Post-radical prostatectomy (RP) outcome for patients with high-risk prostate cancer treated with intense neoadjuvant hormone therapy (NHT): Results of a pooled analysis of contemporary clinical trials.

Abstract

238 Background: Patients with high-risk prostate cancer have an increased risk of recurrence and death from prostate cancer. Intense NHT prior to RP has been associated with favorable pathologic responses in a subset of patients with high-risk disease. We conducted a pooled analysis of post-RP outcomes of four, multicenter, randomized, clinical trials of intense NHT prior to RP. Methods: All patients included were enrolled on trials evaluating intense NHT followed by RP. The primary endpoint was time to biochemical recurrence (BCR), defined as the time from RP to prostate specific antigen (PSA) >0.1 ng/mL or start of first post-RP therapy. Secondary endpoints included metastasis-free survival (MFS), overall survival (OS), and time to testosterone recovery. We evaluated outcomes in the overall population, favorable responders (defined as a pathologic complete response or minimum residual disease ≤ 5 mm at RP), and non-responders. We correlated pathologic parameters, including RP pathologic response, PTEN status, ERG status, and presence of intraductal carcinoma with BCR. Results: 121 patients were included of whom 78.5% (n=95) had high-risk disease by NCCN risk categories. Following NHT, 20.7% (n=25) had 0-5 mm of residual tumor (including 9.1%, n=11, with pathologic complete response). Overall, 52 patients (43.0%) experienced BCR, of whom two were exceptional responders (Table). Testosterone recovery was observed in 94.0% of patients (n=109/116). PTEN loss and presence of intraductal carcinoma were associated with shorter time to BCR. Conclusions: In this pooled analysis of clinical trials, we demonstrate that patients who achieve a favorable pathologic response to NHT prior to RP experienced a decreased PSA relapse rate and prolonged time to BCR. Larger residual tumor volumes and tissue-based parameters, including PTEN loss and intraductal carcinoma, were associated with BCR. Additional follow-up is warranted to evaluate the impact on long-term outcomes. Clinical trial information: NCT00298155; NCT00924469; NCT01547299; NCT02268175 . [Table: see text]