Periprostatic Adipose Tissue and Prostate Cancer Progression: New Insights into the Tumor Microenvironment

Abstract

The high prevalence of both obesity and prostate cancer highlights the importance of understanding the biological features of this relationship. It is estimated that obesity accounts for an increase of about 15% in the incidence of high-grade prostate cancers over the past 30 years. 7 Further understanding the biological relationship between excess adipose tissue and prostate cancer progression may yield new prevention strategies or therapeutic targets. This article reviews the emerging data on the role of periprostatic adipose tissue (PPAT) and the role of adipokines on prostate cancer progression. Adipokines are secreted substances produced by adipocytes, with local or systemic actions, or both. These heterogeneous molecules include cytokines, hormones, and growth factors. We discuss the active role of adipose tissue and adipocytes in the tumor microenvironment. The emerging role of interleukin (IL)-6 is highlighted as an example of the interplay between PPAT and adipocytes in the tumor microenvironment. Further, the evidence implicating the importance of PPAT promoting prostate cancer progression is reviewed, including pathologic findings and in vitro model systems. Finally, we review the clinical studies to date that have demonstrated PPAT to be a risk factor for prostate cancer diagnosis and progression.