Bladder Cancer: A Review of Non-Muscle Invasive Disease

Background: Bladder cancer is one of the most common cancers affecting men and women and thus has a profound impact on health care. The majority of patients (75%) with newly diagnosed urothelial tumors have non-muscle invasive disease confined to the bladder mucosa or the lamina propria. Methods: The authors review the literature as well as recently published clinical guidelines regarding the bladder cancer risk and causative factors, diagnostic and pathologic evaluation, prognostic variables, and management strategies for patients with non-muscle invasive bladder cancer. Results: Recurrence and progression remain problematic for many patients and are dependent on multiple clinical and pathological features, the most important of which are tumor stage, grade, multifocality, size, recurrence patterns, and the association with carcinoma in situ. Accurate assessment of clinical stage and tumor grade is critical in determining management and surveillance strategies. Intravesical therapies positively influence tumor recurrence rates. Disease progression rates may be impacted in high-risk patients who receive both induction bacille Calmette-Guerin (BCG) and a maintenance BCG regimen. Cystectomy still plays a pivotal role in patients with high-risk tumors and in patients who fail more conservative attempts to eradicate non-muscle invasive disease. Conclusions: Non-muscle invasive bladder cancers represent a broad group of tumors with varying biologic potential. Successful treatment depends on the careful integration of diagnostic and surveillance tests, macroablation through transurethral resection, accurate assessment of clinical stage, and the timely and appropriate delivery of intravesical chemotherapeutic and immunomodulatory agents.