The era of molecular taxonomy of neoplasms – Neoplasms of the urinary tract

Urothelial carcinoma of the bladder is a common malignancy causing an estimated 150,000 deaths per year. Treatment for muscle-invasive bladder cancer has not advanced beyond cisplatin-based combination chemotherapy and surgery in the past 30 years and no new drugs for the disease have been approved during that time. In contrast to other malignancies, molecular diagnostics are not established yet for routine clinical management for patients with urothelial cancer of the bladder. Studies have identified gene expression patterns that classify tumors into clinically relevant molecular subtypes. Molecular subtypes were defined by distinct gene expression signatures which are specific for cell cycle, cytokeratins, cell adhesion, receptor tyrosine kinases and immune response. These distinct molecular profiles may help define subsets of patients who are expected to respond positively to chemotherapy and to molecularly targeted therapy. In the current review, two molecular taxonomies of bladder cancer are investigated