Treatment of Biochemical Recurrence and Castrate-Resistant Prostate Cancer

Biochemical Recurrence (Non-Metastatic)

• For patients with biochemical recurrence after radical prostatectomy without metastatic disease, salvage radiation therapy to the prostate bed is the primary curative-intent treatment, with androgen deprivation therapy (ADT) added for those with high-risk features, as recommended by the American Urological Association 1, 2
• High-risk biochemical recurrence (BCR) features include PSA ≥0.7 ng/mL, Gleason Grade Group 4-5, PSA doubling time (PSADT) ≤6 months, persistently detectable post-operative PSA, or seminal vesicle involvement, according to the National Comprehensive Cancer Network (NCCN) 1, 2
• Low-risk BCR features include PSADT >12 months, Gleason score <8, longer time to recurrence (>3 years post-surgery), and pathological stage ≤pT3a N0, as defined by the European Association of Urology 3, 4
• Salvage radiation therapy (minimum 64-66 Gy to prostate bed) PLUS ADT is recommended for high-risk BCR (PSADT ≤9 months), with optimal outcomes when PSA is <0.5 ng/mL at treatment initiation, as suggested by the American Society for Radiation Oncology 1, 2, 3
• Initiate salvage radiation early—outcomes deteriorate significantly when PSA rises above 1.5 ng/mL (6-year progression-free survival drops from 48% to 18%), according to the European Association of Urology 3, 4
• Active surveillance is appropriate for low-risk BCR (PSADT >12 months) without immediate systemic therapy, as recommended by the American Urological Association 5
• Monitor PSA every 3-4 months and reassess risk stratification, as suggested by the American College of Radiology 6

Castrate-Resistant Recurrence

• Disease progression despite ADT with castrate testosterone levels (<50 ng/dL) defines castration-resistant prostate cancer (CRPC), according to the National Comprehensive Cancer Network (NCCN) 7
• Confirm castrate testosterone levels before diagnosing CRPC, as recommended by the NCCN 9
• Clinical trial enrollment is preferred for non-metastatic CRPC (M0), according to the NCCN 9
• Observation is acceptable for asymptomatic patients with non-metastatic CRPC (M0), as suggested by the NCCN 9
• Docetaxel-based chemotherapy (every 3 weeks) plus corticosteroids is the preferred first-line systemic treatment for metastatic CRPC (M1), with proven survival benefit, as recommended by the NCCN 9
• Bisphosphonates should be added for bone metastases in metastatic CRPC (M1), according to the NCCN 9
• 177Lu-PSMA-617 therapy is indicated after progression on at least one androgen receptor pathway inhibitor AND one taxane regimen, with confirmed PSMA-positive disease on PET imaging, as suggested by the European Association of Urology 10

Imaging Considerations

• PSMA PET imaging should be used to exclude low-volume metastatic disease before initiating salvage local therapy, as recommended by the American College of Radiology 7, 6, 8
• Conventional imaging rarely detects metastases when PSA <5 ng/mL, according to the American College of Radiology 6

Critical Pitfalls to Avoid

• Do not delay salvage radiation when indicated—efficacy drops dramatically as PSA rises above 0.5 ng/mL, as warned by the European Association of Urology 3, 4
• Do not add estramustine to docetaxel—increases toxicity without improving efficacy, as cautioned by the NCCN 9
• Do not rely on conventional imaging for BCR with PSA <5 ng/mL—use PSMA PET instead, as recommended by the American College of Radiology 7, 6
• Always verify castrate testosterone levels before diagnosing CRPC to avoid misclassification, as emphasized by the NCCN 9