Novel image-guided marker aimed at organ-preserving therapies for prostate cancer

OBJECTIVE

We developed fiducial imaging-guidance markers for the prostate with less imaging artifacts than currently commercially available markers. The aim of this study was to evaluate the imaging artifacts and potential usefulness and safety of these novel fiducial imaging markers in preclinical experiments.

METHODS

We selected specific metal materials and a shape that can minimize artifacts in line with a license we obtained for a metal with a gold-platinum (Au-Pt) alloy composition that maximized artifact-free MRI images. Both phantom and canine prostate tests were conducted in order to evaluate the imaging artifacts for three imaging modalities, MRI, CT and ultrasound, and the risk of migration of the markers from the site of insertion to elsewhere, as well as crushing.

RESULTS

The newly developed Au-Pt material had less imaging artifacts in the MRI, CT and ultrasound imaging modalities in comparison with current commercially available fiducial markers made from gold materials only. The Au-Pt markers had sufficient strength and durability and were considered to be potentially clinically useful and safe markers.

CONCLUSION

The developed Au-Pt markers could be potential tools for accurate lesion-targeted, organ-preserving therapies such as lesion-targeted focal therapy and active surveillance in addition to conventional radiation therapies.

The influence of Gleason score ≤ 6 histology on the outcome of high-risk localized prostate cancer after modern radiotherapy

We aimed to retrospectively review outcomes in patients with high-risk prostate cancer and a Gleason score ≤ 6 following modern radiotherapy. We analyzed the outcomes of 1374 patients who had undergone modern radiotherapy, comprising a high-risk low grade [HRLG] group (Gleason score ≤ 6; n = 94) and a high-risk high grade [HRHG] group (Gleason score ≥ 7, n = 1125). We included 955 patients who received brachytherapy with or without external beam radio-therapy (EBRT) and 264 who received modern EBRT (intensity-modulated radiotherapy [IMRT] or stereotactic body radiotherapy [SBRT]). At a median follow-up of 60 (2-177) months, actuarial 5-year biochemical failure-free survival rates were 97.8 and 91.8% (p = 0.017), respectively. The frequency of clinical failure in the HRLG group was less than that in the HRHG group (0% vs 5.4%, p = 0.012). The HRLG group had a better 5-year distant metastasis-free survival than the HRHG group (100% vs 96.0%, p = 0.035). As the HRLG group exhibited no clinical failure and better outcomes than the HRHG group, the HRLG group might potentially be classified as a lower-risk group.

Apalutamide versus bicalutamide in combination with androgen deprivation therapy for metastatic hormone sensitive prostate cancer

The objective of this study is to compare the efficacy of apalutamide and bicalutamide in combination with androgen deprivation therapy in patients with metastatic hormone-sensitive prostate cancer (mHSPC). We retrospectively collected the data of about 330 patients with metastatic hormone-sensitive prostate cancer at our hospital and affiliated hospitals between December 2013 and August 2023. Sixty-one patients were administered apalutamide (240 mg/day) with androgen deprivation therapy (group A), and 269 patients were administered bicalutamide (80 mg/day) with androgen deprivation therapy (group B). Propensity score matching was used to adjust for clinical background factors between the two groups. PSA progression-free survival and overall survival were significantly longer in group A than in group B among the matched patients. Apalutamide therapy was a significant independent factor for OS in matched patients. The second progression-free survival of group A was significantly longer than that of group B in matched patients. Patients treated with apalutamide achieved ≥ 90% PSA decline from baseline faster and in larger numbers than those with bicalutamide. Apalutamide combined with ADT may be superior to bicalutamide alone in terms of OS and PSA-PFS in patients with mHSPC.

A big data-based prediction model for prostate cancer incidence in Japanese men

To define a normal range for PSA values (ng/mL) by age and create a prediction model for prostate cancer incidence. We conducted a retrospective analysis using 263,073 observations of PSA values in Japanese men aged 18-98 years (2007-2017), including healthy men and those diagnosed with prostate cancer. Percentiles for 262,639 PSA observations in healthy men aged 18-70 years were calculated and plotted to elucidate the normal fluctuation range for PSA values by age. Univariable and multivariable logistic regression analyses were performed to develop a predictive model for prostate cancer incidence. PSA levels and PSA velocity increased with age in healthy men. However, there was no difference in PSA velocity with age in men diagnosed with prostate cancer. Logistic regression analysis showed an increased risk of prostate cancer for PSA slopes ranging from 0.5 to 3.5 ng/mL/year. This study provides age-specific normal fluctuation ranges for PSA levels in men aged 18-75 years and presents a novel and personalized prediction model for prostate cancer incidence. We found that PSA slope values of > 3.5 ng/mL/year may indicate a rapid increase in PSA levels caused by pathological condition such as inflammation but are unlikely to indicate cancer risk.

Predictive factors for the efficacy of abiraterone acetate therapy in high-risk metastatic hormone-sensitive prostate cancer patients

PURPOSE

There is a discrepancy in the efficacy of abiraterone acetate for overall survival (OS) in patients with high-risk metastatic hormone-sensitive prostate cancer (mHSPC). This study aimed to identify predictive factors for the efficacy of abiraterone acetate for OS in high-risk mHSPC patients by analyzing them over a longer observation period.

METHODS

Five hundred high-risk mHSPC patients were retrospectively identified at our hospital and affiliated hospitals in the Kindai Oncology Study Group and Kyoto Prefectural University of Medicine Oncology Study Group between December 2013 and March 2022. Two hundred patients were treated with abiraterone acetate (1000 mg/day) plus prednisolone (5 mg/day) combined with androgen deprivation therapy (ADT). A total of 300 patients were treated with bicalutamide (80 mg/day) in combination with ADT.

RESULTS

OS was not significantly different between the two treatments in the overall cohort (p = 0.1643). In the subgroup without Gleason pattern 5 at the primary lesion, OS was significantly better in patients treated with abiraterone acetate than in those treated with bicalutamide (p = 0.0192). In the subgroup with Gleason pattern 5 at the primary lesion, no significant difference was found between the two treatments (p = 0.1799). Univariate and multivariate analyses in the subgroup without Gleason pattern 5 at the primary lesion suggested that abiraterone therapy may be an important and independent predictor of OS in high-risk mHSPC patients.

CONCLUSION

The presence of Gleason pattern 5 at the primary lesion may be a predictor for high-risk mHSPC patients who could benefit from abiraterone acetate treatment.

Role of Brachytherapy Boost in Clinically Localized Intermediate and High-Risk Prostate Cancer: Lack of Benefit in Patients with Very High-Risk Factors T3b-4 and/or Gleason 9-10

Simple Summary

In general, brachytherapy (BT) improves biochemical control in intermediate-to high-risk prostate cancer. We previously reported that importance of very high-risk factors (VHR: T3b–4 or Gleason score 9–10) and patients with double VHR (VHR-2) showed the worst prognosis among high-risk groups. We explored the role of BT-boost in patients with VHR and compared it to intermediate- and other high-risk groups. We confirmed that BT-boost improved prostate-specific antigen (PSA) control but resulted in equivalent overall survival rates for the intermediate- and high-risk groups, except for the patients with VHR. In the VHR-1 group (single VHR), BT-boost showed superior PSA control to conventional-dose RT (EQD2 ≤ 72 Gy) but not to the dose-escalated radiotherapy group (EQD2 ≥ 74 Gy). In the VHR-2 group, BT-boost did not improve the biochemical control rate of either Conv RT or DeRT. BT-boost showed no benefit over modern DeRT in the patients with VHR.

Abstract

This study examined the role of brachytherapy boost (BT-boost) and external beam radiotherapy (EBRT) in intermediate- to high-risk prostate cancer, especially in patients with very high-risk factors (VHR: T3b–4 or Gleason score 9–10) as patients with double very high-risk factors (VHR-2: T3b–4 and Gleason score 9–10) previously showed worst prognosis in localized prostate cancer. We retrospectively reviewed multi-institutional data of 1961 patients that were administered radiotherapy (1091 BT-boost and 872 EBRT: 593 conventional-dose RT (Conv RT: equivalent to doses of 2 Gy per fraction = EQD2 ≤ 72 Gy) and 216 dose-escalating RT (DeRT = EQD2 ≥ 74 Gy). We found that BT-boost improved PSA control and provided an equivalent overall survival rate in the intermediate- and high-risk groups, except for patients within the VHR factor group. In the VHR-1 group (single VHR), BT-boost showed a superior biochemical control rate to the Conv RT group but not to the DeRT group. In the VHR-2 group, BT-boost did not improve outcomes of either Conv RT or DeRT groups. In conclusion, BT-boost showed no benefit to modern DeRT in the patients with VHR; therefore, they are not good candidates for BT-boost to improve outcome and may be amenable to clinical trials using multimodal intensified systemic treatments.

Impact of prostate-specific antigen screening on tumor size in patients with prostate cancer in a super-aging district in Kyoto, Japan

BACKGROUND

Population-based prostate-specific antigen (PSA) screening is effective for reducing prostate cancer (PCa)-related mortality rates. In this study, we assessed biopsy-proven maximum cancer core length (MCCL) and maximum cancer diameter on magnetic resonance imaging (MRI; MCDM) in prostate biopsy and multiparametric MRI (mp-MRI) by PCa detection.

METHODS

We retrospectively assessed 214 male PCa patients and 187 PCa patients with Prostate Imaging Reporting and Data System version 2 (PI-RADS) category 3-5 lesions in pre-biopsy mp-MRI and targeted biopsy characteristics. The mean biopsy-proven MCCL and MCDM were compared among three PSA screening groups, namely the population-based PSA screening (PBS), opportunistic PSA screening (OPS), and symptomatic outpatient PSA examination (SOP) groups.

RESULTS

The median age and PSA value of the 214 participants were 75 years and 7.9 ng/mL, respectively. In the PBS, OPS, and SOP groups, the median ages were 73, 76, and 76 years, respectively (p = 0.046); PSA values were 7.2, 9.5, and 11.5 ng/mL, respectively (p < 0.001); and biopsy-proven MCCL and MCDM were significantly increased to 7, 10, and 14 mm (p < 0.001) and to 11, 15, and 17 mm (p < 0.001), respectively. In the 187 PCa patients with PI-RADS category 3-5 lesions on mp-MRI, MCDM were 11, 14, and 17 mm (p < 0.001), respectively.

CONCLUSIONS

The biopsy-proven MCCL and MCDM were significantly smaller in the PBS and OPS groups than in the SOP group, which suggests that PSA screening detected PCa earlier than in symptomatic patients. PSA screening with MRI could objectively lead to earlier diagnosis based on tumor size.

Novel Prognostic Index of High-Risk Prostate Cancer Using Simple Summation of Very High-Risk Factors

This study aimed to examine the role of very high-risk (VHR) factors (T3b-4 and Gleason score 9-10) for prognosis of clinically localized high-risk prostate cancer. We reviewed multi-institutional retrospective data of 1413 patients treated with radiotherapy (558 patients treated with external beam radiotherapy (EBRT) and 855 patients treated with brachytherapy (BT) ± EBRT. We introduced an index by simple summation of the number of VHR factors-VHR-0, VHR-1, and VHR-2. With median follow-up of 69.6 months, the 5-year biochemical disease free survival rate (bDFS), prostate cancer-specific mortality (PCSM), and distant metastasis-free survival (DMSF) rates were 59.4%, 7.65%, and 83.2% for the VHR-2 group, respectively; 86.7%, 1.50%, and 95.4% for the VHR-1 group, respectively; and 93.1%, 0.12%, and 98.2% for the VHR-0 group, respectively. The VHR-2 group had significantly worse bDFS, PCSM, and DMSF than the VHR-0 (hazard ratios: 4.55, 9.607, and 7.904, respectively) and VHR-1 (hazard ratios: 1.723, 2.391, and 1.491, respectively) groups. The VHR-2 group could be identified as a super high-risk group compared with other groups, and could be a good candidate for clinical trials using multimodal intensified treatments. Simple summation of the number of VHR factors is an easy and useful predictive index for bDFS, PCSM, and DMSF.

Challenge and Outcome for the Prostate Squamous Cell Carcinoma Which Developed 8 Years after Low-Dose-Rate Brachytherapy Approached by a Combined Multimodal Treatment with High-Dose-Rate Interstitial Brachytherapy, External Beam Radiation Therapy, and Chemotherapy

Prostate squamous cell carcinoma (pSCC) rarely develops as a secondary cancer after treatment with low-dose-rate brachytherapy (LDR-BT). There is no established effective treatment for the disease condition. Herein, we present a 78-year-old man who developed pSCC 8 years after LDR-BT. He was subsequently selected to receive a combined multimodal treatment with high-dose-rate interstitial brachytherapy (HDR-ISBT), external beam radiation therapy, and chemotherapy for his pSCC. Eleven months later, he displayed no biochemical failure nor clinical radiographic recurrence. However, MRI detected a newly developed prostatic-rectal fistula (grade 4), and a colostomy was performed to relieve pain and inflammation. To our knowledge, this is the first report to perform a combined multimodal treatment with HDR-ISBT for pSCC suspected as a secondary cancer due to LDR-BT.

Abiraterone acetate versus bicalutamide in combination with gonadotropin releasing hormone antagonist therapy for high risk metastatic hormone sensitive prostate cancer

The objective of this study was to compare the efficacy of abiraterone acetate with that of bicalutamide in combination with gonadotropin-releasing hormone (GnRH) antagonist treatment for patients with high-risk metastatic hormone-sensitive prostate cancer (mHSPC). A total of 149 patients with mHSPC who underwent treatment at our hospital and affiliated hospitals between December 2013 and July 2020 were retrospectively identified. Fifty patients were administered abiraterone acetate (1000 mg/day) plus prednisolone (5 mg/day) with a GnRH antagonist (degarelix) (group A), and 99 patients were administered bicalutamide (80 mg/day) with a GnRH antagonist (group B). The prostate-specific antigen (PSA) progression-free survival (PSA-PFS) was significantly longer in group A than in group B. Abiraterone acetate therapy and Gleason score were significant independent factors of PSA-PFS. Using propensity score matching, 56 matched patients were obtained. The PSA-PFS (p < 0.001) and overall survival (OS) (p = 0.0071) of patients with high-risk mHSPC were significantly longer in group A of matched patients. Abiraterone acetate therapy and Gleason score were significant independent factors for PSA-PFS in matched patients. The PSA-PFS and OS of patients treated with abiraterone acetate in combination with a GnRH antagonist were significantly better than those treated with bicalutamide.

High-dose-rate brachytherapy with external beam radiotherapy versus low-dose-rate brachytherapy with or without external beam radiotherapy for clinically localized prostate cancer

To compare the outcomes of localized prostate cancer treatment with high-dose-rate brachytherapy (HDR-BT) and low-dose-rate brachytherapy (LDR-BT), we examined 924 patients treated with HDR-BT + external beam radiotherapy (EBRT) and 500 patients treated with LDR-BT ± EBRT using multi-institutional retrospective data. The HDR-BT treated advanced disease with more hormonal therapy than LDR-BT. To reduce background selection bias, we performed inverse probability of treatment weighting (IPTW) analysis using propensity scores and excluded patients with T3b-4 disease/ initial prostate-specific antigen (PSA) levels > 50 ng/ml. The actuarial 5-year biochemical control rates (5y-bNED) were 96.3% and 95.7% in the HDR-BT and LDR-BT groups, respectively. The corresponding values were 100% and 96.5% in the low-risk group; 97.4% and 97.1% in the intermediate-risk group (97.2% and 97% in the higher titer group and 97.5% and 94.6% in the lower titer group, respectively); and 95.7% and 94.9% in the selected high-risk group, respectively. IPTW correction indicated no significant difference among the groups. The 5y-bNED in the HDR-BT + EBRT, LDR-BT + EBRT, and LDR-BT alone groups were 96.3%, 95.5%, and 97%, respectively (P = 0.3011). The corresponding values were 97.4%, 94.7%, and 96.6% (P = 0.1004) in the intermediate-risk group (97.5%, 100%, and 94.5% in the lower titer group [P = 0.122] and 97.2%, 96.2%, and 100% [P = 0.664] in the higher titer group, respectively) and 95.7%, 95.5%, and 100% (P = 0.859) in the high-risk group, respectively. The HDR-BT group showed a lower incidence of acute grade ≥ 2 genitourinary toxicities; the incidence of other early and late grade ≥ 2 toxicities were similar between the HDR-BT and LDR-BT groups. Acute genitourinary toxicity predicted the occurrence of late genitourinary toxicity. EBRT increased the risk of grade ≥ 2 gastrointestinal toxicity. HDR-BT + EBRT is a good alternative to LDR-BT ± EBRT for low-, intermediate-, and selected high-risk patients.

Intratumoral and s.c. injection of inactivated hemagglutinating virus of Japan envelope (GEN0101) in metastatic castration-resistant prostate cancer

Inactivated hemagglutinating virus of Japan envelope (HVJ‐E) has an antitumor effect and tumor immunity. We undertook an open‐label, phase I, dose‐escalation study in patients with castration‐resistant prostate cancer (CRPC) to determine the safety and efficacy of intratumoral and s.c. injection of HVJ‐E (GEN0101). Patients with CRPC, who were resistant to or unable to receive standard of care, were included. GEN0101 was injected directly into the prostate and s.c. in two 28‐day treatment cycles. The primary end‐points were to evaluate the safety and tolerability of GEN0101 and determine its recommended dose. The secondary end‐points were to analyze the antitumor effect and tumor immunity. Three patients received 30 000 mNAU GEN0101 and 6 received 60 000 mNAU. There was no dose‐limiting toxicity, and the recommended dose of GEN0101 was defined as 60 000 mNAU. Radiographically, 1 patient had stable disease and 2 had progressive disease in the low‐dose group, whereas 5 patients had stable disease and 1 had progressive disease in the high‐dose group. Three patients in the high‐dose group showed reduction in lymph node metastasis. Prostate‐specific antigen increase rates in the high‐dose group were suppressed more than those in the low‐dose group. Natural killer cell activity was enhanced in 2 patients of the low‐dose group and in 5 patients in the high‐dose group. In conclusion, intratumoral and s.c. injections of GEN0101 were well‐tolerated and feasible to use. The study is registered with the UMIN Clinical Trials Registry (no. UMIN000017092).

Focal salvage low-dose-rate brachytherapy for recurrent prostate cancer based on magnetic resonance imaging/transrectal ultrasound fusion biopsy technique

OBJECTIVE

To examine the effect of permanent salvage brachytherapy in prostate cancer patients suffering recurrence after three-dimensional conformal external beam radiotherapy.

METHODS

The ultra-focal (target lesion alone), hemi-lobe (within a hemi-lobe) or focused whole-gland (focusing on the lesion, but extending into the whole gland) pattern was selected based on the Gleason score for the targeted biopsy, the numbers of positive cores in the targeted and systematic biopsies, and the locations of the positive cores. Novel dosimetry criteria derived from three-dimensional cancer mapping, which was based on targeted magnetic resonance imaging/transrectal ultrasound fusion biopsies, were used in these cases.

RESULTS

Permanent salvage brachytherapy was carried out in 13 patients who suffered prostate-specific antigen failure (prostate-specific antigen 2.1-6.8 ng/mL; age range 57-75 years; Gleason score ≤7 [n = 10], Gleason score ≥8 [n = 2] and Gleason score not available [n = 1]) since 2012. The targeted biopsy showed a single focus in three patients. The ultra-focal, hemi-lobe and focused whole-gland patterns were chosen in three, five and five patients, respectively. During the follow-up period (median duration 48 months), prostate-specific antigen failure occurred in zero of three, one of five and three of five of the patients treated with the ultra-focal, hemi-lobe and focused whole-gland patterns, respectively. The 4-year biochemical recurrence-free survival rate was 74%. No grade 3-4 adverse intestinal or urological events occurred.

CONCLUSIONS

Targeted fusion biopsy-based three-dimensional cancer mapping should be used for permanent salvage brachytherapy treatment planning to reduce the incidence of treatment-related adverse events while maintaining good oncological outcomes.

Less nephrotoxicity of paclitaxel and ifosfamide plus nedaplatin for refractory or relapsed germ cell tumors in patients with impaired renal function

OBJECTIVES

To determine the safety and efficacy of the combined regimen of paclitaxel and ifosfamide plus nedaplatin for patients with refractory or relapsed germ cell tumors and impaired renal function.

METHODS

Of a total of 68 patients who received paclitaxel, ifosfamide and nedaplatin chemotherapy for germ cell tumors, those with an estimated glomerular filtration rate <60 mL/min/1.73 m² before paclitaxel, ifosfamide and nedaplatin treatment were defined as having renal dysfunction. The combination chemotherapy regimen included paclitaxel (210 mg/m² on day 1) and ifosfamide (1.2 g/m² on days 2-6) with nedaplatin (100 mg/m² on day 2) on a 3-week cycle.

RESULTS

A total of 10 patients had renal dysfunction with a median estimated glomerular filtration rate of 49.97 mg/mL/1.73 m² (range 31.7-57.5 mg/mL/1.73 m² ). Paclitaxel, ifosfamide and nedaplatin chemotherapy was given as second-line therapy in four patients, third-line in four and fourth-line or later in two. Patients with impaired renal function received pretreatment of a median of 5.5 cycles of platinum-based chemotherapy (range 3-11 cycles) with a median cisplatin dose of 550 mg/m² . The patients were given two to six cycles of paclitaxel, ifosfamide and nedaplatin chemotherapy with no dose reduction, with an overall response rate of 60%. Chemotherapy-induced kidney dysfunction was not observed in any patient with decreased renal function. Furthermore, there was no difference in the frequency of adverse events between patients with renal dysfunction (estimated glomerular filtration rate <60 mL/min/1.73 m² ) and those with normal renal function (estimated glomerular filtration rate ≥60 mL/min/1.73 m² ).

CONCLUSIONS

Paclitaxel, ifosfamide and nedaplatin chemotherapy can be considered a safe and effective regimen that results in less nephrotoxicity in germ cell tumor patients with renal dysfunction.

Prostate cancer meeting the Japanese active surveillance criteria and diagnosed by community-based prostate-specific antigen screening: A 21-year follow-up study

OBJECTIVES

To evaluate the oncological outcomes of Japanese patients with prostate cancer diagnosed by community-based prostate-specific antigen screening during a 21-year period who satisfied the criteria for active surveillance.

METHODS

Active surveillance candidates were extracted from the community-based screening registry of Otokuni district in Kyoto prefecture. The frequency of active surveillance candidates before and after publication of the active surveillance criteria in Japan was analyzed. In addition, we examined the frequency of switching to curative intervention and treatment failure among active surveillance candidates, including the patients who selected active surveillance.

RESULTS

During the study period, 868 patients were diagnosed with prostate cancer and 780 of these patients were analyzed. Among them, 190 patients (24%) satisfied our active surveillance criteria (21 and 169 in the pre-active surveillance era and active surveillance era, respectively). Of the 169 patients in the active surveillance era, 74 initially selected active surveillance. The number of active surveillance candidates increased with increasing age, and the proportion of active surveillance candidates among prostate cancer patients also increased significantly each year (P < 0.001). In the active surveillance group, the median follow-up period was 4 years and 35% switched to curative intervention. Among the 190 active surveillance candidates, seven died of other causes, but there were no deaths from prostate cancer.

CONCLUSIONS

Changes of active surveillance candidates in one district of Japan were successfully analyzed by using consistent active surveillance selection criteria and data obtained by a single pathologist. Oncological outcomes were good among active surveillance candidates in the low-risk group.

Intratumoral and subcutaneous injection of HVJ-E (GEN0101) for metastatic castration-resistant prostate cancer: Open-label, phase I, dose escalation study

e16511

Background: Inactivated Sendai virus particles (hemagglutinating virus of Japan envelope (HVJ-E)) have a novel antitumor effect: HVJ-E fused to prostate cancer cells via cell surface receptor causes apoptosis of prostate cancer cells in vitro and in vivo. HVJ-E also induces antitumor immunity by activating natural killer (NK) cells and cytotoxic T cells and suppressing regulatory T cells in vivo. We conducted an open-label, phase I, dose-escalation study in patients with castration-resistant prostate cancer (CRPC) to determine the safety and efficacy of intratumoral and subcutaneous injection of HVJ-E (GEN0101). Methods: Patients with CRPC who were resistant to standard of care or could not receive standard of care were eligible. GEN0101 was injected directly into the prostate on day 1 and subcutaneously on days 5, 8 and 12 in two 28-day treatment cycles using a modified 3+3 dose-escalation design to determine the recommended dose of GEN0101. The primary end points were to evaluate safety and tolerability of GEN0101 and determine the recommended dose. The secondary end points were to analyze antitumor effect and tumor immunity. The study is registered at UMIN Clinical Trials Registry, number UMIN000017092. Results: Of the 9 patients treated, 3 received 30,000mNAU of GEN0101 and 6 received 60,000mNAU. There were no dose-limiting toxicities, and the recommended dose of GEN0101 was defined as 60,000mNAU. Radiographically, one patient had stable disease and 2 had progressive disease in the low-dose group, and 5 patients had stable disease and one had progressive disease in the high-dose group. Four patients in high dose group had reductions in lymph node metastasis after 2 treatment cycles. Final PSA increase rates in high-dose group were more suppressed than those in low-dose group. NK cell activity was enhanced in 2 patients (66%) in low-dose group and 5 patients (83%) in high-dose group, Serum interleukin-6, and IFN-γ levels were not affected by GEN0101 treatment. Conclusions: Intratumoral and subcutaneous injections of GEN0101 were well tolerated and feasible. Antitumor effect in lymph node metastasis were observed in CRPC patients. It is necessary to test whether the treatment with GEN0101 improves the survival of CRPC patients. Clinical trial information: UMIN000017092.

Magnetic resonance imaging/transrectal ultrasound fusion-targeted prostate biopsy using three-dimensional ultrasound-based organ-tracking technology: Initial experience in Japan

OBJECTIVE

To evaluate the impact of magnetic resonance imaging/transrectal ultrasound fusion-targeted prostate biopsy on the diagnosis of clinically significant prostate cancer using real-time three-dimensional ultrasound-based organ-tracking technology.

METHODS

The present study was a retrospective review of 262 consecutive patients with prostate-specific antigen of 7.1 ng/mL (interquartile range 4.0-19.8). All patients received pre-biopsy magnetic resonance imaging and had a suspicious lesion for clinically significant prostate cancer. All patients underwent a combination of systematic biopsy (6 cores) and three-dimensional ultrasound-based magnetic resonance imaging/transrectal ultrasound fusion-targeted biopsy (2 cores). The positive rate of any cancer, positive rate of clinically significant prostate cancer, Gleason score and maximum cancer core length were compared between systematic biopsy versus magnetic resonance imaging/transrectal ultrasound fusion-targeted prostate biopsy.

RESULTS

Overall, the positive rate of any cancer per patient was 61% (160/262) in systematic biopsy versus 79% (207/262) in magnetic resonance imaging/transrectal ultrasound fusion-targeted biopsy (P < 0.0001); and that of clinically significant prostate cancer per patient was 46% (120/262) in systematic biopsy versus 70% (181/262) in magnetic resonance imaging/transrectal ultrasound fusion-targeted biopsy (P < 0.0001). The positive rate of any cancer per core was 21.7% (330/1523) in systematic biopsy versus 68.6% (406/592) in magnetic resonance imaging/transrectal ultrasound fusion-targeted biopsy (P < 0.0001), and that of clinically significant prostate cancer per core was 12.7% (193/1423) in systematic biopsy versus 60.3% (357/592) in magnetic resonance imaging/transrectal ultrasound fusion-targeted biopsy (P < 0.0001). Adding systematic biopsy leads to 13 more cancer cases (5%). The distribution of Gleason score (6/7/8/9/10) was 59/71/23/6/1 in systematic biopsy versus 48/105/36/15/2 in magnetic resonance imaging/transrectal ultrasound fusion-targeted biopsy (P = 0.005). The maximum cancer core length was 5 mm (0.5-16) in systematic biopsy versus 8 mm (1-19 mm) in magnetic resonance imaging/transrectal ultrasound fusion-targeted biopsy (P < 0.0001).

CONCLUSIONS

Three-dimensional ultrasound-based magnetic resonance imaging/transrectal ultrasound fusion-targeted biopsy seems to be associated with a higher detection rate of clinically significant prostate cancer, with fewer cores than systematic random biopsy. However, significant cancer can still be detected by the systematic technique only. A combination of systematic biopsy with the targeted biopsy technique would avoid the underdiagnosis of clinically significant prostate cancer.

High-dose-rate brachytherapy monotherapy versus low-dose-rate brachytherapy with or without external beam radiotherapy for clinically localized prostate cancer

BACKGROUND

To compare the outcome of high-dose-rate interstitial brachytherapy (HDR-BT) monotherapy and low-dose-rate brachytherapy (LDR-BT) with or without external beam radiotherapy (EBRT) for localized prostate cancer.

METHODS AND MATERIALS

We compared 352 patients treated with HDR-BT as monotherapy (median follow-up time 84 months, NCCN risk classification; low: intermediate: high = 28:145:179) and 486 patients with LDR-BT with or without EBRT (90 months, 194:254:38). HDR-BT treated advanced disease with more hormonal therapy than LDR-BT. LDR-BT excluded patients with T3b-T4 tumor and initial PSA >50 ng/ml. Inverse probability of treatment weighting (IPTW) involving propensity scores was used to reduce background selection bias.

RESULTS

The actuarial 5-year biochemical failure-free survival rates (bNED) were 92.9% and 95.6% (p = 0.25) in the HDR-BT and LDR-BT groups, respectively, and it was 100% and 97.3% (p = 0.99) in the low-risk, 95.6% and 94.3% (p = 0.19) in the intermediate, 89.6% and 94.9% (p = 0.26) in the high-risk groups, and 93.1% and 94.9% (p = 0.98) in selected high-risk group excluding T3b-4 and initial PSA ≥50. IPTW correction also indicated no difference in bNED between LDR-BT and HDR-BT groups. LDR-BT showed a higher incidence of genitourinary (GU) toxicity grade ≥2 than that of HDR-BT in the acute phase and grade 1 toxicity in late phase. Acute GU toxicity grade ≥1 predicted late GU toxicity grade ≥2. External beam radiotherapy plus LDR-BT elevated GI toxicity than LDR-BT only group. Accumulated incidence of late grade ≥2 GU and GU toxicity was equivalent between HDR-BT and LDR-BT. No grade 4 or 5 toxicities were detected in either modality.

CONCLUSION

HDR-BT monotherapy showed an equivalent outcome to that of LDR-BT with or without EBRT for low-, intermediate- and selected high-risk patients. LDR-BT showed equivalent incidence of grade ≥2 late GI and GU toxicities and higher grade ≥2 acute GU toxicity as that of HDR-BT as a monotherapy.

Therapy-related acute myeloid leukemia and myelodysplastic syndrome among refractory germ cell tumor patients

OBJECTIVES

To analyze cases of therapy-related acute myeloid leukemia and myelodysplastic syndrome diagnosed after chemotherapy for refractory testicular and extragonadal germ cell tumor in our experience.

METHODS

A total of 171 consecutive patients who were diagnosed and treated as refractory germ cell tumor and had records of detailed chemotherapy doses between April 1998 and December 2015 were retrospectively reviewed.

RESULTS

Four testicular tumor patients (4/171, 2.3%) developed therapy-related acute myeloid leukemia and myelodysplastic syndrome. Three of them were affected after complete remission of the primary testicular tumor. A median time interval from a start of chemotherapy to a secondary tumor development was 6.8 years (range 3.7-11.5 years). The median total dose of etoposide, ifosfamide, cisplatin and nedaplatin were 3640 mg/m² (range 2906-4000 mg/m² ), 42.7 g (range 19.5-54.0 g), 1100 mg/m² (range 600-1500 mg/m² ) and 500 mg/m² (range 300-1600 mg/m² ), respectively. Etoposide had the only significant relationship between a cumulative dose and leukemogenesis in univariate analysis (P < 0.05). One patient had complete remission, but the other three patients died.

CONCLUSIONS

The present findings show that refractory germ cell tumor patients have an increased risk of therapy-related acute myeloid leukemia and myelodysplastic syndrome. A cumulative dose of etoposide is a significant risk of leukemogenesis. As therapy-related acute myeloid leukemia and myelodysplastic syndrome has a poor prognosis, close follow up is required for refractory germ cell tumor patients.

CNPY2 inhibits MYLIP-mediated AR protein degradation in prostate cancer cells

The androgen receptor (AR) is a ligand-dependent transcription factor that promotes prostate cancer (PC) cell growth through control of target gene expression. This report suggests that Canopy FGF signaling regulator 2 (CNPY2) controls AR protein levels in PC cells. We found that AR was ubiquitinated by an E3 ubiquitin ligase, myosin regulatory light chain interacting protein (MYLIP) and then degraded through the ubiquitin-proteasome pathway. CNPY2 decreased the ubiquitination activity of MYLIP by inhibition of interaction between MYLIP and UBE2D1, an E2 ubiquitin ligase. CNPY2 up-regulated gene expression of AR target genes such as KLK3 gene which encodes the prostate specific antigen (PSA) and promoted cell growth of PC cells. The cell growth inhibition by CNPY2 knockdown was rescued by AR overexpression. Furthermore, positive correlation of expression levels between CNPY2 and AR/AR target genes was observed in tissue samples from human prostate cancer patients. Together, these results suggested that CNPY2 promoted cell growth of PC cells by inhibition of AR protein degradation through MYLIP-mediated AR ubiquitination.

Androgen suppresses testicular cancer cell growth in vitro and in vivo

Silencing of androgen receptor (AR)-meditated androgen signaling is thought to be associated with the development of testicular germ cell tumors (TGCTs). However, the role of the androgen/AR signal in TGCT development has not been investigated. In this study, we show that the androgen/AR signal suppressed the cell growth of seminomas (SEs), a type of TGCT, in vitro and in vivo. Growth of SE cells was suppressed by DHT treatment and reduction of androgen levels by surgical castration promoted cancer cell growth in an in vivo xenograft model. Tryptophan hydroxylase 1 (TPH1), the rate limit enzyme in serotonin synthesis, was one of the genes which expression was reduced in DHT-treated SE cells. TPH1 was highly expressed in SE cancer tissues compared with adjacent normal tissues. Activation of androgen/AR signaling in SE cells reduced the expression of TPH1 in SE cells, followed by the reduction of serotonin secretion in cell culture supernatant. These results suggested that silencing of androgen/AR signaling may cause initiation and progression of SE through increase in TPH1 gene expression level.

Randomized study of intravesical chemotherapy using pirarubicin in patients with non-muscle-invasive bladder cancer in Japan: Comparing one immediate postoperative intravesical chemotherapy with short-term adjuvant intravesical chemotherapy after TURBT: Subanalysis in patients with intermediate risk

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Background: The objective is to evaluate the efficacy defining of 2-year tumor recurrence free rate of intravesical chemotherapy using pirarubicin (THP) for patients with intermediate risk. Methods: Between October 2010 and January 2015, 206 patients were enrolled in this study and finally 113 were randomized to one immediate postoperative intravesical instillation of THP 30mg (Group A), or additional intravesical instillation of THP 30mg weekly for 8 weeks after single postoperative instillation (Group B). The recurrent risk was stratified using EAU guidelines on non-muscle-invasive urothelial carcinoma of the bladder, the 2009 update. Of 113, 100 with intermediate risk were analyzed in this study. The patients were examined by cystoscopy and urine cytology every 3 months after trans urethral resection to determine bladder tumor recurrence. The primary endpoint was 2 year-recurrence-free survival rates. A statistical analysis was performed by SAS (SAS Institute Inc., Cary, USA). Results: The 2-year recurrence free survival rates were 66.2% in Group A and 86.1% in Group B, respectively (log rank test, p = 0.0043). In patients with recurrence score between 5 and 9, the 2-year recurrence free survival was 92.3% in Group B and 22.2% in Group A (log rank test, p = 0.0013). Cox regression analysis revealed that only additional instillation of THP was significant independent factor for recurrence free rate in patients with intermediate risk. There was no patient with progression during this period. Frequent adverse effects were frequent urination and micturition pain without severe adverse effect (Grade 3 or more). Limitation of this study is a failure to enroll sufficient number for statistical analysis. Conclusions: Additional instillation of THP 30mg weekly for 8 weeks reduced the risk of tumor recurrence without severe toxicity in NMIBC patients with intermediate recurrent risk.

Morphometric analysis of prostate zonal anatomy using magnetic resonance imaging: impact on age-related changes in patients in Japan and the USA

OBJECTIVES

To evaluate the impact of morphometric magnetic resonance imaging (MRI) analysis of the prostate zonal anatomy on aging, prostatic hypertrophy and lower urinary tract symptoms in patients from Japan and the USA.

SUBJECTS AND METHODS

A retrospective analysis of 307 men, including 156 men from Japan and 151 from the USA, who consecutively underwent 3-Tesla MRI and International Prostate Symptom Score (IPSS) assessment because of elevated PSA levels. Using Synapse-Vincent (Fujifilm), the prostatic zones were segmented in each axial step-section of the T2-weighted MRI to reconstruct a three-dimensional model of the prostate, which was used to calculate: zonal volumes (whole-gland prostate, transition zone and peripheral zone volumes); the presumed circle area ratio (PCAR); and PZ thickness. Bivariate associations were quantified using Spearman's rank correlation coefficients.

RESULTS

The USA subgroup had a greater prostate volume (49 vs 42 mL; P = 0.003) and TZ volume (26 vs 20 mL; P < 0.001) than the Japan subgroup, with no difference in PZ volume (19 vs 20 mL; P = 0.2). There was no age-related increase in PZ volume in either of the subgroups or in the entire cohort (P = 0.9, P = 0.2, P = 0.3, respectively). PZ thickness had a significant negative correlation with PCAR (P < 0.001) and TZ volume (P < 0.001). The greater the increase in the TZ volume with the increase in PCAR, which probably correlates with obstructive pressure, the thinner the PZ became. PCAR had a significant positive correlation with IPSS (P = 0.003) and obstructive symptoms (P = 0.007), while PZ thickness had a significant negative correlation (P = 0.018).

CONCLUSIONS

No age-related increases and no differences between the Japanese and the US subgroups were found with regard to PZ volume. The more TZ volume increased, the higher the obstructive pressure and the thinner the PZ became; these changes were associated with increased obstructive symptoms. MRI analysis of prostate zonal anatomy enhanced our understanding of age-related changes in morphology and urinary symptoms.

Preoperative lipiodol marking and its role on survival and complication rates of CT-guided cryoablation for small renal masses

Background

Partial nephrectomy for small renal masses (SRM) may be useful for preserving renal function, but is technically more difficult than radical nephrectomy. Cryoablation may be performed under local anesthesia. The objective of the present study is to assess the safety and therapeutic efficacy of cryoablation with lipiodol marking for SRM.

Methods

Cryoablation therapy was performed on 42 patients under local anesthesia. Their median age was 74 years (31–91). The median tumor diameter was 21 mm (10–42). Responses to the treatment were evaluated using modified Response Evaluation Criteria in Solid Tumors (mRECIST) by contrast-enhanced CT. In six patients (14.3%) for whom it was not possible to use contrast medium, plain CT findings were assessed according to Response Evaluation Criteria in Solid Tumors (RECIST).

Results

Twenty-nine (69%) and five (12%) patients achieved complete responses (CR) and partial responses (PR), respectively, while four (10%) and four (10%) patients each had stable disease (SD) and progressive disease (PD) after the first course of therapy. A second course of cryoablation therapy with lipiodol marking was performed on three out of four patients with PD after the first course of therapy, and resulted in a total of 32 patients achieving CR (76%). Four (36.4%) out of 11 patients for whom lipiodol marking was not conducted had PD, whereas none of the 31 patients for whom lipiodol marking was conducted had PD. All grade complications were reported in 11 (24.4%) patients while grade 3 in two (4.4%) patients. 11 (24.4%) A significant difference was observed in postoperative hemorrhagic events in all grades (18% in patients undergoing cryoablation without lipiodol marking vs. 0% in patients undergoing cryoablation without lipiodol marking).

Conclusions

Although further studies involving more patients are needed in order to evaluate long-term results, cryoablation therapy appears to be a useful treatment option for SRM. Preoperative marking with lipiodol was helpful for improving complication and survival rates with cryoablation.

Salvage brachytherapy for locally recurrent prostate cancer after external beam radiotherapy

External beam radiotherapy (EBRT) is a standard treatment for prostate cancer. Despite the development of novel radiotherapy techniques such as intensity-modulated conformal radiotherapy, the risk of local recurrence after EBRT has not been obviated. Various local treatment options (including salvage prostatectomy, brachytherapy, cryotherapy, and high-intensity focused ultrasound [HIFU]) have been employed in cases of local recurrence after primary EBRT. Brachytherapy is the first-line treatment for low-risk and selected intermediate-risk prostate tumors. However, few studies have examined the use of brachytherapy to treat post-EBRT recurrent prostate cancer. The purpose of this paper is to analyze the current state of our knowledge about the effects of salvage brachytherapy in patients who develop locally recurrent prostate cancer after primary EBRT. This article also introduces our novel permanent brachytherapy salvage method.

Comprehensive assessment for novel prostate cancer markers in the prostate-specific antigen era: focusing on Asians and Asian countries

We reviewed the current evidence for three novel prostate tumor markers (PCA3, TMPRSS2:ERG and proPSA) that have been recently reported predominantly in Western countries. We focus our attention on Asian men in both clinical and basic research studies. There have been no reports on the clinical usefulness of these three markers for Asians living in Western countries. In Asian countries, evidence for the clinical usefulness of PCA3 and proPSA-related indices including Prostate Health Index is being accumulated, mainly in Japan. The process for how a novel marker is approved in the clinical setting is also discussed.

Multi-institutional retrospective analysis of learning curves on dosimetry and operation time before and after introduction of intraoperatively built custom-linked seeds in prostate brachytherapy

This multi-institutional retrospective analysis examined learning curves for dosimetric parameters and operation time after introduction of intraoperatively built custom-linked (IBCL) seeds. Data from consecutive patients treated with seed implantation before and after introduction of IBCL seeds (loose seed, n = 428; IBCL seed, n = 426) were collected from 13 centers. Dose-volume histogram parameters, operation times, and seed migration rates were compared before and after introduction of IBCL seeds. At the 1-month CT analysis, no significant differences were seen in dose to 90% of prostate volume between before and after IBCL seed introduction. No learning curve for dosimetry was seen. Prostate and rectal volume receiving at least 150% of prescription dose (V150 and RV150) were higher in the loose-seed group than in the IBCL-seed group. Operation time was extended by up to 10 min when IBCL seeds were used, although there was a short learning curve of about five patients. The percentage of patients with seed migration in the IBCL-seed group was one-tenth that in the loose-seed group. Our study revealed no dosimetric demerits, no learning curve for dosimetry, and a slightly extended operation time for IBCL seeds. A significant reduction in the rate of seed migration was identified in the IBCL-seed group.

Post-chemotherapy laparoscopic retroperitoneal lymph node dissection is feasible for stage IIA/B non-seminoma germ cell tumors

OBJECTIVE

To assess the efficacy, outcome and complications of post-chemotherapy laparoscopic retroperitoneal lymph node dissection (L-RPLND) for stage IIA/B testicular germ cell tumor (GCT) patients in comparison with open RPLND (O-RPLND).

METHODS

L-RPLND was performed in 14 patients with stage IIA/B non-seminoma GCTs among 154 non-seminoma patients who received RPLND after completion of chemotherapy with tumor marker normalization at our institution between 1998 and 2013. Their outcomes were compared with those of 14 patients with stage IIA/B non-seminoma GCTs treated with O-RPLND during the same period. Clinical parameters were compared between L-RPLND and O-RPLND.

RESULTS

There were no significant differences in the background characteristics of the two groups except for follow-up duration (36 months for L-RPLND, 70 months for O-RPLND; p = 0.02). Blood loss during surgery was significantly less for the L-RPLND group than for the O-RPLND group (155 mL for L-RPLND, 700 mL for O-RPLND; p < 0.001). Parameters related to post-operative recovery were significantly better for the L-RPLND group than for the O-RPLND group. Histopathological examination showed no difference between the two groups. Neither group had disease recurrence.

CONCLUSION

Post-chemotherapy L-RPLND with a bilateral template and nerve-sparing method was safe, effective, and showed a high preservation rate of antegrade ejaculation with no deterioration of outcomes compared to O-RPLND.

Laparoendoscopic Single-Site Surgery for Pediatric Urologic Disease

BACKGROUND

Laparoendoscopic single-site surgery (LESS) was performed for 31 cases of pediatric urologic disease in our department.

OBJECTIVE

A retrospective chart review was performed on pediatric patients who underwent LESS.

DESIGN, SETTING, AND PARTICIPANTS

Procedures included pyeloplasty (21), nephrectomy (4), varicocele ligation (3), orchiectomy (1), orchiopexy (1), and removal of female genitalia (1). In all 31 cases, an incision of 15 to 20 mm was made in the umbilical region, and a port for LESS was put in place. A 5-mm flexible scope and 5-mm forceps with a bending tip and regular laparoscopic forceps (3, 5 mm) were used.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Intraoperative and postoperative outcomes were evaluated.

RESULTS AND LIMITATIONS

For the 21 patients with pyeloplasty, the mean operation time was 240 minutes. Postoperative renal pelvis dilatation was relieved in all patients. For the 4 patients with nephrectomy, the mean operation time was 128 minutes. Postoperative urinary incontinence disappeared in all patients. The mean operation time of varicocele ligation was 73 minutes. Postoperation, varicocele disappeared and there was no testicular atrophy. The operation times of orchidectomy, bilateral orchidopexy, and removal of female genitalia mutilation were 60, 170, and 189 minutes, respectively. In all cases, there were no intraoperative or postoperative complications.

CONCLUSIONS

The advantages of LESS include superior aesthetics with a smaller scar and less pain. LESS is considered as a less burdensome surgery for pediatric patients.

PAX2 promoted prostate cancer cell invasion through transcriptional regulation of HGF in an in vitro model

Elucidating the mechanism of prostate cancer cell invasion may lead to the identification of novel therapeutic strategies for its treatment. Paired box 2 (PAX2) and hepatocyte growth factor (HGF) proteins are promoters of prostate cancer cell invasion. We found that PAX2 protein activated the HGF gene promoter through histone H3 acetylation and upregulated HGF gene expression. Deletion analysis revealed that the region from -637 to -314 of the HGF gene was indispensable for HGF promoter activation by PAX2. This region contains consensus PAX2 binding sequences and mutations of the sequences attenuated HGF promoter activation. Using an in vitro invasion model, we found that PAX2 and HGF promoted prostate cancer cell invasion in the same pathway. Knockdown of HGF expression attenuated the cells' invasive capacity. Moreover, in tissue samples of human prostate cancers, HGF and PAX2 expression levels were positively correlated. These results suggested that upregulation of HGF gene expression by PAX2 enhanced the invasive properties of prostate cancer cells. The PAX2/HGF pathway in prostate cancer cells may be a novel therapeutic target in prostate cancer patients.

The efficacy of radio-frequency ablation for metastatic lung or liver tumors of male germ cell tumors as an alternative minimally invasive therapy after salvage chemotherapy

BACKGROUND

The aim of this study was to assess the efficacy of radio-frequency ablation (RFA) for metastatic lung or liver tumors of germ cell tumors (GCTs) after chemotherapy.

METHODS

RFA with computed tomography guidance and monitoring was performed in 24 patients with 48 metastatic lung or liver tumors of GCTs. Group A consisted of 9 patients with tumor marker normalization after salvage chemotherapy and group B consisted of 15 patients without tumor marker normalization in spite ofintensive treatment.

RESULTS

Out of 48 tumors, 41 tumors in 21 patients were evaluated for the efficacy of the RFA treatment. Of the 41 tumors, successful ablation was achieved in 34 (82.9 %). The patients in group A had significantly better survival than the patients in group B (p = 0.0003). In group A, all 9 patients are still alive with no evidence of disease (NED). Patients with a solitary tumor had significantly better survival than those with multiple tumors (p = 0.0247). In group B, 2 patients are alive with NED, 1 patient is alive with disease, and the remaining 12 patients have died a tumor-related death. Three cases of pneumothorax requiring intubation were observed.

CONCLUSIONS

RFA is less invasive than surgery and is an effective treatment option for curative and palliative therapy as an alternative to invasive salvage surgery for post-chemotherapeutic metastatic lung or liver lesions from GCT.