Bisphosphonate therapy in patients under androgen deprivation therapy for prostate cancer: a systematic review and meta-analysis

Management of cancer treatment-induced bone loss (CTIBL) in patients with breast cancer or prostate cancer

Breast cancer and prostate cancer are sex hormone-dependent cancers, and estrogen or androgen suppression therapy is the standard treatment. Cancer treatment-induced bone loss (CTIBL): bone loss and osteoporosis have become important side effects of these therapies. To summarize the current evidences, (1) Endocrine therapy for breast cancer and prostate cancer is associated with a significant decrease in bone mineral density. (2) Aromatase inhibitors (AI) for breast cancer are associated with a significant increase in fractures, and androgen deprivation therapy (ADT) for prostate cancer is likely to be associated with an increase in fractures. (3) Administration of bisphosphonates and denosumab increases bone mass in patients undergoing endocrine therapy for breast cancer. Administration of bisphosphonates, denosumab, and SERMs increased bone mass in patients undergoing ADT therapy for prostate cancer. (4) Bisphosphonates and denosumab reduce fracture risk in patients on AI for breast cancer, and toremifene and denosumab in patients on ADT for prostate cancer.

Bone Metastases and Health in Prostate Cancer: From Pathophysiology to Clinical Implications

Clinically relevant bone metastases are a major cause of morbidity and mortality for prostate cancer patients. Distinct phenotypes are described: osteoblastic, the more common osteolytic and mixed. A molecular classification has been also proposed. Bone metastases start with the tropism of cancer cells to the bone through different multi-step tumor-host interactions, as described by the "metastatic cascade" model. Understanding these mechanisms, although far from being fully elucidated, could offer several potential targets for prevention and therapy. Moreover, the prognosis of patients is markedly influenced by skeletal-related events. They can be correlated not only with bone metastases, but also with "bad" bone health. There is a close correlation between osteoporosis-a skeletal disorder with decreased bone mass and qualitative alterations-and prostate cancer, in particular when treated with androgen deprivation therapy, a milestone in its treatment. Systemic treatments for prostate cancer, especially with the newest options, have improved the survival and quality of life of patients with respect to skeletal-related events; however, all patients should be evaluated for "bone health" and osteoporotic risk, both in the presence and in the absence of bone metastases. Treatment with bone-targeted therapies should be evaluated even in the absence of bone metastases, as described in special guidelines and according to a multidisciplinary evaluation.

Conventional androgen deprivation therapy is associated with an increased risk of fracture in advanced prostate cancer, a nationwide population-based study

PURPOSE

Androgen deprivation therapy (ADT) is the standard of care in advanced prostate cancer. We conducted a Taiwan National Health Insurance Research Database (NHIRD) study to evaluate the association between ADT and fracture risk in patient with prostate cancer in Taiwan.

METHODS

Between 2001 and 2008, data from the Taiwan NHIRD was collected. We separated newly diagnosed prostate cancer patients into four groups: the injection of gonadotropin-releasing hormone agonists and antagonists group, the orchiectomy group, the oral antiandorgens group and the radical prostatectomy only group. A non-cancer matched control group was also assigned for comparison. T tests, chi-squared tests, multivariate Cox proportional hazard regression were performed. A subsequent fracture event was defined according to the appropriate diagnosis codes (ICD9-CM 800-829) with hospitalization. Patients with fracture before their diagnosis with prostate cancer were excluded.

RESULTS

Overall, 22517 newly diagnosed patients with prostate cancer were enrolled in the study. After exclusion criteria were applied, 13321 patients were separated into the injection group (5020 subjects), the orchiectomy group (1193 subjects), the oral group (6059 subjects) and the radical prostatectomy only group (1049 subjects). The mean age of the overall study population was 74.4 years. Multi-variant analysis disclosed a significantly increased risk of fracture in the injection group, the orchiectomy group, and the oral group (hazard ratio [HR] = 1.55, 95%, confidence interval [CI] 1.36 to 1.76, p<0.001, HR = 1.95, 95%, CI 1.61 to 2.37, p<0.001, HR = 1.37, 95%, CI 1.22 to 1.53, p<0.001, respectively). In contrast, a significantly decreased fracture risk was noted in the radical prostatectomy only group (HR = 0.51, 95%, CI 0.35 to 0.74, p = 0.001). Patients receiving osteoporosis medication had a significantly decreased fracture risk (HR = 0.26, 95%, CI 0.19-0.37, p<0.001).

CONCLUSIONS

ADT is associated with an increased risk of fracture. For patients receiving long-term prostate cancer castration therapy, doctors should always keep this complication in mind and arrange proper monitoring and provide timely osteoporosis medication.

Bone health effects of androgen-deprivation therapy and androgen receptor inhibitors in patients with nonmetastatic castration-resistant prostate cancer

Background

Osteoporosis is a skeletal disorder characterized by compromised bone strength, resulting in increased fracture risk. Patients with prostate cancer may have multiple risk factors contributing to bone fragility: advanced age, hypogonadism, and long-term use of androgen-deprivation therapy. Despite absence of metastatic disease, patients with nonmetastatic castrate-resistant prostate cancer receiving newer androgen receptor inhibitors can experience decreased bone mineral density. A systematic approach to bone health care has been hampered by a simplistic view that does not account for heterogeneity among prostate cancer patients or treatments they receive. This review aims to raise awareness in oncology and urology communities regarding the complexity of bone health, and to provide a framework for management strategies for patients with nonmetastatic castrate-resistant prostate cancer receiving androgen receptor inhibitor treatment.

Methods

We searched peer-reviewed literature on the PubMed database using key words “androgen-deprivation therapy,” “androgen receptor inhibitors,” “bone,” “bone complications,” and “nonmetastatic prostate cancer” from 2000 to present.

Results

We discuss how androgen inhibition affects bone health in patients with nonmetastatic castrate-resistant prostate cancer. We present data from phase 3 trials on the three approved androgen receptor inhibitors with regard to effects on bone. Finally, we present management strategies for maintenance of bone health.

Conclusions

In patients with nonmetastatic castrate-resistant prostate cancer, aging, and antiandrogen therapy contribute to bone fragility. Newer androgen receptor inhibitors were associated with falls or fractures in a small subset of patients. Management guidelines include regular assessment of bone density, nutritional guidance, and use of antiresorptive bone health agents when warranted.

Differing Effects of Zoledronic Acid on Bone Microarchitecture and Bone Mineral Density in Men Receiving Androgen Deprivation Therapy: A Randomized Controlled Trial

Androgen deprivation therapy (ADT) given to men with prostate cancer causes rapid and severe sex steroid deficiency, leading to increased bone remodeling and accelerated bone loss. To examine the effects of a single dose of zoledronic acid on bone microarchitecture, we conducted a 2-year randomized placebo controlled trial in 76 men, mean age (interquartile range [IQR]) 67.8 years (63.8 to 73.9) with non-metastatic prostate cancer commencing adjuvant ADT; 39 were randomized to zoledronic acid and 37 to matching placebo. Bone microarchitecture was measured using high-resolution peripheral quantitative computed tomography (HR-pQCT). Using a mixed model, mean adjusted differences (MAD; 95% confidence interval [95% CI]) between the groups are reported as the treatment effect at several time points. Over 24 months, zoledronic acid showed no appreciable treatment effect on the primary outcomes for total volumetric bone mineral density (vBMD); radius (6.7 mg HA/cm³ [-2.0 to 15.4], p = 0.21) and tibia (1.9 mg HA/cm³ [-3.3 to 7.0], p = 0.87). Similarly, there were no between-group differences in other measures of microarchitecture, with the exception of a modest effect of zoledronic acid over placebo in total cortical vBMD at the radius over 12 months (17.3 mgHA/cm³ [5.1 to 29.5]). In contrast, zoledronic acid showed a treatment effect over 24 months on areal bone mineral density (aBMD) by dual-energy X-ray absorptiometry (DXA) at all sites, including lumbar spine (0.10 g/cm² [0.07 to 0.13]), p < 0.001), and total hip (0.04 g/cm² [0.03 to 0.05], p < 0.001). Bone remodeling markers were initially suppressed in the treatment group then increased but remained lower relative to placebo (MADs at 24 months CTX -176 ng/L [-275 to -76], p < 0.001; P1NP -18 mg/L [-32 to -5], p < 0.001). These findings suggest that a single dose of zoledronic acid over 2 years is ineffective in preventing the unbalanced bone remodeling and severe microstructural deterioration associated with ADT therapy. © 2020 American Society for Bone and Mineral Research.

Guidance for the assessment and management of prostate cancer treatment-induced bone loss. A consensus position statement from an expert group

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Bone health should be prioritised when men with prostate cancer start long-term ADT.

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Assessment by FRAX (±bone mineral density) identifies those at highest risk of fracture.

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Treatment can minimise skeletal complications and reduce morbidity and mortality.

Context and objective

Incidence of prostate cancer (PC) is increasing, but androgen deprivation therapy (ADT) and other therapies are substantially improving survival. In this context, careful consideration of skeletal health is required to reduce the risk of treatment-related fragility fractures and their associated morbidity and mortality. This risk is currently not well-managed. ADT causes significant loss of bone mineral density (BMD). In the metastatic setting, systemic treatments (e.g. chemotherapy, abiraterone, enzalutamide) are used alongside ADT and may require concomitant glucocorticoids. Both ADT and glucocorticoids pose significant challenges to skeletal health in a population of patients already likely to have ongoing age-related bone loss and/or comorbid conditions. Current PC guidelines lack specific recommendations for optimising bone health. This guidance presents evidence for assessment and management of bone health in this population, with specific recommendations for clinical practitioners in day-to-day PC management.

Methods

Structured meetings of key opinion leaders were integrated with a systematic literature review. Input and endorsement was sought from patients, nursing representatives and specialist societies.

Summary of guidance

All men starting or continuing long-term ADT should receive lifestyle advice regarding bone health. Calcium/vitamin D supplementation should be offered if required. Fracture risk should be calculated (using the FRAX® tool), with BMD assessment included where feasible. BMD should always be assessed where fracture risk calculated using FRAX® alone is close to the intervention threshold. Intervention should be provided if indicated by local or national guidelines e.g. UK National Osteoporosis Guideline Group (NOGG) thresholds. Men requiring bone protection therapy should be further assessed (e.g. renal function), with referral to specialist centres if available and offered appropriate treatment to reduce fracture risk. Those near to, but below an intervention threshold, and patients going on to additional systemic therapies (particularly those requiring glucocorticoids), should have FRAX® (including BMD) repeated after 12–18 months.

Patient summary

Modern treatments for prostate cancer have led to significant improvements in survival and quality of life. However, some of these treatments may lead to weakening of patient’s bones with risk of fracture and it is therefore important to monitor patients’ bone health and provide bone protection where needed. This paper provides specific guidance to clinical teams, based on the most recent research evidence, to ensure optimal bone health in their patients.

Bone Health in Men with Prostate Cancer: Review Article

PURPOSE OF REVIEW

The improvement in prostate cancer survival over time, even in those with advanced disease, has led to an increasing recognition of the impact of prostate cancer and its treatment on bone health. Cancer treatment-induced bone loss (CTIBL) is a well-recognized entity but greater awareness of the risks associated with CTIBL and its treatment is required.

RECENT FINDINGS

The principal culprit in causing CTIBL is hormonal ablation induced by prostate cancer treatment, including several new agents which have been developed in recent years which significantly improve survival, but may cause CTIBL. This review discusses the impact of prostate cancer and its treatment on bone health, including published evidence on the underlying pathophysiology, assessment of bone health, and strategies for prevention and treatment. It is important to recognize the potential cumulative impact of systemic prostate cancer treatments on bone health.

Management of bone complications in patients with genitourinary malignancies

Skeletal metastases are common in genitourinary malignancies-including prostate cancer, renal cell carcinoma, and urothelial cancer-and portend significant morbidity and poor prognosis. The presence of skeletal metastases can result in decreased quality of life and increased morbidity. Strategies can be employed to prevent bone-related complications including lifestyle modifications and dietary supplementation. Additionally, pharmacologic agents exist to prevent bone loss and may be appropriate for patients at high risk of fragility-related or skeletal complications, such as pathologic fracture related to bone metastases. Finally, advancement in effective systemic treatments, particularly novel hormone-targeted agents and immunotherapies, may limit the morbidity of advanced disease and delay the onset of skeletal-related complications.

Management of Metastatic Hormone-Sensitive Prostate Cancer (mHSPC): an Evolving Treatment Paradigm

OPINION STATEMENT

Combination systemic therapy is now standard of care for all men with metastatic, hormone-sensitive prostate cancer (mHSPC). Patients with mHSPC should be treated with standard androgen deprivation therapy (ADT) and abiraterone acetate with prednisone or docetaxel (chemohormoanl therapy) unless there are contraindications to combination therapy. Based on the Chemohormonal Therapy Versus Androgen Ablation Randomized Trial for Extensive Disease in Prostate Cancer (CHAARTED) study subgroup analysis, chemohormonal therapy may be most beneficial in men with high-volume disease burden, as men with low-volume metastatic disease do not appear to experience a survival benefit with chemohormonal therapy, while abiraterone in combination with ADT appears to be beneficial across both disease volume subgroups. Decisions regarding whether to use chemohormonal therapy or abiraterone and ADT for men with mHSPC should integrate consideration of volume of disease burden, quality of life effects, duration of therapy, and patient preferences for treatment as there is no formally powered prospective head-to-head comparison of these options demonstrating superiority of one approach over the other. Treatment of the primary tumor with radiation should be considered in men with de novo low-volume metastatic disease as radiation is associated with prolonged survival and a tolerable toxicity profile. Men with de novo high-volume metastatic disease do not appear to have improved survival with radiation of the primary tumor. Numerous clinical trials are ongoing to evaluate treatment approaches that may benefit men with mHSPC. Radical prostatectomy in men with mHSPC in combination with optimal systemic therapy is currently being assessed in a clinical trial, but should not be considered outside of a clinical trial. Metastasis-directed therapy with radiotherapy directed at metastatic lesions is still investigational, but can be considered in clinical trials in men with oligometastatic disease. Multiple studies are enrolling worldwide for men with mHSPC, and these should be considered for all interested patients.

Management of bone health in solid tumours: From bisphosphonates to a monoclonal antibody

Patients with solid tumours are at risk of impaired bone health from metastases and cancer therapy-induced bone loss (CTIBL). We review medical management of bone health in patients with solid tumours over the past 30 years, from first-generation bisphosphonates to the receptor activator of nuclear factor κB ligand (RANKL)-targeted monoclonal antibody, denosumab. In the 1980s, first-generation bisphosphonates were shown to reduce the incidence of skeletal-related events (SREs) in patients with breast cancer. Subsequently, more potent second- and third-generation bisphosphonates were developed, particularly zoledronic acid (ZA). Head-to-head studies showed that ZA was significantly more effective than pamidronate for reducing SREs in patients with breast and castrate-resistant prostate cancer (CRPC), becoming the standard of care for more than a decade. The RANKL inhibitor denosumab was licensed in 2010, and head-to-head studies and integrated analyses confirmed its superiority to ZA for preventing SREs, particularly in breast cancer and CRPC. Bisphosphonates and denosumab have also been investigated for prevention of CTIBL in patients receiving hormonal therapy for breast and prostate cancer, and denosumab is licensed in this indication. Despite advances in management of bone health, several issues remain, notably the optimal time to initiate therapy, duration of therapy, and dosing frequency, and how to avoid toxicity, particularly with long-term treatment. In summary, introduction of ZA and denosumab has protected patients with bone metastasis from serious bone complications and improved their quality of life. Ongoing research will hopefully guide the optimal use of these agents to help maintain bone health in patients with solid tumours.

Bone Health Issues in Patients with Prostate Cancer: An Evidence-Based Review

Bone health in prostate cancer patients represents a prerequisite for acceptable quality of life and optimal outcome of this disease. The major threat for bone health in prostate cancer displays cancer treatment induced bone loss as well as the development of bone metastases. In recent years, several new pharmaceuticals targeting bone metabolism such as denosumab or androgen pathway targeting drugs (abiraterone acetate and enzalutamide) have been approved for the treatment of progressive disease aiming to interrupt the vicious circle of bone metastasis and aberrant bone resorption. This development raised the awareness of the pivotal role of bone health in prostate cancer and introduced (symptomatic) skeletal related events as an important end point in recent clinical trials. Bone targeted drugs have become standard of care in patients with metastatic castration resistant prostate cancer, their role in metastatic hormone sensitive prostate cancer has been discussed controversely. In oligometastatic prostate cancer patients several promising approaches in metastasis directed therapy, including conventional surgery, stereotactic ablative radiation and image-guided single-fraction robotic stereotactic radiosurgery (CyberKnife®) were launched but are not in routine clinical use until now caused by sparse clinical evidence.

The skeletal impact of cancer therapies

Both cancer and therapies used in the treatment of cancer can have significant deleterious effects on the skeleton, increasing the risks for both bone loss and fracture development. While advancements in cancer therapies have resulted in enhanced cancer survivorship for patients with many types of malignancies, it is increasingly recognized that efforts to reduce bone loss and limit fractures must be considered for nearly all patients undergoing cancer therapy in order to diminish the anticipated future skeletal consequences. To date, most studies examining the impact of cancer therapies on skeletal outcomes have focused on endocrine-associated cancers of the breast and prostate, with more recent advances in our understanding of bone loss and fracture risk in other malignancies. Pharmacologic efforts to limit the adverse effects of cancer therapies on bone have nearly universally employed anti-resorptive approaches, although studies have frequently relied on surrogate outcomes such as changes in bone mineral density or bone turnover markers, rather than on fractures or other skeletal-related events, as primary study endpoints. Compounding current deficiencies for the provision of optimal care is the recognition that despite clearly written and straightforward society-based guidelines, vulnerable eligible patients are very often neither identified nor provided with appropriate treatments to limit the skeletal impact of their cancer therapies.

Effect of Neoadjuvant Hormone Therapy on Resection Margin and Survival Prognoses in Locally Advanced Prostate Cancer after Prostatectomy Using Propensity-Score Matching

This study aimed to investigate the effect of neoadjuvant hormone therapy (NHT) on resection margin positivity, biochemical-recurrence- (BCR-) free survival, and overall survival (OS) in 176 patients with locally advanced prostate cancer (LAPC) treated with radical prostatectomy using propensity-score matching, including 79 (44.9%) patients treated with the NHT. Fifty pairs of one-to-one propensity-score matching were matched to investigate the pure effect of NHT on resection margin positivity, BCR, and OS with a statistical significance of p<0.050. Before matching, NHT, tumor volume percentage, and extracapsular extension were significant factors for resection margin positivity (p≤0.001); however, after matching, NHT became insignificant in the multivariate analysis (p=0.084). In the survival analysis, NHT was not associated with BCR or OS before and after matching (BCR: hazard ratio, 1.35 and 0.84, respectively; OS: hazard ratio, 1.05 and 0.77, respectively; p≥0.539 for all). Conversely, PSA level (HR, 2.23), extracapsular extension (HR, 2.10), and lymphovascular invasion (HR, 1.85) were significant factors for BCR (p≤0.001 for all), but none were significant factors for OS in the propensity-score matching analysis (p≥0.948). Therefore, NHT was not a significant factor for resection margin positivity, BCR-free survival, and OS before and after propensity-score matching in patients with LAPC.

Medication-related osteonecrosis of the jaw: definition and best practice for prevention, diagnosis, and treatment

Skeletal complications caused by osteoporosis or bone metastases are associated with considerable pain, increased mortality, and reduced quality of life. Furthermore, such events place a burden on health care resources. Agents that prevent bone resorption, such as bisphosphonates or denosumab, can reduce the risk of skeletal-related events and are widely used in patients with osteoporosis or bone metastases of cancer. Medication-related osteonecrosis of the jaw (MRONJ) is a rare, but potentially serious, adverse event associated with high cumulative doses of bisphosphonates or denosumab. However, MRONJ can be treated, and the likelihood of the development of this condition can be reduced through prophylactic dental care and the maintenance of good oral hygiene. Dentists, as part of a multiprofessional team, have a critical role in preventing MRONJ. This review describes the incidence and pathophysiology of MRONJ and provides guidance for dental practitioners with regard to the screening, prophylactic treatment, diagnosis, and management of patients with this condition.

Medical management of metastatic prostate cancer

Androgen deprivation therapy has an important role in the medical treatment of advanced and metastatic prostate cancer

The treatment of metastatic prostate cancer is influenced by whether the patient’s disease has progressed on androgen deprivation therapy or not It is considered to be castrate-resistant disease if the cancer has progressed despite adequate suppression of androgens

Chemotherapy using docetaxel or cabazitaxel and anti-androgen drugs such as abiraterone and enzalutamide can be used to treat castrate-resistant disease Radium-223 is an option for patients with bony metastases

Metastatic castrate-resistant prostate cancer is now considered a chronic illness as the life expectancy of patients has almost doubled due to the new treatments General practitioners are therefore more likely to encounter patients with disease- and treatment-related complications

Harnessing the potential of therapeutic agents to safeguard bone health in prostate cancer

Background

Patients with prostate cancer are at risk of impaired bone health. Prostate cancer has a propensity to metastasize to bone, after which patients are at risk of skeletal-related events (SREs). These complications are associated with increased mortality, substantial pain, and reduced quality of life. Patients are also at risk of bone loss due to androgen deprivation therapy (ADT), which can be compounded in elderly patients with reduced bone density. It is essential, therefore, that aspects of bone health and therapies able to prevent the occurrence of SREs are considered throughout the clinical course of prostate cancer.

Methods

We reviewed the literature regarding the molecular mechanisms underpinning bone lesion formation, the modes of action of therapies that prevent SREs, and the efficacy and safety of these therapies in patients with hormone-sensitive or castration-resistant prostate cancer (CRPC).

Results

Therapies such as denosumab (a RANKL inhibitor) and zoledronic acid (a bisphosphonate) were indicated for prevention of SREs. Radium-223 dichloride also has proven efficacy in delaying symptomatic SREs, as well as in improving overall survival through effects on bone metastases. Before development of bone metastases, low-dose denosumab may also be used for treatment of ADT-associated bone loss. Denosumab may also have the potential to delay bone metastases development in patients with CRPC, although this is not currently an approved indication. The safety profile of therapies to prevent SREs should be considered. This review consolidates the available evidence on use of denosumab and bisphosphonates in prostate cancer, differentiated by hormone-sensitive and castration-resistant disease.

Conclusions

There is convincing evidence to support the use of denosumab and bisphosphonates to maintain bone health in patients with prostate cancer. Clinicians should be mindful of the adverse event risk profile of these therapies.

Rehabilitation Needs of the Elderly Patient with Cancer

Physiatrist taking care of the geriatric patient with cancer should be able to manage an array of conditions that might present from diagnosis throughout completion of treatments and beyond. The elderly cancer population is at greater risk of functional impairments. The physician should anticipate changes in clinical status and must adjust rehabilitation goals accordingly. Treatment options and rehabilitation goals should be tailored to help maximize quality of life in these patients.

Systematic review and network meta-analysis on the relative efficacy of osteoporotic medications: men with prostate cancer on continuous androgen-deprivation therapy to reduce risk of fragility fractures

Androgen-deprivation therapy (ADT) is an effective treatment for men with advanced prostate cancer, but loss of bone mineral density (BMD) is a major risk factor for fractures. This review compared the efficacy of available treatments to provide prescribing guidance to healthcare professionals. This is the first review to compare the effectiveness of different osteoporotic treatments (bisphosphonates, denosumab, toremifene, and raloxifene) on BMD in patients with non-metastatic prostate cancer on ADT using network meta-analysis. Results suggest that all evaluated treatments are effective in improving BMD compared to placebo. Zoledronic acid (ZA) was found to have a greater improvement in BMD compared to other active treatments at all three studied sites, except for risedronate, which had better BMD improvement compared to ZA at the femoral neck site in one small study. Our study did not identify evidence that one drug is unequivocally more effective than another. All drugs appeared to be effective in reducing the rate of bone loss. Healthcare professionals should also consider patient preference, costs, and local availability as part of the decision process.