Neuroendocrine Differentiation Impacts Efficacy of First-Line Abiraterone or Docetaxel for mCRPC

Abiraterone and docetaxel are common first-line therapies for patients with metastatic castration-resistant prostate cancer (mCRPC). A recent study evaluated the prognostic value of neuroendocrine differentiation (NED) in patients receiving 1 of the 2 therapies. The results were presented at the 2023 American Society of Clinical Oncology Genitourinary Cancers Symposium.

Xu et al conducted a retrospective analysis of 262 patients with mCRPC who were treated with either abiraterone or docetaxel as first-line therapy. Patient NED status was evaluated using samples taken from prostate biopsy at the time of mCRPC diagnosis by immunohistochemical staining. The association between NED and treatment outcomes, including prostate-specific antigen progression-free survival (PSA-PFS), radiographic progression-free survival (rPFS), and overall survival (OS), were assessed using Kaplan-Meier curves and Cox regression analysis.

NED was confirmed in 100 (38.2%) patients with mCRPC, with 76 (76.0%) and 24 (24.0%) harboring a NED <10% and NED ≥10%, respectively. In patients who received abiraterone treatment, NED was associated with a significantly shorter median PSA-PFS (mPSA-PFS, 7.5 months vs 10.3 months; P<.001), median rPFS (mrPFS, 15.9 months vs 19.5 months; P=.010), and median OS (mOS, 23.2 months vs 34 months; P=.014).

Similarly, for patients with mCRPC who received docetaxel treatment, the positive detection of NED also predicted shorter mPSA-PFS (3.8 months vs 5.9 months; P=.052), mrPFS (8.4 months vs 20.4 months; P=.016), and mOS (13.6 months vs 29.0 months; P=.033). The adverse prognostic trait of NED was consistent in most subgroups. Survival outcomes also deteriorated as the NED proportion grew in both therapies. Abiraterone and docetaxel showed similar and unfavorable efficacy on patients with NED-positive mCRPC.

NED and its proportion were critical prognostic factors for patients with mCRPC treated with abiraterone or docetaxel. NED detection in mCRPC may help predict patient outcomes and optimize treatment decisions.