Defining Oligometastatic Bladder Cancer: A Systematic Review

Area of Science:

• Oncology
• Urology

Background:

• Oligometastatic disease (OMD) is under-investigated in bladder cancer (BC).
• There is a need for standardized definitions and management guidelines for oligometastatic bladder cancer (OMBC).

Purpose of the Study:

• To conduct a systematic review to aid in defining OMBC.
• To provide recommendations for staging and local therapies in OMBC.

Main Methods:

• Systematic review following PRISMA guidelines.
• Selection of articles defining oligometastatic status in BC.
• Data collection on metastasis number, organ involvement, and sites.

Main Results:

• Sixteen articles were reviewed, including retrospective series, reviews, and guidelines.
• A common definition for OMBC involved 3-5 metastatic lesions.
• Definitions varied regarding organ involvement and lesion size.
• ¹⁸F-Fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) was used for detection.
• Treatment modalities included surgery, radiotherapy, and systemic chemotherapy.

Conclusions:

• Limited literature exists on OMBC, highlighting a need for organized research.
• A frequently identified OMBC setting involves 3-5 metastatic sites responsive to systemic therapy, suitable for combined treatment approaches.
• Establishing clear definitions and management strategies for OMBC is crucial for improving patient outcomes.