Docetaxel and zoledronic acid in patients with metastatic hormone-refractory prostate cancer

CCN1, a candidate target for zoledronic acid treatment in breast cancer

CCN1, also known as CYR61, is a survival and proangiogenic factor overexpressed in about 30% of invasive breast carcinomas, and particularly in triple-negative breast carcinomas (TNBC). CCN1 expression in breast cancer promotes tumorigenicity, metastasis, antihormone, and chemoresistance. TNBCs often develop bone metastasis, thus the vast majority of patients receive bisphosphonate treatment as a companion to chemotherapy. Zoledronic acid (ZOL), a bisphosphonate currently in use, inhibits bone resorption, prevents development of new osteolytic lesions induced by tumor metastasis, and has a direct antitumor activity in breast cancer cells and tumors. We have shown that ZOL inhibits anchorage independent growth as well as branching and morphogenesis in CCN1 overexpressing cells. However, the mechanism is not yet well understood. In this study, we investigate the effect of ZOL in breast cancer cells with high and undetectable CCN1 expression levels. We show that CCN1-expressing cells are more sensitive to ZOL, that ZOL induces downregulation of the CCN1 promoter activity and CCN1 protein expression in a dose-dependent manner, and that ZOL is associated with a decrease in phosphorylated Akt and translocation of FOXO3a, a negative regulator of CCN1 expression, to the nucleus. Deletion of the FOXO3a binding site in the CCN1 promoter prevents ZOL inhibition of the CCN1 promoter activity showing that FOXO3a transcriptional activation is necessary for ZOL to induce CCN1 inhibition. This study provides evidence that ZOL targets the proangiogenic factor (CCN1) through FOXO3a and reveals a new mechanism of ZOL action in breast cancer cells.

Clinical efficacy and safety of zoledronic acid in prostate and breast cancer

The anti-estrogen treatment for hormone-sensitive breast cancer and the androgen deprivation therapy for prostate cancer can lead to the development of osteoporosis and bone fractures. Metastases associated with prostate and breast cancer can also occur in bone. Bisphosphonates are used in these types of bone dysfunction. Zoledronic acid is the most potent bisphosphonate. In osteoporosis, zoledronic acid inhibits bone reabsorption and increases bone mineral density for at least a year after intravenous administration. The efficacy and safety of zoledronic acid in osteoporosis secondary to hormone-sensitive cancers (prostate and breast), and in the bone metastases associated with these cancers are reviewed.

Additive/synergistic antitumoral effects on prostate cancer cells in vitro following treatment with a combination of docetaxel and zoledronic acid

Once bone metastasized and androgen independent, prostate cancer is often associated with skeletal morbidity and disability. New treatment modalities that can palliate symptoms from the skeleton and inhibit further progression are warranted. In this study, the antitumoral effects following treatment with a combination of docetaxel and the new generation bisphosphonate, zoledronic acid, were investigated on two hormone-refractory prostate cancer cell lines: PC3 and DU145. The prostate cancer cells were treated with increasing concentrations of zoledronic acid in the absence or presence of docetaxel. Toxicity was measured using fluorometric microculture cytotoxic assay technique. A concentration of 25 microM, zoledronic acid reduced the viable cell number to 68% and 98% for PC3 and DU145 cells respectively. Docetaxel, on the other hand, at a concentration of 0.1 ng/ml, had no effect on the viability. However, a combination of zoledronic acid and docetaxel reduced the cell number to 60% and 81% respectively. Furthermore, zoledronic acid in the concentration range 12.5 microM-50 microM enhanced the antitumoral effects of docetaxel (0.01-1 ng/ml) in an additive and/or synergistic manner for both cell lines. These data support the hypothesis that zoledronic acid, in addition to having bone resorption inhibiting properties, also exhibits anti-tumoral effects. It also appears that combined treatment with docetaxel causes additive and/or synergistic cytostatic effects on prostate cancer cells.

New research findings on zoledronic acid: survival, pain, and anti-tumour effects

OBJECTIVES

To summarize the current evidence for clinical, anti-tumour, and survival benefits from zoledronic acid in patients with genitourinary cancers.

METHODS

Studies were identified through MEDLINE searches, review of bibliographies of relevant articles, and review of abstracts from scientific meetings.

RESULTS

Among patients with bone metastases from prostate cancer or renal cell carcinoma, zoledronic acid significantly delayed the onset and reduced the incidence of skeletal complications compared with placebo. Zoledronic acid is also the only bisphosphonate that has demonstrated a trend toward improved survival and delayed progression of bone lesions in patients with urologic malignancies. Furthermore, zoledronic acid reduced the incidence of pathologic fracture, a skeletal-related event known to be associated with reduced survival. Bisphosphonates have also demonstrated significant palliative benefits, and preclinical evidence indicates that bisphosphonates may have direct anti-tumour effects.

CONCLUSIONS

Zoledronic acid is the only bisphosphonate that has demonstrated statistically significant, long-term clinical benefits through the prevention and delay of skeletal-related events in patients with metastatic prostate cancer or renal cell carcinoma.

Docetaxel, Vinorelbine, and Zoledronic Acid as First-Line Treatment in Patients with Hormone Refractory Prostate Cancer: A Phase II Study

OBJECTIVES

Combining antineoplastic agents is the key to improving the treatment options for men with hormone refractory prostate cancer (HRPC). The current study investigated the combination of docetaxel, vinorelbine, and zoledronic acid as a first-line treatment for HRPC.

METHODS

Patients were treated repeatedly with docetaxel (25 mg/mq) and vinorelbine (10 mg/mq) intravenously for three consecutive weeks followed by a 1-wk rest until disease progression or side effects. Zoledronic acid was administered every 4 wk. Changes in prostate-specific antigen (PSA) levels and objective responses were evaluated after two and three cycles, respectively. Toxicity and pain evaluation, based on pain intensity reduction and analgesic drug reduction, were assessed every cycle.

RESULTS

Forty men with HRPC (median age: 65 yr) were treated. Among 38 evaluable patients, complete and major PSA responses were observed in seven (18%) and 12 (32%), respectively; a partial objective response was observed in six of 15 (40%) patients with measurable disease. Neutropenia (25%) was the most important grade 3 haematologic toxicity observed. Only three patients (7.5%) reported grade 4 neutropenia. Nineteen patients (47.5%) achieved a reduction of pain intensity and analgesic drug use after two cycles. Median progression-free survival was 7 mo (95% CI: 2-10 mo), with a median overall survival of 17 mo (95% CI: 6-22 mo).

CONCLUSIONS

The combination of docetaxel, vinorelbine, and zoledronic acid is associated with improvement in biochemical, objective, and pain responses and is well tolerated as a first-line treatment for HRPC.

Weekly docetaxel, zoledronic acid and estramustine in hormone-refractory prostate cancer (HRPC)

Treatment options for patients with hormone refractory prostate cancer (HRPC) showed unsatisfactory outcomes. Docetaxel-based combinations could offer more promising and tolerated results. A phase II trial was conducted with the combination of zoledronic acid, docetaxel and estramustine. Eligibility consisted of metastatic prostate adenocarcinoma with objective progression or rising prostate specific antigen levels (PSA) despite androgen deprivation therapy. Zoledronic acid was given at a dose of 4 mg on day 1, docetaxel (25 mg/m2) on days 1, 8 and 15, and estramustine orally at 140 mg two times daily on days 1 to 21 of a 28-day cycle. Twenty-seven patients were enrolled between October 2002 and November 2004. Median age was 68 years (53-83 years). A total of 124 cycles were administered with a median of 4.6 cycles per patient (1-8 cycles). The major toxicities were grades 1 to 3 anemia (55%), fatigue (15%), alopecia (11%) and hypocalcemia (11%). Two patients presented with deep venous thrombosis and died from pulmonary embolism. Another third patient died from Stevens-Johnson syndrome and grade 4 hepatic toxicity. Out of the 25 patients assessed for efficacy, 13 (52%) had a biologic response (>50% PSA decline). Three (21%) patients among the 14 with measurable disease had objective response: 1 complete response (CR) and 2 partial responses (PR). Response duration was 2 months for PR and 4 months for CR. A total of 12 patients (48%) experienced clinical benefit with pain reduction. This combination seemed effective; however toxic deaths especially from venous thrombosis counterbalanced the advantage of this regimen.

Hospitalisation à domicile en onco-urologie : bilan des 5 premières années et enquête de satisfaction

INTRODUCTION

The Cancer Plan emphasizes the importance of home hospitalisation. Over the last 5 years, our department has developed this mode of hospitalisation for patients with urological cancer in order to perform chemotherapy or palliative care. The objective of this study was to determine the growth of the number of patients hospitalised at home over the last 5 years and to evaluate the satisfaction of patients hospitalised in 2005 by means of a self-administered questionnaire.

METHODS

A retrospective study was conducted to identify patients hospitalised at home between 2001 and 2005. A satisfaction questionnaire was sent to 58 patients hospitalised in 2005 to evaluate the degree of satisfaction, management and coordination of all medical and paramedical personnel and the advantages perceived by the patients.

RESULTS

Between 2001 and 2005, 178 patients were hospitalised at home, for chemotherapy in 59% of cases and for palliative care in 41% of cases; 56% of patients were followed for prostate cancer. Among the 58 patients contacted, 44 questionnaires were returned (response rate: 76%) : 43 patients were globally satisfied with their management (28 very satisfied, 13 satisfied and 2 moderately satisfied) and would recommend home hospitalisation to their relatives. No difficulties contacting the nurse, the oncologist or the urologist were reported. The advantages emphasized by patients were maintenance in their usual environment (92%) allowing continuation of daily activities (85%), limitation of ambulance transfers to hospital and decreased waiting time in hospital (90%), as well as the involvement of the general practitioner, freely chosen by the patient, in follow-up (62.5%) ; 98% of patients would not have preferred to be managed by conventional hospitalisation for the treatment received.

CONCLUSION

Home hospitalisation for chemotherapy or palliative care appears to be an effective alternative to conventional hospitalisation requiring good collaboration by the office-hospital network.

The safety of zoledronic acid

Zoledronic acid has been marketed for the past 5 years for the treatment of hypercalcemia of malignancy and malignant bone disease in patients with multiple myeloma or a broad range of solid tumors. The safety profile of zoledronic acid in this patient population is well established from the databases of several large, randomized, Phase III trials and postmarketing clinical experience. Zoledronic acid is well tolerated, with predictable side effects, primarily transient flu-like symptoms, which are manageable with standard treatment. Renal monitoring is recommended, with dose reductions for patients with renal dysfunction. Monitoring for electrolyte imbalance is also important as is calcium and vitamin D supplementation. Ocular complications are rare, and osteonecrosis of the jaw is uncommon and might be avoidable with appropriate dental care.

Targeting factors involved in bone remodeling as treatment strategies in prostate cancer bone metastasis

Prostate cancer is the most commonly diagnosed cancer in men within the western world and the third leading cause of cancer-related deaths. Even if the cancer is considered localized to the prostate, there is a 15% to 20% incidence of subsequent metastatic disease. Prostate cancer has a very high proclivity for metastasizing to bone, with approximately 90% of men with advanced disease having skeletal lesions. The prostate cancer metastases are characteristically osteoblastic, with extensive new bone deposition, unlike other tumors that metastasize to bone and cause an osteolytic response reflective of bone degradation. There are a considerable number of studies relating to inhibition of the osteoblastic response, including interference with endothelin-1, bone morphogenetic proteins, and Wnt signaling pathways. Within the past few years, several studies showed that increased osteolytic activity also occurs in the background of the prostate cancer skeletal metastases. Because growth factors are being released from the bone matrix during degradation, it suggests that inhibition of osteolysis might be effective in slowing tumor growth. Several strategies are being developed and applied to affect directly the osteolytic events, including use of bisphosphonates and targeting the critical biological regulators of osteoclastogenesis, receptor activator of nuclear factor-kappaB and receptor activator of nuclear factor-kappaB ligand. This review focuses on several of the clinical and preclinical strategies to inhibit the growth of prostate cancer cells in bone and to alleviate the multitude of associated skeletal-related events.

Chemotherapy for hormone-refractory prostate cancer

BACKGROUND

Prostate cancer mainly affects elderly men, and its incidence has steadily increased over the last decade. The management of this disease is replete with controversy. In men with advanced, metastatic prostate cancer, hormone therapy is almost universally accepted as the initial treatment of choice and produces good responses in most patients. However, many patients will relapse and become resistant to further hormone manipulation; the outlook for these patients is poor. Many have disease extending to the skeleton, which is associated with severe pain. Therapies for these men include chemotherapy, bisphosphonates, palliative radiotherapy, and radioisotopes. Systemic chemotherapy has been evaluated in men with hormone-refractory prostate cancer (HRPC) for many years, with disappointing results. However, more recent studies with newer agents have shown encouraging results. There is therefore a need to explore the value of chemotherapy in this disease.

OBJECTIVES

The present review aims to assess the role of chemotherapy in men with metastatic HRPC. The major outcome was overall survival. Secondary objectives include the effect of chemotherapy on pain relief, prostate-specific antigen (PSA) response, quality of life, and treatment-related toxicity.

SEARCH STRATEGY

Trials were identified by searching electronic databases, such as MEDLINE, and handsearching of relevant journals and conference proceedings. There was no restriction of language or location.

SELECTION CRITERIA

Only published randomised trials of chemotherapy in HRPC patients were eligible for inclusion in this review. Randomised comparisons of different chemotherapeutic regimens, chemotherapy versus best standard of care or placebo, were relevant to this review. Randomised, dose-escalation studies were not included in this review.

DATA COLLECTION AND ANALYSIS

Data extraction tables were designed specifically for this review to aid data collection. Data from relevant studies were extracted and included information on trial design, participants, and outcomes. Trial quality was also assessed using a scoring system for randomisation, blinding, and description of patient withdrawal.

MAIN RESULTS

Out of 107 randomised trials of chemotherapy in advanced prostate cancer identified by the search strategy, 47 were included in this review and represented 6929 patients with HRPC. Only two trials compared the same chemotherapeutic interventions and therefore a meta-analysis was considered inappropriate. The quality of some trials was poor because of poor reporting, low-patient recruitment, or poor trial design. For clarity, trials were categorised according to the major drug used, but this was not a definitive grouping, since many trials used several agents and would be eligible for inclusion in a number of categories. Drug categories included estramustine, 5-fluorouracil, cyclophosphamide, doxorubicin, mitoxantrone, and docetaxel. Only studies using docetaxel reported a significant improvement in overall survival compared to best standard of care, although the increase was small (< 2.5 months). The mean percentage of patients achieving at least a 50% reduction in PSA compared to baseline was as follows: estramustine 48%; 5-fluorouracil 20%; doxorubicin 50% (one study only); mitoxantrone 33%; and docetaxel 52%. Pain relief was reported in 35% to 76% of patients receiving either single agents or combination regimens. A three weekly regime of docetaxel significantly improved pain relief compared to mitoxantrone plus prednisone (the latter regimen approved as standard therapy for HRPC in the USA). All chemotherapeutics, either as single agents or in combination, were associated with toxicity; the major ones being myelosuppression, gastrointestinal toxicity, cardiac toxicity, neuropathy, and alopecia. Quality of life was significantly improved with docetaxel compared to mitoxantrone plus prednisone.

AUTHORS' CONCLUSIONS

Patients with HRPC have not traditionally been offered chemotherapy as a routine treatment because of treatment-related toxicity and poor responses. Recent data from randomised studies, in particular those using docetaxel, have provided encouraging improvements in overall survival, palliation of symptoms, and improvements in quality of life. Chemotherapy should be considered as a treatment option for patients with HRPC. However, patients should make an informed decision based on the risks and benefits of chemotherapy.

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

Prostate cancer responds initially to hormonal manipulation by androgen withdrawal and peripheral androgen blockade. The inevitable progression to a hormone-refractory state is accompanied by an exacerbation of local symptoms and metastatic spread, principally to the bones, which has a considerable impact on quality of life and survival. Treatment of hormone-refractory prostate cancer is palliative, and surgery and radiotherapy are used for the relief of lower urinary tract symptoms and localized painful bony metastases. Systemic treatments are not widely accepted in this setting, but clinical trials have demonstrated the potential for bone targeting agents such as strontium-89 and the bisphosphonates to palliate painful bone metastases and to delay progression in certain settings. Chemotherapy with mitozantrone in combination with steroids has previously been shown to have palliative benefits and to delay progression. The additional costs incurred by the use of chemotherapy or bone-targeting therapies may be offset by gains in overall care with fewer in-patient admissions compared with steroid monotherapy. Recent clinical trials have demonstrated that docetaxel significantly improves patient quality of life, and importantly, increases survival. Future studies investigating the timing of chemotherapy, combinations with existing treatments or other novel therapies are underway.

New standards in the chemotherapy of metastatic hormone-refractory prostate cancer

Hormone-refractory prostate cancer (HRPC) is a major issue in Western countries and the second leading cause of cancer death in North American men. In the prostate-specific antigen era, most HRPCs are currently diagnosed in asymptomatic patients based on biochemical failure, with increasing demand for active treatment. Until recently, chemotherapy for HRPC patients was not considered a standard of care due to the absence of clear data evidencing an overall survival benefit. In fact, few Phase III studies conducted in the 1980s and early 1990s had documented a superiority over corticosteroids alone in terms of biochemical response (declines in serum prostate-specific antigen levels) and quality of life, but not survival. Due to their impact on pain control, mitoxantrone and prednisone were long considered the best regimen for symptomatic HRPC patients. In recent years, more chemotherapeutic agents have been tested, among which the microtubule inhibitors (vinca alkaloids and taxanes) have obtained the most promising results in Phase II trials and have entered Phase III testing. Two well-designed randomized trials have changed this scenario. Both compared docetaxel (with or without estramustine) against mitoxantrone and prednisone, and demonstrated a significant advantage not only in terms of response, pain control and quality of life, but also in terms of overall survival. Which patients need to be treated, the regimen of choice and duration of chemotherapy will be the next questions to be answered in the coming years in the field of HRPC, along with the role of new signal transduction inhibitors and other targeted therapies.

Characterization of prognostic factors and efficacy in a phase-II study with docetaxel and estramustine for advanced hormone refractory prostate cancer

BACKGROUND

Docetaxel based chemotherapy not only reduces pain and improves quality of life in advanced hormone refractory prostate cancer (HRPC), but it also improves survival. We investigated the combination of docetaxel and estramustine in patients with HRPC regarding efficacy and prognostic parameters.

PATIENTS AND METHODS

We conducted a phase-II trial, administering docetaxel (70 mg/m(2) i.v., day 2, every 3 weeks) and estramustine (280 mg 3 times daily p.o., 1 day prior to docetaxel, on 5 consecutive days) to patients with HRPC. Patients were monitored for PSA (prostate-specific antigen) response and toxicity.

RESULTS

62 patients were treated. The median age was 67.5 years, the median PSA was 177.9 ng/ml. The median number of cycles was 6. The median time to progression (TTP) and median survival time were 14 (+/-2) and 24 (+/-5) months, respectively. A = 50% decrease in PSA levels from baseline occurred in 38 (61.3%) patients of whom 25 (40.3%) had a = 75% PSA decrease. The main grade 3-4 hematologic toxicities were neutropenia 34% and anemia 18%.

CONCLUSIONS

The combination of docetaxel and estramustine exerts substantial activity in HRPC suggesting an overall survival benefit with manageable toxicity. This trial also demonstrated a survival advantage for patients with early chemotherapeutic intervention. We identified PSA relapse, baseline PSA and hemoglobin as valuable prognostic factors in this setting.

Administration of zoledronic acid enhances the effects of docetaxel on growth of prostate cancer in the bone environment

Background

After development of hormone-refractory metastatic disease, prostate cancer is incurable. The recent history of chemotherapy has shown that with difficult disease targets, combinatorial therapy frequently offers the best chance of a cure. In this study we have examined the effects of a combination of zoledronic acid (ZOL), a new-generation bisphosphonate, and docetaxel on LuCaP 23.1, a prostate cancer xenograft that stimulates the osteoblastic reaction when grown in the bone environment.

Methods

Intra-tibial injections of LuCaP 23.1 cells were used to generate tumors in the bone environment, and animals were treated with ZOL, docetaxel, or a combination of these. Effects on bone and tumor were evaluated by measurements of bone mineral density and histomorphometrical analysis.

Results

ZOL decreased proliferation of LuCaP 23.1 in the bone environment, while docetaxel at a dose that effectively inhibited growth of subcutaneous tumors did not show any effects in the bone environment. The combination of the drugs significantly inhibited the growth of LuCaP 23.1 tumors in the bone.

Conclusion

In conclusion, the use of the osteolysis-inhibitory agent ZOL in combination with docetaxel inhibits growth of prostate tumors in bone and represents a potential treatment option.

Weekly docetaxel and zoledronic acid every 4 weeks in hormone-refractory prostate cancer patients

OBJECTIVES

To investigate the safety and efficacy of docetaxel and zoledronic acid in patients with hormone-refractory prostate cancer (HRPC), based on preclinical evidence of synergism between taxanes and bisphosphonates.

METHODS

Twenty-five patients with advanced HRPC received weekly docetaxel 30 mg/m2: in 18 patients with symptomatic bone metastases and normal renal function, docetaxel was combined with zoledronic acid, 4 mg i.v. every 4 weeks. Premedication consisted of intravenous dexamethasone before docetaxel. No oral steroids were given.

RESULTS

Overall, 12 patients (48%) had a PSA response (reduction of 50% or more compared to baseline). A PSA response was achieved in 8/18 patients (44%) receiving concomitant docetaxel and zoledronic acid, and in 7/12 patients (58%) receiving docetaxel and zoledronic acid as first-line therapy. The weekly schedule of docetaxel resulted in a mean received dose intensity of 26 mg/m2/week, or 87% of the planned dose intensity. Toxicity was mild and as expected for docetaxel. The median time to progression was 7 months, and the median overall survival was 16 months.

CONCLUSIONS

Concomitant treatment with docetaxel and zoledronic acid is safe and has encouraging activity in HRPC. The combination should be evaluated in randomised clinical trials.