Evidenced-based clinical practice guideline for prostate cancer (summary: Japanese Urological Association, 2016 edition)

A Phase II, Randomized, Open-Label, Multi-arm Study of TAS-115 for Castration-Resistant Prostate Cancer Patients With Bone Metastases

INTRODUCTION

TAS-115 is an oral multikinase inhibitor targeting the MET proto-oncogene, vascular endothelial growth factor receptor, and colony-stimulating factor 1 receptor. We evaluated the efficacy and safety of TAS-115 in castration-resistant prostate cancer (CRPC) patients with bone metastases.

PATIENTS AND METHODS

This phase II study, conducted in Japan, comprised 2 cohorts of CRPC patients. Cohort A included patients with bone metastasis and no history of docetaxel; TAS-115 200 to 400 mg/d was administered with abiraterone and prednisone. Cohort B included patients with symptomatic multiple bone metastases, post- or unfit for docetaxel, randomized 1:1 to receive TAS-115 400 or 600 mg/d orally, once daily, in a repeated weekly schedule of 5 days on/2 days off. The primary endpoint was bone scan index (BSI) response rate at Week 12 in each dose group.

RESULTS

Cohorts A and B included 24 and 26 patients, respectively. The 12-week BSI response rates for 200, 300, and 400 mg were 0%, 33.3%, and 16.7% in Cohort A, and for 400 and 600 mg were 7.1% and 25.0% in Cohort B. The best BSI response rates for 200, 300, and 400 mg were 0%, 66.7%, and 16.7% in Cohort A, and for 400 and 600 mg were 7.1% and 33.3% in Cohort B. A ≥ 30% reduction in BPI-SF score was shown in 57.7% of patients in Cohort B. The most frequent Grade ≥ 3 adverse drug reactions were hypophosphatemia (20.8%) in Cohort A and anemia (23.1%) in Cohort B.

CONCLUSION

TAS-115 appears to demonstrate anti-tumor activity and acceptable tolerability in CRPC patients with bone metastases.

Enzalutamide + androgen deprivation therapy (ADT) versus flutamide + ADT in Japanese men with castration‐resistant prostate cancer: AFTERCAB study

Objectives

The objective of the study is to compare the efficacy and safety of alternative androgen therapy (AAT) with enzalutamide + androgen deprivation therapy (ADT) and flutamide + ADT in the treatment of Japanese men with metastatic or nonmetastatic castration‐resistant prostate cancer (CRPC) who progressed despite combined androgen blockade (CAB) with bicalutamide + ADT. AAT treatment sequence was also investigated.

Materials and methods

The open‐label, Phase 4 AFTERCAB study (NCT02918968) was conducted from November 2016 to March 2020 in Japanese men aged ≥20 years with asymptomatic or mildly symptomatic CRPC. Patients were initially randomized to enzalutamide (160 mg/day) + ADT (enzalutamide first) or flutamide (375mg/day [125mg three times daily]) + ADT (flutamide first) as first‐line therapy. Following prostate‐specific antigen (PSA) progression, other disease progression, or discontinuation of first‐line therapy due to an adverse event (AE), patients switched to the other treatment as second‐line therapy. The primary endpoint was time to PSA progression with first‐line therapy (TTPP1). Secondary endpoints included TTPP2 (TTPP1 + time to PSA progression with second‐line therapy). AEs were monitored to assess safety.

Results

Overall, 206 men were randomized (enzalutamide first, n = 102; flutamide first, n = 104) and stratified by study site and disease stage; 133 patients transitioned to second‐line therapy (enzalutamide first, n = 48; flutamide first, n = 85). TTPP1 was significantly improved with enzalutamide first versus flutamide first (median 21.4 months vs. 5.8 months; hazard ratio [HR] 0.42; 95% confidence interval [CI] [0.29, 0.61]). TTPP2 was numerically improved with enzalutamide first versus flutamide first (median not reached vs. 21.2 months; HR 0.76; 95% CI [0.48, 1.19]). Both treatments were generally well tolerated, with AEs consistent with their known safety profiles.

Conclusion

First‐line AAT with enzalutamide + ADT provided a significant improvement in time to PSA progression versus flutamide + ADT. Enzalutamide + ADT may therefore be the preferred first‐line AAT option in Japanese men with metastatic or nonmetastatic CRPC who progress despite CAB with bicalutamide + ADT.

Deep lateral transurethral incision for vesicourethral anastomotic stenosis after radical prostatectomy

OBJECTIVES

To investigate the outcomes of deep lateral incision for vesicourethral anastomotic stenosis after radical prostatectomy and its impact on postoperative urinary incontinence.

METHODS

We retrospectively investigated 43 men who underwent deep lateral incision for non-obliterated vesicourethral anastomotic stenosis after radical prostatectomy between 2011 and 2020. The bladder neck was deeply incised through its circular fibers into the surrounding perivesical fat at 3 and 9 o'clock through electrocautery incision using needle-type electrodes. Successful deep lateral incision was defined as the absence of additional treatment, including self-dilatation. The postoperative urinary incontinence status was evaluated based on the number of pads used daily.

RESULTS

Deep lateral incision was successful in 35 (81.4%) patients, with a median follow-up period of 43 months (interquartile range 15-80 months). There was no significant association of age (P = 0.66), body mass index (P = 0.49) and history of diabetes mellitus (P = 0.39), radiation therapy (P = 0.89) or previous vesicourethral anastomotic stenosis treatment (P = 0.71) with the incision outcomes; however, there were significantly more unsuccessful cases in those with preoperative urinary retention (P = 0.04) or indwelling urinary catheters for >5 days post-incision (P = 0.01). A second incision was carried out in eight patients and a third incision in two patients, resulting in 42 (97.7%) successful incisions. A total of 37 (88.1%) patients had urinary incontinence and used at least one pad daily; seven (16.7%) underwent artificial urinary sphincter implantation after the last incision.

CONCLUSIONS

Deep lateral incision is highly effective for treating vesicourethral anastomotic stenosis after radical prostatectomy. Appropriate treatment is required for urinary incontinence, which occurs frequently after incision.

Long-term outcomes of androgen deprivation therapy in prostate cancer among Japanese men over 80 years old

This study aimed to analyze the survival rate and to examine the risk of death from prostate cancer when accounting for competing risk of death, in men aged ≥80 y treated with primary androgen deprivation therapy (ADT). Data of patients with prostate cancer who had received ADT were extracted from a nationwide community‐based database established by the Japan Study Group for Prostate Cancer. Prognostic variables, including progression‐free survival, cancer‐specific survival, overall survival, and death rates were compared between men stratified by prostate cancer risk. Overall, 4760 patients older than 80 y were included. The proportion of low‐, intermediate‐, high‐, or very high‐risk, regional, and metastatic prostate cancer among super‐elderly men was 9.5%, 14.6%, 48.8%, 9.0%, 3.2%, and 24.9%, respectively. Survival rates decreased with increasing risk stratification. The cumulative 5‐y death rate by prostate cancer for low‐, intermediate‐, high‐, or very high‐risk, regional, and metastatic prostate cancer, was 0.92% (95% confidence interval [CI]: 0.2%‐3.6%), 1.6% (95% CI: 0.8%‐3.4%), 5.75% (95% CI: 4.25%‐7.75%), 15.6% (95% CI: 11.6%‐23.3%), 20.7% (95% CI: 13.1%‐31.7%), and 36.9% (95% CI: 32.8%‐41.4%), respectively. Our findings support that there is no need for immediate ADT for low‐ and intermediate‐risk groups. Conversely, in high‐ or very high‐risk, regional, and metastatic prostate cancer, more efforts for curative therapy and intensive therapy are needed in selected patients.

External validation of the Briganti 2019 nomogram to identify candidates for extended pelvic lymph node dissection among patients with high-risk clinically localized prostate cancer

Background

We aimed to establish an external validation of the Briganti 2019 nomogram in a Japanese cohort to preoperatively evaluate the probability of lymph node invasion in patients with high-risk, clinically localized prostate cancer.

Methods

The cohort consisted of 278 patients with prostate cancer diagnosed using magnetic resonance imaging-targeted biopsy who underwent radical prostatectomy and extended pelvic lymph node dissection from 2012 to 2020. Patients were rated using the Briganti 2019 nomogram, which evaluates the probability of lymph node invasion. We used the area under curve of the receiver operating characteristic analysis to quantify the accuracy of the nomogram.

Results

Nineteen (6.8%) patients had lymph node invasion. The median number of lymph nodes removed was 18. The area under the curve for the Briganti 2019 was 0.71. When the cutoff was set at 7%, 84 (30.2%) patients with extended pelvic lymph node dissection could be omitted, and only 1 (1.2%) patient with lymph node invasion would be missed. Sensitivity, specificity, and negative predictive values at the 7% cutoff were 94.7, 32.0, and 98.8%, respectively.

Conclusion

This external validation showed that the Briganti 2019 nomogram was accurate, although there may still be scope for individual adjustments.

Impact of health-related quality of life on repeat protocol biopsy compliance on active surveillance for favorable prostate cancer: results from a prospective cohort in the PRIAS-JAPAN study

OBJECTIVES

This study aimed to evaluate how health-related quality of life (HRQOL) is related to repeat protocol biopsy compliance.

MATERIALS AND METHODS

We conducted a retrospective analysis using data from a prospective cohort in the Prostate Cancer Research International: Active Surveillance (PRIAS)-JAPAN study between January 2010 and August 2019. We used the Short Form 8 Health Survey (SF-8), as patient-reported outcomes, to assess HRQOL at AS enrollment and the first year of the protocol. The physical component summary (PCS) and mental component summary (MCS) were calculated from SF-8 questionnaires. The primary outcome was the evaluation of the association of HRQOL at enrollment on the first repeat biopsy compliance. The secondary outcome was the comparison of SF-8 scores during AS, stratified by repeat protocol biopsy compliance.

RESULTS

Of 805 patients who proceeded to the first year of the protocol, the non-compliance rate was 15% (121 patients). In the adjusted model, lower MCS at enrollment was significantly associated with the first repeat protocol biopsy non-compliance (odds ratio [OR], 2.134; 95% confidence interval [CI], 1.031-4.42; P = 0.041) but not in lower PCS (OR, 0.667; 95% CI, 0.294-1.514; P = 0.333). All subscales of SF-8 were lower in the non-compliance group than in the compliance group at any point. MCS in the non-compliance group improved over time from the time of AS enrollment (2.34 increased, P = 0.152).

CONCLUSION

Our data suggest that lower MCS at AS enrollment using patient-reported outcomes was negatively associated with the first repeat protocol biopsy compliance. Our study may support the availability of a simple questionnaire to extract non-compliance.

Negative impact of neoadjuvant hormonal therapy on detecting biochemical recurrence after radical prostatectomy

Background

Routine use of neoadjuvant hormonal therapy (NHT) before radical prostatectomy (RP) is not recommended, but it is sometimes performed to reduce the prostate size and tumor volume or to prevent tumor progression during the wait times for surgery in clinical practice. On the other hand, the impact of NHT on the pattern of biochemical recurrence (BCR) is unknown.

Methods

We retrospectively examined 1749 consecutive patients who underwent RP between 1996 and 2017. Among the patients who met the inclusion criteria, BCR developed in 240 of non-NHT patients and in 120 of NHT patients during the mean follow-up period of 6.9 years. We examined the impact of NHT on the PSA-doubling time (DT) following BCR at different times after RP.

Results

The median PSA-DTs in non-NHT patients who experienced BCR in the first year after surgery, between 1 and 2 years, between 2 and 3 years, between 3 and 4 years, between 4 and 5 years, and at > 5 years were 5.5, 8.8, 11.3, 17.7, 18.2, and 18.4 months, respectively. On the other hand, those in NHT patients were 1.4, 4.1, 9.1, 13.4, 27.2, and 19.3 months, respectively. The differences of PSA-DTs in the first year after surgery (p < 0.001) and between 1 and 2 years (p = 0.005) were significant between non-NHT and NHT patients.

Conclusion

Patients who received NHT had a higher risk of a rapid PSA increase when they experienced BCR, especially within 2 years after RP. In order to not miss the optimal timing of salvage treatment for BCR, intensive PSA follow-up is necessary.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10147-021-01942-8.

Safety and efficacy of abiraterone acetate plus prednisolone in patients with castration-resistant prostate cancer: a prospective, observational, post-marketing surveillance study

Background

Abiraterone acetate plus prednisolone is approved to treat patients with castration-resistant prostate cancer. This study evaluated the safety and efficacy of abiraterone acetate plus prednisolone in castration-resistant prostate cancer patients with or without previous chemotherapy in a real-world setting in Japan.

Methods

This study was an observational, prospective, post-marketing surveillance. Castration-resistant prostate cancer patients, who initiated abiraterone acetate after its approval in Japan, were enrolled. Data were collected during an observation period of 12 months and a follow-up period of another 12 months. Adverse events and adverse drug reactions were evaluated for safety. Prostate-specific antigen levels and overall survival were evaluated for efficacy.

Results

From 141 participating institutions, 497 patients were registered: 492 patients including 180 chemotherapy-naïve, 311 chemotherapy-experienced and one off-label-use patient received abiraterone and were evaluated for safety. Adverse events were observed in 225/492 patients (45.7%), adverse drug reactions in 131/492 patients (26.6%) and serious adverse drug reactions in 61/492 patients (12.4%). The most commonly observed adverse drug reaction was abnormal hepatic function (6.5%), followed by hypokalemia (3.0%) and decreased appetite (2.0%). At week 12, 110/432 patients (25.5%) achieved ≥50% decrease from baseline in prostate-specific antigen, and the proportion was higher in chemotherapy-naïve patients (56/161 patients; 34.8%) compared with chemotherapy-experienced patients (54/271 patients; 19.9%, P < 0.001). Survival rates at 24 months were 68.3% (295/432 patients), 73.9% (119/161 chemotherapy-naïve patients) and 64.9% (176/271 chemotherapy-experienced patients).

Conclusions

This large-scale, real-world, post-marketing surveillance study confirmed the safety and efficacy of abiraterone acetate plus prednisolone in Japanese castration-resistant prostate cancer patients with or without previous chemotherapy.

Epidemiology and genomics of prostate cancer in Asian men

Prostate cancer is a global health problem, but incidence varies considerably across different continents. Asia is traditionally considered a low-incidence area, but the incidence and mortality of prostate cancer have rapidly increased across the continent. Substantial differences in epidemiological features have been observed among different Asian regions, and incidence, as well as mortality-to-incidence ratio, is associated with the human development index. Prostate cancer mortality decreased in Japan and Israel from 2007 to 2016, but mortality has increased in Thailand, Kyrgyzstan and Uzbekistan over the same period. Genomic analyses have shown a low prevalence of ERG oncoprotein in the East Asian population, alongside a low rate of PTEN loss, high CHD1 enrichments and high FOXA1 alterations. Contributions from single-nucleotide polymorphisms to prostate cancer risk vary with ethnicity, but germline mutation rates of DNA damage repair genes in metastatic prostate cancer are comparable in Chinese and white patients from the USA and UK. Pharmacogenomic features of testosterone metabolism might contribute to disparities seen in the response to androgen deprivation between East Asian men and white American and European men. Overall, considerable diversity in epidemiology and genomics of prostate cancer across Asia defines disease characteristics in these populations, but studies in this area are under-represented in the literature. Taking into account this intracontinental and intercontinental heterogeneity, translational studies are required in order to develop ethnicity-specific treatment strategies.

Efficacy and safety of abiraterone acetate plus prednisolone in patients with early metastatic castration-resistant prostate cancer who failed first-line androgen-deprivation therapy: a single-arm, phase 4 study

Aim

The aim was to evaluate the efficacy and safety of abiraterone acetate plus prednisolone in patients with chemotherapy-naïve early metastatic castration-resistant prostate cancer who failed first-line androgen deprivation therapy.

Methods

Patients with early metastatic castration-resistant prostate cancer with confirmed prostate-specific antigen progression within 1-year or prostate-specific antigen progression without having normal prostate-specific antigen level (<4.0 ng/mL) during first-line androgen deprivation therapy were enrolled and administered abiraterone acetate (1000 mg) plus prednisolone (10 mg). A minimum of 48 patients were required according to Simon’s minimax design. The primary endpoint was prostate-specific antigen response rate (≥50% prostate-specific antigen decline by 12 weeks), secondary endpoints included prostate-specific antigen progression-free survival and overall survival. Safety parameters were also assessed.

Results

For efficacy, 49/50 patients were evaluable. Median age was 73 (range: 55–86) years. The median duration of initial androgen deprivation therapy was 32.4 (range: 13.4–84.1) weeks and 48 patients experienced prostate-specific antigen progression within 1-year after initiation of androgen deprivation therapy. prostate-specific antigen response rate was 55.1% (95% confidence interval: 40.2%–69.3%), median prostate-specific antigen–progression-free survival was 24.1 weeks, and median overall survival was 102.9 weeks (95% confidence interval: 64.86 not estimable [NE]). Most common adverse event was nasopharyngitis (15/50 patients, 30.0%). The most common ≥grade 3 adverse event was alanine aminotransferase increased (6/50 patients, 12.0%).

Conclusions

Abiraterone acetate plus prednisolone demonstrated a high prostate-specific antigen response rate of 55.1%, suggesting tumor growth still depends on androgen synthesis in patients with early metastatic castration-resistant prostate cancer. However, prostate-specific antigen–progression-free survival was shorter than that reported in previous studies. Considering the benefit–risk profile, abiraterone acetate plus prednisolone would be a beneficial treatment option for patients with chemotherapy-naive metastatic prostate cancer who show early castration resistance.

Narrative review of urinary glycan biomarkers in prostate cancer

Prostate cancer (PC) is the second most common cancer in men worldwide. The application of the prostate-specific antigen (PSA) test has improved the diagnosis and treatment of PC. However, the PSA test has become associated with overdiagnosis and overtreatment. Therefore, there is an unmet need for novel diagnostic, prognostic, and predictive biomarkers of PC. Urinary glycoproteins and exosomes are a potential source of PC glycan biomarkers. Urinary glycan profiling can provide noninvasive monitoring of tumor heterogeneity and aggressiveness throughout a treatment course. However, urinary glycan profiling is not popular due to technical disadvantages, such as complicated structural analysis that requires specialized expertise. The technological development of glycan analysis is a rapidly advancing field. A lectin-based microarray can detect aberrant glycoproteins in urine, including PSA glycoforms and exosomes. Glycan enrichment beads can enrich the concentration of N-linked glycans specifically. Capillary electrophoresis, liquid chromatography-tandem mass spectrometry, and matrix-assisted laser desorption/ionization-time of flight mass spectrometry can detect glycans directory. Many studies suggest potential of urinary glycoproteins, exosomes, and glycosyltransferases as a biomarker of PC. Although further technological challenges remain, urinary glycan analysis is one of the promising approaches for cancer biomarker discovery.

Cabazitaxel versus abiraterone or enzalutamide in metastatic castration-resistant prostate cancer: post hoc analysis of the CARD study excluding chemohormonal therapy for castrate-naive disease

Background

In the CARD study (NCT02485691), cabazitaxel significantly improved clinical outcomes versus abiraterone or enzalutamide in patients with metastatic castration-resistant prostate cancer previously treated with docetaxel and the alternative androgen-signalling-targeted inhibitor. However, some patients received docetaxel or the prior alternative androgen-signalling-targeted inhibitor in the metastatic hormone-sensitive (mHSPC) setting. Therefore, the CARD results cannot be directly translated to a Japanese population.

Methods

Patients (N = 255) received cabazitaxel (25 mg/m² IV Q3W, prednisone, G-CSF) versus abiraterone (1000 mg PO, prednisone) or enzalutamide (160 mg PO) after prior docetaxel and progression ≤12 months on the alternative androgen-signalling-targeted inhibitor. Patients who received combination therapy for mHSPC were excluded (n = 33) as docetaxel is not approved in this setting in Japan.

Results

A total of 222 patients (median age 70 years) were included in this subanalysis. Median number of cycles was higher for cabazitaxel versus androgen-signalling-targeted inhibitors (7 versus 4). Clinical outcomes favoured cabazitaxel over abiraterone or enzalutamide including, radiographic progression-free survival (rPFS; median 8.2 versus 3.4 months; P < 0.0001), overall survival (OS; 13.9 versus 11.8 months; P = 0.0102), PFS (4.4 versus 2.7 months; P < 0.0001), confirmed prostate-specific antigen response (37.0 versus 14.4%; P = 0.0006) and objective tumour response (38.9 versus 11.4%; P = 0.0036). For cabazitaxel versus androgen-signalling-targeted inhibitor, grade ≥ 3 adverse events occurred in 55% versus 44% of patients, with adverse events leading to death on study in 2.7% versus 5.7%.

Conclusions

Cabazitaxel significantly improved outcomes including rPFS and OS versus abiraterone or enzalutamide and are reflective of the Japanese patient population. Cabazitaxel should be considered the preferred treatment option over abiraterone or enzalutamide in this setting.

Real-world safety and effectiveness of radium-223 in Japanese patients with castration-resistant prostate cancer (CRPC) and bone metastasis: exploratory analysis, based on the results of post-marketing surveillance, according to prior chemotherapy status and in patients without concomitant use of second-generation androgen-receptor axis-targeted agents

BACKGROUND

Based on results from Japanese post-marketing surveillance, exploratory analyses were performed to investigate real-world outcomes of radium-223 for metastatic CRPC (mCRPC) according to patient characteristics.

METHODS

This non-interventional, prospective study enrolled mCRPC patients selected for radium-223 treatment in clinical practice. Six-month safety and effectiveness were evaluated in subgroups who had/had not received prior chemotherapy (prior-chemo/no prior-chemo groups), and a subgroup who had not received concomitant androgen-receptor axis-targeted agents (ARATs).

RESULTS

In the overall population (n = 296), the prior-chemo group (n = 126) tended to have more bone metastases, more analgesic use, and higher prostate-specific antigen values than the no prior-chemo group (n = 170). Incidences of treatment-emergent adverse events (TEAEs), drug-related TEAEs, and ≥ grade 3 drug-related hematological TEAEs were 47% vs. 53%, 25% vs. 29%, and 4% vs. 7% in the no prior-chemo and prior-chemo groups, respectively. Incidences of TEAEs (61%), drug-related TEAEs (36%), and ≥ grade 3 drug-related hematological events (12%) were numerically higher in 33 patients who had received two lines of prior chemotherapy. Multivariate analysis showed that two lines of prior chemotherapy, and hemoglobin, platelet, and lactate dehydrogenase values were baseline factors significantly related to ≥ grade 2 platelet count decreased. Safety and effectiveness in patients without concomitant ARATs (n = 201) were similar to those in the overall population.

CONCLUSION

In a real-life setting, radium-223 was well tolerated irrespective of prior chemotherapy, but relatively higher incidences of TEAEs and hematotoxicities were suggested in patients with two lines of prior chemotherapy, possibly reflecting more advanced disease. Radium-223 safety and effectiveness in patients without concomitant ARATs were favorable.

Treatment of nonmetastatic castration-resistant prostate cancer: focus on second-generation androgen receptor inhibitors

BACKGROUND

Nonmetastatic castration-resistant prostate cancer (nmCRPC) is defined as a rising prostate-specific antigen concentration, despite castrate levels of testosterone with ongoing androgen-deprivation therapy or orchiectomy, and no detectable metastases by conventional imaging. Patients with nmCRPC progress to metastatic disease and are at risk of developing cancer-related symptoms and morbidity, eventually dying of their disease. While patients with nmCRPC are generally asymptomatic from their disease, they are often older and have chronic comorbidities that require long-term concomitant medication. Therefore, careful consideration of the benefit-risk profile of potential treatments is required.

METHODS

In this review, we will discuss the rationale for early treatment of patients with nmCRPC to delay metastatic progression and prolong survival, as well as the factors influencing this treatment decision. We will focus on oral pharmacotherapy with the second-generation androgen receptor inhibitors, apalutamide, enzalutamide, and darolutamide, and the importance of balancing the clinical benefit they offer with potential adverse events and the consequential impact on quality of life, physical capacity, and cognitive function.

RESULTS AND CONCLUSIONS

While the definition of nmCRPC is well established, the advent of next-generation imaging techniques capable of detecting hitherto undetectable oligometastatic disease in patients with nmCRPC has fostered debate on the criteria that inform the management of these patients. However, despite these developments, published consensus statements have maintained that the absence of metastases on conventional imaging suffices to guide such therapeutic decisions. In addition, the prolonged metastasis-free survival and recently reported positive overall survival outcomes of the three second-generation androgen receptor inhibitors have provided further evidence for the early use of these agents in patients with nmCRPC in order to delay metastases and prolong survival. Here, we discuss the benefit-risk profiles of apalutamide, enzalutamide, and darolutamide based on the data available from their pivotal clinical trials in patients with nmCRPC.

Prostate cancer

Prostate cancer is a complex disease that affects millions of men globally, predominantly in high human development index regions. Patients with localized disease at a low to intermediate risk of recurrence generally have a favourable outcome of 99% overall survival for 10 years if the disease is detected and treated at an early stage. Key genetic alterations include fusions of TMPRSS2 with ETS family genes, amplification of the MYC oncogene, deletion and/or mutation of PTEN and TP53 and, in advanced disease, amplification and/or mutation of the androgen receptor (AR). Prostate cancer is usually diagnosed by prostate biopsy prompted by a blood test to measure prostate-specific antigen levels and/or digital rectal examination. Treatment for localized disease includes active surveillance, radical prostatectomy or ablative radiotherapy as curative approaches. Men whose disease relapses after prostatectomy are treated with salvage radiotherapy and/or androgen deprivation therapy (ADT) for local relapse, or with ADT combined with chemotherapy or novel androgen signalling-targeted agents for systemic relapse. Advanced prostate cancer often progresses despite androgen ablation and is then considered castration-resistant and incurable. Current treatment options include AR-targeted agents, chemotherapy, radionuclides and the poly(ADP-ribose) inhibitor olaparib. Current research aims to improve prostate cancer detection, management and outcomes, including understanding the fundamental biology at all stages of the disease.

Prostate cancer

Prostate cancer is a complex disease that affects millions of men globally, predominantly in high human development index regions. Patients with localized disease at a low to intermediate risk of recurrence generally have a favourable outcome of 99% overall survival for 10 years if the disease is detected and treated at an early stage. Key genetic alterations include fusions of TMPRSS2 with ETS family genes, amplification of the MYC oncogene, deletion and/or mutation of PTEN and TP53 and, in advanced disease, amplification and/or mutation of the androgen receptor (AR). Prostate cancer is usually diagnosed by prostate biopsy prompted by a blood test to measure prostate-specific antigen levels and/or digital rectal examination. Treatment for localized disease includes active surveillance, radical prostatectomy or ablative radiotherapy as curative approaches. Men whose disease relapses after prostatectomy are treated with salvage radiotherapy and/or androgen deprivation therapy (ADT) for local relapse, or with ADT combined with chemotherapy or novel androgen signalling-targeted agents for systemic relapse. Advanced prostate cancer often progresses despite androgen ablation and is then considered castration-resistant and incurable. Current treatment options include AR-targeted agents, chemotherapy, radionuclides and the poly(ADP-ribose) inhibitor olaparib. Current research aims to improve prostate cancer detection, management and outcomes, including understanding the fundamental biology at all stages of the disease.

Latent prostate cancer among Japanese males: a bibliometric study of autopsy reports from 1980-2016

Prostate cancer is one of the most common malignancies, but a substantial portion remains latent throughout the patients' lifetime. Analysis of temporal change in the latent prostate cancer pool would be beneficial for clinical decision-making, but longitudinal autopsy studies are rare. We conducted a hand-search of the Annual of Pathological Autopsy Cases in Japan from 1980 to 2016 for cases of latent prostate cancer. Of 570 997 males aged 30 or older, latent prostate cancer was detected in 12 562 patients (2.2%). Proportion of detected cases correlated strongly with 'aging rate', the percentage of population aged 65 or older (squared Pearson's correlation coefficient r2 = 0.972, P value <0.0001). Temporal increase in proportion was also seen in each age group as well. This continuous growth reinforces evidence from past Japanese reports on latent prostate cancer. The rapidly rising ageing rate of Japan may forecast further increase in the latent prostate cancer pool moving forward.

Influence of prostate cancer status on the prevalence of medication-related osteonecrosis of the jaw

OBJECTIVE

The aim of this study was to evaluate the risk of osteonecrosis of the jaw (ONJ) in patients with prostate cancer, particularly the relationship between prostate cancer progression and ONJ development.

STUDY DESIGN

This single-center, retrospective, observational study included 113 patients who received zoledronic acid or denosumab for prostate cancer with bone metastasis between January 2012 and March 2020. The risk of ONJ was evaluated regarding age; antiresorptive drugs; duration of antiresorptive treatment; prostate cancer status, including castration-resistant prostate cancer (CRPC) and prostate-specific antigen level; chemotherapy; radium-223 treatment; corticosteroid treatment; diabetes mellitus; and dental extractions.

RESULTS

Overall, 28 patients had ONJ; 10 patients received zoledronic acid and 18 patients received denosumab. Multiple logistic regression analysis demonstrated that CRPC (odds ratio = 6.01; 95% confidence interval, 1.76-20.05; P = .004) and dental extractions (odds ratio = 12.40; 95% confidence interval, 3.42-44.70; P < .001) were significantly associated with ONJ. In addition, antiresorptive treatment lasting more than 1 year partially mediated between CRPC and development of ONJ.

CONCLUSION

CRPC and dental extraction are risk factors for developing ONJ, and antiresorptive treatment lasting more than 1 year is a partial mediator between CRPC and ONJ.

Shared decision making, physicians' explanations, and treatment satisfaction: a cross-sectional survey of prostate cancer patients

Background

Hormone therapy is one option for some types of prostate cancer. Shared decision making (SDM) is important in the decision making process, but SDM between prostate cancer patients receiving hormone therapy and physicians is not fully understood. This study tested hypotheses: “Patients’ perception of SDM is associated with treatment satisfaction, mediated by satisfaction with physicians’ explanations and perceived effective decision making” and “The amount of information provided to patients by physicians on diseases and treatment is associated with treatment satisfaction mediated by patients’ perceived SDM and satisfaction with physicians’ explanations.”

Methods

This cross-sectional study was conducted using an online panel via a private research company in Japan. The participants in this study were patients registered with the panel who had received or were currently receiving hormone therapy for prostate cancer and physicians registered with the panel who were treating patients with prostate cancer. Measures used in this study included a nine-item Shared Decision Making Questionnaire, levels of satisfaction with physicians’ explanations and treatment satisfaction, and effective decision making for patients (feeling the choice is informed, value-based, likely to be implemented and expressing satisfaction with the choice), and a Shared Decision Making Questionnaire for Doctors. The hypotheses were examined using path analysis.

Results

In total, 124 patients and 150 physicians were included in the analyses. In keeping with our hypotheses, perceived SDM significantly correlated with the physicians’ explanations and perceived effective decision making for patients, and satisfaction with physicians’ explanations and perceived effective decision making for patients were both related to treatment satisfaction. Although the amount of information provided to patients was correlated with the perceived SDM, it was indirectly related to their satisfaction with physicians’ explanations.

Conclusions

When physicians encourage patients to be actively involved in making decisions about treatment through the SDM process while presenting a wide range of information at the start of hormone therapy, patients’ effective decision making and physicians’ explanations may be improved; consequently, the patients’ overall treatment satisfaction may be improved. Physicians who treat patients with prostate cancer may have underestimated the importance of SDM before starting hormone therapy, even greater extent than patients.

Efficacy and safety of darolutamide in Japanese patients with nonmetastatic castration-resistant prostate cancer: a sub-group analysis of the phase III ARAMIS trial

Background

Darolutamide, an oral androgen receptor inhibitor, has been approved for treating nonmetastatic castration-resistant prostate cancer (nmCRPC), based on significant improvements in metastasis-free survival (MFS) in the ARAMIS clinical trial. Efficacy and safety of darolutamide in Japanese patients are reported here.

Methods

In this randomized, double-blind, placebo-controlled phase III trial, 1509 patients with nmCRPC and prostate-specific antigen (PSA) doubling time ≤ 10 months were randomized 2:1 to darolutamide 600 mg twice daily or matched placebo while continuing androgen deprivation therapy. The primary endpoint was MFS.

Results

In Japan, 95 patients were enrolled and randomized to darolutamide (n = 62) or placebo (n = 33). At the primary analysis (cut-off date: September 3, 2018), after 20 primary end-point events had occurred, median MFS was not reached with darolutamide vs. 18.2 months with placebo (HR 0.28, 95% CI 0.11–0.70). Median OS was not reached due to limited numbers of events in both groups but favored darolutamide in the Japanese subgroup. Time to pain progression, time to PSA progression, and PSA response also favored darolutamide. Among Japanese patients randomized to darolutamide vs. placebo, incidences of treatment-emergent adverse events (TEAEs) were 85.5 vs. 63.6%, and incidences of treatment discontinuation due to TEAEs were 8.1 vs. 6.1%.

Conclusions

Efficacy outcomes favored darolutamide in Japanese patients with nmCRPC, supporting the clinical benefit of darolutamide in this patient population. Darolutamide was well tolerated; however, due to the small sample size, it is impossible to conclude with certainty whether differences in the safety profile exist between Japanese and overall ARAMIS populations.

Electronic supplementary material

The online version of this article (10.1007/s10147-020-01824-5) contains supplementary material, which is available to authorized users.

Prostate cancer detection rate and Gleason score in relation to prostate volume as assessed by magnetic resonance imaging cognitive biopsy and standard biopsy

OBJECTIVE

This study aimed to assess the relationship of the prostate cancer and Gleason scores (GSs) or ISUP Grade system with prostate volume (PV) as assessed by magnetic resonance imaging (MRI) cognitive biopsy and standard biopsy.

MATERIAL AND METHODS

Data were collected from 659 patients who underwent MRI cognitive biopsy and standard biopsy from January 2014 to January 2018. The biopsies were performed because of increased prostate-specific antigen (PSA) levels (>4 ng/mL) and/or abnormal digital rectal examination findings. Transrectal ultrasound was used to measure PV.

RESULTS

Prostate cancer detection rates in patients with increased PVs of ≤40 cc and >40 cc were 68.8% and 51.6% (p<0.001), respectively. ISUP Grade group ≥2 (Gleason score ≥3+4) detection rates for increased PVs of ≤40 cc and >40 cc were 68% and 73%, and 22.3% and 37.8%, respectively, for those with ISUP Grade group ≥4 (Gleason score ≥8) (p=0.003). Among the patients with PV>40 cc, univariate logistic regression showed a significant relationship between ISUP Grade group ≥2 and PSA, free/total PSA, PSA density, and MRI (p<0.05). On multivariable logistic regression, MRI (p=0.014) and PSA (p=0.039) predicted ISUP Grade group ≥2 in patients with PV>40 cc.

CONCLUSION

Although the detection rates of prostate cancer decreased as PV increased, the detection of prostate cancer aggressiveness increased as PV increased. This increase in high ISUP Grade lesions with the rise in PV is due to the use of MRI during prostate biopsy with standard biopsy.

Updated evidence on oncological outcomes of surgery versus external beam radiotherapy for localized prostate cancer

Radical prostatectomy and external beam radiotherapy are recognized as comparable treatment options for localized prostate cancer. Previous studies of oncological outcomes of surgery versus radiotherapy have reported their comparability or possible superiority of surgery. However, the issue of which treatment is better remains controversial. Several factors make fair comparison of their outcomes difficult: different patient backgrounds caused by selection bias, different definitions of biochemical recurrence and different complication profiles between the treatment modalities. In 2016, the first large randomized controlled trial was published, which compared radical prostatectomy, external beam radiotherapy and active monitoring in localized prostate cancer. More recently, another study has reported comparative outcomes of robot-assisted radical prostatectomy and volumetric modulated arc therapy, as the leading surgery and radiotherapy techniques, respectively. Furthermore, there has been a trend toward combining external beam radiotherapy with brachytherapy boost, especially in patients with high-risk prostate cancer. This review summarizes the updated evidence on oncological outcomes of surgery versus external beam radiotherapy for localized prostate cancer.

The impact of complications after initial prostate biopsy on repeat protocol biopsy acceptance rate. Results from the Prostate Cancer Research International: Active Surveillance JAPAN study

BACKGROUND

Patients with favorable-risk prostate cancer on active surveillance (AS) are strictly followed for safer execution. Repeat protocol biopsy is essential for evaluating cancer aggressiveness. However, the acceptance rate of repeat biopsy is not high enough because of the burdens of biopsy. We assessed the impact of complications after the initial biopsy on repeat protocol biopsy at 1 year using data from the Prostate Cancer Research International: Active Surveillance (PRIAS)-JAPAN study.

METHODS

We performed a retrospective analysis using a prospective cohort in the PRIAS-JAPAN study. Patients with favorable-risk prostate cancer (n = 856) who consented to participate in the PRIAS-JAPAN study from 2010 to 2018 were enrolled. Follow-up evaluations included regular prostate-specific antigen, digital rectal examination and biopsy. Rates of complications after biopsies and repeat protocol biopsy non-acceptance rate at 1 year were reported. Logistic regression analysis explored the association between the complications after the initial biopsy and repeat protocol biopsy non-acceptance.

RESULTS

Altogether, 759 patients (88.7%) actually proceeded to protocol at 1 year. Repeat protocol biopsy non-acceptance rate at 1 year was 14.9%. Regarding complications after the initial biopsy, hematuria (p = 0.028) and pain (p < 0.001) rates were significantly higher in the repeat biopsy non-acceptance group, but infection (p = 0.056) and hematospermia (p = 0.337) rates were not different. On multivariate logistic regression analysis, pain was a significant predictor for repeat protocol biopsy non-acceptance (odds ratio 4.68, 95% confidence interval 1.864-11.75; p = 0.001).

CONCLUSIONS

Pain at the initial biopsy negatively impacts patients' compliance with further protocol biopsies during AS.

The m6A methylation regulator-based signature for predicting the prognosis of prostate cancer

Aim: To construct a survival prediction signature for prostate cancer (PC) based on the RNA N6-methyladenosine (m6A) methylation regulator. Materials & methods: This paper explores the interaction network of differentially expressed m6A RNA methylation regulators in PC by Pearson correlation analysis. Univariate Cox risk regression and LASSO regression analysis were used to construct a predictive signature of PC. Kaplan-Meier survival analysis compared the overall survival of the high- and low-risk groups. Results & Conclusion: We first constructed a prognostic two gene signature for PC based on the m6A RNA methylation regulators MRTTL14 and YTHDF2. The interaction network of m6A RNA methylation regulators in PC was also established.

Real-world efficacy and safety of two doses of cabazitaxel (20 or 25 mg/m2) in patients with castration-resistant prostate cancer: results of a Japanese post-marketing surveillance study

Background

The recommended starting dose of cabazitaxel for castration-resistant prostate cancer (CRPC) is 25 mg/m² in Japan and Europe. Although lower doses are established alternatives based on randomized controlled trials, the safety and efficacy of 25 and 20 mg/m² in real-world settings are not well established. Therefore, we investigated the safety and efficacy of cabazitaxel at the recommended starting dose or a lower dose (20 mg/m²) in real-world clinical practice.

Methods

We compared the safety and efficacy of cabazitaxel between patients who received cabazitaxel at starting doses of 25 and 20 mg/m² (C25 and C20, respectively) in a Japanese post-marketing surveillance study of 662 patients with docetaxel-refractory CRPC. Safety was assessed in terms of adverse drug reactions (ADRs). Prostate-specific antigen (PSA) response rate, overall survival (OS), and time-to-treatment failure (TTF) were compared between the C25 and C20 groups in unmatched patients and after applying propensity score matching.

Results

The C20 and C25 groups comprised 190 and 159 patients without matching and 112 patients per group after matching. In unmatched patients, any-grade (C25 vs C20: 89.3% vs 78.4%, Fisher’s p < 0.01) and grade ≥ 3 (81.1% vs 61.1%) ADRs were more frequent in the C25 group. Neutropenia (any grade: 61.6% vs 54.2%; grade ≥ 3: 55.3% vs 42.6%) and febrile neutropenia (grade ≥ 3: 30.2% vs 14.7%) were more frequent in the C25 group. In matched patients, the PSA response rate (reduction in PSA ≥30% from a baseline ≥5 ng/mL) was 26.4 and 32.0% in the C20 and C25 groups, respectively, median OS was 291 days (95% CI 230–not reached) versus not reached (hazard ratio 0.73, 95% CI 0.50–1.08), and TTF favored C25 (hazard ratio 0.75, 95% CI 0.57–0.99).

Conclusions

Clinicians should consider the patient’s risk of clinically significant ADRs and prophylactic granulocyte colony stimulating factor when selecting the starting dose of cabazitaxel for CRPC. Some patients at high risk of ADRs or unfit patients may benefit from a lower starting dose of 20 mg/m², whereas fit patients may be candidates for a starting dose of 25 mg/m².

Trial registration

Not applicable.

Geriatric 8 screening of frailty in patients with prostate cancer

OBJECTIVES

To evaluate the association between the score of the Geriatric 8 screening tool and treatment by disease stages in patients with prostate cancer.

METHODS

Between January 2017 and June 2019, we prospectively evaluated the Geriatric 8 in 540 prostate cancer patients who were treated with robot-assisted radical prostatectomy, radiotherapy, androgen deprivation therapy alone and standard of care for metastatic hormone-naïve prostate cancer or castration-resistant prostate cancer. The primary purpose was the association between frailty (Geriatric 8 ≤14) and robot-assisted radical prostatectomy, radiotherapy, androgen deprivation therapy alone, and metastatic diseases. Secondary purposes included a comparison of the Geriatric 8 scores among the disease status and the influence of Geriatric 8 score on overall survival.

RESULTS

The median age was 75 years. Geriatric 8 scores ≤14 were seen in 36% of robot-assisted radical prostatectomy (n = 78/214), 57% of radiotherapy (n = 119/209), 91% of androgen deprivation therapy alone (n = 19/21) and 70% of metastatic diseases (n = 67/96). The median Geriatric 8 score in patients treated with robot-assisted radical prostatectomy, radiotherapy, androgen deprivation therapy alone and metastatic diseases was 15.0, 14.0, 12.0 and 12.8, respectively. The median Geriatric 8 score was significantly higher in the metastatic disease than that in localized disease (14.5 vs 12.8, respectively). Robot-assisted radical prostatectomy patients had a significantly higher Geriatric 8 score than radiotherapy patients, with the cut-off value of <14.5. The overall survival was significantly different between Geriatric 8 scores ≤13 and >13 in metastatic hormone-naïve prostate cancer patients, and between Geriatric 8 scores ≤12 and >12 in castration-resistant prostate cancer patients.

CONCLUSION

The Geriatric 8 score is significantly associated with treatment by disease stages in patients with prostate cancer.

Efficacy and safety of apalutamide in Japanese patients with nonmetastatic castration-resistant prostate cancer: a subgroup analysis of a randomized, double-blind, placebo-controlled, Phase-3 study

Background

In the global Phase-3 Selective Prostate Androgen Receptor Targeting with ARN-509 study, apalutamide plus ongoing androgen deprivation therapy (ADT) significantly increased metastasis-free survival (MFS) and improved other clinical outcomes in men with nonmetastatic castration-resistant prostate cancer (nm-CRPC) who were at high risk of developing metastases. In this subpopulation analysis of Selective Prostate Androgen Receptor Targeting with ARN-509 study, the efficacy and safety of apalutamide plus ADT were evaluated in Japanese patients with nm-CRPC.

Methods

The primary efficacy end point was MFS. Secondary efficacy end points were time to metastasis, progression-free survival, symptomatic progression, initiation of cytotoxic chemotherapy, and overall survival. Safety and pharmacokinetic parameters were also assessed.

Results

Fifty-five Japanese patients with ongoing ADT were randomized (apalutamide: n = 34, placebo: n = 21). Median treatment duration was 5.7 months in the apalutamide group and 11.0 months in the placebo group. Median MFS was not reached in the apalutamide group (95% confidence interval: 10.97, not estimable) and was 18.23 months (95% confidence interval: 11.04, 18.50) in the placebo group. Secondary end points were improved in the apalutamide group. The safety profile of apalutamide with ADT was comparable with the global population, and no new safety signals were identified in this Japanese subpopulation. Although, apalutamide exposure tended to be higher in the Japanese subpopulation compared with the non-Japanese population, this was likely to be explained by body weight and considered not clinically meaningful.

Conclusion

In the Japanese subpopulation, treatment with apalutamide with ADT resulted in favorable efficacy outcomes with comparable benefit-risk profile to the global population with nm-CRPC who are at high-risk of developing metastases.

Frailty is a predictor of moderate to severe pain after robot‐assisted laparoscopic prostatectomy: A case‐control study (FRAP study)

Objective

To investigate the association of pain with frailty in patients with localized prostate cancer (PC) who underwent robot‐assisted laparoscopic radical prostatectomy (RARP).

Materials and Methods

Between January 2017 and June 2019, we prospectively evaluated the geriatric 8 (G8) score, simplified frailty index (sFI), and numerical rating scale (NRS) of 154 patients with localized PC who underwent RARP at our institution. NRS was measured on preoperative day 0, postoperative days 1, 2, 3, and at discharge. Moderate to severe pain was defined as NRS ≥ 5, whereas frailty was defined as G8 ≤ 14. The primary objectives of this study were to investigate the effects of moderate to severe pain (NRS ≥ 5) on frailty, postoperative complications, and the use of analgesics after RARP. Our secondary objectives were the effect of frailty on postoperative complications and the use of analgesics.

Results

The median age of participants was 69 years. Of 154 patients, 37 (24%) and 61 (40%) were classified to have NRS ≥ 5 and G8 ≤ 14, respectively. Patients with NRS > 5 presented significantly association with G8 < 14, whereas they did not show the association with sFI, complication, or analgesics. Multivariate logistic regression analysis showed that G8 ≤ 14 was significantly associated with NRS ≥ 5. Frailty was not significantly associated with postoperative complications and analgesics.

Conclusions

Frailty was significantly associated with moderate to severe pain after RARP, and might be a potential predictor of postoperative pain. Frail patients require individual care to avoid painful experiences.

External validation of the "optimal PSA follow-up schedule after radical prostatectomy" in a new cohort

BACKGROUND

Biochemical recurrence (BCR) after radical prostatectomy (RP) is most commonly diagnosed by detecting an increase in asymptomatic prostate-specific antigen (PSA). We previously reported the "optimal PSA follow-up schedule after RP". The aim of this study was to confirm the usefulness and safety of that follow-up schedule in another cohort.

METHODS

We retrospectively reviewed the clinicopathological data of 798 consecutive patients who underwent radical prostatectomy between 2009 and 2017. We examined all PSA values measured during follow-up. Furthermore, we estimated the PSA value when we observed the "optimal PSA follow-up schedule" at each timing in the virtual follow-up. BCR was defined as an elevation of PSA to greater than 0.2 ng/ml, and the ideal PSA range for detection of BCR was regarded to be 0.2-0.4 ng/ml.

RESULTS

During the mean follow-up period of 5.8 years, BCR occurred in 115 (14.9%) patients and the frequency of virtual follow-up was significantly lower than the actual frequency. However, overlooking of BCR (detecting BCR when PSA exceeded 0.4 ng/ml) was observed in 17 patients, which is higher than the actual frequency of overlooking (12 patients). Therefore, we modified the follow-up schedule, which could achieve the lower follow-up frequency and a limited number of overlooking of BCR (7 patients).

CONCLUSION

This external validation study revealed that the "modified optimal PSA follow-up schedule after RP" can reduce the frequency of PSA measurement with a limited risk of overlooking BCR.

Cabazitaxel in patients aged ≥80 years with castration-resistant prostate cancer: Results of a post-marketing surveillance study in Japan

OBJECTIVES

Data on the safety and efficacy of cabazitaxel in patients aged ≥80 years with castration-resistant prostate cancer (CRPC) are limited. We report the safety (adverse drug reactions [ADRs]) and efficacy (overall survival [OS], time to treatment failure [TTF], and prostate-specific antigen [PSA] response rates) in patients aged <80 or ≥80 years treated with cabazitaxel for CRPC in clinical practice.

MATERIALS AND METHODS

We performed post-hoc subgroup analyses of a Japanese post-marketing surveillance study involving 662 patients with CRPC treated with cabazitaxel between September 2014 and June 2016.

RESULTS

In patients aged <80 (n = 610) and ≥80 years (n = 49), median PSA at baseline was 168.7 and 109.0 ng/mL, and 86.7% and 83.7% of patients were previously treated with enzalutamide and/or abiraterone. ADRs (all grade) occurred in 77.2% and 79.6% of patients aged <80 and ≥80 years, with grade three/worse ADRs in 61.8% and 63.3% of patients. Hematologic toxicities were the most common grade three/worse ADRs, including neutropenia, febrile neutropenia, and anemia in both subgroups. No specific ADRs were observed in patients aged ≥80 years. The PSA response and median OS and TTF were 28.3%, 292 days, and 116 days in patients aged ≥80 years, and 29.7%, 319 days, and 125 days in patients aged <80 years.

CONCLUSION

Cabazitaxel could be a treatment option for CRPC in patients aged ≥80 years based on its safety and efficacy profiles. This is the first report to investigate the safety and efficacy of cabazitaxel in patients aged ≥80 years with CRPC.

Quality of life in active surveillance for early prostate cancer

Recently, the prevalence of the prostate-specific antigen screening test for early-stage prostate cancer has increased, but this has also resulted in an increase in insignificant cancers. The treatment outcome of early-stage prostate cancer is excellent, but such a radical treatment also leaves the patient with undesired adverse consequences. To resolve such problems, attention should be paid to active surveillance as a modern treatment option. This study aimed to systematically review the literature about quality of life in prostate cancer patients undergoing active surveillance. Evidence was acquired from PubMed databases in March 2019 using quality of life, prostate cancer, well-being, anxiety, depression, stress, outcomes, active surveillance, radiation therapy and radical prostatectomy as keywords. Five clinical active surveillance studies measured health-related quality of life and related psychological factors, and seven compared active surveillance with other treatments (radical therapy and hormone therapy). Active surveillance was superior to radical therapy for urinary and sexual function. Furthermore, most patients who opted for active surveillance showed lower anxiety and fear of progression, whereas health-related quality of life was maintained. Although active surveillance has the advantage of being non-invasive, its diagnosis and follow-up protocols are unreliable. Because such uncertainty can affect patients' quality of life, utilization of imaging modalities, such as magnetic resonance imaging, and the development of new biomarkers are required.

Safety and efficacy of cabazitaxel in 660 patients with metastatic castration-resistant prostate cancer in real-world settings: results of a Japanese post-marketing surveillance study

Objective

To evaluate the real-world safety and efficacy of cabazitaxel in Japanese patients with metastatic castration-resistant prostate cancer (mCRPC) previously treated with a docetaxel-containing regimen.

Methods

This prospective multicenter observational study registered all patients with mCRPC treated with cabazitaxel following its launch in Japan in September 2014. Patient enrollment continued until at least 500 patients were enrolled. Adverse drug reactions (ADRs) were evaluated according to CTCAE ver. 4.0. Efficacy endpoints were assessed for up to 1 year, and included prostate specific antigen (PSA) response rates (defined as a decrease of ≥30% or ≥50% from baseline), overall survival (OS), and time to treatment failure (TTF).

Results

A total of 660 mCRPC patients were enrolled across 316 centers by June 2016. Frequent ADRs (any grade) were neutropenia (49.1%), febrile neutropenia (18.0%) and anemia (15.0%). Most ADRs occurred in cycle 1. Neutropenia and febrile neutropenia were significantly less frequent in patients who received prophylactic granulocyte colony-stimulating factor. The PSA response rates for decrease of ≥30% or ≥50% from baseline were 28.1% and 17.5%, respectively, in patients with baseline PSA of ≥5 ng/ml. Median OS and TTF were 319 days (95% confidence interval: 293.0–361.0) and 116 days (95% confidence interval: 108.0–135.0), respectively.

Conclusions

This study of cabazitaxel in 660 Japanese patients treated in real-world settings, the largest study of cabazitaxel to date, demonstrated a safety profile that was generally consistent with those of pivotal clinical studies. Cabazitaxel was also effective in terms of the PSA response, OS, and TTF.

Health Related Quality of Life in Japanese Patients with Localized Prostate Cancer: Comparative Retrospective Study of Robot-Assisted Laparoscopic Radical Prostatectomy Versus Radiation Therapy

Background

Radical prostatectomy and radiotherapy are standard treatments for localized prostate cancer. When making decisions about treatment, it is important to not only consider medical information such as the patient's age, performance status, and complications, but also the impact on quality of life (QOL) after treatment.

Our purpose was to compare health related quality of life (HRQOL) after robot-assisted laparoscopic radical prostatectomy (RARP) versus radiation therapy in Japanese patients with localized prostate cancer retrospectively.

Methods

Patients with localized prostate cancer receiving RARP or radiotherapy at Tottori University Hospital between October 2010 and December 2014 were enrolled in a retrospective observational study with follow-up for 24 months to December 2016. The Medical Outcome Study 8-Item Short-Form Health Survey was performed before treatment and 1, 3, 6, 12, and 24 months post-treatment.

Results

Complete responses to the questionnaire were obtained from 154/227 patients receiving RARP, 41/67 patients receiving intensity-modulated radiation therapy, 35/82 patients receiving low dose rate brachytherapy, and 18/28 patients given low dose rate brachytherapy plus external beam radiation therapy. The median physical component summary score of the Medical Outcome Study 8-Item Short-Form Health Survey was significantly lower at 1 month after prostatectomy than radiotherapy, but was similar for both treatments at 3 months, and was significantly higher at 6, 12 and 24 months after prostatectomy. The median mental component summary score was also significantly lower in the prostatectomy group at 1 month, but not from 3 months onwards.

Conclusion

Our study suggested that HRQOL was inferior at 1 month after RARP, however, recovered at 3 months after RARP and was better than after radiotherapy at 6, 12, and 24 months.

Diagnostic performance of 18F-fluciclovine PET/CT for regional lymph node metastases in patients with primary prostate cancer: a multicenter phase II clinical trial

OBJECTIVE

This multicenter, phase II clinical trial evaluated the diagnostic performance of 18F-fluciclovine, a novel amino acid for positron-emission tomography (PET), for detection of small lymph node metastases with short-axis diameters of 5-10 mm in patients with prostate cancer.

METHODS

Patients with prostate cancer were eligible after screening of laboratory tests and pelvic contrast-enhanced computed tomography (CT). Pelvic region 18F-fluciclovine PET/CT was then acquired within 28 days and dissection of regional lymph nodes was performed within 60 days of pelvic contrast-enhanced CT. Diagnostic performance of 18F-fluciclovine-PET/CT was evaluated by comparison with standard histopathology of lymph nodes.

RESULTS

In a total of 28 patients, 40 regional lymph nodes with short-axis diameters of 5-10 mm were eligible for efficacy evaluation; seven of these showed metastases confirmed by histopathology. The sensitivity of 18F-fluciclovine PET/CT was 57.1% (4/7). All four true positive lymph nodes detected by 18F-fluciclovine PET/CT had a metastatic lesion with a long-axis diameter of ≥7 mm and a high proportion of cancer volume (60-100%) according to pathology evaluation. The specificity, diagnostic accuracy, positive predictive value, and negative predictive value of 18F-fluciclovine PET/CT in lymph node-based analysis were 84.8% (28/33), 80.0% (32/40), 44.4% (4/9), and 90.3% (28/31), respectively. No clinically significant adverse events occurred.

CONCLUSIONS

18F-fluciclovine PET/CT detected small lymph node metastases; however it also showed positive findings in benign lymph nodes. Refinement of the image assessment criteria may improve the diagnostic performance of 18F-fluciclovine PET/CT for small lymph node metastases in patients with prostate cancer.

Treatment characteristics for nonmetastatic castration-resistant prostate cancer in the United States, Europe and Japan

Aim: We conducted this study to describe nonmetastatic castration-resistant prostate cancer (nmCRPC) patient characteristics and treatment patterns in the US, Europe and Japan. Materials & methods: Descriptive analyses were conducted using the 2015–2017 Ipsos Global Oncology Monitor Database. Results: A total of 2065 (442 in the US, 509 in Europe and 1114 in Japan) patients (median age: 74–80 years; stage III at diagnosis : 38.5%; Eastern Cooperative Oncology Group [ECOG] score ≤1: 79.4%; treated by urologist : 88.4%) were included in the analytic cohort. Luteinizing hormone-releasing hormone agonists and antiandrogens were the most commonly used first regimen treatments. With subsequent nmCRPC regimens their use decreased, while the use of chemotherapy, corticosteroids, androgen synthesis inhibitors and second-generation androgen receptor inhibitors increased. Conclusion: These data represent real-world treatment patterns in nmCRPC.

Factors contributing to the ceiling effect of the EQ-5D-5L: an analysis of patients with prostate cancer judged "no-problems"

Purpose

The goal of the present study was to determine factors related to a ceiling effect (CE) on the EQ-5D-5L among Japanese patients with prostate cancer (PC).

Methods

An existent cross-sectional observational study dataset was used. Patients were ≥ 20 years of age and diagnosed with PC. For CE determinants on the EQ-5D-5L, we excluded possible “full-health” patients flagged by the EQ-VAS (score = 100) and/or FACT-P (score = 156) instruments. We then divided them into binary variables: A CE group (EQ-5D-5L score = 1) and others (< 1). The associations between CE, sociodemographic and medical characteristics, and FACT-P subscale scores were examined using a multivariate LASSO selection followed by a binomial logistic regression analysis performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs).

Results

A total of 362 patients were analyzed. The LASSO selection variables, including all obtained variables, were as follows: age, palliative treatment, FACT-P physical well-being, and PC subscale score. Statistically significant variables predicting CE were palliative treatment (OR 0.23; 95% CI 0.09–0.60), physical well-being (OR 1.54; 95% CI 1.34–1.76), and PC subscale (OR 1.08; 95% CI 1.03–1.14).

Conclusions

This study revealed that palliative treatment and two FACT-P physical well-being and PC subscale scores were positively related to CE on the EQ-5D-5L. To our knowledge, this is the first study to examine predictors of CE on the EQ-5D-5L. The present results may be helpful for facilitating the consideration of “bolt-on” studies from the standpoint of PC patients.

Enzalutamide versus flutamide for castration-resistant prostate cancer after combined androgen blockade therapy with bicalutamide: the OCUU-CRPC study

BACKGROUND

Before the androgen target therapy era, flutamide was widely used for castration-resistant prostate cancer in Japan. Enzalutamide is currently the recommended treatment; however, the efficacy and safety of enzalutamide and flutamide after combined androgen blockade therapy with bicalutamide, has not been compared.

METHODS

Patients with castration-resistant prostate cancer who received combined androgen blockade therapy with bicalutamide were randomly assigned to receive either enzalutamide or flutamide. The primary endpoint for efficacy was the 3-month prostate-specific antigen response rate. This trial is registered with ClinicalTrials.gov (NCT02346578) and the University hospital Medical Information Network (UMIN000016301).

RESULTS

Overall, 103 patients were enrolled. The 3- (80.8% vs. 35.3%; p < 0.001) and 6-month (73.1% vs. 31.4%; p < 0.001) prostate-specific antigen response rates were higher in the enzalutamide than in the flutamide group. The 3-month disease progression rates (radiographic or prostate-specific antigen progression) were 6.4% and 38.8% in the enzalutamide and flutamide groups, respectively [hazard ratio (HR): 0.16; 95% confidence interval (CI): 0.05-0.47; p < 0.001]; the 6-month rates were 11.4% and 51.1%, respectively (HR 0.22; 95% CI 0.09-0.50; p < 0.001). Enzalutamide provided superior prostate-specific antigen progression-free survival compared with flutamide (HR 0.29; 95% CI 0.15-0.54; p < 0.001). Median time to prostate-specific antigen progression-free survival was not reached and was 6.6 months in the enzalutamide and flutamide groups, respectively.

CONCLUSIONS

As an alternative anti-androgen therapy in patients with castration-resistant prostate cancer who fail bicalutamide-combined androgen blockade therapy, enzalutamide provides superior clinical outcomes compared with flutamide. Enzalutamide should be preferred over flutamide in these patients.

The Effect of Treatment Sequence on Overall Survival for Men With Metastatic Castration-resistant Prostate Cancer: A Multicenter Retrospective Study

INTRODUCTION

We aimed to evaluate the treatment sequence for patients with metastatic castration-resistant prostate cancer (mCRPC) in real-world practice and compare overall survival in each sequential therapy.

PATIENTS AND METHODS

We retrospectively evaluated 146 patients with mCRPC who were initially treated with androgen deprivation therapy as metastatic hormone-naive prostate cancer in 14 hospitals between January 2010 and March 2019. The agents for the sequential therapy included new androgen receptor-targeted agents (ART: abiraterone acetate or enzalutamide), docetaxel, and/or cabazitaxel. We evaluated the treatment sequence for mCRPC and the effect of sequence patterns on overall survival.

RESULTS

The median age was 71 years. A total of 35 patients received ART-ART, 33 received ART-docetaxel, 68 received docetaxel-ART, and 10 received docetaxel-cabazitaxel sequences. The most prescribed treatment sequence was docetaxel-ART (47%), followed by ART-ART (24%). Overall survival calculated from the initial diagnosis reached 83, 57, 79, and 37 months in the ART-ART, ART-docetaxel, docetaxel-ART, and docetaxel-cabazitaxel, respectively. Multivariate Cox regression analyses showed no significant difference in overall survival between the first-line ART (n = 68) and first-line docetaxel (n = 78) therapies (hazard ratio [HR], 0.84; P = .530), between the ART-ART (n = 35) and docetaxel-mixed (n = 111) sequences (HR, 0.82; P = .650), and between the first-line abiraterone (n = 32) and first-line enzalutamide (n = 36) sequences (HR, 1.58; P = .384).

CONCLUSION

The most prescribed treatment sequence was docetaxel followed by ART. No significant difference was observed in overall survival among the treatment sequences in real-world practice.

Clinical Characterization of Low Prostate-specific Antigen on Prognosis in Patients With Metastatic Castration-naive Prostate Cancer

INTRODUCTION

This study aimed to investigate the effect of low prostate-specific antigen (PSA) on prognosis, as the association of initial PSA level with prognosis in patients with metastatic castration-naive prostate cancer (mCNPC) remains unclear.

PATIENTS AND METHODS

We evaluated 575 patients with mCNPC from 10 hospitals. Patients were stratified into 2 groups according to their initial PSA: PSA < 100 and PSA ≥ 100 groups. We compared castration-resistant prostate cancer (CRPC)-free survival, overall survival (OS), and OS from the CRPC diagnosis between the groups. Multivariate Cox regression analysis was performed to evaluate the effect of initial PSA level on prognosis.

RESULTS

Of the 575 patients, 196 (34%) patients belonged to the PSA < 100 group. No significant difference was found in patients' backgrounds except for PSA, the extent of disease, and high tumor burden between the groups. CRPC-free survival was significantly shorter in the PSA ≥ 100 group than in the PSA < 100 group. However, the OS after CRPC diagnosis was significantly shorter in the PSA < 100 group than that of the PSA ≥ 100 group. Multivariate analyses showed that PSA < 100 ng/mL was an independent factor for OS after CRPC, whereas no significant association was observed in the CRPC-free survival and OS.

CONCLUSIONS

A significant effect of initial PSA < 100 ng/mL on OS after CRPC was observed. PSA < 100 ng/mL might be a poor prognostic factor in patients with mCNPC after CRPC.

Phase I trial of TAK-385 in hormone treatment-naïve Japanese patients with nonmetastatic prostate cancer

This open‐label, phase I dose‐finding study evaluated the gonadotropin‐releasing hormone antagonist, TAK‐385, in Japanese patients with nonmetastatic prostate cancer. In a two‐part design, patients received daily oral TAK‐385 at doses of 320 (loading, day 1)/80 (maintenance, day 2 and thereafter), 320/120, 320/160, or 360/120 mg for 28 days in a dose‐escalation phase (part A, n = 13), and at 320/80 or 320/120 mg for up to 96 weeks in a randomized expansion phase (part B, n = 30). Primary endpoint in both parts was safety, including dose‐limiting toxicity in part A. Secondary endpoints included pharmacokinetics, pharmacodynamics, and prostate‐specific antigen concentration. Ten (77%) patients in part A and all patients in part B experienced an adverse event; hot flush (part A, n = 4; part B, n = 15), viral upper respiratory tract infection (part A, n = 1; part B, n = 10), and diarrhea (part B, n = 8) were most frequent. No dose‐limiting toxicities were observed (part A). In 12 evaluable patients (part A), TAK‐385 was rapidly absorbed after a single loading dose; on day 28 (maintenance dose), median steady‐state T_max was ~1‐2 hours and mean t_1/2z was 67‐79 hours. All doses rapidly reduced testosterone concentrations to castration levels within 1 week. Durable reductions in prostate‐specific antigen of >90% from baseline were observed through 96 weeks. TAK‐385 appeared tolerable and resulted in sustained reductions in testosterone to castration levels at all doses. The lowest loading/maintenance dose required for a clinical effect was 320/80 mg.

http://ClinicalTrials.gov: NCT02141659.

Time Trends for Prostate Cancer Incidence from 2003 to 2013 in South Korea: An Age-Period-Cohort Analysis

PURPOSE

Prostate cancer (PCa) incidence is affected by aging phenomenon and performance of screening test. In United States, PCa incidence is affected by period effect of U.S. Preventive Services Task Force (USPSTF) recommendation. However, no study has reported the effect of USPSTF recommendation or aging phenomenon on PCa incidence in South Korea. Thus, the objective of this study was to investigate effects of age, period, and birth cohort on PCa incidence using age-period-cohort analysis.

Materials and Methods

Annual report of cancer statistics between 2003 and 2013 from National Health Insurance Service (NHIS) in South Korea for the number of PCa patients and Korean Statistical Information Service (KOSIS) data between 2003 and 2013 from national statistics in South Korea for the number of Korean male population were used. Age-period-cohort models were used to investigate effects of age, period, and birth cohort on PCa incidence.

RESULTS

Overall PCa incidence in South Korea was increased 8.8% in annual percentage (95% confidential interval, 6.5 to 11.2; p < 0.001). It showed an increasing pattern from 2003 to 2011 but a decreasing pattern from 2011 to 2013. Age increased the risk of PCa incidence. However, the speed of increase was slower with increasing age. PCa incidence was increased 1.4 times in 2008 compared to that in 2003 or 2013. Regarding cohort effect, the risk of PCa incidence started to increase from 1958 cohort.

CONCLUSION

PCa incidence was affected by period of specific year. There was a positive cohort effect on PCa incidence associated with age structural change.

Screening for prostate cancer: History, evidence, controversies and future perspectives toward individualized screening

Differences in the incidence and mortality rate of prostate cancer between the USA and Japan have been decreasing over time, and were only twofold in 2017. Therefore, countermeasures against prostate cancer could be very important not only in Western countries, but also in developed Asian countries. Screening for prostate cancer in the general population using transrectal ultrasonography, digital rectal examination and/or prostate acid phosphatase began in Japan in the early 1980s, and screening with prostate-specific antigen and digital rectal examination has been widespread in the USA since the late 1980s. Large- and mid-scale randomized controlled trials on screening for prostate cancer began around 1990 in the USA, Canada and Europe. However, most of these studies failed as randomized controlled trials because of high contamination in the control arm, low compliance in the screening arm or insufficient screening setting about screening frequency and/or biopsy indication. The best available level 1 evidence is data from the European Randomized Study of Screening for Prostate Cancer and the Göteborg screening study. However, several non-urological organizations and lay media around the world have mischaracterized the efficacy of prostate-specific antigen screening. To avoid long-term confusion about screening for prostate cancer, leading professional urological organizations, including the Japanese Urological Association, are moving toward the establishment of an optimal screening system that minimizes the drawbacks of overdetection, overtreatment and loss of quality of life due to treatment, and maximizes reductions in the risk of death as a result of prostate cancer and the development of metastatic prostate cancer.

Efficacy of Androgen Deprivation Therapy in Patients with Metastatic Castration-Resistant Prostate Cancer Receiving Docetaxel-Based Chemotherapy

PURPOSE

The purpose of this study was to determine the comparative effectiveness of androgen deprivation therapy (ADT) combined with docetaxel (DTX)-based chemotherapy in Korean and Japanese castration-resistant prostate cancer (CRPC) patient cohorts.

MATERIALS AND METHODS

Metastatic CRPC patients who underwent more than three DTX-based chemotherapy cycles in Korea and Japan between 2002 and 2017 were retrospectively analyzed and divided into the DTX-only (DTX, n=30) and combination (DTX+ADT, n=46) groups. Progression-free survival (PFS) was calculated as the time from the start of chemotherapy to the occurrence of either disease progression (prostate-specific antigen [PSA] progression or radiographic progression) or death. The primary end point was PFS and the secondary end point was overall survival (OS).

RESULTS

In the DTX and DTX+ADT groups, the median PFS was 6.0 and 11.0 months (log-rank p=0.053). The multivariate Cox regression analysis revealed that the significant predicting factors of PFS were ADT administration (hazard ratio [HR], 0.478; 95% confidence interval [CI], 0.284-0.804; p=0.005) and number of DTX-based chemotherapy cycles (HR, 0.934; 95% CI, 0.899-0.970; p<0.001). In the DTX and DTX+ADT groups, the median OS was 16.0 and 19.5 months (log-rank p=0.825). Through multiple Cox regression analysis, we found that the significant predicting factors of OS were the PSA nadir level (HR, 1.001; 95% CI, 1.000-1.002; p<0.001) and number of DTX-based chemotherapy cycles (HR, 0.932; 95% CI, 0.876-0.991; p=0.024).

CONCLUSIONS

Concurrent DTX-based chemotherapy and ADT may be beneficial compared with DTX-based chemotherapy alone in chemotherapy-naïve metastatic CRPC patients in terms of the PFS, but not the OS.

Health utility and health-related quality of life of Japanese prostate cancer patients according to progression status measured using EQ-5D-5L and FACT-P

PURPOSE

To obtain health utility data to allow for cost-effectiveness analysis in groups stratified by disease progression along with health-related quality of life (HRQoL) information in Japanese prostate cancer (PC) patients.

METHODS

In this cross-sectional observational study, EuroQol-5 Dimension- 5 Level (EQ-5D-5L), EuroQol Visual Analog Scale (EQ-VAS), and Functional Assessment of Cancer Therapy-Prostate (FACT-P) measures were used to examine utility, VAS scores, and disease-specific HRQoL, respectively. Scores obtained were statistically examined for the correlation among measures and domains. Parameter estimates of statistically significant factors were assessed using generalized linear models (GLM).

RESULTS

A total of 380 patients stratified by their disease progression status were analyzed. The numbers (%) of patients in groups stratified as having localized (L), localized progression (LP), distant metastatic (DM), and DM-castration-resistant PC (CRPC) were 275 (72.4), 40 (10.5), 27 (7.1), and 38 (10.0), respectively. EQ-5D-5L mean (standard deviation, SD) scores of L, LP, DM, and DM-CRPC in study participants were 0.87 (0.15), 0.86 (0.15), 0.85 (0.18), and 0.84 (0.17), respectively. The mean (SD) scores assessed by EQ-5D-5L, EQ-VAS, and FACT-P instruments were 0.86 (0.16), 74.6 (16.8), and 110.8 (19.6), respectively. Utility scores correlated well with FACT-P scores. Eastern Cooperative Oncology Group performance status had significant influences on all instruments' scores.

CONCLUSIONS

We obtained health utility and HRQoL scores of Japanese PC patients stratified by disease progression in detail. Our results will be useful for establishing cost-effectiveness analyses in Japanese PC settings.

Three-year follow-up of a phase II study of radium-223 dichloride in Japanese patients with symptomatic castration-resistant prostate cancer and bone metastases

BACKGROUND

Radium-223 is a first-in-class targeted alpha therapy to prolong overall survival (OS) in castration-resistant prostate cancer with bone metastases (mCRPC). The aim of the present analysis was to assess the long-term safety with radium-223 in Japanese patients with mCRPC.

METHODS

Patients with symptomatic mCRPC, ≥ 2 bone metastases and no known visceral metastases received up to 6 injections of radium-223 (55 kBq/kg), one every 4 weeks. Adverse events (AEs) considered to be related to radium-223 were reported until 3 years after the first injection. Pre-specified conditions, such as acute myelogenous leukemia, myelodysplastic syndrome, aplastic anemia, primary bone cancer, or other primary malignancies, were reported regardless of causality.

RESULTS

Of the 49 patients enrolled in the study, 44 (89.8%) entered the survival follow-up period and 33 (67.3%) died. Throughout the entire study, there were no reports of second primary malignancy or other pre-specified conditions. Eight patients (16.3%) experienced post-treatment drug-related AEs, which were all hematological (anemia and decreased lymphocyte, platelet, and white blood cell counts). No serious post-treatment drug-related AEs were reported. Updated median OS was 19.3 months (95% CI: 14.2, 28.5).

CONCLUSIONS

In Japanese patients with symptomatic mCRPC and bone metastases, radium-223 had a favorable long-term safety profile with no second primary malignancies reported. Taken together with median OS, which was comparable to that in the pivotal phase III ALSYMPCA study, these results support continued benefit from radium-223 in Japanese patients with mCRPC.