The role of biomarkers in bladder preservation management of muscle-invasive bladder cancer.

PURPOSE: Patients with localized muscle-invasive bladder cancer (MIBC) can choose to undergo either neoadjuvant chemotherapy followed by radical cystectomy or radiation therapy-based bladder preservation treatment modality with subsequent close cystoscopic surveillance with salvage cystectomy reserved for patients with evidence of local disease recurrence. At the present time, the decision regarding bladder-directed local therapy for MIBC is based on physicians' and patients' preferences, and does not take into account tumor biology. Predictive biomarkers, once validated, could offer a more patient-centered and biology-driven selection of bladder-directed therapies.

METHODS: We provide a narrative review of clinical data pertaining to the biomarkers in bladder preservation management of MIBC.

RESULTS: There are currently no validated and clinically used biological markers used for stratification of radical bladder treatment and selection of bladder-preserving therapies. This article summarizes biomarkers that could have a potential clinical utility-PD-L1, molecular subtypes, Ki-67, MRE-11 and markers of hypoxia-and offers a hypothetical pathway model for a marker-driven precision management of medically operable patients with a newly diagnosed MIBC.

CONCLUSION: When selecting the optimal cancer treatment, both patient and tumor factors need to be considered. Once validated, biological markers will help clinicians tailor the management of MIBC to individual patients.