Immune cell infiltration-based prognosis in prostate cancer: a review of current knowledge

Abstract

Background Despite the widespread use of tumor immune cell infiltrates as prognostic biomarkers in many cancers , their use in prostate cancer remains relatively unexplored. More recently, many studies are validating the use of tumor-infiltrating lymphocytes, macrophages and neutrophils for predicting cancer progression for other cancers. This review aims to identify what tumor-infiltrating immune cells have prognostic value for prediction prostate cancer progression. Main body of the abstract PubMed and Scopus were searched for eligible studies published from inception to May 31, 2023. Studies assessing tumor immune cell infiltrates were included. Twenty-six studies met the inclusion criteria. Infiltrating CD4+ and CD8+ T cell lymphocytes were prognostic and were associated with improved prostate cancer outcomes. Increased infiltration of M1 and M2 macrophages was prognostic and associated with worsening prostate cancer outcomes. High levels of infiltrating mast cells prognostically improve prostate cancer outcomes. Evidence of increased infiltration of neutrophils, monocytes and dendritic cells are conflicting and will require further studies to validate their role in prostate cancer prognosis. Short conclusion Despite the widespread use of tumor immune cell infiltrates for prediction outcome of many cancers, their use in prostate cancer is still limited. More evidence is required to help understand the landscape of immune cell infiltrates for predicting prostate cancer outcome.