Marcello Tucci

Metabolic bone disease induced by prostate cancer: rationale for the use of bisphosphonates.

PURPOSE Increasing evidences indicate that despite the osteoblastic nature of metastatic bone lesions due to prostate cancer osteolysis is a regular feature and may cause skeletal morbidity. This observation provides the rationale for the use of bisphosphonates for managing bone metastatic prostate cancer. MATERIALS AND METHODS We reviewed the literature on the mechanisms by which prostate cancer affects bone cell function and disrupts physiological bone turnover. We also summarized the clinical results of bisphosphonate for treating bone pain in patients with prostate cancer. RESULTS Metastatic prostate cancer in bone interferes with physiological bone remodeling by abnormal release of the hormones and paracrine factors physiologically involved in the modulation of osteoblastic and osteoclastic activity. Tumor induced bone formation and resorption develop within the same metastasis but excessive new bone is deposited away from bone resorption sites and does not contribute to bone strength. The increase in bone resorption may also be a generalized phenomenon that is most likely due to iatrogenic osteoporosis or related to hyperparathyroidism in response to the increased calcium demand. The bone resorption index in patients with bone metastatic prostate cancer correlates with bone pain and is an independent predictor of adverse skeletal events. However, small clinical studies of the efficacy of bisphosphonates for controlling bone pain in patients with prostate cancer show contradictory results. CONCLUSIONS Improved understanding of the pathophysiology of prostate cancer induced metabolic bone disease implies that bisphosphonates may have a role in the treatment of this disorder. This issue is being addressed by large-scale ongoing randomized studies.

Radium-223 and concomitant therapies in patients with metastatic castration-resistant prostate cancer: an international, early access, open-label, single-arm phase 3b trial

BACKGROUND In the previously reported ALSYMPCA trial in patients with castration-resistant prostate cancer and symptomatic bone metastases, overall survival was significantly longer in patients treated with radium-223 dichloride (radium-223) than in patients treated with placebo. In this study, we investigated safety and overall survival in radium-223 treated patients in an early access programme done after the ALSYMPCA study and before regulatory approval of radium-223. METHODS We did an international, prospective, interventional, open-label, single-arm, phase 3b study. Enrolled patients were aged 18 years or older with histologically or cytologically confirmed progressive bone-predominant metastatic castration-resistant prostate cancer with two or more skeletal metastases on imaging (with no restriction as to whether they were symptomatic or asymptomatic; without visceral disease but lymph node metastases were allowed). Patients received intravenous injections of radium-223, 50 kBq/kg (current recommendation 55 kBq/kg after implementation of National Institute of Standards and Technology update on April 18, 2016) every 4 weeks for up to six injections. Other concomitant anticancer therapies were allowed. Primary endpoints were safety and overall survival. The safety and efficacy analyses were done on all patients who received at least one dose of the study drug. The study has been completed, and we report the final analysis here. This study is registered with ClinicalTrials.gov, number NCT01618370, and the European Union Clinical Trials Register, EudraCT number 2012-000075-16. FINDINGS Between July 22, 2012, and Dec 19, 2013, 839 patients were enrolled from 113 sites in 14 countries. 696 patients received one or more doses of radium-223; 403 (58%) of these patients had all six planned injections. Any-grade treatment-emergent adverse events occurred in 523 (75%) of 696 patients; any-grade treatment-emergent adverse events deemed to be related to treatment were reported in 281 (40%) patients. The most common grade 3 or worse treatment-related treatment-emergent adverse events were anaemia in 32 (5%) patients, thrombocytopenia in 15 (2%) patients, neutropenia in ten (1%) patients, and leucopenia in nine (1%) patients. Any grade of serious adverse events were reported in 243 (35%) patients. Median follow-up was 7·5 months (IQR 5-11) and 210 deaths were reported; median overall survival was 16 months (95% CI 13-not available [NA]). In an exploratory analysis of overall survival with predefined factors, median overall survival was longer for: patients with baseline alkaline phosphatase concentration less than the upper limit of normal (ULN; median NA, 95% CI 16 months-NA) than for patients with an alkaline phosphatase concentration equal to or greater than the ULN (median 12 months, 11-15); patients with baseline haemoglobin levels 10 g/dL or greater (median 17 months, 14-NA) than for patients with haemoglobin levels less than 10 g/dL (median 10 months, 8-14); patients with a baseline Eastern Cooperative Oncology Group performance status (ECOG PS) of 0 (median NA, 17 months-NA) than for patients with an ECOG PS of 1 (median 13 months, 11-NA) or an ECOG PS of 2 or more (median 7 months, 5-11); and for patients with no reported baseline pain (median NA, 16 months-NA) than for those with mild pain (median 14 months, 13-NA) or moderate-severe pain (median 11 months, 9-13). Median overall survival was also longer in patients who received radium-223 plus abiraterone, enzalutamide, or both (median NA, 95% CI 16 months-NA) than in those who did not receive these agents (median 13 months, 12-16), and in patients who received radium-223 plus denosumab (median NA, 15 months-NA) than in patients who received radium-223 without denosumab (median 13 months, 12-NA). INTERPRETATION Our findings show that radium-223 can be safely combined with abiraterone or enzalutamide, which are now both part of the standard of care for patients with metastatic castration-resistant prostate cancer. Furthermore, our findings extend to patients who were asymptomatic at baseline, unlike those enrolled in the pivotal ALSYMPCA study. The findings of prolonged survival in patients treated with concomitant abiraterone, enzalutamide, or denosumab require confirmation in prospective randomised trials. FUNDING Pharmaceutical Division of Bayer.

Addition of Docetaxel to Androgen Deprivation Therapy for Patients with Hormone-sensitive Metastatic Prostate Cancer: A Systematic Review and Meta-analysis

CONTEXT Several randomized clinical trials (RCTs) have recently tested the early addition of docetaxel to androgen deprivation therapy (ADT) in hormone-sensitive metastatic prostate cancer (PCa). OBJECTIVE To perform a systematic review and meta-analysis of RCTs evaluating the combination of docetaxel and ADT in hormone-sensitive metastatic PCa. The primary end point was overall survival (OS). Secondary end point was progression-free survival. Exploratory subgroup analysis according to high-volume versus low-volume disease was performed. EVIDENCE ACQUISITION A systematic review of PubMed/Medline, Embase, and the proceedings of major international meetings was performed in June 2015 and updated in August 2015. Three trials were selected for inclusion. EVIDENCE SYNTHESIS Overall, 2951 patients were included in the three trials. Two trials enrolled only metastatic patients; in the third trial, 61% were metastatic. A total of 2262 patients (951 docetaxel and ADT; 1311 ADT alone) were metastatic. Most patients had a good performance status. In metastatic patients, the addition of docetaxel was associated with improved OS (hazard ratio [HR]: 0.73; 95% confidence interval [CI], 0.60-0.90; p=0.002), with nonsignificant heterogeneity among the three trials. Considering the whole study population (2951 patients), the addition of docetaxel was associated with a similar OS improvement (HR: 0.74; 95% CI, 0.61-0.91; p=0.003). Although with limited statistical power, no significant interaction was demonstrated between the addition of docetaxel and the high or low volume of disease (p=0.5). The addition of docetaxel was associated with improvement in progression-free survival (metastatic patients: HR: 0.63; 95% CI, 0.57-0.70; p<0.001). CONCLUSIONS This meta-analysis shows a significant OS benefit from concomitant administration of docetaxel and ADT in patients with metastatic hormone-sensitive PCa. PATIENT SUMMARY We synthesized the evidence available about the early administration of docetaxel in patients starting hormonal treatment for metastatic prostate cancer. Based on the results of this meta-analysis, we believe the combination of chemotherapy and hormonal treatment should be considered in fit patients.

Predictive factors for skeletal complications in hormone-refractory prostate cancer patients with metastatic bone disease

Factors predictive of skeletal-related events (SREs) in bone metastatic prostate cancer patients with hormone-refractory disease were investigated. We evaluated the frequency of SREs in 200 hormone-refractory patients consecutively observed at our Institution and followed until death or the last follow-up. Baseline parameters were evaluated in univariate and multivariate analysis as potential predictive factors of SREs. Skeletal-related events were observed in 86 patients (43.0%), 10 of which (5.0%) occurred before the onset of hormone-refractory disease. In univariate analysis, patient performance status (P=0.002), disease extent (DE) in bone (P=0.0001), bone pain (P=0.0001), serum alkaline phosphatase (P=0.0001) and urinary N-telopeptide of type one collagen (P=0.0001) directly correlated with a greater risk to develop SREs, whereas Gleason score at diagnosis, serum PSA, Hb, serum albumin, serum calcium, types of bone lesions and duration of androgen deprivation therapy did not. Both DE in bone (hazard ratio (HR): 1.16, 95% confidence interval (CI): 1.07–1.25, P=0.000) and pain score (HR: 1.13, 95% CI: 1.06–1.20, P=0.000) were independent variables predicting for the onset of SREs in multivariate analysis. In patients with heavy tumour load in bone and great bone pain, the percentage of SREs was almost twice as high as (26 vs 52%, P<0.02) and occurred significantly earlier (P=0.000) than SREs in patients with limited DE in bone and low pain. Bone pain and DE in bone independently predict the occurrence of SREs in bone metastatic prostate cancer patients with hormone-refractory disease. These findings could help physicians in tailoring the skeletal follow-up most appropriate to individual patients and may prove useful for stratifying patients enrolled in bisphosphonate clinical trials.

Clinical Outcomes of Castration-resistant Prostate Cancer Treatments Administered as Third or Fourth Line Following Failure of Docetaxel and Other Second-line Treatment: Results of an Italian Multicentre Study

BACKGROUND The availability of new agents (NAs) active in patients with metastatic castration-resistant prostate cancer (mCRPC) progressing after docetaxel treatment (abiraterone acetate, cabazitaxel, and enzalutamide) has led to the possibility of using them sequentially to obtain a cumulative survival benefit. OBJECTIVE To provide clinical outcome data relating to a large cohort of mCRPC patients who received a third-line NA after the failure of docetaxel and another NA. DESIGN, SETTING, AND PARTICIPANTS We retrospectively reviewed the clinical records of patients who had received at least two successive NAs after the failure of docetaxel. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS The independent prognostic value of a series of pretreatment covariates on the primary outcome measure of overall survival was assessed using Cox regression analysis. RESULTS AND LIMITATIONS We assessed 260 patients who received one third-line NA between January 2012 and December 2013, including 38 who received a further NA as fourth-line therapy. The median progression-free and overall survival from the start of third-line therapy was, respectively, 4 mo and 11 mo, with no significant differences between the NAs. Performance status, and haemoglobin and alkaline phosphatase levels were the only independent prognostic factors. The limitations of the study are mainly due its retrospective nature and the small number of patients treated with some of the sequences. CONCLUSIONS We were unable to demonstrate a difference in the clinical outcomes of third-line NAs regardless of previous NA therapy. PATIENT SUMMARY It is debated which sequence of treatments to adopt after docetaxel. Our data do not support the superiority of any of the three new agents in third-line treatment, regardless of the previously administered new agent.

Understanding and overcoming the mechanisms of primary and acquired resistance to abiraterone and enzalutamide in castration resistant prostate cancer

In recent years, in castration resistant prostate cancer (CRPC), several new drugs have been approved that prolong overall survival, including enzalutamide and abiraterone, two new-generation hormonal therapies. Despite the demonstrated benefit of these agents, not all patients with CRPC are responsive to treatment, the gain in median progression-free survival with these therapies compared to standard of care is, rather disappointingly, still less than six months and the appearance of acquired resistance is almost universal. Approximately one third of patients treated with abiraterone and 25% of those treated with enzalutamide show primary resistance to these agents. Even if the mechanisms of resistance to these agents are not fully defined, many hypotheses are emerging, including systemic and intratumoral androgen biosynthesis up-regulation, androgen receptor (AR) gene mutations and amplifications, alteration of pathways involved in cross-talk with AR signaling, glucocorticoid receptor overexpression, neuroendocrine differentiation, immune system deregulation and others. The aim of this paper is to review currently available data about mechanisms of resistance to abiraterone and enzalutamide, and to discuss how these mechanisms could be potentially overcome through novel therapeutic agents.

Effects of Serum Testosterone Levels After 6 Months of Androgen Deprivation Therapy on the Outcome of Patients With Prostate Cancer

BACKGROUND Controversy exists about whether testosterone serum levels at a cutoff point of < 50 ng/dL during luteinizing hormone-releasing hormone analogue (LHRHA) treatment are related to the outcome of patients with prostate cancer. We assessed the relationship between serum testosterone levels after 6 months of LHRHA therapy and disease outcome in a consecutive series of patients with prostate cancer. PATIENTS AND METHODS Serum testosterone levels were measured prospectively in a cohort of patients given LHRHA for 6 months. End points were time to progression (TTP) and overall survival (OS). RESULTS The study population was 153 patients: 54 with metastatic disease and 99 with biochemical failure. In multivariate analysis, adjustment for age, baseline serum prostatic specific antigen (PSA) levels, Gleason score, and disease stage, testosterone levels < 50 ng/dL failed to be associated with TTP and OS. A cutoff of < 20 ng/dL was associated with a nonsignificant lower risk of progression (adjusted hazard ratio [HR] 0.58; 95% confidence interval [CI] 0.30-1.15; P = .12) and a significant lower risk of death (adjusted HR, 0.19; 95% CI, 0.04-0.76; P = .02). Only 25 patients attained serum testosterone levels < 20 ng/dL. Using a receiver operating characteristic curve (ROC), we found that a testosterone value of 30 ng/dL offered the best overall sensitivity and specificity for prediction of death. Serum testosterone levels < 30 ng/mL were associated with a significantly lower risk of death (adjusted HR, 0.45; 95% CI, 0.22-0.94; P = .034. CONCLUSIONS Serum testosterone levels lower than the currently adopted cutoff of 50 ng/dL have a prognostic role in patients with prostate cancer receiving LHRHA and are a promising surrogate parameter of LHRHA efficacy.

Real-world cabazitaxel safety: the Italian early-access program in metastatic castration-resistant prostate cancer.

AIM Cabazitaxel is a novel taxane that is approved for use in metastatic castration-resistant prostate cancer based on the Phase III TROPIC study, which showed improved overall survival with cabazitaxel/prednisone versus mitoxantrone/prednisone. A global early-access program was initiated in order to provide early access to cabazitaxel in docetaxel-pretreated patients and to obtain real-world data. PATIENTS & METHODS We report interim safety results from an Italian prospective, single-arm, multicenter, open-label trial of 218 patients receiving cabazitaxel 25 mg/m2 every 3 weeks plus prednisolone 10 mg/day, until disease progression, unacceptable toxicity, investigators decision or death. RESULTS Patients completing treatment received a median of six cabazitaxel cycles. The most common grade 3/4 adverse events were neutropenia (33.9%), leukopenia (15.6%), anemia (6%) and asthenia (6%). No peripheral neuropathy or nail disorders were observed. CONCLUSION These results confirm that cabazitaxel has a manageable safety profile in daily clinical practice and support its use in patients with prostate cancer who progress during or after a docetaxel-based therapy.

Prognostic significance of disordered calcium metabolism in hormone-refractory prostate cancer patients with metastatic bone disease

Bone metabolic disruption that occurs in bone metastatic prostate cancer could lead to disturbances of calcium metabolism. The prognostic role of either hypocalcemia or hypercalcemia was assessed in a consecutive series of hormone-refractory bone metastatic prostate cancer patients. Serum calcium was measured in 192 patients. The presence of hypocalcemia and hypercalcemia was related with baseline biochemical and clinical characteristics and the role of these two calcium disturbances in predicting prognosis and adverse skeletal-related events (SREs) was assessed. As compared to normocalcemic patients, hypocalcemic patients (n=51) had higher tumor load in bone (P=0.005), higher plasma chromogranin A (CgA, P=0.01), serum alkaline phosphatase (P=0.01), urinary N-telopeptide (NTX, P=0.002) and lower hemoglobin values (P=0.01), while hypercalcemic patients (n=16) had higher plasma CgA (P=0.001) and serum lactate dehydrogenase values (P=0.001), higher bone pain (P=0.003) and a lower frequency of pure osteoblastic lesions (P=0.001). Hypercalcemia was significantly associated with poor prognosis: hazard ratio (HR), 1.9 (95% confidence Interval (CI) 1.2–3.3) and higher risk to develop SREs HR, 2.5 (95% CI 1.2–5.2, P=0.01), while hypocalcemia was not associated with poor prognosis. The prognostic role of hypercalcemia was maintained in multivariate analysis after adjusting for validated prognostic parameters: HR, 2.72 (95% CI 1.1–6.8, P=0.03). These data suggest that serum calcium levels should be taken into account in the clinical decision-making process of bone metastatic prostate cancer patients. Patients with asymptomatic hypercalcemia could benefit of a strict follow-up and an immediate bisphosphonate treatment. Further prospective clinical trials are needed to confirm this finding.

Metabolic effects of single-dose pamidronate administration in prostate cancer patients with bone metastases

BACKGROUND Increased osteolysis usually accompanies sclerotic bone metastases from prostate cancer. This provides a rationale for the use of bisphosphonates to treat bone pain and prevent skeletal complications. METHODS The fasting urinary levels of calcium, hydroxyproline (OHPRO), pyridinolines (PYD), deoxypyridinolines (DPYD), collagen cross-linked N-telopeptide (NTX) and the serum values of calcium, total alkaline phosphatase and relevant bone isoenzyme, bone gla protein (BGP), carboxy-telopeptide of type I collagen (ICTP) and parathyroid hormone (PTH) were determined at baseline and on the 15th, 30th, 60th and 90th days after single-dose (90 mg) pamidronate administration in 35 consecutive prostate cancer patients with bone metastases. These biochemical indices and serum interleukin 6 (IL-6) were also measured after four days in the last consecutive 17 cases. RESULTS PYD, DPYD and NTX showed a significant decrease lasting four weeks (p<0.01, <0.01 and <0.001, respectively). OHPRO and ICTP did not change significantly. The NTX decline was greater than that of PYD and DPYD (maximum percent decrease: -71.3, -23.1 and -28.2, respectively). Bone formation markers and serum calcium did not change significantly. Serum PTH showed a rapid initial increase followed by a slow decrease (p<0.001). DPYD and NTX patterns did not correlate with changes in bone pain. As observed in the last 17 cases, the maximum osteolysis inhibition after pamidronate occurred on the fourth day after drug infusion. Serum IL-6 levels showed a short-lived decrease preceded by a transient rise on the fourth day. CONCLUSIONS Pamidronate is able to induce a decrease in bone resorption without significantly influencing bone formation. The maximum decrease in bone resorption occurs very early. NTX is the most sensitive bone resorption marker in bisphosphonate therapy monitoring. Changes in IL-6 but not bone resorption markers may be useful in the prediction of symptomatic response.