The prognostic significance of bladder neck invasion in prostate cancer: is microscopic involvement truly a T4 disease?

Since the widespread of prostate-specific antigen-based screening, prostate cancer at clinical stage T4 has become rare. Most bladder invasion is actually detected on radical prostatectomy specimens as a microscopic bladder neck involvement (BNI). The 2002 Tumour-Node-Metastasis (TNM) classification system classified prostate cancer with BNI within a unified pT4 category and rendered it equivalent to invasion into the pelvic wall musculature or external sphincter; this decision is controversial. Various series have assessed the clinical relevance and the effect of BNI on prognosis. This evidence-based review provides evidence that BNI should be assigned within the subset of pT3 stage, and that further improvement of the actual TNM staging system should be considered. However, BNI remains strongly associated with adverse pathology and should be regarded as a factor that worsens the prognosis of the underlying tumour stage.