Stratification of patients with metastatic prostate cancer based on extent of disease on initial bone scan

Impact of nutritional status on the prognosis of patients with metastatic hormone-naïve prostate cancer: a multicenter retrospective cohort study in Japan

PURPOSE

To investigate the association between the Geriatric Nutritional Risk Index (GNRI) and prognosis of patients with metastatic hormone-naïve prostate cancer (mHNPC) and to design the optimal risk score predicting for prognosis.

METHODS

We retrospectively reviewed data from the Michinoku Japan Urological Cancer Study Group database, containing information about 656 patients with mHNPC who initially received androgen-deprivation therapy between 2005 and 2017. The baseline GNRI was calculated using serum albumin level and body mass index. Poor nutrition was defined as GNRI < 92.0. The impact of GNRI, CHAARTED criteria, and laboratory parameters on oncological outcomes was investigated using the multivariable Cox regression models. We developed the risk comprising GNRI and laboratory parameters and compared its prognostic performance with the CHAARTED criteria using the receiver operating characteristic curve with the DeLong method.

RESULTS

Of 339 patients with sufficient data, 66 (19%) were diagnosed with poor nutrition. Multivariate analyses showed that GNRI < 92.0 was an independent prognostic factor of cancer-specific survival [hazard ratio (HR) 1.76; 95% confidence interval (CI) 1.04-2.98, P = 0.035] and overall survival (HR 1.80; 95% CI 1.13-2.89, P = 0.013), in addition to hemoglobin (Hb) and lactic dehydrogenase (LDH) levels. We designed the risk score comprising GNRI < 92.0, Hb < 13.0 g/dL, and LDH > 222 IU/L. The predictive value of the risk score was significantly superior to that of the CHAARTED criteria.

CONCLUSIONS

Poor nutrition may predict mortality in patients with mHNPC. Risk factors, such as nutritional status and laboratory parameters, may be useful in decision-making regarding aggressive treatments for patients with mHNPC.

Development and Validation of a Novel Prognostic Model for Predicting Overall Survival in Treatment-naïve Castration-sensitive Metastatic Prostate Cancer

BACKGROUND

There has been growth in the treatment options for castration-sensitive metastatic prostate cancer (mPCa), but without clear guidance for risk stratification.

OBJECTIVE

To identify clinical parameters associated with overall survival (OS) and establish a prognostic model for use with treatment-naïve castration-sensitive mPCa.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective review of 304 patients treated at Kyoto University Hospital was performed. A prognostic model was created using clinical parameters associated with OS. The model was externally validated in an independent cohort of 520 patients.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Multivariable analysis was performed to identify the clinical parameters associated with OS. Risk scores were calculated using Cox proportional hazards analysis for each combination of risk factors, and patients were grouped into categories based on those scores.

RESULTS AND LIMITATIONS

Over 80% of the cohort had a Gleason sum score ≥8. The median OS was 53mo among patients with CHAARTED high-volume PCa (n=172) and 131mo among those with low-volume PCa (n=100). Independent factors associated with OS were extent of disease score ≥2 or the presence of liver metastasis; lactate dehydrogenase >250U/L; and a primary Gleason score of 5. The median OS for the high-, intermediate-, and low-risk groups according to the new model were 28mo, 59mo, and not reached, respectively; the corresponding values in the validation cohort were 41mo, 63mo, and not reached. Harrell's C-index was 0.649.

CONCLUSIONS

Our simple and reproducible prognostic model for treatment-naïve castration-sensitive mPCa could aid in risk stratification and treatment selection.

PATIENT SUMMARY

We identified clinical parameters associated with prognosis in castration-sensitive metastatic prostate cancer and established a reproducible prognostic model that could be used to guide treatment decisions.

Treatment of the primary tumor in metastatic prostate cancer

The cornerstone of treatment for metastatic prostate cancer patients has been conventional androgen deprivation therapy, with additional systemic therapy initiated only after castration resistance, and local therapy reserved for palliation. Compelling results from modern trials challenge this paradigm, arguing for initiating escalated hormone therapy and/or chemotherapy during the castration-sensitive disease state for many patients. Furthermore, modern radiotherapy techniques allow for local control of disease with low risk of toxicity. Finally, new PET probes with enhanced sensitivity and accuracy are likely to become a part of routine staging and will lead to an increased incidence of patients with metastatic disease at presentation, with a shift toward identification of patients with limited metastatic disease. As such, the landscape is primed for investigations aimed to explore the role of primary tumor therapy for patients with metastatic prostate cancer. We review the existing data evaluating primary tumor therapy for patients with metastatic prostate cancer and describe ongoing clinical trials testing the hypothesis that primary tumor therapy may benefit patients with metastatic prostate cancer.

Novel Insights into the Management of Oligometastatic Prostate Cancer: A Comprehensive Review

CONTEXT

The current standard of care for metastatic prostate cancer (PCa) is androgen deprivation therapy (ADT) plus either docetaxel or abiraterone. Growing evidence suggests that metastasis-directed therapy (MDT) and/or local therapy targeted to the primary tumour (ie, prostate) may be of benefit in the setting of oligometastatic disease. Several prospective studies are underway; however, until robust evidence is available to guide treatment decisions, physicians are challenged with how best to manage patients with oligometastases.

OBJECTIVE

This comprehensive review aims to collate the available evidence to date for a role of MDT and/or prostate-targeted therapy in the setting of oligometastatic PCa, as well as discuss ongoing trials in this setting.

EVIDENCE ACQUISITION

We searched PubMed for the combination of "prostate cancer" and "oligometastatic", "oligometastases", "oligometastasis", "solitary metastases", "stereotactic body radiotherapy", "SBRT", "stereotactic ablative radiotherapy", "SABR", "salvage lymphadenectomy", or "metastasectomy" in publications over the last 20yr. We also searched ClinicalTrials.gov to identify relevant ongoing trials.

EVIDENCE SYNTHESIS

The studies were divided according to the timing of metastasis into synchronous (ie, detected at the time of primary PCa diagnosis) and metachronous (ie, detected after treatment of the primary tumour), and according to treatment modality into MDT (including salvage lymph node dissection [sLND]) and prostate-targeted treatment. For MDT of synchronous/metachronous metastases, we included 16 completed studies and 11 ongoing prospective studies. In the case of sLND for nodal-only recurrence after primary treatment with curative intent, we included 11 completed studies. Finally, for prostate-targeted treatment of synchronous metastatic PCa, we included 25 completed studies and 11 ongoing prospective studies. In selected patients with oligorecurrent disease, early detection and aggressive treatment of metastatic lesions (surgery or radiotherapy) appears to be a feasible strategy and may delay the use of systemic therapies. MDT is a promising option in oligometastatic PCa patients, but more robust data are needed. In the setting of synchronous oligometastatic disease, aggressive cytoreductive treatment needs further data to confirm the benefits.

CONCLUSIONS

In this review, we provide a comprehensive overview of the current literature on the treatment of patients with oligometastatic PCa. The data suggest that although ADT plus either docetaxel or abiraterone remains the mainstay of treatment for mPCa, in oligometastatic PCa, improved outcomes may be achieved with metastasis- and prostate-targeted therapies. The studies included in this review are mainly retrospective in nature, limiting the strength of the evidence they provide. Prospective studies are ongoing, and their results are eagerly awaited.

PATIENT SUMMARY

We reviewed the treatment of patients with prostate cancer that has spread to five sites or fewer. We conclude that while androgen deprivation plus either docetaxel or abiraterone should remain the standard of care, there is evidence that treatment targeted at the metastases and the primary tumour may improve the outcome for the patient and potentially delay the use of systemic treatment.

Collateral resistance to taxanes in enzalutamide-resistant prostate cancer through aberrant androgen receptor and its variants

Currently, the optimal sequential use of androgen receptor (AR) axis-targeted agents and taxane chemotherapies remains undetermined. We aimed to elucidate the resistance status between taxanes and enzalutamide, and the functional role of the AR axis. Enzalutamide-resistant 22Rv1 cells showed collateral resistance to taxanes, including docetaxel and cabazitaxel. However, taxane-resistant cells showed no collateral resistance to enzalutamide; taxane-resistant cells expressed comparable protein levels of full-length AR and AR variants. Knockdown of both full-length AR and AR variants rendered cells sensitive to taxanes, whereas knockdown of AR variants sensitized cells to enzalutamide, but not to taxanes. In contrast, overexpression of full-length AR rendered cells resistant to taxanes. Consistently, the prostate-specific antigen response and progression-free survival in docetaxel chemotherapy were worse in cases with prior use of ARAT agents compared with cases without. Collateral resistance to taxanes was evident after obtaining enzalutamide resistance, and aberrant AR signaling might be involved in taxane resistance.

Evaluation of RECIST, PERCIST, EORTC, and MDA Criteria for Assessing Treatment Response with Ga68-PSMA PET-CT in Metastatic Prostate Cancer Patient with Biochemical Progression: a Comparative Study

Purpose

The aim of the study was to compare response evaluation criteria in solid tumours 1.1 (RECIST 1.1), positron emission tomography response criteria in solid tumours (PERCIST), European organisation for research and treatment of cancer (EORTC), and MD Anderson (MDA) criteria for response assessment by Gallium 68-prostate-specific membrane antigen positron emission tomography-computed tomography (Ga68-PSMA PET-CT) in metastatic adenocarcinoma prostate cancer (mPCa) patients with biochemical progression.

Methods

Eighty-eight mPCa patients with pre and post treatment Ga68-PSMA PET-CT were included. A ≥ 25% increase and ≥ 2 ng/ml above the nadir if prostate specific antigen (PSA) drop or ≥ 2 ng/ml above the baseline if PSA does not drop was considered as biochemical progression. RECIST 1.1 and MDA criteria for morphology and PERCIST and EORTC criteria for molecular response were investigated. Percentages of progressive disease (PD), partial response (PR), and stable disease (SD) were calculated. Chi-square test was used for statistical significance.

Results

Proportion of PD, SD, and PR by RECIST 1.1 and MDA criteria were 44 (50.57%), 39 (44.83%), 4 (4.6%), and 33 (39.76%), 48 (57.83%), 2 (2.41%) respectively. Proportion of PD, SD, and PR by PERCIST and EORTC criteria were 71 (80.68%), 11 (12.50%), 6 (6.82%), and 74 (84.09%), 8 (9.09%), 6 (6.82%) respectively. Chi-square test showed statistically significant (P < 0.05) higher proportion of progression detected by both molecular criteria as compare to both morphological criteria.

Conclusion

We concluded that for Ga68-PSMA PET-CT response evaluation, molecular criteria performed better than morphological criteria in mPCa patient with PSA progression.

Is cryosurgery a feasible local therapy for bone metastatic prostate cancer?

INTRODUCTION

This study aims to assess whether cryosurgery is a feasible local therapy for bone metastatic prostate cancer (bmPCa).

METHODS

A total of 23 patients with bmPCa who received cryosurgery and adjuvant androgen deprivation therapy (ADT) were included in the cryosurgery group (Group 1). Another 23 matched patients who received only ADT served as the control (Group 2). Prostate-specific antigen (PSA) nadir level, time to PSA nadir, time to castration-resistant prostate cancer (CRPC), progression-free survival and therapy response of bone metastases were compared between the groups.

RESULTS

The median follow-up time in Group 1 and Group 2 patients was 37 (range 19-53) months and 42 (range 24-56) months, respectively. Patients in Group 1 had fewer local complications, lower PSA nadir level (0.23 ng/mL vs. 4.01 ng/mL; p = 0.024), shorter median time to PSA nadir (3 months vs. 7 months; p < 0.001), longer median time to CRPC (36 months vs. 27 months; p = 0.002) and longer progression-free survival (35 months vs. 26 months; p = 0.003) compared to those in Group 2. Therapy responses of bone metastases were similar in the two treatment groups (p = 0.689).

CONCLUSION

Cryosurgery is a feasible local therapy for bmPCa patients with prostate volume less than 50 mL and without bulk tumours outside the prostate capsula. Cryosurgery may decrease PSA nadir level, local complications and time to PSA nadir, delay time to CRPC and improve progression-free survival.

Time of metastatic disease presentation and volume of disease are prognostic for metastatic hormone sensitive prostate cancer (mHSPC)

BACKGROUND

Currently, there is no universally accepted prognostic classification for patients (pts) with metastatic hormone sensitive prostate cancer (mHSPC) treated with androgen deprivation therapy (ADT). Subgroup analyses demonstrated that pts with low volume (LV), per CHAARTED trial definition, mHSPC, and those who relapse after prior local therapy (PLT) have longer overall survival (OS) compared to high volume (HV) and de-novo (DN), respectively. Using a hospital-based registry, we aimed to assess whether a classification based on time of metastatic disease (PLT vs DN) and disease volume (LV vs HV) are prognostic for mHSPC pts treated with ADT.

METHODS

A retrospective cohort of consecutive patients with mHSPC treated with ADT between 1990 and 2013 was selected from the prospectively collected Dana-Farber Cancer Institute database and categorized as DN or PLT and HV or LV, at time of ADT start. Primary and secondary endpoints were OS and time to castration-resistant prostate cancer (CRPC), respectively, which were measured from date of ADT start using Kaplan-Meier method. Multivariable Cox proportional hazards models using known prognostic factors was used.

RESULTS

The analytical cohort consisted of 436 patients. The median OS and time to CRPC for PLT/LV were 92.4 (95%CI: 80.4-127.2) and 25.6 (95%CI: 21-35.7) months and 43.2 (95%CI: 37.2-56.4) and 12.2 (95%CI: 9.8-14.8) months for DN/HV, respectively, whereas intermediate values were observed for PLT/HV and DN/LV. A robust gradient for both outcomes was observed (Trend test P < 0.0001) in the four groups. In a multivariable analysis, DN presentation, HV, and cancer-related pain were independent prognostic factors.

CONCLUSIONS

In our hospital-based registry, time of metastatic presentation and disease volume were prognostic for mHSPC pts treated with ADT. This simple prognostic classification system can aid patient counseling and future trial design.

Prospective comparative study of 18F-sodium fluoride PET/CT and planar bone scintigraphy for treatment response assessment of bone metastases in patients with prostate cancer

AIM

To compare ¹⁸F-sodium fluoride positron emission tomography/computed tomography (NaF PET/CT) and ^99mTc-labelled diphosphonate bone scan (BS) for the monitoring of bone metastases in patients with prostate cancer undergoing anti-cancer treatment.

MATERIAL AND METHODS

Data from 64 patients with prostate cancer were included. The patients received androgen-deprivation therapy (ADT), next-generation hormonal therapy (NGH) or chemotherapy. The patients had a baseline scan and 1-3 subsequent scans during six months of treatment. Images were evaluated by experienced nuclear medicine physicians and classified for progressive disease (PD) or non-PD according to the Prostate Cancer Working Group 2 (PCWG-2) criteria. The patients were also classified as having PD/non-PD according to the clinical and prostate-specific antigen (PSA) responses.

RESULTS

There was no difference between NaF PET/CT and BS in the detection of PD and non-PD during treatment (McNemar's test, p = .18). The agreement between BS and NaF PET/CT for PD/non-PD was moderate (Cohen's kappa 0.53, 95% confidence interval 0.26-0.79). Crude agreement between BS and NaF PET/CT for the assessment of PD/non-PD was 86% (89% for ADT, n = 28; 88% for NGH, n = 16, and 80% for chemotherapy, n = 20). In most discordant cases, BS found PD when NaF PET/CT did not, or BS detected PD on an earlier scan than NaF PET/CT. Biochemical progression (27%) occurred more frequently than progression on functional imaging (BS, 22% and NaF PET/CT, 14%). Clinical progression was rare (11%), and almost exclusively seen in patients receiving chemotherapy.

CONCLUSION

There was no difference between NaF PET/CT and BS in the detection of PD and non-PD; however, BS seemingly detects PD by the PCWG-2 criteria earlier than NaF-PET, which might be explained by the fact that NaF-PET is more sensitive at the baseline scan.

223Ra-Dichloride in castration-resistant metastatic prostate cancer: improving outcomes and identifying predictors of survival in clinical practice

Purpose

We first assessed whether the pattern of referrals to a nuclear medicine clinic improved as experience with ²²³Ra-dichloride increased, and whether referral patterns affected patient outcomes, and second assessed the value of bone scintigraphy, total alkaline phosphatase (tALP) and lymphadenopathy as prognostic factors in patients receiving ²²³Ra-dichloride.

Methods

A total of 57 patients eligible to receive ²²³Ra-dichloride over a 2-year period (March 2014 to March 2016) were retrospectively assessed and prospectively followed (median follow up 298 days). ²²³Ra-Dichloride was administered at 4-week intervals for a maximum of six injections. The numbers of patients in years 1 and 2 referred in relation to extent of bone disease (EOBD) category and overall survival (OS) were determined. The prognostic factors EOBD category, baseline tALP (tALP_BL), tALP response, greatest percentage reduction in tALP from baseline in any treatment cycle (ALP_max; among patients with elevated ALP_BL), and the presence of lymphadenopathy were assessed as predictors of OS.

Results

The proportion of patients with EOBD1 was higher in year 2 than in year 1 (29% and 4%, respectively), and in year 2 there was a lower rate of symptomatic skeleton-related events, a higher proportion of patients completing six cycles, and longer (albeit nonsignificant) OS (p = 0.55). There were significant differences in OS between EOBD4 patients and those in all other groups and between EOBD1 and EOBD3 patients (p < 0.05). OS was longer in patients with normal tALP_BL than in those with elevated tALP_BL (p = 0.01), in ALP responders than in nonresponders (p < 0.05), and in patients without lymphadenopathy than in those with lymphadenopathy (p = 0.29). OS was correlated with ALP_max (r² = 0.24).

Conclusion

A collaborative multidisciplinary referrals pathway, together with increased experience with ²²³Ra-dichloride, led to improved outcomes. In patients with elevated tALP_BL, tALP dynamics may be useful for monitoring response and predicting OS. Imaging and prognostic markers may therefore be of value for individualizing ²²³Ra-dichloride treatment and planning retreatment; however, further studies are required.

Extensive periosteal new bone formation in a skeleton from post-Medieval Chichester, England: A probable case of metastatic prostatic carcinoma

An elderly male skeleton from a site in Chichester, UK, was found with a widespread periosteal reaction, principally affecting the axial skeleton and the pelvis. Radiography showed the presence of sclerosing infiltrates, mainly involving the lumbar vertebrae and pelvis. The differential diagnosis is discussed, reaching the conclusion that hypertrophic osteo-arthopathy (HOA) is the only reasonable alternative condition likely to produce such a widespread periosteal reaction as found here. HOA does not produce secondary deposits in the skeleton, however, and we conclude that his is most likely a case of prostatic carcinoma.

AR-V7 in circulating tumor cells cluster as a predictive biomarker of abiraterone acetate and enzalutamide treatment in castration-resistant prostate cancer patients

OBJECTIVE

We examined whether androgen receptor splice variant 7 (AR-V7) in circulating tumor cell(CTC)clusters can be used to predict survival in patients with bone metastatic castration resistant-prostate cancer (mCRPC) treated with abiraterone or enzalutamide.

METHODS

We retrospectively enrolled 98 patients with CRPC on abiraterone or enzalutamide, and investigated the prognostic value of CTC cluster detection (+ v -) and AR-V7 detection (+ v -) using a CTC cluster detection - based AR-V7 mRNA assay. We examined ≤50% prostate-specific antigen (PSA) responses, PSA progression-free survival (PSA-PFS), clinical and radiological progression-free survival (radiologic PSF), and overall survival (OS). We then assessed whether AR-V7 expression in CTC clusters identified after On-chip multi-imaging flow cytometry was related to disease progression and survival after first-line systemic therapy.

RESULTS

All abiraterone-treated or enzalutamide-treated patients received prior docetaxel. The median follow-up was 20.7 (range: 3.0-37.0) months in the abiraterone and enzalutamide cohorts, respectively. Forty-nine of the 98 men (50.0%) were CTC cluster (-), 23 of the 98 men (23.5%) were CTC cluster(+)/AR-V7(-), and 26 of the 98 men (26.5%) were CTC cluster(+)/AR-V7(+). CTC cluster(+)/AR-V7(+) patients were more likely to have EOD ≥3 at diagnosis (P = 0.003), pain (P = 0.023), higher alkaline phosphatase levels (P < 0.001), and visceral metastases (P < 0.001). On multivariable analysis, pretherapy CTC cluster(+), CTC cluster(+)/AR-V7(-), and ALP >UNL were independently associated with a poor PSA-PFS, radiographic PFS, and OS in abiraterone-treated patients and enzalutamide-treated patients.

CONCLUSION

The CTC clusters and AR-V7-positive CTC clusters detected were important for assessing the response to abiraterone or enzalutamide therapy and for predicting disease outcome.

Usefulness of combined androgen blockade therapy with gonadotropin-releasing hormone antagonist for bone metastatic prostate cancer with pretreatment prostate-specific antigen level ≥ 50 ng/mL

BACKGROUND

This study was performed to examine the usefulness of combined androgen blockade (CAB) therapy with a gonadotropin-releasing hormone (GnRH) antagonist (CAB-antagonist therapy), instead of CAB therapy with GnRH agonist (CAB-agonist therapy) against very high-risk prostate cancer (Pca).

METHODS

We retrospectively studied 84 Pca patients with pretreatment prostate-specific antigen (PSA) level ≥ 50 ng/mL, who were pathologically diagnosed between January 2007 and December 2016. GnRH antagonist was administered to 34 patients and GnRH agonist was administered to 50 patients. All patients received concurrent antiandrogen treatment. The primary end point was PSA progression-free survival (PSA-PFS).

RESULTS

PSA-PFS was significantly longer for the CAB-antagonist group compared to the CAB-agonist group (log-rank test, P <  0.01) in Pca patients with more than six bone metastases (the extent of disease [EOD] grade 2-4). On multivariate analysis, CAB-antagonist therapy was shown to be a possible prognostic factor for PSA-PFS (adjusted hazard ratio: 0.41, 95% confidence interval: 0.16-0.90, P = 0.03).

CONCLUSIONS

CAB-antagonist therapy may be a useful option in bone metastatic Pca patients with EOD grade 2-4.

Mineralocorticoid receptor signaling affects therapeutic effect of enzalutamide

BACKGROUND

Corticosteroids play important roles in prostate cancer therapeutics. However, their role when combined with enzalutamide remains obscure. Then, we aimed to elucidate the functional and clinical impact of corticosteroids on steroid receptors in androgen receptor (AR)-targeting therapy utilizing enzalutamide.

METHODS

The therapeutic effect was studied according to concomitant use of corticosteroids in 86 men treated with enzalutamide. The sensitivity to various agents was evaluated using cytotoxicity assays in prostate cancer cells. Gene expression levels were evaluated by quantitative real-time polymerase chain reaction in prostate cancer cells and tissues.

RESULTS

The therapeutic effect of enzalutamide was particularly lessened with concomitant treatment with dexamethasone. Consistently, dexamethasone increased cellular resistance to enzalutamide while prednisolone and aldosterone decreased cellular resistance to enzalutamide in prostate cancer cells. Inversely, mineralocorticoid receptor (MR) knockdown augmented the activity of AR signaling and the cellular resistance to enzalutamide.

CONCLUSIONS

MR plays a critical role in resistance to AR-targeting therapies, which may be overcome by activation of MR signaling.

Impact of early changes in serum biomarkers following androgen deprivation therapy on clinical outcomes in metastatic hormone-sensitive prostate cancer

Background

Less evidence is known about the role of early changes in serum biomarker after androgen deprivation therapy (ADT) in patients with metastatic hormone-sensitive prostate cancer (mHSPC). Here we evaluated the impact of pre-treatment prognostic factors and early changes in serum biomarkers on prostate specific antigen (PSA) progression-free and overall survival rates in mHSPC.

Methods

We retrospectively reviewed the medical records of 60 mHSPC patients (median age 72 years) treated with ADT whose laboratory data at baseline and following 12 weeks were available.

Results

Forty-four patients (73%) had PSA progression and 27 patients (45.0%) died during a median follow-up of 34 months. The multivariable Cox hazard model demonstrated that a log-transformed baseline PSA level (p = 0.003) and an extent of bone disease (EOD) score of ≥3 (p = 0.004) were statistically associated with an increased risk for PSA progression whereas one unit increase in a log-transformed PSA change (baseline-12 weeks) was associated with a decreased risk for PSA progression (p = 0.004). For overall survival, a high level of alkaline phosphatase (ALP) at 12 weeks was associated with increased risk (p = 0.030) whereas a one-unit increase in the log-transformed PSA change was associated with decreased risk (p = 0.001).

Conclusions

An increased level of PSA at baseline, or an EOD score of ≥3 may be a good predictor of PSA progression, and a high level of ALP at 12 weeks may be a risk predictor of death. A larger decline in PSA at 12 weeks from the baseline was associated with both PSA progression-free and overall survival time. Early changes in serum biomarkers may be useful in predicting poor outcomes in patients with mHSPC who are initially treated with ADT.

Radium-223 for primary bone metastases in patients with hormone-sensitive prostate cancer after radical prostatectomy

Radium-223 dichloride (Ra-223) is the first bone-targeting agent showing improvement in overall survival in patients with castration-resistant prostate cancer (CRPC) and bone metastases. We aimed to assess feasibility of Ra-223 treatment in patients with metastatic hormone-sensitive prostate cancer (mHSPC). Ten patients with primary bone metastases received Ra-223 following radical prostatectomy (RP). Changes in alkaline phosphatase (ALP) and prostate-specific antigen (PSA) were recorded, while pain intensity was evaluated using the self-reporting Brief Pain Inventory (BPI) questionnaire. Bone scintigraphy (BS) was performed to assess treatment response. Seven patients completed six cycles of Ra-223. Discontinuation was due to leuko- and lymphopenia, progressive lymph node metastasis or newly diagnosed liver metastasis. Treatment-related adverse events occurred in three patients and included leuko- and lymphopenia, fatigue, abdominal discomfort and nausea. Overall, a median decrease of 28% in ALP and a median decrease of 83% in PSA were noted at follow-up. However, PSA progressed in five patients at follow-up. Improvement of pain was observed in all patients (median decrease of 36% after 3 cycles and of 40% at the end of therapy). On BS, three patients showed remission, four had stable disease, and one showed progressive disease at follow-up. Our results suggest that Ra-223 for primary bone metastases in patients with mHSPC after RP is feasible and alleviates pain. ALP, rather than PSA, may be a good marker for assessing treatment response. Ra-223 could therefore be taken into consideration as part of a multimodal approach for carefully selected patients with advanced prostate cancer.

The Value of Pretreatment Clinical and Biochemical Parameters in Staging and Prognostic Stratification of Patients with Newly Diagnosed Prostate Carcinoma

Purpose

To determine whether it is possible to select patients in whom and for what reason bone scintigraphy should be performed or not, a retrospective study was performed of 161 consecutive patients with newly diagnosed prostate cancer.

Materials and methods

Follow-up varied from 1 to 88 months during which 67 patients died. Bone scans were classified from 0 (= normal) to 3 (typical pattern of metastases) and were correlated with age, alkaline phosphatase (AP), prostate specific antigen (PSA), tumor grade, TNM-stage and survival. For survival, 68 patients who were not referred for bone scintigraphy were also evaluated.

Results

All parameters demonstrated a correlation with the incidence of a positive bone scan, but PSA was the best overall predictor in this (p<0.0001). None of the patients with PSA ≤ 20 ng/ml (n=64) showed metastases, whereas 8 of 9 patients with PSA > 1000 ng/ml and patients with PSA values between 20 and 1000 ng/ml in combination with AP >90 U/L (n=24) had bone metastases. Furthermore, a class 3 bone scan was found to be the most important parameter in assessing prognosis and survival (p<0.0001), whereas no differences were found in patients with a class 0, 1 and 2 scintigram.

Conclusions

For staging and prognostic stratification purposes, bone scintigraphy and additional roentgenograms are of value in a selected group of patients. In contrast with a typical pattern of metastases on bone scintigraphy, an abnormal scan (class 1 and 2) at the time of diagnosis is not a poor prognostic parameter of the risk of death. Bone scintigraphy can be omitted in patients with PSA values < 20 ng/ml. In patients with PSA levels > 1000 ng/ml or less increased levels combined with alkaline phosphatase levels > 90 U/L, bone scintigraphy seems to be of no value in staging disease.

First Report of NRG Oncology/Radiation Therapy Oncology Group 0622: A Phase 2 Trial of Samarium-153 Followed by Salvage Prostatic Fossa Irradiation in High-Risk Clinically Nonmetastatic Prostate Cancer After Radical Prostatectomy

PURPOSE

To investigate the utility of ¹⁵³Sm lexidronam (Quadramet) in the setting of men with prostate cancer status post radical prostatectomy who develop biochemical failure with no clinical evidence of osseous metastases.

PATIENTS AND METHODS

Trial NRG Oncology RTOG 0622 is a single-arm phase 2 trial that enrolled men with pT2-T4, N0-1, M0 prostate cancer status post radical prostatectomy, who meet at least 1 of these biochemical failure criteria: (1) prostate-specific antigen (PSA) > 1.0 ng/mL; (2) PSA > 0.2 ng/mL if Gleason score 9 to 10; or (3) PSA > 0.2 ng/mL if N1. Patients received ¹⁵³Sm (2.0 mCi/kg intravenously × 1) followed by salvage external beam radiation therapy (EBRT) to the prostatic fossa (64.8-70.2 Gy in 1.8-Gy daily fractions). No androgen deprivation therapy was allowed. The primary objective was PSA response within 12 weeks of receiving ¹⁵³Sm. The secondary objectives were to: (1) assess the completion rate for the regimen of ¹⁵³Sm and EBRT; (2) evaluate the hematologic toxicity and other adverse events (AEs) at 12 and 24 weeks; and (3) determine the freedom from progression rate at 2 years.

RESULTS

A total of 60 enrolled eligible patients were included in this analysis. Median follow-up was 3.97 years. A PSA response was achieved in 7 of 52 evaluable patients (13.5%), compared with the 25% hypothesized. The 2-year freedom from progression rate was 25.5% (95% confidence interval 14.4%-36.7%), and the biochemical failure rate was 64.4% (95% CI 50.5%-75.2%). Samarium-153 was well tolerated, with 16 (of 60) grade 3 to 4 hematologic AEs and no grade 5 hematologic AEs. Radiation therapy was also well tolerated, with no grade 3 to 5 acute radiation therapy-related AEs and 1 grade 3 to 4 and no grade 5 late radiation therapy-related AEs.

CONCLUSIONS

Trial NRG Oncology RTOG 0622 did not meet its primary endpoint of PSA response, although the regimen of ¹⁵³Sm and salvage EBRT was well tolerated. Although the toxicity profile supports study of ¹⁵³Sm in high-risk disease, it may not be beneficial in men receiving EBRT.

APE1/Ref-1 redox-specific inhibition decreases survivin protein levels and induces cell cycle arrest in prostate cancer cells

A key feature of prostate cancer progression is the induction and activation of survival proteins, including the Inhibitor of Apoptosis (IAP) family member survivin. Apurinic/apyrimidinic endonuclease 1/redox effector factor 1 (APE1/Ref-1) is a multifunctional protein that is essential in activating oncogenic transcription factors. Because APE1/Ref-1 is expressed and elevated in prostate cancer, we sought to characterize APE1/Ref-1 expression and activity in human prostate cancer cell lines and determine the effect of selective reduction-oxidation (redox) function inhibition on prostate cancer cells in vitro and in vivo. Due to the role of oncogenic transcriptional activators NFĸB and STAT3 in survivin protein expression, and APE1/Ref-1 redox activity regulating their transcriptional activity, we assessed selective inhibition of APE1/Ref-1's redox function as a novel method to halt prostate cancer cell growth and survival. Our study demonstrates that survivin and APE1/Ref-1 are significantly higher in human prostate cancer specimens compared to noncancerous controls and that APE1/Ref-1 redox-specific inhibition with small molecule inhibitor, APX3330 and a second-generation inhibitor, APX2009, decreases prostate cancer cell proliferation and induces cell cycle arrest. Inhibition of APE1/Ref-1 redox function significantly reduced NFĸB transcriptional activity, survivin mRNA and survivin protein levels. These data indicate that APE1/Ref-1 is a key regulator of survivin and a potentially viable target in prostate cancer.

Usefulness of Prostate-Specific Antigen Nadir as Predictor of Androgen-Independent Progression of Metastatic Prostate Cancer

The objective of this study was to analyze the value of the nadir level of prostate-specific antigen (PSA) to predict androgen-independent progression (AIP) in metastatic prostate cancer patients after androgen deprivation therapy. In a group of 185 metastatic prostate cancer patients who received androgen deprivation therapy serum PSA was determined every three months until AIP occurred. Multiple regression analysis was performed to define independent clinical and PSA-related predictors of AIP. AIP was assumed to be present after two consecutive increases in serum PSA after the PSA nadir. Independent predictors of the duration of AIP-free survival (less than 12 months versus more than 12 months) were the extent of bone involvement (six or fewer hot spots versus more than six) with an odds ratio (O.R.) of 3.95, Gleason score (7 or less versus more than 7) with an O.R. of 3.47, and PSA nadir (2 μg/L or less versus more than 2 μg/L) with an O.R. of 14.63. AIP was independently predicted by the extent of bone involvement with an O.R. of 1.72, Gleason score with an O.R. of 1.74, PSA nadir with an O.R. of 3.22, and time to reach the PSA nadir (9 months or less versus more than 9 months) with an O.R. of 2.84. When patients were stratified according to these predictors, those with three good prognostic factors had a median AIP-free survival of 58 months while those with two, one or no good prognostic factors had a median AIP-free survival of 19 months, 12 months and 7 months, respectively. We conclude that the PSA nadir seems to be a good predictor of AIP in patients with metastatic prostate cancer after androgen deprivation therapy. Time to PSA nadir, extent of bone involvement and Gleason score are also independent predictors. The combination of these prognostic factors allows to stratify metastatic prostate cancer patients for the prediction of AIP.

A 3-variable prognostic score (3-PS) for overall survival prediction in metastatic castration-resistant prostate cancer treated with 223Radium-dichloride

OBJECTIVE

In mCRPC patients treated with ²²³Ra, a major issue is the validation of reliable prognostic and predictive biomarkers to maximize clinical benefit and minimize toxicities and costs. Bearing in mind how changes in tALP did not meet statistical requirements as surrogate marker for survival, aim of this single-center retrospective study was to characterize the prognostic and predictive role of baseline clinical variables associated with overall survival in patients receiving ²²³Ra treatment.

METHODS

92 consecutive CRPC patients with symptomatic bone metastases receiving ²²³Ra treatment were included. Available baseline clinical data relevant to the survival analysis were retrospectively collected. The primary end-point of the study was overall survival, which was established from the first ²²³Ra administration until date of death from any cause.

RESULTS

Median follow-up time from the first ²²³Ra administration was 6 months (range 1-31 months). The univariate analysis evaluating the prognostic value of all baseline clinical variables showed that patients' weight, BMI, ECOG PS, Hb and tALP values were independently associated with OS. On multivariable analysis only baseline Hb value and ECOG PS remained significantly correlated with OS. To determine reliable baseline predictive factors for survival in patients receiving ²²³Ra treatment, we produced a predictive score. We tried all possible variable combinations, and found that the best score was obtained by combining baseline ECOG PS with Hb < 12 g/dl and PSA ≥ 20 ng/ml. This resulted in a score ranging from 0 to 4, with AUC 78.4% (p < 0.001).

CONCLUSIONS

We propose a multidimensional clinical evaluation to select those mCRPC subjects suitable to receive the maximum benefit from ²²³Ra treatment.

Evaluation of bone metastatic burden by bone SPECT/CT in metastatic prostate cancer patients: defining threshold value for total bone uptake and assessment in radium-223 treated patients

Objectives

To establish a new three-dimensional quantitative evaluation method for bone metastasis, we applied bone single photon emission tomography with computed tomography (SPECT/CT). The total bone uptake (TBU), which measures active bone metastatic burden, was calculated as the sum of [mean uptake obtained as standardized uptake value (SUV) above a cut-off level] × (the volume of the lesion) in the trunk using bone SPECT/CT. We studied the threshold value and utility of TBU in prostate cancer patients treated with radium-223 (Ra-223) therapy.

Methods

To establish the threshold value of TBU, we compared bone metastatic and non-metastatic regions in 61 prostate cancer patients with bone metastasis and 69 without. Five fixed sites in each patient were selected as evaluation points and divided into bone metastatic and non-metastatic sites. Sensitivity and specificity analysis was applied to establish the threshold level. Using the obtained threshold value, we then calculated the TBU in nine prostate cancer patients who received Ra-223 therapy, and compared the results with the bone scan index (BSI) by BONENAVI^® and visual evaluation of bone scintigraphy.

Results

Uptake was significantly lower in non-metastatic sites in patients with bone metastasis than in patients without metastasis. Sensitivity and specificity analysis revealed SUV = 7.0 as the threshold level. There was a discrepancy between TBU and BSI change in two of the nine patients, in whom TBU change correlated with visual judgement, but BSI change did not. In two patients, BSI was nearly 0 throughout the course, but the TBU was positive and changed, although the change was not large. These results suggest that TBU may be more accurate and sensitive than BSI for quantitative evaluation of active bone metastatic burden.

Conclusion

We established a threshold value (SUV > 7.0) for three-dimensional TBU for evaluating active bone metastatic burden in prostate cancer patients using bone SPECT/CT. Despite the small number of patients, we expect the change in TBU could be more accurate and sensitive than the change in BSI among patients who received Ra-223.

Exploiting machine learning for predicting skeletal-related events in cancer patients with bone metastases

The aim of the bone metastases (BM) treatment is to prevent the occurrence of skeletal-related events (SREs). In clinical, physicians could only predict the occurrence of SREs by subjective experience. Machine learning (ML) could be used as predictive models in the medical field. But there is no published research using ML to predict SREs in cancer patients with BM. The purpose of this study was to assess the associations of clinical variables with the occurrence of SREs and to subsequently develop prediction models to help identify SREs risk groups.

We analyzed 1143 cancer patients with BM. We used the statistical package of SPSS and SPSS Modeler for data analysis and the development of the prediction model. We compared the performance of logistic regression (LR), decision tree (DT) and support vector machine(SVM). The results suggested that Visual Analog Scale (VAS) scale was a key factor to SREs in LR, DT and SVM model. Modifiable factors such as Frankel classification, Mirels score, Ca, aminoterminal propeptide of type I collagen (PINP) and bone-specific alkaline phosphatase (BALP) were identified. We found that the result of applying LR, DT and SVM classification accuracy was 79.2%, 85.8% and 88.2%, with 9, 4 and 8 variables, respectively.

In conclusion, DT and SVM achieved higher accuracies with smaller number of variables than the number of variables used in LR. ML techniques can be used to build model to predict SREs in cancer patients with BM.

Skeletal standardized uptake values obtained by quantitative SPECT/CT as an osteoblastic biomarker for the discrimination of active bone metastasis in prostate cancer

Purpose

To investigate the improvement of prognostication of active bone metastatic burden by discriminating bone metastases from degenerative changes in hot foci, using skeletal standardized uptake values (SUVs) by quantitative bone single photon emission tomography/computed tomography (SPECT/CT) in patients with prostate cancer.

Methods

We investigated 170 patients with prostate cancer who underwent skeletal quantitative SPECT/CT using ^99mTc-methylene-diphosphonate (MDP), through conjugate gradient reconstruction with tissue zoning, attenuation, and scatter corrections applied, called as CGZAS reconstruction, in a retrospective cohort study. The maximum, peak, and average SUVs (SUVmax, SUVpeak, and SUVave, respectively) were obtained for visually normal thoracic (T; n = 100) and lumbar (L; n = 140) vertebral bodies as controls, as well as for bone metastases (n = 126) and degenerative changes (n = 114) as hot foci. They were also correlated with age, body-weight, height, biochemistry data, and extent of disease (EOD). Discrimination accuracy of the SUVs for bone metastases in hot foci was evaluated by a patient-based and lesion-based receiver-operator characteristic curve (ROC) analysis.

Results

The skeletal SUVmax was 7.58 ± 2.42 for T, 8.12 ± 12.24 for L, 16.73 ± 6.74 for degenerative changes, and 40.90 ± 33.46 for bone metastases. The SUVs of the bone metastasis group were significantly (p < 0.001) greater than of the other three groups. With disease extent, serum alkaline phosphatase and prostate specific antigen were increased, while SUVs for bone metastases were decreased in EOD grade 4. In ROC analyses for bone metastases by skeletal SUVs demonstrating the diagnostic accuracy of skeletal SUVs for discriminating bone metastasis from degenerative changes in hot foci, area under curves were 0.840, 0.817, and 0.845 in patient-based mode, and 0.932, 0.920, and 0.930 in lesion-based mode.

Conclusions

The skeletal SUVs by ^99mTc-MDP SPECT/CT for active bone metastases were greater than those for degenerative changes in patients with prostate cancer, with a feasible discrimination accuracy in the hot foci. Therefore, skeletal SUVs, especially SUVmax, in quantitative bone SPECT/CT may be helpful indices for the prognostication of bone metastatic burden, improving discrimination of active bone osteoblastic metastases in patients with prostate cancer from frequently coexisting degenerative changes.

Molecular radiotheragnostics in prostate cancer

Two different molecular radio-theragnostic principles are applied in prostate cancer, providing a personalised management for those patients. Firstly, radiopharmaceuticals with the same or similar mechanism of action but different energy (gamma-γ, eg 99mTc-diphosphonates or positron-β+, eg 18F-NaF emitting isotopes) can be used to identify patients with osteoblastic metastases for a treatment with bone seeking beta (β-) or alpha (α-) emitting radionuclides to deliver targeted molecular radiotherapy. A number of such β- emitting molecules have been used for bone palliation. More recently, an alpha emitting 223Ra-dicholoride demonstrated not only symptomatic relief but also significantly improved overall survival in castration-resistant prostate cancer with predominant bone metastases. The second principle involves utilisation of the same prostatic specific membrane antigen (PSMA) or similar compound (eg PSMA-11, PSMA-617), but different label with either β+ (68Ga) or γ (99mTc) emitting radioisotope for imaging and subsequently β- (177Lu) or α (225Ac) emitting radionuclide for treatment.

Prostate-specific antigen decline pattern in advanced prostate cancer receiving androgen deprivation therapy and relationship with prostate-specific antigen progression

INTRODUCTION

The aim of this study is to evaluate prostate-specific antigen decline pattern including prostate-specific antigen kinetics following androgen deprivation therapy on prostate-specific antigen progression in the patients with advanced prostate cancer.

MATERIALS AND METHODS

Ninety-seven advanced prostate cancer patients receiving maximum androgen deprivation therapy were enrolled in case-control study. Baseline prostate-specific antigen, Gleason Score, bone metastase, nadir prostate-specific antigen, time to nadir prostate-specific antigen, declining slope to nadir prostate-specific antigen, estimated baseline prostate-specific antigen half-time, current prostate-specific antigen, post-nadir prostate-specific antigen time, estimated prostate-specific antigen, estimated decline of baseline prostate-specific antigen as quantitative, and ratio were recorded and calculated.

RESULTS

The ratio of prostate-specific antigen progression was significantly lower at the patients who had slower declining slope to prostate-specific antigen, longer time to nadir prostate-specific antigen, and lower estimated decline ratio of baseline prostate-specific antigen (p: .016, p: .020, and p: .026, respectively).

CONCLUSIONS

The shorter time to nadir prostate-specific antigen following androgen deprivation therapy, faster declining slope to nadir prostate-specific antigen and higher estimated decline ratio of baseline prostate-specific antigen are associated with higher risk of disease progression in patients with hormone-sensitive prostate cancer.

The role of metastasis-directed therapy and local therapy of the primary tumor in the management of oligometastatic prostate cancer

Oligometastasis has been proposed as an intermediate stage of cancer spread between localized disease and widespread metastasis. Oligometastatic malignancy is now being diagnosed more frequently as the result of improvements in diagnostic modalities such as functional imaging. The importance of oligometastasis in managing metastatic prostate cancer is that it is possible to treat with a curative aim by metastasis-directed or local therapy in selected patients. Many studies have shown that these aggressive treatments lead to improved survival in other oligometastatic malignancies. However, few studies have shown definitive benefits of metastasis-directed or local therapy in oligometastatic prostate cancer. Review of the available studies suggests that stereotactic radiotherapy (RT) of metastatic lesions in oligorecurrent disease is a feasible and safe modality for managing oligometastatic prostate cancer. Also, stereotactic RT can delay the start of androgen deprivation therapy. Many retrospective studies of metastatic prostate cancer have shown that patients undergoing local therapy seem to have superior overall and cancer-specific survival compared with patients not receiving local therapy. Ongoing prospective randomized trials would be helpful to evaluate the role of local therapy in oligometastatic prostate cancer.

Bone Scan Index Is an Independent Predictor of Time to Castration-resistant Prostate Cancer in Newly Diagnosed Prostate Cancer: A Prospective Study

OBJECTIVE

To prospectively determine the prognostic value of the bone scan index (BSI) for time to development of castration-resistant prostate cancer (CRPC) in consecutive, hormone-naïve patients with newly diagnosed prostate cancer.

PATIENTS AND METHODS

Eligible patients participated in a prospective, observational, multicenter study of the value of bone scintigraphy (BS) at staging. BSI was determined using the EXINI Bone^BSI software in 208 consecutive patients undergoing androgen deprivation therapy. The presence or absence of bone metastases at staging was classified by BS with or without supplementary imaging. Follow-up was performed >5 years after including the last patient.

RESULTS

During follow-up, 149 of the 208 patients (72%) were diagnosed with CRPC. Median time to CRPC was 20 months. Median follow-up time was 4.4 years in patients without CRPC. In univariate analyses, presence of bone metastases (M1) (hazard ratio [HR] 3.00, 95% confidence interval [CI] 2.10-4.30), Gleason grade (HR 1.53, 95% CI 1.31-1.79), and BSI (HR 1.17, 95% CI 1.12-1.23) but not PSA significantly predicted time to CRPC (all, P < .001). The predictive values of M1 (HR 2.06), Gleason grade (HR 1.47), and BSI (HR 1.10) were confirmed in multivariate analyses. Log-rank test for equality of time to CRPC showed the significant predictive value of BSI (BSI = 0 vs 0 < BSI ≤ 1 vs BSI > 1, P < .001). In addition to routine assessment of M1 vs M0 status, BSI contributed to the predictive power.

CONCLUSIONS

BSI is an independent risk factor for the time from initiation of androgen deprivation therapy to CRPC in hormone-naïve patients. The significant prognostic factors, in rank order, were M1 status, Gleason grade, and BSI.

A phase II randomized trial of Observation versus stereotactic ablative RadiatIon for OLigometastatic prostate CancEr (ORIOLE)

Background

We describe a randomized, non-blinded Phase II interventional study to assess the safety and efficacy of stereotactic ablative radiotherapy (SABR) for hormone-sensitive oligometastatic prostate adenocarcinoma, and to describe the biology of the oligometastatic state using immunologic, cellular, molecular, and functional imaging correlates. 54 men with oligometastatic prostate adenocarcinoma will be accrued. The primary clinical endpoint will be progression at 6 months from randomization with the hypothesis that SABR to all metastases will forestall progression by disrupting the metastatic process. Secondary clinical endpoints will include local control at 6 months post-SABR, toxicity and quality of life, and androgen deprivation therapy (ADT)-free survival (ADT-FS). Further fundamental analysis of the oligometastatic state with be achieved through correlation with investigational ¹⁸F–DCFPyL PET/CT imaging and measurement of circulating tumor cells, circulating tumor DNA, and circulating T-cell receptor repertoires, facilitating an unprecedented opportunity to characterize, in isolation, the effects of SABR on the dynamics of and immunologic response to oligometastatic disease.

Methods/design

Patients will be randomized 2:1 to SABR or observation with minimization to balance assignment by primary intervention, prior hormonal therapy, and PSA doubling time. Progression after 6 months will be compared using Fisher’s exact test. Hazard ratios and Kaplan-Meier estimates of progression free survival (PFS), ADT free survival (ADT-FS), time to locoregional progression (TTLP) and time to distant progression (TTDP) will be calculated based on an intention-to-treat. Local control will be assessed using Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria. Withdrawal from the study prior to 6 months will be counted as progression. Adverse events will be summarized by type and grade. Quality of life pre- and post- SABR will be measured by Brief Pain Inventory.

Discussion

The ORIOLE trial is the first randomized, non-blinded Phase II interventional study in the North America evaluating the safety and efficacy of SABR in oligometastatic hormone-sensitive prostate cancer. Leading-edge laboratory and imaging correlates will provide unique insight into the effects of SABR on the oligometastatic state.

Trial registrations

ClinicalTrials.gov Identifier: NCT02680587.

URL of Registry: https://clinicaltrials.gov/show/NCT02680587

Date of Registration: 02/08/2016.

Date of First Participant Enrollment: 05/23/2016.

Therapies for castration-resistant prostate cancer in a new era: The indication of vintage hormonal therapy, chemotherapy and the new medicines

When advanced prostate cancer recurred during hormonal therapy and became the castration-resistant prostate cancer, "vintage hormonal therapy," such as antiandrogen alternating therapy or estrogen-related hormonal therapy, was widely carried out in Japan until 2013. This vintage hormonal therapy controlled the progression of castration-resistant prostate cancer. When castration-resistant prostate cancer relapses during these therapies, chemotherapy using docetaxel has been carried out subsequently. Since new hormonal therapies using abiraterone acetate and enzalutamide, which improve the prognosis of castration-resistant prostate cancer, became available in Japan from 2014, therapeutic options for castration-resistant prostate cancer have increased. Furthermore, the improvement of the further prognosis is promising by using cabazitaxel for docetaxel-resistant castration-resistant prostate cancer and radium-223 for castration-resistant prostate cancer with bone metastasis. An increase in therapeutic options gives rise to many questions, including best timing to use them and the indication. Furthermore, physicians have to consider the treatment for the recurrence after having carried out chemotherapy. We want to argue the difference in hormonal therapy between Japan and Western countries, and problems when carrying out new treatments, and the importance of imaging in the present review article.

Predictors for progression of metastatic prostate cancer to castration-resistant prostate cancer in Indians

Background & objectives:

There is lack of data on natural history and progression of prostate cancer (PC) which have implications in the management of the disease. We undertook this retrospective study to analyze factors predicting progression of metastatic PC to castration-resistant prostate cancer (CRPC) in Indian men.

Methods:

Complete records of 223 of the 489 patients with metastatic PC were obtained from computerized data based system in a tertiary care hospital in north India between January 2000 to June 2012. Patients with follow up of < 6 months were excluded. Age (≤ and > 65 yr), baseline PSA (< and ≥ 50 ng/ml), bone scan and Gleason score (≤7 and >7) were recorded. Extent of bone disease (EOD) was stratified according to the number of bone lesions i.e., < 5, 5-10, > 10. CRPC was defined as two consecutive PSA rise of > 50 per cent from nadir or an absolute value of > 5 ng/ml.

Results:

Mean age of patients was 61.5 ± 12.45 yr and their PSA level was 325.6 ± 631.35 ng/dl. Of the 223 patients, 193 (86%) progressed to CRPC at median time of 10.7 (4-124) months. Median follow up was 24 (6-137) months. On univariate and multivariate analyses EOD on bone scan was found to be a significant predictor (P=0.006) for time to CRPC. Median time to CRPC was 10 months (CI 95%, 7.5-12.48) with >10 lesions or super scan versus 16 months (CI 95%, 10.3-21.6) with <10 bone lesion (P=0.01). Ninety (46.6 %) patients of CRPC died with median time to death from time of CRPC 21 (10-120) months.

Interpretation & conclusions:

Median time for progression of metastatic PC to CRPC ranged from 10-16 months depending on the extent of the bone involvement. In Indians, the aggressive course of advanced prostate cancer warrants further clinical trials to explore the need for additional treatment along with initial castration.

Coexistent Superscan and Lincoln Sign on Bone Scintigraphy

A 70-year-old man underwent Tc-methylene diphosphonate scintigraphy for staging of adenocarcinoma prostate. Scintigraphy revealed diffuse increased tracer uptake in skeletal system along with faint renal visualization, a pattern compatible with metastatic superscan. The scintigraphy also revealed increased radiotracer uptake in the body of the mandible-Lincoln sign or black beard sign. Radiological imaging revealed sclerotic lesions throughout the skeleton including the mandible, confirming widespread skeletal metastases. Lincoln sign is previously described in monostotic Paget disease of the mandible and in contiguous spread of oral malignancy. We describe this pattern in distant metastatic involvement from carcinoma prostate with coexistent superscan pattern.

Influence of the location and number of metastases in the survival of metastatic prostatic cancer patients

INTRODUCTION

The prognosis of patients diagnosed with metastatic prostate cancer seems to be modulated by factors such as the number and site of metastases. Our objective is to evaluate survival outcomes according to the number and site of metastases in our series of metastatic patients over the last 15 years.

MATERIALS AND METHODS

A retrospective analysis was performed on patients diagnosed between 1998 and 2014. We analyzed overall survival and progression-free survival, depending on the number and location of metastases on patients with newly diagnosed metastatic prostate cancer. Other potential prognostic factors were also evaluated: age, clinical stage, PSA at diagnosis, Gleason, PSA nadir, time till PSA nadir and first-line or second-line treatment after progression.

RESULTS

We analyzed a series of 162 patients. The mean age was 72.7yr (SD: 8.5). The estimated median overall survival was 3.9 yr (95% CI 2.6-5.2). The overall survival in patients with only lymph node metastases was 7 yr (95% CI 4.1-9.7), 3.9 (95%CI 2.3-5.5) in patients with only bone metastases, 2.5 yr (95% CI 2-2.3) in lymph nodes and bone metastases, and 2.2 yr (95% CI 1.4-3) in patients with visceral metastases (P<.001). In multivariate analysis, the location of metastasesis significantly associated with overall survival and progression-free survival. The number of metastases showed no association with survival.

CONCLUSIONS

The site of metastases has a clear impact on both overall survival and progression-free survival. Patients with only lymph node involvement had a better prognosis. The number of metastases showed no significant impact on survival in our series.

Diagnostic performance of a computer-assisted diagnosis system for bone scintigraphy of newly developed skeletal metastasis in prostate cancer patients: search for low-sensitivity subgroups

Purpose

The computer-assisted diagnostic system for bone scintigraphy (BS) BONENAVI is used to evaluate skeletal metastasis. We investigated its diagnostic performance in prostate cancer patients with and without skeletal metastasis and searched for the problems.

Methods

An artificial neural network (ANN) value was calculated in 226 prostate cancer patients (124 with skeletal metastasis and 101 without) using BS. Receiver operating characteristic curve analysis was performed and the sensitivity and specificity determined (cutoff ANN = 0.5). Patient’s situation at the time of diagnosis of skeletal metastasis, computed tomography (CT) type, extent of disease (EOD), and BS uptake grade were analyzed. False-negative and false-positive results were recorded.

Results

BONENAVI showed 82% (102/124) of sensitivity and 83% (84/101) specificity for metastasis detection. There were no significant differences among CT types, although low EOD and faint BS uptake were associated with low ANN values and low sensitivity. Patients showed lower sensitivity during the follow-up period than staging work-up. False-negative lesions were often located in the pelvis or adjacent to it. They comprised not only solitary, faint BS lesions but also overlaying to urinary excretion.

Conclusions

BONENAVI with BS has good sensitivity and specificity for detecting prostate cancer’s osseous metastasis. Low EOD and faint BS uptake are associated with low sensitivity but not the CT type. Prostate cancer patients likely to have false-negative results during the follow-up period had a solitary lesion in the pelvis with faint BS uptake or lesions overlaying to urinary excretion.

A radiobiological model of metastatic burden reduction for molecular radiotherapy: application to patients with bone metastases

Skeletal tumour burden is a biomarker of prognosis and survival in cancer patients. This study proposes a novel method based on the linear quadratic model to predict the reduction in metastatic tumour burden as a function of the absorbed doses delivered from molecular radiotherapy treatments. The range of absorbed doses necessary to eradicate all the bone lesions and to reduce the metastatic burden was investigated in a cohort of 22 patients with bone metastases from castration-resistant prostate cancer. A metastatic burden reduction curve was generated for each patient, which predicts the reduction in metastatic burden as a function of the patient mean absorbed dose, defined as the mean of all the lesion absorbed doses in any given patient. In the patient cohort studied, the median of the patient mean absorbed dose predicted to reduce the metastatic burden by 50% was 89 Gy (interquartile range: 83-105 Gy), whilst a median of 183 Gy (interquartile range: 107-247 Gy) was found necessary to eradicate all metastases in a given patient. The absorbed dose required to eradicate all the lesions was strongly correlated with the variability of the absorbed doses delivered to multiple lesions in a given patient (r  =  0.98, P  <  0.0001). The metastatic burden reduction curves showed a potential large reduction in metastatic burden for a small increase in absorbed dose in 91% of patients. The results indicate the range of absorbed doses required to potentially obtain a significant survival benefit. The metastatic burden reduction method provides a simple tool that could be used in routine clinical practice for patient selection and to indicate the required administered activity to achieve a predicted patient mean absorbed dose and reduction in metastatic tumour burden.

Phase I/II trials of 186Re-HEDP in metastatic castration-resistant prostate cancer: post-hoc analysis of the impact of administered activity and dosimetry on survival

PURPOSE

To investigate the role of patient-specific dosimetry as a predictive marker of survival and as a potential tool for individualised molecular radiotherapy treatment planning of bone metastases from castration-resistant prostate cancer, and to assess whether higher administered levels of activity are associated with a survival benefit.

METHODS

Clinical data from 57 patients who received 2.5-5.1 GBq of 186Re-HEDP as part of NIH-funded phase I/II clinical trials were analysed. Whole-body and SPECT-based absorbed doses to the whole body and bone lesions were calculated for 22 patients receiving 5 GBq. The patient mean absorbed dose was defined as the mean of all bone lesion-absorbed doses in any given patient. Kaplan-Meier curves, log-rank tests, Cox's proportional hazards model and Pearson's correlation coefficients were used for overall survival (OS) and correlation analyses.

RESULTS

A statistically significantly longer OS was associated with administered activities above 3.5 GBq in the 57 patients (20.1 vs 7.1 months, hazard ratio: 0.39, 95 % CI: 0.10-0.58, P = 0.002). A total of 379 bone lesions were identified in 22 patients. The mean of the patient mean absorbed dose was 19 (±6) Gy and the mean of the whole-body absorbed dose was 0.33 (±0.11) Gy for the 22 patients. The patient mean absorbed dose (r = 0.65, P = 0.001) and the whole-body absorbed dose (r = 0.63, P = 0.002) showed a positive correlation with disease volume. Significant differences in OS were observed for the univariate group analyses according to disease volume as measured from SPECT imaging of 186Re-HEDP (P = 0.03) and patient mean absorbed dose (P = 0.01), whilst only the disease volume remained significant in a multivariable analysis (P = 0.004).

CONCLUSION

This study demonstrated that higher administered activities led to prolonged survival and that for a fixed administered activity, the whole-body and patient mean absorbed doses correlated with the extent of disease, which, in turn, correlated with survival. This study shows the importance of patient stratification to establish absorbed dose-response correlations and indicates the potential to individualise treatment of bone metastases with radiopharmaceuticals according to patient-specific imaging and dosimetry.

Predictors of Positive Bone Metastasis in Newly Diagnosed Prostate Cancer Patients

BACKGROUND

The prevalence of prostate cancer (PCa) has been increasing in recent years. Treatment strategies are largely based on the results of bone scan screening. Therefore, our aim was to investigate predictors of positive bone metastasis in newly diagnosed PCa patients.

MATERIALS AND METHODS

After extensive review, 336 consecutive patients newly diagnosed with PCa between April 2010 and November 2013 at our institution were enlisted in the study. Patients were divided into two groups according to bone scan results. Univariate analyses (Chi-square test for discrete variables and independent t-test for continuous variables) were applied to determine the potentially significant risk factors associated with distant bone metastasis. Binary logistic regression analyses were used to further investigate the influence of these factors on bone metastasis.

RESULTS

The patient mean age was 71.9 ± 8.6 years (range: 48 to 94 years). The mean prostate specific antigen (PSA) level and biopsy Gleason score were 260.2 ± 1107.8 ng/mL and 7.4 ± 1.5, respectively. The body mass index (BMI) for the series was 24.5 ± 3.4 kg/m2. Sixty-four patients (19.0%) had a positive bone scan result. Patients with positive bone scan results had a significantly lower BMI (23.3 ± 3.5 vs. 24.8 ± 3.3; p=0.003), a higher Gleason score (8.5 ± 1.1 vs. 7.1 ± 1.5; p < 0.001), and a higher PSA level (1071.3 ± 2337.1 vs. 69.4 ± 235.5; p < 0.001) than those without bone metastasis. Multivariate logistic regression analysis employing the above independent predictors demonstrated that a Gleason score of ≥7, clinical stage ≥T3, BMI ≤22 kg/m2, and an initial PSA level of ≥20 ng/mL were all independent predictors of bone metastasis.

CONCLUSIONS

A bone scan might be necessary in newly diagnosed PCa patients with any of the following criteria: clinical stage T3 or higher, a Gleason score of 7 or higher, BMI equal to or less than 22, and a PSA level of 20 or higher.

Prognostic Value of Automated Bone Scan Index in Men With Metastatic Castration-resistant Prostate Cancer Treated With Enzalutamide or Abiraterone Acetate

PURPOSE

Bone scan index (BSI) is an objective tool for quantifying bone metastasis load. We assessed its prognostic usefulness in patients with metastatic castration-resistant prostate cancer (CRPC) treated with enzalutamide (ENZ) or abiraterone acetate (AA).

MATERIALS AND METHODS

We analyzed 40 patients who received ENZ or AA treatment (ENZ/AA) for metastatic CRPC. The Cox proportional hazards model and a C-index were used to investigate associations between overall survival (OS) and BSI, and patient age, prostate-specific antigen, time to CRPC, previous docetaxel use, and pain.

RESULTS

Median OS after ENZ/AA was 17.8 months. All patient deaths (n = 19; 47.5%) were from prostate cancer. In multivariate analysis, decreased BSI was an independent predictor for longer OS (hazard ratio, 8.97; P = .011). Inclusion of BSI improved the C-index from 0.721 to 0.792 in predicting OS after ENZ/AA.

CONCLUSIONS

Decreased BSI after ENZ/AA independently predicts longer OS.