Introduction

Prostate cancer (PCa) is the most frequently diagnosed, and the second leading cause of death from cancer in North American and European men (1). It has the highest incidence rate among all epithelial tumors in the United States. Approximately 1 in 6 men over the age of 65 is diagnosed with PCa (2). Age, racial background, dietary factors, life-style related factors, and androgens are known contributors to the risk of PCa.

Heterogeneity in PCa

There is a high variability in the natural history of PCa ranging from indolent and asymptomatic to aggressive and metastatic disease. It is also multi-focal and heterogeneous in clinical, histological, and biological dispositions. Healthy glands, precursor, and neoplastic lesions with varying degrees of differentiation often exist in juxtaposition and evolve independently in the same PCa tissue (3,4).

Prostate intra-epithelial neoplasia (PIN) is thought to be a precursor lesion for PCa. High-grade PIN with increased nuclear enlargement, prominent nucleoli, chromatin alterations, and luminal complexity in acinar epithelium is often detected together with PCa in biopsy samples (4,5). PIN shares many common genetic, molecular, and phenotypic characteristics of prostate adenocarcinoma (3,5).

Gleason grade has been used to indicate the severity of the disease.AhigherGleason grade suggests a poorly diferentiated, advanced carcinoma and is used as a prognostic indicator (4).