The changing pattern of management for hormone-refractory, metastatic prostate cancer

Palliative radiotherapy to dominant symptomatic lesion in patients with hormone refractory prostate cancer (PRADO)

Background

This study was conducted to investigate a new short-course radiotherapy regimen for patients with metastatic hormone refractory prostate cancer (HRPC) presenting with a dominant debilitating symptom.

Methods / design

This is an international, multi-center single arm prospective feasibility study that aims to include 34 patients with HRPC and a dominant debilitating symptom. The dominant symptomatic lesion will receive 4 × 5 Gy of high-precision radiotherapy, and the most aggressive part of the lesion 4 × 7 Gy using a simultaneous integrated boost technique. Based on advanced magnetic resonance imaging (MRI), an apparent diffusion coefficient (ADC) map will be calculated for the lesion using diffusion weighted imaging sequences. The dominant symptomatic lesion (GTV1) is drawn manually using the information from T2w-MRI and computed tomography scans. The most aggressive part of the dominant lesion (GTV2) is defined by using the ADC map. An auxiliary volume is created including only voxels in the GTV1 that presents with ADC values below 1200 × 10^− 6 mm²/s. The most aggressive part is defined as voxels with an ADC value below the median ADC value. Primary endpoint is feasibility, i.e. proportion of patients who complete radiotherapy with ≥90% of the prescribed dose. Secondary endpoints include dominant symptom score, progression-free survival (freedom from symptoms), overall survival, acute toxicity, quality of life, change in ADC from baseline to end of treatment and 6 months following treatment.

Discussion

If this new radiotherapy regimen proves to be feasible, a prospective randomized phase II/III dose escalation study will be designed in order to improve the outcomes of palliative radiotherapy of symptomatic metastatic HRPC.

Study status

The study is ongoing and will be recruiting patients soon.

Trial registration

clinicaltrials.gov NCT03658434. Initially registered on 30th of July, 2018

Can bone scans guide therapy with radium-223 dichloride for prostate cancer bone metastases?

BACKGROUND

Radium-223 dichloride (Ra-223 Xofigo) has recently been approved as an addition to the host of available therapies in the USA as a treatment option for metastatic castrate-resistant prostate cancer (mCRPC) with bone metastases. This study describes our initial experience in patients treated with Ra-223 dichloride. It attempts to optimize patients' selection for the best outcome from Ra-223 dichloride therapy.

METHODS

Consecutive patients who were referred for treatment with Ra-223 dichloride were prospectively followed. Patients' demographics, functional status per the Eastern Cooperative Oncology Group (ECOG) performance score, pain level per the numeric rating score (NRS), prostate-specific antigen (PSA), creatinine, and hematological values were compared at baseline and at the end of therapy. Patients also had a bone scan before starting therapy and at the end of therapy. Patients were divided into the favorable response (FR) group if their pain and/or functional status improved and the unfavorable response (UR) group if they did not improve, deteriorated, or deceased. Bone scan findings before and after Ra-223 dichloride therapy were compared in both the FR and UR groups.

RESULTS

Twenty patients were treated with Ra-223 dichloride. Twelve patients had innumerable bone metastases, three patients had super scans, and three patients had two to seven bone lesions. Two patients were lost to follow-up after the first injection. There were eight patients in the FR group and 10 patients in the UR group. Patients with UR had mean ECOG and NRS pain scores of 1.3 and 5.0 versus 0.8 and 4.4 in the FR group. The mean PSA and creatinine levels in the UR group were 445.2 ng/mL and 1.2 mg/dL versus 22.7 ng/mL and 1.1 mg/dL in the FR group. The mean hemoglobin, platelets, and absolute neutrophil values were 11.2 g/dL, 314.9 K/cmm, and 7.3 K/cmm in the UR group versus 11.6 g/dL, 207.0 K/cmm, and 6.2 K/cmm in the FR group. Seven of the eight patients with FR had a bone scan at the end of therapy showing improvement in five patients, a mixed response in one patient, and progression in another patient. Five patients in the UR group completed five or six injections and had bone scans showing flare of bone metastases in three patients, progression in one patient, and improvement in the fifth patient. Three patients in the UR group died after the first or second injections. Two of these patients had baseline super scans and the third one had widespread bone metastases.

CONCLUSION

mCRPC patients with lower PSA levels at baseline and fewer bone lesions are more likely to respond favorably to Ra-223 dichloride therapy.

Clinical and economic burden of bone metastasis and skeletal-related events in prostate cancer

PURPOSE OF REVIEW

We review the clinical trials and observational studies literature regarding the clinical and economic burden of bone metastasis and skeletal-related events (SREs) in prostate cancer, and discuss current gaps in understanding the impact of bone metastasis in this disease.

RECENT FINDINGS

Trial data indicate that SREs occur in half of prostate cancer patients with bone metastasis in the absence of treatment, and 30-45% among those who receive bone-modifying agents. In the United States, the cost of SRE ranged from $7553 per radiation episode to $88 838 per bone surgery episode. Prevalence of SRE, time to SRE occurrence, and cost of SRE varied across studies because of differences in study populations, follow-up period, and the algorithm used to measure SRE. There is limited evidence on the clinical and economic impact by SRE subtype. Information regarding patient-reported outcomes and costs from the patient's perspective is lacking.

SUMMARY

Bone metastasis and SREs in prostate cancer patients are associated with considerable morbidity, reduced survival, and substantial economic burden. Consistent study methodology, particularly the measurement of SREs, is necessary to allow comparison of estimates across studies. The inclusion of patient-centered clinical and economic outcomes in future research will provide pertinent information regarding the burden of bone metastasis and SREs.

Health-related quality of life in advanced prostate cancer and its treatments: biochemical failure and metastatic disease populations

INTRODUCTION

This study aimed to examine the impact of advanced prostate cancer and its treatments on patients' perceptions of their health and to better understand concerns not captured by currently available health-related quality of life (HRQL) instruments.

PATIENTS AND METHODS

Open ended one-on-one interviews were conducted with patients with prostate cancer who had biochemical failure or metastatic cancer to understand the impacts of disease and treatments on patients' perceptions of their lives. Interviews with 25 patients (7 biochemical failure and 18 metastatic) and 6 clinicians were conducted. Patient responses were analyzed to assess whether information saturation (ie, the point at which no new information is collected) was attained and compared with currently available HRQL instruments. The data informed the development of a comprehensive conceptual model illustrating the impacts of advanced disease and treatments. Clinical expert interviews also informed the conceptual model.

RESULTS

Patients with prostate cancer reported many of the key symptoms already captured by current measures, such as bone pain, urinary functioning, bowel functioning, and fatigue. However, a number of impacts reported as bothersome by patients were identified that are not fully captured by existing HRQL measures. Specific examples include genital atrophy, muscle atrophy, stamina, body image, and emotional well-being.

CONCLUSION

The conceptual model identified herein describes the impacts of prostate cancer and its treatments from the patient's perspective. The model can be useful in identifying key concepts important to patients that should be measured in trials to capture treatment benefits. The model also can help inform the selection of patient-reported outcomes to assess these benefits.

Expression of osteoprotegerin from a replicating adenovirus inhibits the progression of prostate cancer bone metastases in a murine model

Metastatic involvement of the skeleton is a frequent consequence of advanced prostate cancer. These skeletal metastases cause a number of debilitating complications and are refractory to current treatments. New therapeutic options are being explored, including conditionally replicating adenoviruses (CRAds). CRAds are engineered to selectively replicate in and destroy tumor cells and can be 'armed' with exogenous transgenes for enhanced potency. We hypothesized that a CRAd armed with osteoprotegerin (OPG), an inhibitor of osteoclastogenesis, would inhibit the progression of prostate cancer bone metastases by directly lysing tumor cells and by reducing osteoclast activity. Although prostate cancer bone metastases are predominantly osteoblastic in nature, increased osteoclast activity is critical for the growth of these lesions. Ad5-Δ24-sOPG-Fc-RGD is a CRAd that carries a fusion of the ligand-binding domains of OPG and the Fc region of human IgG1 in place of the viral E3B genes. To circumvent low tumor cell expression of the native adenoviral receptor, an arginine-glycine-aspartic acid (RGD) peptide insertion within the viral fiber knob allows infection of cells expressing α(v) integrins. A 24-base pair deletion (Δ24) within viral E1A limits replication to cells with aberrant retinoblastoma cell cycle regulator/tumor suppressor expression. We have confirmed that Ad5-Δ24-sOPG-Fc-RGD replicates within and destroys prostate cancer cells and, in both murine and human coculture models, that infection of prostate cancer cells inhibits osteoclastogenesis in vitro. In a murine model, progression of advanced prostate cancer bone metastases was inhibited by treatment with Ad5-Δ24-sOPG-Fc-RGD but not by an unarmed control CRAd.

Epidemiology of castration resistant prostate cancer: a longitudinal analysis using a UK primary care database

BACKGROUND

Castration resistant prostate cancer (CRPC) is defined clinically as a failure of castration to prevent an increase in circulating hormones which are associated with worsening prostate cancer. Published information on the frequency and characteristics of CRPC patients are lacking. This may be partly because there is no specific code which doctors can use to record CRPC, making research in existing data sources such as the General Practice Research Database (GPRD) difficult.

METHODS

The aim of this study was to firstly develop a method to accurately and thoroughly identify CRPC patients in the GPRD, using a combination of codes for treatments and diagnostic tests which these patients are likely to have received. Secondly, the anonymised electronic medical records were used to study the identified CRPC patient characteristics, such as age, treatments, comorbidity and expected survival.

RESULTS

After comprehensive exploratory research, the final algorithm was selected to identify patients' assumed recording on the GPRD of either a rising prostate specific antigen (PSA) value (clinical definition of CRPC) or evidence of a switch in treatment after castration. Using the algorithm, over the 1999-2009 study period, 11600 castrated prostate cancer patients were identified. Of these, 3277 (28%) developed CRPC during the study period, with an incidence rate of 8.3 per 100 person years in castrated prostate cancer patients, and 3.8 per 100 person years in all prostate cancer patients. Mean patient age at CRPC was 76.8 years, and mean survival duration from CRPC status was 13.5 months, and from first prostate cancer diagnosis was 48.2 months. The most common comorbidities among CRPC patients were hypertension, dyspnoea, and anaemia.

CONCLUSIONS

Sensitivity analyses to test algorithms with differing inclusion criteria suggested that the primary algorithm was robust, reducing bias through missing data, while avoiding 'false positives' and retaining clinical credibility. Overall, our study has documented a reliable method for identifying CRPC patients in GPRD, and thus we have been able to characterise these patients more accurately.

Time associated with intravenous zoledronic acid administration in patients with breast or prostate cancer and bone metastasis

Purpose

Intravenous (IV) zoledronic acid (ZA) is commonly used to delay skeletal complications secondary to bone metastases. However, the time associated with ZA administration may represent a significant burden to healthcare providers and patients. This study assessed the time associated with IV ZA infusion in patients with bone metastases secondary to breast or prostate cancer (BC or PC) in the clinic setting.

Methods

Eligible BC or PC patients with bone metastases scheduled to receive IV ZA were observed at seven US-based oncology clinics. Trained observers recorded the time for preinfusion tasks, ZA drug preparation, intravenous infusion, and follow-up activities.

Results

Data are reported for 39 patients (BC: 24; PC: 15). Mean administration time was 69 (standard deviation [SD] 42) minutes for all patients combined, 72 (SD 47) minutes for BC, and 65 (SD 33) minutes for PC. Activity times were comparable between tumor types. Mean time for preinfusion tasks (eg, assessment of vital signs, blood draw) and ZA preparation were 12 (SD 20) minutes and 2 (SD 1) minutes, respectively. Mean time required for intravenous infusion (ZA infusion and hydration, when provided) and follow-up activities were 54 (SD 31) minutes and 2 (SD 1) minutes, respectively.

Conclusion

Infusion time was the greatest time commitment associated with IV ZA administration, representing 78% of the total time on average. Time for preinfusion activities varied substantially. Overall, the mean time for ZA administration represents a notable time burden for healthcare providers and patients.

Economic burden and healthcare utilization associated with castration-resistant prostate cancer in a commercial and Medicare Advantage US patient population

OBJECTIVE

Prostate cancer is a leading cause of cancer death in men in the US. Castration-resistant prostate cancer (CRPC) is an advanced form of the disease and has a poor prognosis and limited treatment options. The objective of this study was to identify patients with CRPC from a medical claims database, and determine the prostate cancer-related economic burden and healthcare utilization of these patients.

METHODS

This was a retrospective study using claims and enrollment information from a large US database linkable to laboratory data. Male patients aged 40 or older who were diagnosed with prostate cancer and received surgical or medical castration between July 1, 2001 and December 1, 2007 were considered for study inclusion. Patients with CRPC were initially identified based on at least two increases in prostrate-specific antigen (PSA) values. Due to the small number of patients with available PSA results data, logistic regression modeling using characteristics of patients with known CRPC was used to identify a larger set of patients with likely CRPC. Per-patient per-month healthcare utilization and costs were determined using medical and pharmacy claims data.

RESULTS

The final sample of patients with likely CRPC as determined by regression modeling included 349 patients with known CRPC identified from the database on the basis of PSA results and an additional 2391 with likely CRPC. Within this final sample of 2740 CRPC patients, there was a per-patient per-month average of 1.43 prostate cancer-related ambulatory visits, 0.04 prostate cancer-related inpatient stays, and 0.01 prostate cancer-related ER visits. Average per-patient per-month prostate cancer-related costs were $1152 (SD = $2073) for ambulatory visits, $559 (SD = $2383) for inpatient stays, $72 (SD = $229) for pharmacy costs, and $1 (SD = $14) for ER visits. Total per-patient per-month prostate cancer-related costs were on average $1799 (SD = $3505), and these costs comprised about half of the all-cause healthcare costs for these patients.

CONCLUSIONS

CRPC is a costly disease, with ambulatory visits and inpatient care accounting for a substantial proportion of the economic burden. Limitations related to the use of retrospective claims data should be considered when interpreting these results.

EANM procedure guideline for treatment of refractory metastatic bone pain

INTRODUCTION

Bone pain is a common symptom of metastatic disease in cancer, experienced with various intensities by about 30% of cancer patients, during the development of their disease, up to 60-90% in the latest phases.

DISCUSSION

In addition to other therapies, such as analgesics, bisphosphonates, chemotherapy, hormonal therapy and external beam radiotherapy, bone-seeking radiopharmaceuticals are also used for the palliation of pain from bone metastases. Substantial advantages of bone palliation radionuclide therapy include the ability to simultaneously treat multiple sites of disease with a more probable therapeutic effect in earlier phases of metastatic disease, the ease of administration, the repeatability and the potential integration with the other treatments.

CONCLUSION

The Therapy, Oncology and Dosimetry Committees have worked together to revise the EANM guidelines on the use of bone-seeking radiopharmaceuticals. The purpose of this guideline is to assist the nuclear medicine physician in treating and managing patients undergoing such treatment.

Safety and efficacy of the specific endothelin-A receptor antagonist ZD4054 in patients with hormone-resistant prostate cancer and bone metastases who were pain free or mildly symptomatic: a double-blind, placebo-controlled, randomised, phase 2 trial

BACKGROUND

The endothelin-A receptor (ETAR) has been implicated in the progression of prostate cancer.

OBJECTIVES

To investigate the safety and efficacy of the specific ETAR antagonist ZD4054 in patients with metastatic hormone-resistant prostate cancer (HRPC).

DESIGN, SETTING, AND PARTICIPANTS

Double-blind, placebo-controlled, randomised, parallel-group, multicentre, phase 2 trial in patients attending cancer centres with HRPC and bone metastases who were pain free or mildly symptomatic for pain.

INTERVENTION

Patients were randomised to receive once-daily oral tablets of ZD4054 10 mg, or ZD4054 15 mg, or placebo.

MEASUREMENTS

The primary end point was time to progression, defined as clinical progression, requirement for opiate analgesia, objective progression of soft-tissue metastases, or death in the absence of progression. Secondary end points included overall survival, time to prostate-specific antigen (PSA) progression, and safety. Statistical significance was preset at 20%.

RESULTS AND LIMITATIONS

A total of 312 patients were randomised (ZD4054 10 mg, n=107; ZD4054 15 mg, n=98; placebo, n=107). At the primary analysis, median time to progression was 3.6 mo, 4.0 mo, and 3.8 mo in the placebo, ZD4054 10 mg, and ZD4054 15 mg groups, respectively, with no statistically significant difference between ZD4054 groups and placebo (hazard ratio [HR] vs placebo for the ZD4054 10mg group: 0.88 [80% CI: 0.71-1.09]; HR vs placebo for the ZD4054 15 mg group: 0.83 [80% CI: 0.66-1.03]). However, a signal for prolonged overall survival was observed in the ZD4054 treatment groups versus placebo, based on 40 deaths. At a subsequent analysis after 118 deaths, this survival benefit was confirmed (HR vs placebo for the ZD4054 10 mg group, 0.55 [80% CI: 0.41-0.73], p=0.008; HR vs placebo for the ZD4054 15 mg group, 0.65 [80% CI: 0.49-0.86], p=0.052) but the differences in time to progression remained nonsignificant. Median overall survival was 17.3 mo, 24.5 mo, and 23.5 mo in the placebo group, the ZD4054 10 mg group, and the ZD4054 15 mg group, respectively. Discordance between results for time to progression and overall survival may be due to the sensitivity of the definition of progression. Adverse events were in line with the expected pharmacologic effects of an ETAR antagonist.

CONCLUSIONS

The primary end point of time to progression was not achieved in this study, but an improvement was seen in overall survival in both active treatment arms. ZD4054 was well tolerated.

TRIAL REGISTRATION

Clinicaltrials.gov NCT00090363.

[Algorithm for the treatment of patients with obstructive uropathy secondary to prostate cancer]

BACKGROUND

One of the prostate cancer progression complications is the obstructive uropathy, by infiltration and compression of the distal ureteral section, that can entail to an acute renal insufficiency, with affectation of the quality of life and the survival of these patients. The treatment of prostate cancer with secondary ureterohidronefrosis is palliative and following the present tendencies, the positioning of a nephrostomy is considered.

MATERIALS AND METHODS

A search was made in PUBMED and the most representative articles were reviewed. The algorithm was constructed with the daily routine clinical base, the protocol of our center and with the scientific evidence available in medical literature.

RESULTS

An algorithm of decisions sets out to define the urinary derivation in patients with obstructive uropathy secondary to prostate cancer.

CONCLUSIONS

The indication to place a nephrostomy in patients with obstructive uropathy secondary to prostate cancer must be approached individually, according to the general conditions and the quality of life of the patient with base in scales defined in literature (ECOG and Karnofsky) and in factors of good or bad prognosis, always considering ethical considerations and the consent of the patient and his family.

Evidence of a novel docetaxel sensitizer, garlic-derived S-allylmercaptocysteine, as a treatment option for hormone refractory prostate cancer

The recent introduction of docetaxel in the treatment of hormone refractory prostate cancer (HRPC) has made a small but significant impact on patient survival. However, its effect is limited by intolerance and resistance. The aim of our study was to investigate if the garlic-derived compound, S-allylmercaptocysteine (SAMC), was able to act as a docetaxel sensitizing agent. First, the effect of SAMC on docetaxel sensitivity was examined on 3 HRPC cell lines by colony forming assay. We found that SAMC increased the efficacy of docetaxel on colony forming inhibition by 9-50% compared to single agent treatment. Second, using the HRPC CWR22R nude mice model, we found that the combination of SAMC and docetaxel was 53% more potent than docetaxel alone (p = 0.037). In addition, there was no additive toxicity in the mice treated with the combination therapy evidenced by histological and functional analysis of liver, kidney and bone marrow. These results suggest that SAMC is able to increase the anticancer effect of docetaxel without causing additional toxic effect in vivo. Third, flow cytometry and Western blotting analysis on HRPC cell lines demonstrated that SAMC promoted docetaxel-induced G2/M phase cell cycle arrest and apoptotic induction. In addition, immunohistochemistry on CWR22R xenograft revealed a suppression of Bcl-2 expression and upregulation of E-cadherin in the SAMC and docetaxel treated animals. These results suggest that SAMC may promote docetaxel-induced cell death through promoting G2/M cell cycle arrest and apoptosis. Our study implies a potential role for SAMC in improving docetaxel based chemotherapy for the treatment of HRPC.