Predicting occult lymph node-positive disease at the time of radical cystectomy: a systematic review

The aim of this paper is to provide a systematic examination of the available evidence identifying factors that predict the detection of occult nodal metastatic disease at the time of radical cystectomy in patients with urothelial cancer of the bladder (BCa).

A systematic literature search of the PubMed database was performed in August 2015 using medical subject headings and free-text protocol. The search was conducted by applying keywords: bladder cancer, urothelial cancer, lymph node metastasis, node positive, micrometastasis and occult metastasis.

High-quality evidence assessing clinical factors that predict the discovery of occult nodal disease at the time of radical cystectomy is sparse. Despite the large number of studies examining this topic, there is a vast heterogeneity across the publications in patient selection, extent of lymph node dissection, and pathological assessment. The majority of studies reporting clinical and molecular characteristics associated with positive nodal status are based on univariable analysis and not corrected for known markers of tumor biology (stage, grade, lymphovascular invasion).

Identifying BCa with occult lymph node metastasis holds the promise of facilitating patient selection for neoadjuvant medical therapy and tailoring surgical interventions, potentially improving clinical outcomes for BCa patients. Molecular markers need to be externally validated in prospectively well-designed trials and need to prove clinical utility. Image-guided surgical technologies need further development before being adopted in routine practice.