Biology of nonmuscle-invasive bladder cancer: pathology, genomic implications, and immunology

Purpose of review Despite that nearly 75% of bladder cancer patients are diagnosed with nonmuscle-invasive disease, our understanding of the biological landscape in bladder cancer is primarily within the context of muscle-invasive bladder cancer. More recent studies addressing the genomic changes and immunology of nonmuscle-invasive bladder cancer (NMIBC) have helped to extend our understanding of this prevalent disease. Recent findings Genomic studies reveal that NMIBC possesses complexity that can be defined by specific gene expression signatures and has helped to define subsets within this disease. These subsets possess different risk profiles that may impact treatment decisions. In addition, the baseline or posttreatment immunological response to the growing tumor may help to inform whether a specific NMIBC subset is likely to progress. Summary Findings from studies addressing the molecular landscape of NMIBC may help to establish parameters for stratifying patient risk within this disease as well as establish novel or targeted treatment strategies. Inclusion of information about the immune response within tumors will likely contribute to defining the relative risk and treatment strategy for these patients.