Need for a personalized approach for muscle invasive bladder cancer: role of tumor biology in response to neoadjuvant chemotherapy

Bladder cancer (BC) is the 2^nd most common genitourinary malignancy with an annual occurrence of 81,190 new cases and 17,240 deaths (1). The majority of patients are diagnosed with superficial BC [non-muscle invasive bladder cancer (NMIBC)] and are managed by a non-systemic therapy approach, which includes transurethral resection (TUR) of tumor with or without intravesical treatment depending on the grade of tumor, depth of invasion and presence of carcinoma in situ. However, BC with muscle invasive disease (MIBC) requires use of cisplatin-based neoadjuvant chemotherapy (NAC) followed by radical cystectomy (RC) or bladder sparing approach with systemic chemotherapy plus definitive radiation therapy. Cisplatin-based NAC in MIBC seems to achieve a pathological complete response in about 40% of patients (2), however a majority of patients tend to have residual disease making them high risk for recurrence of cancer locally or distantly. This highlights a need for identifying biomarkers that predict resistance to cisplatin-based NAC.