Predictive factors for the effectiveness of novel androgen receptor axis-targeted agents in patients with metastatic prostate cancer.

OBJECTIVE: Novel androgen receptor axis-targeted agents (ARATAs) have been developed for mCRPC and improved overall survival (OS). Here, we aimed to find predictors who will receive the greatest benefits from ARATAs. METHODS: We previously performed a multicenter study to identify prognostic factors for metastatic hormone-sensitive prostate cancer (mHSPC, n = 148) and mCRPC (n = 99), and showed that the bone scan index (BSI) was one of the significant prognostic factors for 3-year OS (PROSTAT-BSI study). mHSPC progressed to mCRPC (n = 101), for which 69 patients were treated with (n = 39) or without ARATAs (n = 30, prior to the approval of ARATAs). The 69 patients were divided into two groups according to patient factors, and these cohorts were further divided into two subgroups by usage of ARATAs. OS was compared between subgroups in each group. RESULTS: The predictors were age (<71.4 years), serum levels of C-reactive protein (≥0.16 ng/ml) and alkaline phosphatase (≥548 U/L), time to PSA progression after ADT (<8.9 months), the lowest PSA level (≥1 ng/ml) after ADT, and the rate of PSA decline 3 months after ADT (<0.987), whereas hemoglobin levels, PSA before ADT, Gleason scores, existence of visceral metastases, and BSI were not. CONCLUSIONS: The present study identified predictors for the effectiveness of ARATAs. The number of bone metastases (≒BSI), existence of visceral metastases, and Gleason scores, which were identified as high-risk factors in the LATITUDE study and disease volume in CHAARTED criteria, did not appear to be useful for predicting effectiveness from ARATAs.

Prognosis of patients with prostate cancer and bone metastasis from the Japanese Prostatic Cancer Registry of Standard Hormonal and Chemotherapy Using Bone Scan Index cohort study.

OBJECTIVE: To determine prognostic factors including the Bone Scan Index in prostate cancer patients receiving standard hormonal therapy and chemotherapy. METHODS: This multicenter Prostatic Cancer Registry of Standard Hormonal and Chemotherapy Using Bone Scan Index study involved 30 hospitals and enrolled 247 patients (age 71 ± 8 years) with metastatic hormone-sensitive prostate cancer (n = 148) under hormone therapy and metastatic castration-resistant prostate cancer (n = 99) under chemotherapy. The Bone Scan Index (%) was determined by whole-body bone scintigraphy using 99m Tc-methylenediphosphonate. Patients were classified into tertiles and binary groups, and predictors of all-cause death including Bone Scan Index, prostate-specific antigen, and bone metabolic markers were determined using survival and proportional hazard analyses. RESULTS: During a mean follow-up period of 716 ± 404 days, 81 (33%) of the patients died, and 3-year mortality rates were 20% and 52% in the metastatic hormone-sensitive prostate cancer and metastatic castration-resistant prostate cancer groups, respectively. Survival analysis showed that a Bone Scan Index >3.5% was a significant determinant of death in the metastatic hormone-sensitive prostate cancer group, whereas prostate-specific antigen >55 ng/mL before chemotherapy was a determinant of prognosis in the metastatic castration-resistant prostate cancer group. A Bone Scan Index >3.5% was also associated with a high incidence of prostate-specific antigen progression in the metastatic hormone-sensitive prostate cancer group. Patients with metastatic hormone-sensitive prostate cancer and a better Bone Scan Index response (>45%) to treatment had lower mortality rates than those without such response. CONCLUSION: The Bone Scan Index and hot spot number are significant determinants of 3-year mortality, and combining the Bone Scan Index with prostate-specific antigen should contribute to the management of prostate cancer patients with bone metastasis.

An exploratory retrospective multicenter study of prognostic factors in mCRPC patients undergoing enzalutamide treatment: Focus on early PSA decline and kinetics at time of progression.

BACKGROUND: Recent studies have shown that an early prostate-specific antigen (PSA) response to androgen receptor-targeting agents in metastatic castration-resistant prostate cancer (mCRPC) is associated with a better prognosis. We analyzed the early PSA response to enzalutamide (ENZ) by measuring the PSA doubling time (PSADT) and PSA velocity (PSAV) while monitoring oncologic outcomes and survival in Japanese patients. METHODS: We analyzed a total of 241 patients with mCRPC who were treated with ENZ. The patients' median age was 75 ± 7.9 years (range, 53-93 years). There were 171 (71%) predocetaxel cases, and 70 (29%) post docetaxel cases. PSA-progression-free survival (PFS) and overall survival (OS) were assessed according to Prostate Cancer Working Group 2 criteria. This study was approved by the Institutional Review Board of Gunma University Hospital (No. 1595). RESULTS: We observed 77 good response (GR; case in which PSA remained low after treatment) cases (31.9%), 125 acquired resistance (AR; decline in PSA after treatment followed by progression) cases (51.9%), and 39 primary resistance (PR; lack of decline in PSA) cases (16.2%). Predocetaxel, PSA-PFS, and OS were significantly higher compared with post docetaxel (PSA-PFS: 47.0 vs 13.4 weeks, P < .001; OS: not yet reached vs 80.7 weeks, P < .001). Multivariate analysis of prognostic factors, including PSA response at 4 weeks, was performed using Cox regression analysis. ECOG PS (0 vs 1-2), hemoglobin (Hb; ≥ 12.2 vs < 12.2 g/dL), time to CRPC ( ≥ 12 vs < 12 m), docetaxel treatment history (no vs yes), and a PSA reduction of 50% at 4 weeks were significant predictors of OS (all, P < .05). In cases of AR (n = 125), multivariate analysis showed that PSA kinetic factors, such as PSADT and PSAV (ng/mL/m), Hb, time to CRPC, PSADT ( ≥ 2 vs < 2 m), and PSAV ( < 20 vs ≥ 20 ng/mL/m), were all predictive of OS following PSA-progression (P < .05). CONCLUSIONS: Our study has demonstrated that PSA dynamics after ENZ administration may be a useful prognostic factor for mCRPC patients.

Role of bone scan index in the prognosis and effects of therapy on prostate cancer with bone metastasis: Study design and rationale for the multicenter Prostatic Cancer Registry of Standard Hormonal and Chemotherapy Using Bone Scan Index (PROSTAT-BSI) study.

OBJECTIVE: To present the study design and rationale of Prostatic Cancer Registry of Standard Hormonal and Chemotherapy Using Bone Scan Index, a prospective study aiming to determine the role of the bone scan index, the amount of bone metastasis, in the treatment and prognosis of prostate cancer patients. METHODS: A total of 237 patients were recruited at 30 hospitals in Japan. All had prostate cancer with bone metastasis and were scheduled to undergo either hormonal therapy (group H) or chemotherapy (group C). Bone scans were carried out with 99m Tc-methylenediphosphonate. Follow-up studies are planned to continue for 3 years, and changes in biochemical and tumor markers in response to hormonal therapy and chemotherapy will be recorded in addition to skeletal-related events, recurrence, disease progression and death. RESULTS: The basic characteristics of the patients (n = 200) at the time of registration during December 2016 were as follows: mean age 71 ± 8 years; median bone scan index calculated on-site 1.9% (range 0.02-13.3%); median number of hot spots 18 (range 1-128); median prostate-specific antigen 155 ng/mL (range 0.04-22 412 ng/mL); and the most frequent Gleason score 9 (47%). The prostate-specific antigen value was higher in group H than group C (288 vs 33 ng/mL, P < 0.0001), whereas bone scan indexes were comparable (1.7 vs 2.3%, not significant) between the two groups. Liver metastasis was more frequent in group C than group H (6.1% vs 0.8%, P = 0.035). CONCLUSIONS: The baseline characteristics of the Prostatic Cancer Registry of Standard Hormonal and Chemotherapy Using Bone Scan Index database have been established. This collaborative study can now proceed with clarifying the role of the bone scan index for patient management including treatment strategies and prognosis.

[SQUAMOUS CELL CARCINOMA WITH CLOACAL EXSTROPHY: A CASE REPORT].

A 41-year-old man with a history of cloacal exstrophy presented to a local clinic with abdominal pain and bowel sounds. He was noted to have pain at the site of scarring due to cloacal exstrophy and a laceration at its center, which was stained with feces. He was referred to our department because of an enterocutaneous fistula. Skin biopsy of the neoplastic lesion at this site led to a diagnosis of squamous cell carcinoma. Computed tomography showed tumor invasion of the ileum and right inguinal lymph node enlargement. We performed tumor resection, partial enterectomy, intestinal anastomosis, abdominal wall reconstruction with a left pedicled anterolateral thigh flap, split-thickness skin grafting, and right inguinal lymph node biopsy. Histopathological examination revealed cancer growth, invasion, and pearl formation in the lymph nodes, leading to a diagnosis of abdominal squamous cell carcinoma with metastasis to the inguinal lymph nodes. The skin graft took well, and the patient was discharged. He is scheduled for right inguinal lymph node dissection at a later date.

Efficacy of Androgen Receptor-targeted Drugs After Prostate Cancer Recurrence With Bone Metastases: PROSTAT-BSI Sub-analysis.

BACKGROUND/AIM: This study aimed to evaluate the therapeutic benefit of novel androgen receptor-targeted agents (ARTAs) in castration-resistant prostate cancer (CRPC) with bone metastases in Japan. PATIENTS AND METHODS: In followup to our prospective observational study (PROSTAT-BSI) from 2012 to 2018 on metastatic hormone-sensitive prostate cancer (mHSPC) and metastatic CRPC (mCRPC) before docetaxel initiation, we conducted this sub-analysis to investigate the benefit of ARTAs after clinical recurrence on overall survival (OS) in the real-world clinical setting in Japan. In this study, we compared patients who were treated with ARTA with those who received only vintage hormone therapy including docetaxel after clinical recurrence. RESULTS: In the mHSPC group, 69 patients became mCRPC and were treated with or without ARTAs. No significant difference was observed in prostate-specific antigen (PSA) progression-free survival between the ARTA (+) and ARTA (-) groups; however, OS after clinical recurrence was significantly better in the ARTA (+) group than in the ARTA (-) group (median OS 31.9 vs. 23.0 months; p<0.01). CONCLUSION: The ARTAs are beneficial even after mHSPC recurrence in Japanese patients in the real-world clinical setting. Since ARTAs are beneficial after clinical recurrence, it may be better to switch to ARTAs whenever necessary based on PSA response after combined androgen blockade therapy, considering the adverse effects and cost. This approach may be suitable to reduce overtreatment in Japanese patients with mHSPC.

YM155 Reverses Cabazitaxel Resistance in Castration-resistant Prostate Cancer by Reducing Survivin Expression.

BACKGROUND/AIM: The purpose of the present study was to clarify whether treatment with YM155, a novel small-molecule inhibitor of survivin, reversed cabazitaxel resistance in castration-resistant prostate cancer (CRPC). MATERIALS AND METHODS: Cabazitaxel resistance was induced in the castration-resistant prostate cancer cell line, 22Rv1-CR. In vitro and in vivo models were used to test the efficacy of YM155 and cabazitaxel. RESULTS: Survivin gene expression was significantly higher in 22Rv1-CR than its parent cells (22Rv1). In 22Rv1-CR cells, YM155 significantly reduced expression of the survivin gene in a concentration-dependent manner. YM155 alone was poorly effective; however, it significantly enhanced the anticancer effects of cabazitaxel on 22Rv1-CR in vitro and in vivo. CONCLUSION: Inhibition of survivin by YM155 overcomes cabazitaxel resistance in CRPC cells.

YM155 Reverses Statin Resistance in Renal Cancer by Reducing Expression of Survivin.

AIM: The purpose of the present study was to clarify whether treatment with YM155, a novel small-molecule inhibitor of survivin, reverses statin resistance in statin-resistant renal cell cancer (RCC). MATERIALS AND METHODS: We induced simvastatin resistance in a renal clear cell carcinoma cell line (Caki-1-staR). In vitro and in vivo models were used to test the efficacy of YM155 and simvastatin. RESULTS: Survivin gene expression was significantly stronger in Caki-1-staR cells than in its parent cells (Caki-1). In Caki-1-staR cells, YM155 significantly reduced expression of survivin gene and cell proliferation in a dose-dependent manner. Treatment with YM155 significantly reversed simvastatin resistance in Caki-1-staR cells. YM155 significantly inhibited the growth of Caki-1-staR tumors in a nude mouse tumor xenograft model. Furthermore, YM155 significantly enhanced the antitumor effects of simvastatin on Caki-1-staR tumors. CONCLUSION: Our results indicate that inhibition of survivin by YM155 overcomes statin resistance in RCC cells.

Consequences of an Early PSA Response to Enzalutamide Treatment for Japanese Patients with Metastatic Castration-resistant Prostate Cancer.

BACKGROUND/AIM: Recent studies have shown that an early prostate-specific antigen (PSA) response to androgen receptor (AR)-targeting agents in metastatic castration-resistant prostate cancer (mCRPC) is associated with a better prognosis. We analyzed early PSA response to enzalutamide and oncological outcomes to study their prognostic significance in the Japanese population. PATIENTS AND METHODS: Fifty-one patients with mCRPC (26 of pre-docetaxel and 25 of post-docetaxel status) were treated with enzalutamide. The PSA progression-free survival (PFS), radiographic PFS (rPFS) and overall survival (OS) were assessed. The association of rPFS and OS in patients with an early PSA response at 4 weeks after commencement of enzalutamide was studied. RESULTS: Early PSA responses were significantly associated with a longer rPFS (median of 47.9 vs. 20.1 weeks, p<0.001, in patients exhibiting a 50% PSA response; median of 40.9 vs. 20.1 weeks, p=0.016, in patients exhibiting a 30% PSA response). OS was also significantly associated with an early PSA response (p=0.002 for patients exhibiting a 50% PSA response, p=0.003 for patients exhibiting a 30% PSA response). Multivariate analysis showed that the predictors of a 50% PSA response were an interval to mCRPC and a docetaxel treatment history, while the predictor of a 30% PSA response was a docetaxel treatment history. Furthermore, a 50% PSA response was independently prognostic of rPFS. CONCLUSION: An early PSA response to enzalutamide was significantly associated with a longer rPFS and OS. This information will aid in the management of patients treated with enzalutamide.