Purpose: The aim of this study was to evaluate the clinical and biochemical response to neoadjuvant hormonal therapy (NAHT) before radical external radiotherapy (EBRT).
Materials and methods: From June 1986 to June 1994, 105 patients with histologically proven and non-metastatic prostate adenocarcinoma (stage B2-C2) received a short induction hormonal therapy (median: 3 months) with a luteinizing hormone releasing hormone (LHRH) analog associated with an anti-androgen followed in all cases by EBRT (66 Gy). All patients underwent a prostate-specific acid (PSA) determination, pelvic computed tomography (CT) scan and bone scan before the combined treatment. Response, treatment toxicity and PSA concentration were analyzed after the NAHT, 3 months after the completion of radiotherapy and every 6 months there after. Relapse was defined by PSA elevations above 4 ng/mL or two consecutive elevation above 1 ng/mL.
Results: Median follow-up was 52 months. According to the Withmore-Jewett clinical classification, 85 tumors were stage C. Pre-treatment PSA (PSAi) was above 20 ng/mL in 63.8% of the patients (median PSAi: 26 ng/mL). A clinical evaluation and a PSA determination (PSAPH) were both performed for all patients after NAHT. Most of the time, urinary obstructive symptoms disappeared with androgen ablation; tumor volume regression exceeded 50% in 99 cases and was complete in 50 cases. Median PSAPH was 0.6 ng/mL for the entire group. Clinical and biochemical tumor response were coherent: 84% of patients with clinical total remission had a PSAPH < 1 ng/mL. PSAPH value was significantly correlated with tumor stage and pre-treatment PSAi: among the 11 patients with a PSAPH > 4 ng/mL, ten were stage C and nine had a PSAi > 20 ng/mL. A PSAPH value exceeding 4 ng/mL predicted biochemical relapse (P < 0.0001).
Conclusion: We conclude that biochemical response to hormonal therapy has a major prognostic value before EBRT can help to identify patients for an adjuvant hormonal therapy.