How is androgen-dependent metastatic prostate cancer best treated?

Beyond boundaries: unraveling innovative approaches to combat bone-metastatic cancers

Evidence demonstrated that bones, liver, and lungs are the most common metastasis sites in some human malignancies, especially in prostate and breast cancers. Bone is the third most frequent target for spreading tumor cells among these organs and tissues. Patients with bone-metastatic cancers face a grim prognosis characterized by short median survival time. Current treatments have proven insufficient, as they can only inhibit metastasis or tumor progression within the bone tissues rather than providing a curative solution. Gaining a more profound comprehension of the interplay between tumor cells and the bone microenvironment (BME) is of utmost importance in tackling this issue. This knowledge will pave the way for developing innovative diagnostic and therapeutic approaches. This review summarizes the mechanisms underlying bone metastasis and discusses the clinical aspects of this pathologic condition. Additionally, it highlights emerging therapeutic interventions aimed at enhancing the quality of life for patients affected by bone-metastatic cancers. By synthesizing current research, this review seeks to shed light on the complexities of bone metastasis and offer insights for future advancements in patient care.

The presenting dental status of solid tumours with bone metastases requiring bone-targeting agents - part 3: prostate cancer

Introduction Metastatic prostate cancer (MPC) patients due to receive bone-targeting agents (BTAs) are expected to undertake a dental assessment before commencing. The aim of this study was to determine the dental status of this tumour group and understand the challenges the dental practitioner faces in attempting to achieve 'dental fitness'.Materials and methods Data were retrospectively collected from a dedicated pre-BTA dental assessment clinic and analysed for MPC. Statistical analysis and observational data were used to compare patient and tumour demographics.Results A total of 111 patients were included in this cohort, with the majority of patients presenting with only bone metastases (BM) and no additional metastatic sites. On average, MPC patients presented with 19.3 teeth and were below the threshold for functional dentition. The 75-84-year-old age group had the worst horizontal bone loss score and subsequently lose six teeth over a decade (p = 0.001). In addition, all MPC tumour sub-categories showed favourable survival rates.Conclusion MPC patients have a high dental burden on presentation, likely associated with their age. Favourable survival prospects and the cumulation of BTAs and dental disease would suggest a heightened risk of medication-related osteonecrosis of the jaw in this group compared to many other tumour sites.

Osteoblast Dysfunction in Non-Hereditary Sclerosing Bone Diseases

A review of the available literature was performed in order to summarize the existing evidence between osteoblast dysfunction and clinical features in non-hereditary sclerosing bone diseases. It has been known that proliferation and migration of osteoblasts are concerted by soluble factors such as fibroblast growth factor (FGF), platelet-derived growth factor (PDGF), transforming growth factor (TGF), bone morphogenetic protein (BMP) but also by signal transduction cascades such as Wnt signaling pathway. Protein kinases play also a leading role in triggering the activation of osteoblasts in this group of diseases. Post-zygotic changes in mitogen-activated protein kinase (MAPK) have been shown to be associated with sporadic cases of Melorheostosis. Serum levels of FGF and PDGF have been shown to be increased in myelofibrosis, although studies focusing on Sphingosine-1-phosphate receptor was shown to be strongly expressed in Paget disease of the bone, which may partially explain the osteoblastic hyperactivity during this condition. Pathophysiological mechanisms of osteoblasts in osteoblastic metastases have been studied much more thoroughly than in rare sclerosing syndromes: striking cellular mechanisms such as osteomimicry or complex intercellular signaling alterations have been described. Further research is needed to describe pathological mechanisms by which rare sclerosing non hereditary diseases lead to osteoblast dysfunction.

Bone mineral density in Nigerian men on androgen deprivation therapy for advanced prostate cancer

Background

Cancer of the prostate (CaP) is the most frequently diagnosed non-cutaneous malignancy worldwide, and it is the second leading cause of death from cancer in men. In the developing world, majority of patients with CaP present in advanced stage and often times, androgen deprivation therapy (ADT) is the only treatment option available. ADT has been reported to increase the risk of osteopenia and osteoporosis in patients with CaP in studies done predominantly among the Caucasians. There is a dearth of report of the effect of ADT on CaP in the black population most especially Nigerian population despite our high incidence of CaP. The aim of this study was to determine the effect of advanced CaP and its treatment using ADT on bone mineral density (BMD) in our patients.

Results

The age of the patients ranged from 54 to 88 years (mean 70.15 ± 6.7) and 50 to 85 years (mean 68.92 ± 8.5) for the case and control groups, respectively. The mean BMD of the control group (0.26 ± 1.5) was significantly higher than the case group pre-ADT (− 0.78 ± 1.7) (p = 0.044). Post-ADT, the BMD was significantly lower (− 1.15 ± 1.7) than pre-ADT (p = 0.001) among the case group.

Conclusion

Advanced CaP was found to be associated with a decrease in BMD, and ADT was associated with a further decline in the BMD. Therefore, prevention and treatment of skeletal-related events is vital in management of patients with advanced CaP.

Principles of Management of Extremity Skeletal Metastasis

Understanding the epidemiology of extremity skeletal metastasis and the factors deciding the treatment decision-making are essential in developing a diagnostic and treatment strategy. This leads to optimum care and reduces disease-related burden. With the evolution of medical, radiation therapy, and surgical methods, cancer care has improved the quality of life for patients with improved survival and functional status in patients with skeletal metastasis. Based on the currently available literature, we have described a step-wise evaluation and management strategy of metastatic extremity bone disease. The present review article addresses various aspects and related controversies related to evaluation, staging, and treatment options in the management of extremity bone metastasis. This article also highlights the role of multidisciplinary involvement in management of extremity skeletal metastasis.

The Osteoclast in Bone Metastasis: Player and Target

Bone metastases are frequently the final fate of breast and prostate cancer patients. According to the definition of metastasis as an incurable disease, to date there are no effective treatments for tumor-associated bone metastases and this represents a real challenge for the researchers in the field. The bone is a heterogeneous environment that represents a fertile soil for tumor cells, supporting their growth. Among the different cell types present in the bone, in this review we will focus our attention on the osteoclasts, which are crucial players in the so called “vicious cycle”, a phenomenon triggered by tumor cells eventually leading to both tumor proliferation as well as bone deregulation, thus fueling the development of bone metastasis. The complex network, linking tumor cells to the bone by activating osteoclasts, represents a fruitful target for the treatment of bone metastases. In this review we will describe how tumor cells perturb the bone microenvironment by actively influencing osteoclast formation and activity. Moreover, we will describe the current antiresorptive drugs employed in the treatment of bone metastases as well as new, targeted therapies able to affect both cancer cells and osteoclasts.

CD44 collaborates with ERBB2 mediate radiation resistance via p38 phosphorylation and DNA homologous recombination pathway in prostate cancer

CD44, a glycoprotein, has been reported to have relationship with resistance to radiation in prostate cancer (Cap) cells. However, its molecular mechanism remains unknown. In this study, we demonstrated that inhibited CD44 enhanced the radiosentivity in Cap cells. It has been hypothesized that CD44 combine with ERBB2 and activate downstream phosphated protein to mediate DNA damage repair. Therefore, we conducted a detailed analysis of effects of radiation by clonogenic assay and immunofluorescence stain for p-H2AX foci. The downstream of CD44/ERBB2 and DNA damage repair proteins was detected by western blot. The results reveal that CD44 interacted with ERBB2, the downstream of CD44/ERBB2 was p-p38 when Cap cells were irradiated. Among the pathways, homologous recombination (HR) related proteins Mre11 and Rad50 were involved in CD44/ERBB2/p-p38 mediated radioresistance in Cap. In conclusion, CD44 could stabilize ERBB2 and co-activate p-p38 expression then promote the DNA damage repair by HR pathway, which finally contribute to the radioresistance of CaP.

Bone Metastases: An Overview

Bone is a frequent site of metastases and typically indicates a short-term prognosis in cancer patients. Once cancer has spread to the bones it can rarely be cured, but often it can still be treated to slow its growth. The majority of skeletal metastases are due to breast and prostate cancer. Bone metastasis is actually much more common than primary bone cancers, especially in adults. The diagnosis is based on signs, symptoms and imaging. New classes of drugs and new interventions are given a better quality of life to these patients and improved the expectancy of life. It is necessary a multidisciplinary approach to treat patients with bone metastasis. In this paper we review the types, clinical approach and treatment of bone metastases.

Denosumab is really effective in the treatment of osteoporosis secondary to hypogonadism in prostate carcinoma patients? A prospective randomized multicenter international study

INTRODUCTION

Osteoporosis is a complication of androgen deprivation therapy (ADT) in men with prostate carcinoma. The best defense against osteoporosis in prostate cancer is to identify patients with a high risk for fracture during the first clinical visit, select an effective anti-osteoporosis agent, and advise the patient to change his lifestyle and diet to prevent further bone loss. New agents include denosumab, a human monoclonal antibody that inhibits the RANK ligand (RANKL). RANKL promotes the formation, activity, and survival of osteoclasts and, thus, supports the breakdown of bone.

PURPOSE

This is a multicenter, randomized, double-blind prospective study on use of denosumab versus alendronate in the therapy of secondary osteoporosis related to ADT in prostate cancer patients in three European countries (Italy, France, Switzerland).

PATIENTS AND METHODS

In this 24-month observation study we enrolled 234 patients with diagnosis of osteoporosis underwent ADT for prostate cancer. All patients aged ≥55 years and had a dual-energy X-ray absorptiometry (DEXA) T-score <-1.0 (hip or spine, measured within last 2 years) and ≥ 1 fragility fracture. Patients were randomly assigned 1:1 to receive denosumab 60 mg subcutaneously every 6 months or alendronate (70 mg weekly) for 2 years. All patient received supplemental vitamin D (600 IU per day) and supplemental calcium to maintain a calcium intake of 1200 mg per day. Effectiveness of therapy in both groups (denosumab group and alendronate group) was assessed by changes in bone turnover markers (BTMs), Bone Mineral Density (BMD), fracture incidence, Visual Analogue Scale (VAS) score for back pain, and Short Form-8 (SF-8TM) health survey score for health-related quality of life (HRQoL). Percent changes from baseline in BTMs and BMD were assessed using the paired t test; a P-value 0.05). Mean changes in BMD at final follow-up differed significantly between two groups. BMD changes at the lumbar spine at 24 months were 5.6% with denosumab vs -1.1% with alendronate (P<0.001). New vertebral fractures developed in fewer patients in the denosumab group than in the alendronate group during the 24-month period, although this difference was not significant (P=0.10). Back pain significantly (P<0.001) improved from baseline at all time points during the study in both study groups. SF-8 health survey scores significantly improved following treatment with both drugs. Incidence of adverse drug reactions were similar in both groups.

CONCLUSION

In our study denosumab and alendronate showed similar clinical efficacy in the therapy of ADT-related osteoporosis in men with prostate carcinoma; both drugs provided significant improvements in back pain and general health conditions. Denosumab showed significant increase of BTMs and BMD than alendronate with lower rate of new vertebral fractures.

Targeted prodrug approaches for hormone refractory prostate cancer

Due to the propensity of relapse and resistance with prolonged androgen deprivation therapy (ADT), there is a growing interest in developing non-hormonal therapeutic approaches as alternative treatment modalities for hormone refractory prostate cancer (HRPC). Although the standard treatment for HRPC consists of a combination of ADT with taxanes and anthracyclines, the clinical use of chemotherapeutics is limited by systemic toxicity stemming from nondiscriminatory drug exposure to normal tissues. In order to improve the tumor selectivity of chemotherapeutics, various targeted prodrug approaches have been explored. Antibody-directed enzyme prodrug therapy (ADEPT) and gene-directed enzyme prodrug therapy (GDEPT) strategies leverage tumor-specific antigens and transcription factors for the specific delivery of cytotoxic anticancer agents using various prodrug-activating enzymes. In prostate cancer, overexpression of tumor-specific proteases such as prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSMA) is being exploited for selective activation of anticancer prodrugs designed to be activated through proteolysis by these prostate cancer-specific enzymes. PSMA- and PSA-activated prodrugs typically comprise an engineered high-specificity protease peptide substrate coupled to a potent cytotoxic agent via a linker for rapid release of cytotoxic species in the vicinity of prostate cancer cells following proteolytic cleavage. Over the past two decades, various such prodrugs have been developed and they were effective at inhibiting prostate tumor growth in rodent models; several of these prodrug approaches have been advanced to clinical trials and may be developed into effective therapies for HRPC.

Predictive clinical indicators of biochemical progression in advanced prostate cancer patients receiving Leuplin depot as androgen deprivation therapy

Therapeutic planning and counseling for advanced prostate cancer patients receiving androgen deprivation therapy (ADT) is complicated because the prognoses are highly variable. The purpose of this study is to identify predictive clinical indicators of biochemical progression (BCP). In this retrospective analysis, data from 107 newly diagnosed patients (from November 1995 to April 2008) with advanced prostate adenocarcinoma receiving Leuprorelin acetate depot were analyzed. Data was collected from the computerized registry of two collaborating medical centers in Taiwan. Cox regression and Kaplan-Meier analyses were used to evaluate the relationship between potential predictive parameters and BCP. Univariate analysis revealed that predictors of BCP included (1) initial serum prostate-specific antigen (PSA) (hazard ratio [HR], 1.00; 95% confidence interval [CI] 1.00–1.00); (2) log of initial PSA (HR, 1.35; 95% CI 1.17–1.56); (3) PSA density at diagnosis (HR, 1.00; 95% CI 1.00–1.01), and (4) pathological bone fracture (HR, 2.22; 95% CI 1.20–4.11). Age (HR, 0.94; 95% CI 0.91–0.98) and hemoglobin levels (HR, 0.86; 95% CI 0.76–0.97) were also associated with greater risk of BCP. After adjusting for age, pathologic fracture, and hemoglobin level, the initial PSA and PSA density were no longer significantly associated with BCP. However, age and hemoglobin levels continued to be associated with greater risk of BCP (P≤0.007). Using Kaplan-Meier analysis, patients with higher initial PSA concentration, pathological bone fracture, and low hemoglobin had a greater probability of BCP. Thus, low hemoglobin and age are predictive indicators of BCP and therefore early indicators of BCP despite ADT therapy.

IL-6/IL-6R as a potential key signaling pathway in prostate cancer development

Interleukin-6 (IL-6) is a pleiotropic cytokine involved in prostate regulation and in prostate cancer (PC) development/progression. IL-6 acts as a paracrine and autocrine growth stimulator in benign and tumor prostate cells. The levels of IL-6 and respective receptors are increased during prostate carcinogenesis and tumor progression. Several studies reported that increased serum and plasma IL-6 and soluble interleukin-6 receptor levels are associated with aggressiveness of the disease and are associated with a poor prognosis in PC patients. In PC treatment, patients diagnosed with advanced stages are frequently submitted to hormonal castration, although most patients will eventually fail this therapy and die from recurrent castration-resistant prostate cancer (CRPC). Therefore, it is important to understand the mechanisms involved in CRPC. Several pathways have been proposed to be involved in CRPC development, and their understanding will improve the way to more effective therapies. In fact, the prostate is known to be dependent, not exclusively, on androgens, but also on growth factors and cytokines. The signaling pathway mediated by IL-6 may be an alternative pathway in the CRPC phenotype acquisition and cancer progression, under androgen deprivation conditions. The principal goal of this review is to evaluate the role of IL-6 pathway signaling in human PC development and progression and discuss the interaction of this pathway with the androgen recepto pathway. Furthermore, we intend to evaluate the inclusion of IL-6 and its receptor levels as a putative new class of tumor biomarkers.The IL-6/IL-6R signaling pathway may be included as a putative molecular marker for aggressiveness in PC and it may be able to maintain tumor growth through the AR pathway under androgen-deprivation conditions. The importance of the IL-6/IL-6R pathway in regulation of PC cells makes it a good candidate for targeted therapy.

Telomerase enzyme inhibition (TEI) and cytolytic therapy in the management of androgen independent osseous metastatic prostate cancer

BACKGROUND

Recurrent prostate cancer can be osseous, androgen independent and lethal. The purpose is to discern the efficacy of synthetic small molecule telomerase enzyme inhibitors (TEI) alone or in combination with other cytotoxic therapies in controlling metastatic osseous prostate cancer.

METHODS

C4-2B was pre-treated with a match or mismatch TEI for 6 weeks and then inoculated into nude mice subcutaneously or intraosseously. In a separate experiment, untreated C4-2B was injected into femur of nude mice. The mice were divided into seven systemic "combination" treatment groups of control, Ad-BSP-E1a virus, docetaxel, mismatch and match TEI. Serum PSA was followed longitudinally. Histology analyses and histomorphometry were performed. Repeated measure analysis was applied for statistical analysis and Bonferroni method was used in multiple comparisons.

RESULTS

In the pre-treated study, the PSA of match treated cells in subcutaneous or intraosseous model was significantly lower than mismatch TEI or PBS treated group (P < 0.05). Histology revealed increased fibrosis, apoptosis and decreased PSA staining in the match TEI treated subcutaneous xenografts. In the combination treatment study, the PSA was significantly lower in single/double treatment and triple treatment than control (P < 0.05). Histology revealed that triple therapy mice had normal femur architecture. Histomorphometrics revealed that the area of femur tumor and woven bone was significantly positively correlated (P = 0.007).

CONCLUSIONS

Multiple lines of data point toward the efficacy of systemically administered telomerase inhibitors. Combining cytotoxic regimens with telomerase inhibitors could be beneficial in controlling prostate cancer. Clinical trials are warranted to explore the efficacy of TEI in prostate cancer.

Cancer treatment-related bone loss: a review and synthesis of the literature

Cancer therapy can result in significant bone loss and increased risk of fragility fracture. Chemotherapy, aromatase inhibitors, and gonadotropin-releasing hormone analogues contribute to increases in the rate of bone remodelling and reduce bone mineral density. Patients with prostate cancer on androgen deprivation therapy experience an increase in the risk of fracture. New research has demonstrated the key role played by bisphosphonates in preventing declines in bone density and increases in bone remodelling. Novel antiresorptive agents targeting receptor activator of nuclear factor κB ligand have great potential in skeletal protection and prevention of bone loss related to cancer therapy. Early assessment of skeletal health, followed by initiation of calcium, vitamin D, and an exercise program are valuable in the prevention and treatment of osteoporosis. In addition, individuals at increased risk for fracture should be offered antiresorptive therapy. Early data have demonstrated that bisphosphonates are able to prevent the bone loss and increased bone remodelling associated with cancer therapy, including aromatase inhibition and androgen deprivation therapy. The present paper reviews the new research and advances in the management of bone loss associated with both cancer therapy and estrogen deficiency in the postmenopausal female.

Management of cancer treatment-induced bone loss in early breast and prostate cancer -- a consensus paper of the Belgian Bone Club

Cancer treatment-induced bone loss (CTIBL) is one of the most important side effects of adjuvant antineoplastic treatment in hormone-dependent neoplasms. Chemotherapy, GnRH analogs and tamoxifen can induce marked bone loss in premenopausal women with early breast cancer. Aromatase inhibitors (AIs) are replacing tamoxifen as the preferred treatment for postmenopausal women. As a class effect, steroidal (exemestane) and non-steroidal (anastrozole and letrozole) AIs increase bone turnover and cause bone loss (4%-5% over 2 years). When compared to tamoxifen, the risk of getting a clinical fracture under AI treatment is increased by 35%-50%. In patients with prostate cancer, androgen deprivation therapy (ADT) increases bone turnover, reduces bone mass (4%-5% per year) and increases the fracture rate depending on the duration of therapy. Zoledronic acid can prevent accelerated bone loss induced by goserelin in premenopausal women, by letrozole in postmenopausal women and by ADT in men. More limited data indicate that weekly alendronate or risedronate could also be effective for preventing CTIBL. Initiation of therapy early, prior to the occurrence of severe osteoporosis, rather than after, may be more effective. Bisphosphonate treatment should be considered in osteoporotic but also in osteopenic patients if other risk factor(s) for fractures are present.

Clinical features of metastatic bone disease and risk of skeletal morbidity

The skeleton is the most common organ to be affected by metastatic cancer and the site of disease that produces the greatest morbidity. Skeletal morbidity includes pain that requires radiotherapy, hypercalcemia, pathologic fracture, and spinal cord or nerve root compression. From randomized trials in advanced cancer, it can be seen that one of these major skeletal events occurs on average every 3 to 6 months. Additionally, metastatic disease may remain confined to the skeleton with the decline in quality of life and eventual death almost entirely due to skeletal complications and their treatment. The prognosis of metastatic bone disease is dependent on the primary site, with breast and prostate cancers associated with a survival measured in years compared with lung cancer, where the average survival is only a matter of months. Additionally, the presence of extraosseous disease and the extent and tempo of the bone disease are powerful predictors of outcome. The latter is best estimated by measurement of bone-specific markers, and recent studies have shown a strong correlation between the rate of bone resorption and clinical outcome, both in terms of skeletal morbidity and progression of the underlying disease or death. Our improved understanding of prognostic and predictive factors may enable delivery of a more personalized treatment for the individual patient and a more cost-effective use of health care resources.

New molecular targets in advanced prostate cancer

Classically, advanced prostate cancer has been treated with hormonal therapy and, most recently, chemotherapy. This treatment clearly demonstrated a survival benefit, but never a cure. With the ever-expanding understanding of the pathophysiology of prostate cancer, there has been a recent explosion in the potential molecular targets and novel therapeutic approaches to both advanced and potentially localized prostate cancer. This review will focus on what the author perceives to be the most promising of these new strategies. The endothelin pathway has been identified as pivotal in the viscous cycle of tumorigenesis in bone, leading to the development of endothelial receptor antagonists. Vaccine therapy using autologous granulocyte-macrophage colony-stimulating factor-producing prostate cancer cells has been effective in producing both immune and clinical responses. Randomized clinical trials of the immunotherapy cell product APC8015 (Provenge) have demonstrated improved survival in the hormone-refractory setting. The development of antisense oligonucleotides to segments of mRNA critical to the progression to androgen-independent disease has emerged as one further tool in the expanding armamentarium of potential therapies being tested. Clearly, headway is being made in improving outcomes in this most prevalent health problem.

Phase II study evaluating oral triamcinolone in patients with androgen-independent prostate cancer

OBJECTIVES

To assess the effect of triamcinolone administration on the serum prostate-specific antigen (PSA) response and the time to progression in patients with androgen-independent prostate cancer (AIPC).

METHODS

Patients with AIPC were prospectively treated with oral triamcinolone 4 mg twice daily, and their serum PSA and cortisol levels were measured monthly. Patients with greater than 25% increases in serum PSA from baseline were considered to have progressive disease and were removed from the study. Those patients who had a decrease in serum PSA levels or stable disease continued in the study until disease progression. Bone scans were obtained every 12 weeks and at progression.

RESULTS

Twenty-four patients with AIPC were treated from November 2002 to June 2004. A partial response with a more than 50% decrease in serum PSA level was seen in 29%. Another 21% achieved stable disease. No statistically significant difference was found in the time to progression in the partial responders and patients with stable disease. The median time to progression in both groups was 7.5 months. Treatment was well tolerated without any grade 3 or 4 toxicity.

CONCLUSIONS

Oral triamcinolone was well tolerated by patients with AIPC, with 50% of the patients exhibiting a good response to therapy in terms of serum PSA level and time to progression.

Prostate cancer metastases to bone: pathophysiology, pain management, and the promise of targeted therapy

Bone metastases are a significant cause of pain and morbidity in prostate cancer, especially if they lead to complications such as pathological fractures and spinal cord compression. Palliation of pain can be achieved with radiation, radioisotopes, hormone therapy, chemotherapy, and bisphosphonates. Bisphosphonates also reduce the risk of skeletal complications. Studies with animal models and advances in understanding the molecular basis for bone metastases have yielded new targets for therapy. Some of the promising therapeutic trials are reviewed in this paper.

[Prognostic value of DNA ploidy and nuclear morphometry in metastatic prostate cancer]

PURPOSE

To assess the prognostic value of DNA ploidy and nuclear morphometry in metastatic prostate cancer after androgenic deprivation treatment.

METHODS

Fifty four patients with prostate cancer and bone metastases who had undergone androgenic suppression treatment were retrospectively studied. The deoxyribonucleic acid (DNA) content was analysed by flow cytometry. Nuclear morphometry characterized 14 nuclear descriptors. The study also included age, Gleason score, T classification, haematocrite, serum albumin, serum alkaline phosphatase, serum prostatic acid phosphatase and the amount of metastatic foci detected during radioisotope bone scan. Univariate survival analyses were performed and Cox's proportional hazards model was used to identify significant prognostic factors. To assess how the experimental factors improve the capacity of the classical factors for predicting the patients who reach median survival, logistic regression multivariate analysis was performed for the classical prognostic factors only and after added experimental variables (DNA content and Nuclear Area).

RESULTS

The univariate survival analyses assigned a prognostic value to T category, level of albumin, alkaline phosphatase, Gleason score, bone scan, DNA ploidy and mean nuclear area. In the case of the Cox regression model only Gleason score, bone scan, mean nuclear area and DNA ploidy provided independent prognostic information. In logistic regression for classic prognostic factors only Gleason score is significant (sensibility 89.3%, specificity 64%). However, when the experimental factors are added, in addition to Gleason score, radioisotope bone scan and DNA ploidy are of prognostic value (sensibility 90% and specificity 72%).

CONCLUSIONS

The study of DNA content and nuclear morphometry in the primitive tumor provides independent prognostic information in survival analysis for patients with metastatic prostate cancer. However, there is limited improvement with respect to the classical factors in predicting survival. This questions its utility in the daily clinical usage.

Update on hormone-refractory prostate cancer

PURPOSE OF REVIEW

Androgen deprivation therapy is the cornerstone treatment for men with de novo or recurrent metastatic prostate cancer. Unfortunately, androgen deprivation therapy is primarily palliative, with nearly all men progressing to an androgen-independent state. Hormone-refractory prostate cancer presents significant management challenges and is the focus of this review.

RECENT FINDINGS

Investigations into the pathophysiology of hormone-refractory prostate cancer, the exploration of chemotherapeutic combinations, novel biological targets, skeletal protectants, and radiopharmaceuticals, as well as new prognostic tools are expanding the clinician's armamentarium and improving patient outcomes.

SUMMARY

Bisphosphonates and chemotherapy are providing effective palliative approaches. Phase II trials of taxane-based regimens show higher response rates and longer survival than has typically been achieved with existing standards. Two completed randomized phase III studies to be reported in mid-2004 will more definitively answer the question of whether currently available chemotherapy can improve survival.

Management of treatment-related osteoporosis in men with prostate cancer

Osteoporosis is an important and preventable adverse effect of androgen deprivation therapy for prostate cancer. Androgen deprivation therapy by either bilateral orchiectomies or administration of a gonadotropin-releasing hormone agonist decreases bone mineral density and increases fracture risk. Treatment-related osteoporosis can be prevented by intermittent administration of either intravenous pamidronate or zoledronic acid. Pamidronate (60 mg intravenously every 3 months) prevents bone loss during androgen deprivation therapy. Zoledronic acid (4 mg intravenously every 3 months) not only prevents bone loss but also increases bone mineral density. Alendronate and other oral bisphosphonates may be effective but have not been evaluated in men with castrate testosterone levels. Oestrogen replacement therapy and treatment with selective ooestrogen receptor modulators may prevent bone loss during androgen deprivation therapy. Bicalutamide (150 mg daily) monotherapy increases serum ooestrogen levels and maintains bone mineral density.

Bisphosphonates to prevent osteoporosis in men receiving androgen deprivation therapy for prostate cancer

Osteoporosis is an important complication of androgen deprivation therapy for prostate cancer. Androgen deprivation therapy either by bilateral orchiectomies or treatment with a gonadotropin-releasing hormone agonist decreases bone mineral density (BMD) and increases the risk of fracture. Dietary factors and lifestyle may contribute to bone loss. There are limited prospective data about treatment or prevention of osteoporosis in men with prostate cancer and many recommendations are based on studies of postmenopausal osteoporosis. Lifestyle modification including smoking cessation, moderation of alcohol consumption, and regular weight bearing exercise should be encouraged. Supplemental calcium and vitamin D are recommended. Additional treatment may be warranted for men with osteoporosis, fractures, or high rates of bone loss during androgen deprivation therapy. Recent studies have evaluated the efficacy of bisphosphonates to prevent bone loss during androgen deprivation therapy. Pamidronate (pamidronic acid), a second-generation bisphosphonate, prevents bone loss in the hip and spine during androgen deprivation therapy. Zoledronic acid, a more potent third-generation bisphosphonate, not only prevents bone loss but also increases BMD in the hip and spine. Alendronate (alendronic acid) is approved for the treatment of osteoporosis in men although its efficacy and that of other oral bisphosphonates has not been evaluated in men receiving androgen deprivation therapy. Additional prospective studies are needed to evaluate the long-term effects of bisphosphonates on fracture risk and disease-related outcomes.

Diagnosis and management of treatment-related osteoporosis in men with prostate carcinoma

Osteoporosis is a complication of androgen deprivation therapy in men with prostate carcinoma. Androgen deprivation therapy, caused by either bilateral orchiectomy or treatment with a gonadotropin-releasing hormone agonist, decreases bone mineral density and increases fracture risk. Other factors including diet and lifestyle may contribute to bone loss. There is limited information regarding the best strategy to prevent osteoporosis in men with prostate carcinoma. Lifestyle modification including smoking cessation, moderation of alcohol consumption, and regular weight-bearing exercise should be encouraged. Supplemental calcium and vitamin D are also recommended. Additional treatment may be warranted for men with osteoporosis, fractures, or high rates of bone loss during androgen deprivation therapy. Intravenous pamidronate, a second-generation bisphosphonate, prevents bone loss during androgen deprivation therapy. Zoledronic acid, a more potent third-generation bisphosphonate, not only prevents bone loss but also increases bone mineral density during androgen deprivation therapy. Other bisphosphonates may be effective although they have not been evaluated in this clinical setting. Treatment with estrogens or selective estrogen receptor modulators may also be effective. Monotherapy with bicalutamide or other antiandrogens may cause less bone loss than androgen deprivation therapy.

Depression in men receiving androgen deprivation therapy for prostate cancer: a pilot study

PURPOSE

Prostate cancer is the most common malignancy in men and one of the leading causes of cancer death in men internationally. Treatment for prostate cancer frequently includes androgen deprivation therapy (ADT). Reports of depressive symptoms arising during ADT are emerging. This study examines the prevalence rates and risk factors associated with major depression in this population.

METHOD

45 men with prostate cancer receiving ADT at the MGH Cancer Center were surveyed for depression with the SCID for Axis I disorders for DSM-IV and the Beck Depression Inventory.

RESULTS

Major depressive disorder was prevalent in 12.8% of the men with prostate cancer receiving ADT, eight times the national rate of depression in men, 32 times the rate in men over 65 years old. Major depression was not associated with worsening disease, medical response to ADT, receiving chemotherapy, or the type of ADT. Past history of depression was associated with current depression in this population (p<0.000). No first onset cases of depression occurred on ADT in this sample.

CONCLUSION

This data suggests a significant rate of major depression in men with prostate cancer receiving ADT and that men with past histories of depression may be at particular risk for recurrence of their depression while undergoing this treatment.

Metastatic bone disease: clinical features, pathophysiology and treatment strategies

Metastatic bone disease develops as a result of the many interactions between tumour cells and bone cells. This leads to disruption of normal bone metabolism, with the increased osteoclast activity seen in most, if not all, tumour types providing a rational target for treatment. The clinical course of metastatic bone disease in multiple myeloma, breast and prostate cancers is relatively long, with patients experiencing sequential skeletal complications over a period of several years. These include bone pain, fractures, hypercalcaemia and spinal cord compression, all of which may profoundly impair a patient's quality of life. External beam radiotherapy and systemic endocrine and cytotoxic treatments are the mainstay of treatment in advanced cancers. However, it is now clear that the bisphosphonates provide an additional treatment strategy, which reduces both the symptoms and complications of bone involvement. Ongoing research is aimed at trying to define the optimum route, dose, schedule and type of bisphosphonate in metastatic bone disease and in the prevention and treatment of osteoporosis in cancer patients. In vitro suggestions of direct anticancer activity and some promising clinical data in early breast cancer have resulted in considerable interest in the possible adjuvant use of bisphosphonates to inhibit the development of bone metastases.

Trends in hormonal management of prostate cancer: a population-based study in Ontario

OBJECTIVE

To provide a population-based description of current practice in the use of hormonal management of prostate cancer. DESIGN,SETTING & PARTICIPANTS: All men in Ontario, Canada, age 65 and older, with confirmed prostate cancer starting maintained hormonal therapy, from July 1992 through December 1998 (11,435 patients). Data sources included the provincial drug benefit plan, hospital services data, and Ontario Cancer Registry.

OUTCOME MEASURES

Rates and trends in the use of: surgical or medical castration; total androgen blockade (TAB); and monotherapies based on steroidal or nonsteroidal antiandrogens.

RESULTS

In 5.5 years, use of 'standard' therapy based on surgical or medical castration alone dropped from 36% to 26% of patients, while the use of TAB doubled from 22% to 41%. Approximately 15% of patients received nonsteroidal antiandrogens without evidence of therapy aimed at central androgen blockade. Marked regional differences were observed and not explained by patient age or practitioner specialty.

CONCLUSIONS

New hormonal therapies for prostate cancer have implications in terms of disease control, patient survival, side effects, and costs. Rapid growth in prescribing of antiandrogens may represent an unnecessary expense for public or private payers, and observed regional differences likely reflect lack of consensus on the relative merit of TAB. Patients and practitioners must have current information on the advantages and disadvantages of different therapeutic options, and quality-of life, particularly with respect to emerging drug therapies.

Chemotherapy in advanced androgen-independent prostate cancer 1990-1999: a decade of progress?

BACKGROUND AND PURPOSE

A great number of clinical research studies have been reported in the field of chemotherapy for advanced androgen-independent prostate cancer during the last ten years. The aims of the present review were to assess their impact on management of the disease and on survival of patients.

METHODS

The review of full published reports was facilited by the use of a MEDLINE computer search.

RESULTS

Clinical research studies have focused on defining guidelines for eligibility criteria and accurate endpoints for patients to be enrolled onto clinical trials and developing new agents or combination of drugs including estramustine phosphate. Any combination of current chemotherapy has no impact on overall survival of patients. Among drugs in development, only the promising activity observed with docetaxel deserves randomized trials to assess its impact on survival. The major innovative advance of the 90s is the demonstration of the impact of chemotherapy (mitoxantrone + prednisone) on quality of life as compared to prednisone alone. A greater and longer-lasting improvement in quality of life along with a concomitant decrease in costs was observed.

CONCLUSIONS

At the present time, chemotherapy should be considered as a palliative treatment in patients with symptomatic androgen-independent disease. The enrollment of patients into clinical trials dealing with quality of life as primary endpoint is strongly solicited. A standard methodology should be used in phase II trials with a primary goal of selection of agents which should progress to randomized trials using survival as an endpoint. Hopefully new specific strategies targeted to reverse the molecular changes that underlie prostate tumorigenesis should rapidly impact the multimodality management of AIPC in the third millenium.

Intermittent androgen deprivation

Intermittent androgen deprivation is a controversial approach to management of prostate cancer. Preclinical models have demonstrated delay in time to prostate-specific antigen (PSA) progression in athymic mice bearing LNCaP tumors and a delay in time to androgen independence in androgen-dependent Shionogi carcinoma tumors in castrated animals exposed to intermittent androgen. Phase II clinical trials have demonstrated improved sexual function and quality of life in men discontinuing androgen deprivation. The average percentage of time spent off androgen deprivation ranges from 37% to 58%. Most men respond to retreatment with hormonal therapy. Current ongoing phase III clinical trials of intermittent versus continuous androgen deprivation in men with metastatic disease or recurrent disease after localized therapy will assess the comparative impact on quality of life and survival. Final analyses of these critical trials will define the ultimate role of this approach in prostate cancer. In the interim, intermittent androgen deprivation should be considered an experimental approach.

Differential posttranscriptional regulation of androgen receptor gene expression by androgen in prostate and breast cancer cells

Androgens, via the androgen receptor (AR), modulate the growth and proliferation of prostate and breast cancer cells. However, the molecular mechanisms underlying the regulation of AR gene expression by androgen in these cells remain to be fully elucidated. To explore differences in AR gene expression between these hormone-responsive tumor cell types, we studied androgen-responsive LNCaP prostate cancer and AR positive MDA453 breast cancer cells. Dihydrotestosterone (DHT) 10 nM increased LNCaP cell proliferation and the proportion of LNCaP cells in S-phase of the cell cycle but inhibited MDA453 cell proliferation and reduced the proportion of MDA453 cells in S-phase of cell cycle. In both these cell lines, DHT decreased total AR messenger RNA (mRNA) but increased AR protein. In LNCaP cells, DHT down-regulated AR mRNA transcription but stabilized AR mRNA. In contrast, in MDA453 cells, DHT had no effect on AR mRNA transcription but destabilized AR mRNA. In summary, transcriptional down-regulation induced by androgens in LNCaP cells results in down-regulation of steady-state AR mRNA despite an androgen-induced increase in AR mRNA stability. However, in MDA453 cells, posttranscriptional destabilization of AR mRNA appears to be the predominant mechanism resulting in down-regulation of AR mRNA by androgen. These results demonstrate cell-specific and divergent regulation of AR mRNA turnover by androgen and identify a novel pathway of androgen-induced posttranscriptional destabilization and down-regulation of AR mRNA in human breast cancer cells. Furthermore, these data establish an important role for posttranscriptional pathways in the regulation of AR gene expression by androgen in human prostate and breast cancer cells.

Anemia after orchiectomy

The decrease in testosterone production associated with bilateral orchiectomy may result in normocytic anemia in men. We sought to determine the effect of orchiectomy on hemoglobin concentration. Patients were evaluated at the Mayo Clinic in 1993 and 1994 and underwent bilateral orchiectomy for prostate carcinoma. All patients were seen by one of the staff urologists. Patients were included if they had a normal preoperative complete blood cell count and serum levels of creatinine, if they remained without disease progression (suppressed prostate-specific antigen level and no evidence of clinical progression on review), and if they had normal serum levels of creatinine and mean corpuscular volume during the follow-up period. The patients could have no other cause of anemia. The complete blood cell count, prostate-specific antigen level, and serum level of creatinine were determined preoperatively and at least once (>90 days) after orchiectomy. Sixty-four patients were included in the analysis (median age, 68 years). The median decrease in hemoglobin concentration was 1.2 g/dL after orchiectomy. There was a statistically significant difference in the hemoglobin concentration before orchiectomy compared with postoperative values at all the intervals studied, both by the paired group t-test and the Kruskal-Wallis test. There is a clinically and statistically significant decrease in hemoglobin concentration after orchiectomy. Knowledge of this phenomenon may prevent unnecessary diagnostic work-up in men with normocytic anemia after bilateral orchiectomy.

Management of metastatic prostate cancer

Metastatic prostate cancer remains an incurable disease. However, palliative treatment based on hormonal manipulation can effectively control symptoms and prolong life. The development of progressive "hormone-refractory disease" requires a multidisciplinary approach, with the involvement of general practitioners, urologists, radiation oncologists, medical oncologists and palliative care physicians. Some of the newer therapies, such as chemotherapy, have proved successful in improving the quality of life for many patients, and modern palliative care techniques can provide good symptom control.

The prognostic value of pretreatment expression of androgen receptor and bcl-2 in hormonally treated prostate cancer patients

PURPOSE

We determined the prognostic value of oncoprotein bcl-2 and androgen receptor expression in pretreatment transurethral resection specimens of hormonally treated prostate cancer patients.

MATERIALS AND METHODS

A total of 68 pretreatment transurethral resection specimens, 30 radical prostatectomy specimens and 21 palliative transurethral resection specimens with androgen independent prostate cancer was stained with a monoclonal antibody against bcl-2. Androgen receptor immunohistochemistry was performed on pretreatment transurethral resection specimens only. Results were scored semiquantitatively and were correlated with tumor stage and grade and with the occurrence of clinical progression or tumor related death.

RESULTS

Bcl-2 expression by adenocarcinoma cells was found in 32, 17 and 24% of pretreatment transurethral resection, radical prostatectomy and palliative transurethral resection specimens, respectively. The bcl-2 scores did not correlate with tumor stage or grade. Androgen receptor was expressed in 88% of pretreatment transurethral resection specimens. Androgen receptor scores were marginally related to tumor grade, but not to tumor stage. A prognostic value of bcl-2 or androgen receptor in pretreatment transurethral resection specimens was not found. When a combined bcl-2/androgen receptor score was used, this parameter was an independent prognostic marker to predict clinical progression with Gleason grade and stage classification. Gleason grade was the only independent prognostic marker to predict tumor related death.

CONCLUSIONS

The expression of bcl-2 and androgen receptor in pretreatment prostate cancer specimens is not related to the prognosis of hormonally treated prostate cancer. Bcl-2 expression is not increased in endocrine therapy resistant prostate cancer. Surprisingly, a combined bcl-2/androgen receptor score acts as an independent prognosticator for clinical progression.