The Emerging Role of B Cells and Tertiary Lymphoid Structures in Bladder Cancer.

PURPOSE OF REVIEW: To provide a comprehensive review of new and emerging literature on B cells and tertiary lymphoid structures (TLS) in urothelial cancer. RECENT FINDINGS: The presence of certain subsets of B cells and TLS in MIBC are associated with improved outcomes and response to immunotherapy. However, the role in NMIBC is less clear. TLS in NMIBC is likely associated with more aggressive disease but may also be associated with improved outcomes to intravesical BCG. This review outlines an emerging potential biomarker (TLS) for predictive and prognostic outcomes for patients with urothelial cancer receiving either intravesical BCG or systemic immunotherapy. B cells play a complex role in the tumor immune microenvironment and can be either anti- or pro-tumor. Activated B cells form TLS which lead to a robust response to immunotherapy. This has led some investigators to attempt therapeutic manipulation to induce TLS in otherwise immunologically "cold" tumors.