What is the recommended adjuvant treatment for a patient with post-radical prostatectomy pT3 acinar prostatic adenocarcinoma Gleason 7?

Adjuvant Treatment for pT3 Gleason 7 Prostate Cancer Post-Radical Prostatectomy

Adjuvant radiotherapy should be offered to patients with pT3 disease following radical prostatectomy, with treatment delivered at 64-70 Gy to the prostate bed within the first year after surgery once operative side effects have stabilized. 1

Primary Recommendation: Adjuvant Radiotherapy

You should offer adjuvant radiotherapy based on the presence of adverse pathologic features including extraprostatic extension (pT3), which has been demonstrated in multiple randomized trials to reduce biochemical recurrence, local recurrence, and clinical progression. 1, 2

Supporting Evidence from Randomized Trials

The recommendation for adjuvant radiotherapy is supported by three major randomized controlled trials:

• SWOG 8794: Demonstrated improved 10-year biochemical failure-free survival in high-risk patients receiving adjuvant RT versus observation (36% vs 12%, p=0.001), with median follow-up of 12.6 years showing improved overall survival (HR 0.72, p=0.023) 1, 2, 3

• EORTC 22911: Showed 5-year biochemical progression-free survival significantly improved with RT compared to observation for patients with positive surgical margins (78% vs 49%) 1, 2

• German ARO 96-02 (Wiegel et al): Found postoperative radiation improved 5-year biochemical progression-free survival compared to observation (72% vs 54%; HR 0.53) in pT3 patients 1, 2

Technical Specifications for Radiotherapy

Radiation Dose and Timing

• Prescribed dose: 64-70 Gy in standard fractionation 1, 2
• Timing: Within 1 year after radical prostatectomy, once operative side effects have improved/stabilized 1
• Target volume: Prostate bed (pelvic lymph nodes may be irradiated but are not necessary in most cases) 1, 2

Delivery Technique

• Use conformal techniques with image-guided radiotherapy 1
• High-dose IMRT (>70 Gy) has shown excellent biochemical relapse-free survival (93% at 3-5 years) with acceptable toxicity 4

Additional Risk Factors to Consider

While pT3 disease alone is an indication for adjuvant RT, the following additional adverse features strengthen the recommendation:

• Positive surgical margins (especially if diffuse: >10 mm involvement or ≥3 sites) 1, 2
• Seminal vesicle invasion 1, 2
• Gleason score 8-10 (your patient has Gleason 7, which is intermediate) 1, 2
• PSA doubling time <9 months (if PSA becomes detectable) 1, 2

Alternative: Observation with Close Monitoring

If the patient declines adjuvant radiotherapy or has significant comorbidities, observation is an acceptable alternative with salvage radiotherapy reserved for biochemical recurrence. 1

Salvage RT Criteria (if observation chosen)

• Biochemical recurrence definition: PSA ≥0.2 ng/mL with confirmatory second level ≥0.2 ng/mL 1, 2, 3
• Salvage RT is most effective when: Pre-treatment PSA <1 ng/mL and PSA doubling time is slow 1, 3
• Monitoring schedule: PSA every 3-6 months 1, 3

Role of Androgen Deprivation Therapy

ADT is NOT routinely indicated for pT3 disease without lymph node involvement. 1

ADT should only be considered if:

• Positive lymph nodes are present (category 1 indication) 1, 2
• High-risk features with salvage RT (category 2B) 1

Expected Outcomes and Toxicity

Efficacy

• 5-year disease-free survival: 67% with adjuvant RT 5
• 10-year disease-free survival: 53% with adjuvant RT 5
• Local recurrence rate: Only 5% with adjuvant RT 5

Toxicity Profile

• Acute: Grade 3 genitourinary toxicity in approximately 8% of patients 4
• Late: Grade 3 genitourinary toxicity in 4% of patients; urethral stricture in 6% 4
• Gastrointestinal: Grade 3 toxicity is rare (<1%) 4

Clinical Decision Algorithm

1. Confirm pathology: pT3 disease with Gleason 7 ✓
2. Exclude metastatic disease: Ensure no lymph node involvement or distant metastases
3. Assess patient factors: Life expectancy >10 years, recovered from surgery
4. Offer adjuvant RT: 64-70 Gy to prostate bed within 1 year 1, 2
5. If patient declines: Implement close PSA monitoring every 3-6 months with salvage RT at biochemical recurrence 1, 3

Common Pitfalls to Avoid

• Delaying RT too long: Adjuvant RT should be given within 1 year; effectiveness decreases with delay 1
• Waiting for PSA rise: The trials supporting adjuvant RT enrolled patients with undetectable PSA; don't wait for biochemical recurrence in pT3 disease 1, 2
• Under-dosing: Doses <64 Gy are associated with higher failure rates; aim for 64-70 Gy 1, 6
• Adding unnecessary ADT: ADT is not indicated for pT3 disease without nodal involvement 1