Effectiveness and safety of enzalutamide and apalutamide in the treatment of patients with non-metastatic castration-resistant prostate cancer (nmCRPC): a multicenter retrospective study.

OBJECTIVE: Phase III clinical trials demonstrated the efficacy of enzalutamide and apalutamide in patients with non-metastatic castration-resistant prostate cancer (nmCRPC) and PSA doubling time ≤10 months. Although these drugs have been shown to vary in their adverse event (AE) profiles, the differences in their efficacy profiles remain to be evaluated. Therefore, this retrospective study was conducted to evaluate the efficacy of these drugs in patients with nmCRPC. METHODS: This study evaluated 191 patients with nmCRPC treated with enzalutamide (n = 137) or apalutamide (n = 54) in the first-line setting at Jikei University Hospital or its affiliated hospitals between May 2014 and November 2022. Endpoints were defined as oncological outcomes (i.e., PSA response, PFS, PSA-PFS, MFS, CSS, and OS) and AEs. RESULTS: No significant differences were noted in patient backgrounds between the two groups. Patients exhibiting a maximum PSA response of >50% and >90% accounted for 74.5% and 48.9% of patients in the enzalutamide group, and 75.9% and 42.6% of patients in the apalutamide group, respectively, with no significant difference between the groups. The median PSA-PFS was 10 months in the enzalutamide group but not in the apalutamide group, with no significant difference between the groups (P = 0.48). No significant differences were observed in MFS, CSS, or OS between the groups. Patients reporting AEs of all grades and grade 3 or higher accounted for 56.2% and 4.3% of those in the enzalutamide group and 57.4% and 7.4% of those in the apalutamide group, respectively. The most common AE was fatigue (26.3%) in the enzalutamide group and skin rash (27.8%) in the apalutamide group. CONCLUSION: In this retrospective study of their efficacy and safety, enzalutamide and apalutamide were shown to exhibit comparable oncological outcomes but quite different AE profiles, suggesting that their differential use may be warranted based on these findings.

Perioperative renal function change and oncological outcomes of radical nephroureterectomy in patients with upper tract urothelial carcinoma: A multicenter retrospective study.

BACKGROUND: The effect of radical nephroureterectomy (RNUx) on postoperative renal function in patients diagnosed with upper tract urothelial carcinoma (UTUC) has not been thoroughly explored. METHODS: We conducted a retrospective analysis including 785 patients who underwent RNUx for UTUC. We assessed the preoperative and postoperative estimated glomerular filtration rates (eGFRs) and factors related to the decline in eGFR. Additionally, we examined the effect of comorbidities (diabetes or hypertension) on the postoperative eGFR at 1 year. Cox proportional hazard models were employed to investigate the clinical effect of RNUx on oncological outcomes, including non-urothelial tract recurrence-free survival (NUTRFS), cancer-specific survival (CSS), and overall survival (OS). RESULTS: The median preoperative and postoperative eGFR levels were 54.7 and 40.6 ml/min/1.73 m2 respectively. The proportions of patients with preoperative and postoperative eGFR ≥60 mL/min/1.73 m2 were 35.9% and 5.1%, respectively. The median decline in the eGFR after surgery was 26.8%. Patients with preoperative eGFR <60 ml/min/1.73 m2 demonstrated significantly lower odds of a postoperative decline in eGFR of 25% or more. The effect of comorbidities on postoperative eGFR at 1 year was significant (P = 0.048). The 3-year NUTRFS, CSS, and OS rates were 72.9%, 85.2%, and 81.5%, respectively. Preoperative chronic kidney disease was an independent factor associated with inferior NUTRFS, CSS, and OS. CONCLUSION: Different degrees of impairment of renal function occur among UTUC patients. Only 5.1% of patients retain a postoperative eGFR ≥60 ml/min/1.73 m2. Preoperative renal impairment was linked to reduced odds of postoperative eGFR decrease and associated with survival. In addition, the presence of comorbidities had a significant effect on the decline in eGFR. These findings emphasize the importance of developing evidence-based perioperative treatment strategies for UTUC patients with impaired renal function.

Effect of a variant histology on the oncological outcomes of Japanese patients with upper tract urothelial carcinomas after radical nephroureterectomy: a multicenter retrospective study.

Background: An earlier systematic review and meta-analysis found that patients with a certain histological variant of upper tract urothelial carcinoma (UTUC) exhibited more advanced disease and poorer survival than those with pure UTUC. A difference in the clinicopathological UTUC characteristics of Caucasian and Japanese patients has been reported, but few studies have investigated the clinical impact of the variant histology in Japanese UTUC patients. Methods: We retrospectively enrolled 824 Japanese patients with pTa-4N0-1M0 UTUCs who underwent radical nephroureterectomy without neoadjuvant chemotherapy. Subsequently, we explored the effects of the variant histology on disease aggressiveness and the oncological outcomes. We used Cox's proportional hazards models to identify significant predictors of oncological outcomes, specifically intravesical recurrence-free survival (IVRFS), recurrence-free survival (RFS), cancer-specific survival (CSS), and overall survival (OS). Results: Of the 824 UTUC patients, 32 (3.9%) exhibited a variant histology that correlated significantly with a higher pathological T stage and lymphovascular invasion (LVI). Univariate analysis revealed that the variant histology was an independent risk factor for suboptimal RFS, CSS, and OS. However, significance was lost on multivariate analyses. Conclusions: The variant histology does not add to the prognostic information imparted by the pathological findings after radical nephroureterectomy, particularly in Japanese UTUC patients.

Clinical Significance of Intraductal Carcinoma of the Prostate After High-Dose Brachytherapy With External Beam Radiation Therapy: A Single Institution Series and an Updated Meta-Analysis.

BACKGROUND: We compared oncological outcomes between prostate cancer (PCa) patients with and without intraductal carcinoma of the prostate (IDC-P) after high-dose-rate brachytherapy (HDR-BT) with external beam radiation therapy (EBRT). METHODS: We performed a retrospective analysis of 138 patients with clinically high-risk, very high-risk, or locally advanced PCa who received HDR-BT with EBRT. Of these, 70 (50.7 %) patients were diagnosed with IDC-P; 68 (49.3 %) patients with acinar adenocarcinoma of prostate. The oncological outcomes, including biochemical recurrence-free survival (BCRFS) and clinical progression-free survival (CPFS), were assessed using Kaplan-Meier curves. Additionally, Cox proportional hazards models were used to identify significant prognostic indicators or biochemical recurrence (BCR). Meta-analysis of existing literatures was performed to evaluate the risk of BCR in patients with IDC-P after radiation therapy, compared to those without IDC-P. RESULTS: Kaplan-Meier curves demonstrated significantly inferior BCRFS and CPFS in patients with IDC-P. Multivariate analysis revealed that IDC-P and Grade Group 5 status were associated with increased BCR risk. in our meta-analysis, IDC-P was associated with BCR (HR = 2.13, P = .003). CONCLUSION: Amongst the patients who received HDR-BT, patients with IDC-P displayed significantly more rapid disease progression, compared with patients who did not have IDC-P.

Real-world outcomes of adjuvant immunotherapy candidates with upper tract urothelial carcinoma: results of a multicenter cohort study.

BACKGROUND: Recent clinical trials have reported improved disease-free survival rates of patients with stage pT3-4/ypT2-4 or pN + upper tract urothelial carcinoma (UTUC) on adjuvant nivolumab therapy. However, the appropriateness of the patient selection criteria used in clinical practice remains uncertain. METHODS: We retrospectively analyzed 895 patients who underwent nephroureterectomy to treat UTUC. The patients were divided into two groups: grade pT3-4 and/or pN + without neoadjuvant chemotherapy (NAC) or grade ypT2-4 and/or ypN + on NAC (adjuvant immunotherapy candidates) and others (not candidates for adjuvant immunotherapy). Kaplan-Meier curves were drawn to assess the oncological outcomes, including recurrence-free survival (RFS), cancer-specific survival (CSS), and overall survival (OS). Cox proportional hazards models were used to identify significant prognostic factors for oncological outcomes. RESULTS: The Kaplan-Meier curves revealed notably inferior RFS, CSS, and OS of patients who were candidates for adjuvant immunotherapy. Multivariate analysis revealed that pathological T and N grade and lymphovascular invasion (LVI) status were independent risk factors for poor RFS, CSS, and OS. CONCLUSION: In total, 44.8% of patients were candidates for adjuvant immunotherapy. In addition to pathological T and N status, LVI was a significant predictor of survival, and may thus play a pivotal role in the selection of patients eligible for adjuvant immunotherapy.

The clinical impact of ureteroscopy for upper tract urothelial carcinoma: A multicenter study.

BACKGROUND: With the development of kidney-sparing surgery and neoadjuvant chemotherapy, ureteroscopic biopsy (URSBx) has become important for the management of upper tract urothelial carcinoma (UTUC). METHODS: We retrospectively analyzed data from 744 patients with UTUC who underwent radical nephroureterectomy (RNU), stratified into no ureteroscopy (URS), URS alone, and URSBx groups. Intravesical recurrence-free survival (IVRFS) was examined using the Kaplan-Meier method. We conducted Cox regression analyses to identify risk factors for IVR. We investigated differences between clinical and pathological staging to assess the ability to predict the pathological tumor stage and grade of RNU specimens. RESULTS: Kaplan-Meier curves and multivariate Cox regression revealed significantly more IVR and inferior IVRFS in patients who underwent URS and URSBx. Superficial, but not invasive, bladder cancer recurrence was more frequent in the URS and URSBx groups than in the no URS group. Clinical and pathological staging agreed for 55 (32.4%) patients. Downstaging occurred for 48 (28.2%) patients and clinical understaging occurred for 67 (39.4%) patients. Upstaging to muscle-invasive disease occurred for 39 (35.8%) of 109 patients with ≤cT1 disease. Clinical and pathological grading were similar for 72 (42.3%) patients. Downgrading occurred for 5 (2.9%) patients, and clinical undergrading occurred for 93 (54.7%) patients. CONCLUSION: URS and URSBx instrumentation will be risk factors for superficial, but not invasive, bladder cancer recurrence. Clinical understaging/undergrading and upstaging to muscle-invasive disease occurred for a large proportion of patients with UTUC who underwent RNU. These data emphasize the challenges involved in accurate UTUC staging and grading.

Novel technique for cognitive magnetic resonance imaging-transperineal ultrasound fusion transperineal prostate biopsy with injection of bubbled jelly into urethra after abdominoperineal excision.

Introduction: Prostate biopsy is commonly performed using a transrectal ultrasound probe through a transrectal or transperineal approach. However, this is not possible for patients without a rectum. Case presentation: A 75-year-old male was referred to our hospital because of an elevated prostate-specific antigen and a suspicious prostate lesion (PIRADS 5) in the left peripheral zone. The patient had previously undergone abdominoperineal resection for rectal cancer, which excluded the use of transrectal ultrasound. We describe the use of the transperineal ultrasound-guided biopsy with cognitive magnetic resonance imaging-transperineal ultrasound fusion and the utility of the injection of bubbled lidocaine jelly into urethra to improve its visualization. The pathological findings revealed clinically significant cancer with a Gleason score of 5 + 4. Conclusion: Cognitive magnetic resonance imaging-transperineal ultrasound fusion transperineal prostate biopsy with injection of bubbled jelly into urethra is a feasible and practical technique that does not require any specialized equipment.

A case of urinary bladder metastasis of hepatocellular carcinoma following use of immunotherapy/tyrosine kinase inhibitor.

Introduction: Here we present a rare case of hepatocellular carcinoma metastasis to the urinary bladder in a patient with metastatic HCC. Case presentation: An 83-year-old man developed gross hematuria during combined treatment with an anti-programmed death-ligand 1 inhibitor and an anti-vascular endothelial growth factor for metastatic HCC. A contrast-enhanced CT revealed a 15 × 15 mm soft tissue mass protruding from the posterior bladder wall. Cystoscopy further revealed a solitary submucosal mass located on the posterior wall. The patient underwent transurethral resection of bladder tumor. The pathological findings were consistent with a diagnosis of bladder metastasis from HCC. Following a 3-week interval after the surgical intervention, salvage therapy was resumed. Conclusion: During follow-up after TUR-BT in HCC patients who present with a bladder tumor, the possibility of HCC metastases to the urinary bladder should be excluded.

Presurgical immune-oncology/tyrosine kinase inhibitor combination therapy for renal cell carcinoma with a vena cava tumor thrombus: a single-institution case series.

Background: Although current guidelines recommend administering adjuvant immunotherapy following resection of advanced primary renal cell carcinoma (RCC), the clinical benefit of presurgical immunotherapy for patients with RCC remains uncertain. Case Description: We conducted a retrospective analysis of five patients diagnosed with RCC who developed inferior vena cava (IVC) tumor thrombus and were treated with radical nephrectomy following combined immunotherapy with a tyrosine kinase inhibitor. The median follow-up after nephrectomy was 23 months (range, 19-30 months). In all cases, the size of the IVC tumor thrombus decreased, and three of the cases demonstrated a decrease in the tumor thrombus level. Surgical margins were negative in all cases, and none of the patients experienced any major intraoperative complications. However, adhesions were encountered at the operative sites during surgery in all cases. One patient required a lymphatic intervention due to abdominal lymphatic leakage (Clavien IIIa) within 90 days after operation. Our case series demonstrated a median progression-free survival (PFS) of 11 months [95% confidence interval (CI)]: 5.5-22.5 months). No patient died during the follow-up period. Conclusions: Presurgical therapy combined with immunotherapy and tyrosine kinase inhibitors warrants consideration. Nevertheless, surgeons should be mindful of the difficulties that may arise beyond the clinical stage.

Comparison of neoadjuvant and adjuvant chemotherapy for upper tract urothelial carcinoma in real-world practice: a multicenter retrospective study.

BACKGROUND: Multiple studies have demonstrated the effectiveness of neoadjuvant chemotherapy and adjuvant chemotherapy in patients with upper tract urothelial carcinoma compared with surgery alone. However, no clinical trial has established the superiority of neoadjuvant chemotherapy or adjuvant chemotherapy in terms of perioperative outcomes. METHODS: We conducted a retrospective analysis encompassing 164 upper tract urothelial carcinoma patients who underwent radical nephroureterectomy and received perioperative chemotherapy. Of these patients, 65 (39.6%) and 99 (60.4%) received neoadjuvant chemotherapy and adjuvant chemotherapy, respectively. Recurrence-free survival and cancer-specific survival were computed using the Kaplan-Meier method. Additionally, we conducted Cox regression analyses to evaluate the risk factors for recurrence-free survival and cancer-specific survival. RESULTS: Pathological downstaging was seen in 37% of the neoadjuvant chemotherapy group. However, no pathological complete response was observed in this cohort. The Kaplan-Meier curves demonstrated significantly lower recurrence-free survival and cancer-specific survival in patients who received adjuvant chemotherapy. Multivariate Cox regression analysis revealed patients treated with adjuvant chemotherapy exhibited a marked association with inferior recurrence-free survival and cancer-specific survival. CONCLUSION: Our study has suggested that neoadjuvant chemotherapy would be more effective in high-risk upper tract urothelial carcinoma patients compared with adjuvant chemotherapy.

Clinical characteristics of secondary bladder cancer developing after low-/high-dose-rate brachytherapy to treat localized prostate cancer.

BACKGROUND: To explore correlations between the clinical attributes of secondary bladder cancer and brachytherapy, we retrospectively reviewed our institutional database on patients with localized prostate cancer who underwent low-dose-rate brachytherapy (LDR-BT) or high-dose-rate brachytherapy (HDR-BT) with or without external beam radiation therapy (EBRT) or radical prostatectomy (RP). METHODS: From October 2003 to December 2014, 2551 patients with localized prostate cancer were treated at our institution. Of these, data on 2163 were available (LDR-BT alone: n = 953; LDR-TB with EBRT: n = 181; HDR-BT with EBRT: n = 283; RP without EBRT: n = 746). The times of secondary bladder cancer development subsequent to radical treatment, and their clinical characteristics, were studied. RESULTS: Age-adjusted Cox's regression analyses indicated that brachytherapy did not significantly impact the incidence of secondary bladder cancer. However, the pathological characteristics of such cancer differed between patients treated via brachytherapy and RP without EBRT; invasive bladder cancer was more common in such patients. CONCLUSION: The risk for secondary bladder cancer was not significantly increased after brachytherapy compared to non-irradiation therapy. However, brachytherapy patients exhibited a higher incidence of invasive bladder cancer. Therefore, meticulous follow-up is crucial for early detection and treatment of bladder cancer in such patients.

Treatment Results of High-dose-rate Brachytherapy and External Beam Radiation With Long-term Androgen Deprivation Therapy for Patients With Metastatic Prostate Cancer.

BACKGROUND/AIM: A recent clinical trial indicated the usefulness of local radiation therapy of the prostate in patients with low-volume metastatic prostate cancer. High-dose-rate brachytherapy (HDR-BT) is used mainly for high-risk, localized, and locally advanced cases. However, few studies exist on the efficacy of HDR-BT and external beam radiation therapy (EBRT) for metastatic prostate cancer. PATIENTS AND METHODS: We conducted a retrospective analysis of 39 patients diagnosed with regional lymph node metastasis and/or a limited number of metastases who underwent HDR-BT and EBRT with long-term androgen deprivation therapy. We utilized Cox's proportional hazards models to identify predictors of oncological outcomes. Treatment outcomes, including biochemical recurrence-free survival (BCRFS), clinical progression-free survival (CPFS), and castration-resistant prostate cancer-free survival (CRPCFS), were compared according to the clinical stage. RESULTS: The median follow-up duration was 49 months (range=23-136 months). The 5-year BCRFS, CPFS, CRPCFS, and cancer-specific survival rates were 62.2%, 67.2%, 83.2%, and 93.4%, respectively. Based on Kaplan-Meier analysis, N1M0 and N0-1M1b showed favorable outcomes compared with N1M1a. Multivariate analysis revealed that N1M1a prostate cancer was an independent risk factor for poor BCRFS, CPFS, and CRPCFS. CONCLUSION: HDR-BT and EBRT with androgen deprivation therapy is a feasible approach for patients with newly diagnosed regional and low-metastatic-burden prostate cancer. However, in our cohort M1a prostate cancer had significantly inferior outcomes. A well-controlled prospective study is imperative to confirm our results.

Comparison of Quality of Life and Injection Site Reactions After Switching from Degarelix 80 mg to 480 mg in Advanced Prostate Cancer: A Prospective Trial.

BACKGROUND/AIM: Degarelix has been widely used for prostate cancer; however, injection site reactions (ISRs) can be a clinical issue. We assessed differences in ISR intensity and patient quality of life (QOL) between degarelix 80 mg and 480 mg, a three-month formulation launched in 2020 in Japan. PATIENTS AND METHODS: We prospectively analyzed 25 patients with advanced prostate cancer. ISR intensity and patient QOL were evaluated before and after switching from degarelix 80 mg to 480 mg. A visual analogue scale (VAS) and faces rating scale (FRS) were applied to assess the ISRs. We applied a rating format from the M. D. Anderson Symptom Inventory (MDASI) to assess patient QOL. RESULTS: For degarelix 80 mg and a first dose of 480 mg, the incidence rate of ISRs was 84% and 92%, respectively (p=0.083). ISR pain on the third day after injection scored by VAS was 2.7±2.8 and 5.2±2.7, respectively (p<0.001). Other ISR findings such as redness, induration, swelling, warmth, and itching were significantly worse for degarelix 480 mg than for 80 mg. In the category of patient QOL, interference with activities of daily living such as general activity was significantly worse after degarelix 480 mg (p=0.003). However, 80% of patients were able to continue degarelix 480 mg during the nine months of follow-up. CONCLUSION: Degarelix 480 mg seems to exacerbate pain and other ISR findings, and to reduce patient QOL, compared with degarelix 80 mg. Optimal management of ISRs is essential to maintain patient QOL when using degarelix 480 mg.

Percutaneous cryoablation versus partial nephrectomy for cT1b renal tumors: An inverse probability weight analysis.

PURPOSE: To investigate differential clinical outcomes in patients treated with partial nephrectomy (PN) vs. percutaneous cryoablation (PCA) for cT1b renal tumors. MATERIALS AND METHODS: We retrospectively analyzed the records of 119 patients who had undergone PN (n = 90) or PCA (n = 29) for cT1b renal tumors. Inverse probability weighting (IPW) was used for balancing patient demographics, including renal function and tumor complexity. Perioperative complications, renal function preservation rates, and oncological outcomes such as local recurrence-free, metastasis-free, cancer-specific, and overall survival were compared using IPW-adjusted restricted mean survival times (RMSTs). RESULTS: PCA was more likely to be selected for octogenarians (odds ratio: 11.4, 95% confidence interval [CI]: 3.33-45.1). During the median follow-up of 43 months in the PCA group and 36.5 months in the PN group, unablated local residue or local recurrence was noted in 6 patients in the PCA group and local recurrence was noted in 4 patients in the PN groups. Of the 6 patients in the PCA group, 4 underwent salvage PCA, and local control had been achieved at the last visit. In the IPW-adjusted population, PCA had significantly worse local recurrence-free survival compared with PN (IPW-adjusted RMST difference: -22.7 months, 95% CI: -45.3 to -0.4, P = 0.046). IPW-adjusted RMST for metastasis-free survival (P = 0.23), cancer-specific survival (P = 0.77), and overall survival (P = 0.11) did not differ between PCA and PN. In addition, PN was not a predictor for local control failure at the last visit (odds ratio: 0.30, 95%CI: 0.05-1.29). There were no statistically significant differences between PN and PCA in renal function preservation or overall/severe complication rates. CONCLUSIONS: In patients with cT1b renal tumor, although the local recurrence rate is higher for PCA than for PN, PCA provides comparable distant oncologic outcomes. PCA can be an alternative treatment option for elderly, comorbid patients, even those with cT1b renal tumors.

Docetaxel versus abiraterone for metastatic hormone-sensitive prostate cancer with focus on efficacy of sequential therapy.

PURPOSE: We aimed to assess the oncologic efficacy of combining docetaxel (DOC) versus abiraterone (ABI) with androgen deprivation therapy (ADT) in patients with high-risk metastatic hormone-sensitive prostate cancer (mHSPC), with a focus on the efficacy of sequential therapy, in a real-world clinical practice setting. METHODS: The records of 336 patients who harbored de novo high-risk mHSPC, based on the LATITUDE criteria, and had received ADT with either DOC (n = 109) or ABI (n = 227) were retrospectively analyzed. Overall survival (OS), cancer-specific survival (CSS), progression-free survival (PFS), including time to castration-resistant prostate cancer (CRPC), time to 2nd-line progression (PFS2), and 2nd- and 3rd-line PFS, were compared. We used one-to-two propensity score matching to minimize the confounders. The differential efficacy of 2nd-line therapy based on agents in each arm was evaluated using the unmatched cohort as an additional interest. RESULTS: After propensity score matching, 86 patients treated with DOC + ADT and 172 with ABI + ADT were available for analyses. The 3-year OS and CSS for DOC versus ABI were 76.2% versus 75.1% (p = 0.8) and 78.2% versus 78.6% (p = 1), respectively. There was no difference in the median PFS2 (49 vs. 43 months, p = 0.39), while the median time to CRPC in patients treated with ABI was significantly longer compared to those treated with DOC (42 vs. 22 months; p = 0.006). The median 2nd-line PFS (14 vs. 4 months, p < 0.001) and 3rd-line PFS (4 vs. 2 months, p = 0.012) were significantly better in the DOC group than in the ABI group. Among the unmatched cohort, after ABI for mHSPC, the median 2nd-line PFS did not differ between the patients treated with DOC and those treated with enzalutamide as 2nd-line therapy (both 3 months, p = 0.8). CONCLUSIONS: ADT with DOC or ABI has comparable oncologic outcomes in terms of OS, CSS, and PFS2 in patients with de novo high-risk mHSPC. Compared to DOC, ABI resulted in longer time to CRPC but worse 2nd and 3rd-line PFS. Further studies are needed to clarify the optimal sequence of therapy in the upfront intensive treatment era.

Abiraterone acetate versus nonsteroidal antiandrogen with androgen deprivation therapy for high-risk metastatic hormone-sensitive prostate cancer.

BACKGROUND: Although prostate cancer is a very common form of malignancy in men, the clinical significance of androgen deprivation therapy (ADT) with abiraterone acetate versus the nonsteroidal antiandrogen bicalutamide has not yet been verified in patients with high-risk metastatic hormone-sensitive prostate cancer (mHSPC). The present study was designed to initiate this verification in real-world Japanese clinical practice. METHODS: We retrospectively analyzed the records of 312 patients with high-risk mHSPC based on LATITUDE criteria and had received ADT with bicalutamide (n = 212) or abiraterone acetate (n = 100) between September 2015 and December 2020. Bicalutamide was given at 80 mg daily and abiraterone was given at 1000 mg daily as four 250-mg tablets plus prednisolone (5-10 mg daily). Overall survival (OS), cancer-specific survival (CSS), and time to castration-resistant prostate cancer (CRPC) were compared. The prognostic factor for time to CRPC was analyzed by Cox proportional hazard model. RESULTS: Patients in the bicalutamide group were older, and more of them had poor performance status (≧2), than in the abiraterone group. Impaired liver function was noted in 2% of the bicalutamide group and 16% of the abiraterone group (p < 0.001). Median follow-up was 22.5 months for bicalutamide and 17 months for abiraterone (p < 0.001). Two-year OS and CSS for bicalutamide versus abiraterone was 77.8% versus 79.5% (p = 0.793) and 81.1% versus 82.5% (p = 0.698), respectively. Median time to CRPC was significantly longer in the abiraterone group than in the bicalutamide group (NA vs. 13 months, p < 0.001). In multivariate analysis, Gleason score ≧9, high alkaline phosphatase, high lactate dehydrogenase, liver metastasis, and bicalutamide were independent prognostic risk factors for time to CRPC. Abiraterone prolonged the time to CRPC in patients with each of these prognostic factors. CONCLUSIONS: Despite limitations regarding the time-dependent bias, ADT with abiraterone acetate significantly prolonged the time to CRPC compared to bicalutamide in patients with high-risk mHSPC. However, further study with longer follow-up is needed.