Efficacy of Treatments for T3bN0M0 Prostate Cancer Patients: A Systematic Review and Meta-Analysis

Patients with prostate cancer (PC) invading into the seminal vesicles (SV) constitute a specific subgroup of high-risk patients (staged as T3b) with a particularly high risk of disease recurrence, even when lymph node or distant metastases are absent (N0M0). The aim of the current systematic review and meta-analysis was to investigate efficacy of available treatments for men with PC invading the SV without metastasis.

A systematic review was performed according to the Cochrane guidance and reported according to the guidelines for the Preferred Reporting Items for Systematic Reviews and Meta-analyses. The review protocol was registered prospectively in the PROSPERO database. Studies identified in MEDLINE, EMBASE, and trial registries were selected by two independent reviewers. Treatment modalities included radical prostatectomy with pelvic lymphadenectomy; external beam radiotherapy (EBRT), high-dose rate or low-dose rate brachytherapy, androgen deprivation therapy (ADT), or a combination of treatments. Primary outcome measure was 5-year biochemical recurrence free survival (BRFS).

Twenty-five studies, comprising 2 881 patients, were included. For EBRT and ADT pooled estimated 5-year BRFS was 68%, varying from 56% in studies on low-dose radiotherapy (< 74 Gray [Gy]), up to 78% in studies on high-dose radiotherapy (≥ 74 Gy). For EBRT with brachytherapy and ADT pooled estimated 5-year BRFS was 83%. For radical prostatectomy pooled estimated 5-year BRFS was 32%. When combining surgery with adjuvant treatment (EBRT or ADT) pooled estimated 5-year BRFS was 54% and 63%, respectively.

These results indicate a role for high-dose radiotherapy (≥ 74 Gy) and long-term ADT in T3bN0 PC rather than primary surgical treatment. In addition to dose-escalated radiotherapy to the entire prostate gland (≥ 74 Gy), selected patients should be offered focal dose-escalation to the tumor, by high-dose rate brachytherapy. If proven safe for this patient group, focal dose-escalation could also be offered with EBRT.