Seventh AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 9-12, 2014; San Antonio, TX. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2015;24(10 Suppl):Abstract nr A70.