ABSTRACT
BACKGROUND/AIM: No practical biomarkers predict the response to enzalutamide in chemotherapy-naïve metastatic castration-resistant prostate cancer (mCRPC). The present study aimed to evaluate the prognostic value of the initial-to-nadir prostate-specific antigen (PSA) ratio (I/N PSA) in primary hormone therapy for metastatic hormone-naïve prostate cancer associated with the response to first-line enzalutamide in mCRPC. PATIENTS AND METHODS: Twenty-eight patients with mCRPC received first-line enzalutamide to determine the associations between I/N PSA in combined androgen blockade and clinical outcomes. The PSA response was defined as ≥90% decline from baseline in patients with mCRPC. RESULTS: The optimal cutoff I/N PSA value for PSA response was 1,219 (sensitivity=71.4%, specificity=92.9%, area under the receiver operating characteristic curve=0.85). The PSA response was 90.9% in the high I/N PSA group and 23.5% in the low I/N PSA group. The median overall survival, prostate cancer-specific survival, and radiographic progression-free survival after initiation of enzalutamide were statistically greater for the high I/N PSA group than the low group. Multivariable analysis showed that I/N PSA was an independent predictor of overall survival (hazard ratio=0.23; p=0.026). CONCLUSION: In chemotherapy-naïve patients with mCRPC, I/N PSA was a predictive and prognostic biomarker for first-line enzalutamide. The I/N PSA can enable optimization of individual treatment in real-world clinical practice.
ABSTRACT
BACKGROUND/AIM: This study retrospectively investigated the impact of enfortumab vedotin (EV) monotherapy on the oncological outcome, safety profile, and health-related quality of life (HRQoL) in patients with metastatic urothelial carcinoma. PATIENTS AND METHODS: We assessed 26 consecutive patients who had received EV monotherapy after failure of platinum-based chemotherapy and immune checkpoint blockade therapy at our single institution from December 2021 to January 2023. The objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS), incidence of adverse events (AEs), and EORTC QLQ-C30 as an HRQoL instrument were evaluated. RESULTS: The ORR and DCR were 57.7% and 80.8%, respectively. EV was effective regardless of the patient and tumor characteristics, including the efficacy of previous systemic therapy, performance status, number of Bellmunt risk factors, and presence of variant histology. With a median follow-up time of 7.5 months, the median durations of PFS and OS were 5.4 months and 10.3 months, respectively. Grade ≥3 AEs included neutropenia (15.4%), fatigue (7.7%), appetite loss (7.7%), rash (3.8%), febrile neutropenia (3.8%), hyperglycemia (3.8%), and interstitial pneumonia (3.8%). AEs resulting in withdrawal of EV, interruption of EV, and dose reduction occurred in two (7.7%), nine (34.6%), and 13 patients (50.0%), respectively. The EORTC QLQ-C30 scores from baseline to post-EV introduction remained stable. CONCLUSION: EV monotherapy demonstrated promising anti-tumor activity and tolerability in patients with metastatic urothelial carcinoma.
