Pathologic response as an early endpoint for survival following neoadjuvant androgen deprivation therapy plus abiraterone acetate for metastatic prostate cancer.

Abstract

Purpose: This study aimed to explore the factors affecting pathologic complete response (pCR) and prognosis of locally advanced prostate cancer (LAPCa) or metastatic prostate cancer (mPCa) treated with neoadjuvant androgen deprivation therapy (ADT) with abiraterone acetate (AA).

Methods: This retrospective study enrolled patients diagnosed with LAPCa or mPCa who were divided into three groups based on prostate-specific antigen (PSA) nadir following ADT with AA: group 1 (PSA ≤ 0.2 ng/ml), group 2 (PSA 0.2-4.0 ng/ml), and group 3 (PSA > 4.0 ng/ml). Univariate and multivariate logistic regression models were utilized to investigate the relationship between the variables and pCR, and risk factors of castration-resistant prostate cancer (CRPC).

Results: Among 79 enrolled patients, 33 (41.8%) patients presented with tumor downstaging and 12 (15.2%) patients presented with pCR. PSA nadir was an independent risk factor for tumor downstaging and pCR. Total 71 (89.87%) patients developed CRPC. The median progression time to CRPC in group 1, 2, and 3 was 28, 26, and 24.5 months, respectively. Compared to control group, patients with tumor downstaging, pCR, or PSA nadir < 0.2 ng/ml had better progression-free survival. Tumor downstaging, pCR, and PSA nadir were independent risk factors for progression to CRPC in LAPCa or mPCa.

Conclusion: For patients with LAPCa or mPCa after neoadjuvant AA plus ADT, PSA nadir help predict tumor downstaging or pCR. The patients with tumor downstaging, pCR, or PSA nadir < 0.2 ng/ml have a longer progression time to CRPC.