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

A Case of Paraphilia with Osteoporosis and Administered with Depot Leuprorelin

Paraphilia is a complex psychological and psychiatric disorder that has been difficult to treat. Leuprorelin has been used as one of the therapeutic methods for paraphilia. Leuprorelin administration could change insulin resistance and accelerate bone loss. The case study in this work was a 59-year-old man who visited a hospital with the chief complaints of frotteuristic behaviors in public places, a continuous increase in sexual desire, and sexual molestation behavior that started in 2007. We injected leuprorelin (3.6 mg) intramuscularly every month for this patient with paraphilia and comorbidities of osteoporosis and hyperthyroidism. The clinical global impression (CGI), Sex Addiction Screening Test (SAST), Wilson Sex Fantasy Questionnaire (WSFQ), physical examination, and laboratory tests were performed. After 12 months of leuprorelin injection for paraphilia, we found a significant improvement in abnormal sexual behavior/desire without aggravation of osteoporosis/hyperthyroidism. Gonadotrophin-Releasing Hormone (GnRH) analogs could be used as alternative or supplementary treatment methods for paraphilia with osteoporosis/hyperthyroidism.

New therapeutics in spine metastases

The number of patients who will develop metastatic spinal tumors is estimated to be between 5 and 10% of all cancer patients. As the therapy for systemic cancer improves, the number of patients developing symptomatic spinal tumors that require local therapy will increase. Over the last 10 years there has been a dramatic evolution in our ability to treat spinal tumors. These advances have not only been created by improvements in surgical techniques and instrumentation, but also developments in radiographic imaging, radiation therapy and chemotherapy. It is important for spine surgeons, radiologists, and radiation and medical oncologists to continue developing techniques for spinal salvage that will improve pain relief, achieve mechanical stability, improve or maintain neurologic function and sustain local tumor control. The evolution of these technologies will help to provide palliation and improve quality of life for patients with metastatic disease.

Prostate cancer and osteoporosis

Adenocarcinoma of the prostate is one of the commonest cancers in the world. Due to a combination of earlier detection and better treatments, survival has increased dramatically. Prostate cancer itself is associated with lower bone density and increased fractures. This is compounded by the use of androgen deprivation therapy, which causes dramatic falls in circulating testosterone and estrogen, resulting in rapid falls in bone density, decreased muscle mass, and increased fracture rates. Bisphosphonates have been demonstrated to prevent and reverse this bone loss, but there are no anti-fracture data. Denosumab, a monoclonal antibody to RANKL, has recently been shown to increase bone density and reduce fracture rates. Prostate cancer also commonly metastasizes to bone where it can cause complications such as fracture and pain. Both zoledronic acid and denosumab have been demonstrated to reduce skeletal related events. Comparative studies would suggest that densosumab may have an advantage over zoledronic acid.

Functional imaging for prostate cancer: therapeutic implications

Functional radionuclide imaging modalities, now commonly combined with anatomical imaging modalities computed tomography (CT) or magnetic resonance imaging (single photon emission computed tomography [SPECT]/CT, positron emission tomography [PET]/CT, and PET/magnetic resonance imaging), are promising tools for the management of prostate cancer, particularly for therapeutic implications. Sensitive detection capability of prostate cancer using these imaging modalities is one issue; however, the treatment of prostate cancer using the information that can be obtained from functional radionuclide imaging techniques is another challenging area. There are not many SPECT or PET radiotracers that can cover the full spectrum of the management of prostate cancer from initial detection to staging, prognosis predictor, and all the way to treatment response assessment. However, when used appropriately, the information from functional radionuclide imaging improves, and sometimes significantly changes, the whole course of the cancer management. The limitations of using SPECT and PET radiotracers with regard to therapeutic implications are not so much different from their limitations solely for the task of detecting prostate cancer; however, the specific imaging target and how this target is reliably imaged by SPECT and PET can potentially make significant impact in the treatment of prostate cancer. Finally, although the localized prostate cancer is considered manageable, there is still significant need for improvement in noninvasive imaging of metastatic prostate cancer, in treatment guidance, and in response assessment from functional imaging, including radionuclide-based techniques. In this review article, we present the rationale of using functional radionuclide imaging and the therapeutic implications for each of radionuclide imaging agent that have been studied in human subjects.

[Effects of zoledronic acid in adults with osteogenesis imperfecta]

BACKGROUND AND OBJECTIVE

Osteogenesis imperfecta (OI) is a genetic disorder that results in bone fragility. Several studies have demonstrated the effectiveness of bisphosphonate therapy. The aim of this study was to evaluate the effects of intravenous zoledronic acid on bone mineral density (BMD) and biochemical markers of bone turnover in adults with OI.

MATERIAL AND METHODS

We carried out a prospective non-randomized study in patients with osteoporosis or severe osteopenia (T score < -2) related to OI and intolerance or contraindication to oral bisphosphonates. The patients were treated with a zoledronic acid infusion every 6 months. Densitometry was carried out annually. Calcium (Ca), phosphate (P), intact parathormone (PTH), 25 hydroxyvitamin D and biochemical markers of bone turnover [bone alkaline phosphatase (BAP), beta-cross-laps (CTX) and urinary deoxypyridoxine (DOP)] were measured every year. Adverse events and new fractures were registered.

RESULTS

Ten patients (2 men and 8 women) were treated. Treatment increased BMD measured in the lumbar spine after 24 (0.738+/-0.141 vs 0.788+/-0.144 g/cm(2); p=0.048) and 36 months (0.720+/-0.139 vs 0.820+/-0.128; p=0.01). Significant increases in BMD were also observed after 24 months in the femoral neck (0.677+/-0.121 vs 0.703+/-0.122 g/cm(2); p<0.016). Serum Ca, P, BAP and CTX concentrations remained unchanged. PTH concentrations increased and vitamin D concentrations decreased after 36 months of treatment. DOP excretion decreased significantly after 24 months. Seven patients had mild influenza-like symptoms occurring within the first 24 h after the first infusion. No severe adverse events were observed. None of the patients had new fractures.

CONCLUSION

Zoledronic acid seems to be a safe and effective treatment option in adults with osteoporosis related to OI.

Management of osteoporosis in the aging male: focus on zoledronic acid

Osteoporosis in the aging male remains an important yet under-recognized and undertreated disease. Current US estimates indicate that over 14 million men have osteoporosis or low bone mass, and men suffer approximately 500,000 osteoporotic fractures each year. Men experience fewer osteoporotic fractures than women but have higher mortality after fracture. Bisphosphonates are potent antiresorptive agents that inhibit osteoclast activity, suppress in vivo markers of bone turnover, increase bone mineral density, decrease fractures, and improve survival in men with osteoporosis. Intravenous zoledronic acid may be a preferable alternative to oral bisphosphonate therapy in patients with cognitive dysfunction, the inability to sit upright, or significant gastrointestinal pathology. Zoledronic acid (Reclast) is approved in the US as an annual 5 mg intravenous infusion to treat osteoporosis in men. The zoledronic acid (Zometa) 4 mg intravenous dose has been studied in the prevention of bone loss associated with androgen deprivation therapy.

Comparative study of the protective effect of different intravenous bisphosphonates on the decrease in bone mineral density in patients submitted to radical prostatectomy undergoing androgen deprivation therapy. A prospective open-label controlled study

OBJECTIVES

To establish whether androgen deprivation therapy (ADT) promotes osteoporosis and osteopenia

METHODS

Ninety-four prostatectomized men with rising prostrate-specific antigen (PSA) were enrolled into the placebo group (31), monthly i.v. clodronate (39) or monthly i.v. zoledronic acid (24) groups for 36 months. Dual-energy X-ray absorptiometry measured the bone density in the lumbar (L2-L4) area. chi(2) and anova tests were used to analyze data..

RESULTS

After 6 months of androgen deprivation, 17 of the 31 control cases developed osteopenia in the lumbar area. At 12 months, nine control cases had osteoporosis with 13 additional cases of osteopenia. At the end of the 36-month study period, the untreated group showed an average bone mineral density (BMD) loss of -1.82 (+/-0.94) with 13 cases of osteopenia and 18 cases of osteoporosis. The clodronate group had two cases of osteoporosis out of 39 subjects after 6 months of ADT with 28 developing osteopenia and seven cases of osteoporosis after 36 months of follow up. Mean BMD loss in this group was -0.72 (+/-0.34). The zoledronic acid studied arm had seven cases of osteopenia after 6 months of ADT while 20 and five cases developed osteopenia and osteoporosis, respectively, after 36 months of follow up. The former group had a mean bone loss of -0.88 (+/-0.32). There was statistical difference for BMD loss in the treated groups starting at 6 months in comparison to the control group.

CONCLUSIONS

Six months of ADT promoted impressive bone loss in the lumbar area of the non-treated patients. This tendency is progressive and may be delayed by i.v. bisphosphonates.

The effect of zoledronic acid on bone mineral density in patients undergoing androgen deprivation therapy

PURPOSE

The aim of this study was to evaluate the efficacy and safety of zoledronic acid compared with placebo in preventing bone mineral density (BMD) loss and suppressing bone markers when initiated during the first year of androgen deprivation therapy in patients with locally advanced prostate cancer.

PATIENTS AND METHODS

Patients were randomized to receive zoledronic acid 4 mg or placebo intravenously every 3 months. Lumbar spine (LS) and total hip BMD was measured using dual-energy x-ray absorptiometry at baseline and at week 52. N-telopeptide (NTX) and bone-specific alkaline phosphatase (BSAP) were evaluated at baseline and every 12 weeks. Safety assessments were performed throughout the study.

RESULTS

Efficacy analyses included 106 patients and 109 patients in the zoledronic acid and placebo groups, respectively. At week 52, the least squares mean BMD percentage differences were 6.7% for LS and 3.7% for total hip (P < 0.0001 for both). In the zoledronic acid group, decreases in NTX ((-)14% to (-)28%) and BSAP ((-)31% to (-)37%) levels were significant and sustained; changes in NTX levels and LS BMD (r = (-)0.25; P = 0.04) and in BSAP levels and hip BMD (r = (-)0.28; P = 0.02) were significantly correlated. Only traumatic fractures were reported for 2 and 3 patients receiving zoledronic acid and placebo, respectively. One patient in each group experienced acute renal failure. Osteonecrosis of the jaw was not reported.

CONCLUSION

Zoledronic acid (4 mg intravenously every 3 months) was safe and effective in preventing bone loss and reducing bone turnover in patients with prostate cancer when initiated during the first year of androgen deprivation therapy; patients with low baseline BMD experienced the greatest benefit.

The role of bisphosphonates in the management of prostate cancer

Current therapies have extended the survival of patients with prostate cancer. However, these patients often develop skeletal morbidity from disease- and treatment-related effects that undermine skeletal integrity throughout the course of the disease. Low bone mineral density (BMD) is prevalent in patients with early-stage prostate cancer, and androgen-deprivation therapy by either pharmaceutical agent (including hormonal) or surgical castration causes significant decreases in BMD. Fractures can result in a loss of independence and have been associated with shorter survival in patients with prostate cancer. Zoledronic acid is the only bisphosphonate that has demonstrated objective and long-term benefits in reducing skeletal morbidity in patients with bone metastases due to prostate cancer, and it has produced long-term reductions in pain levels compared with placebo in this setting. Therefore, bisphosphonates, particularly zoledronic acid, may provide important benefits for preserving bone health during the course of prostate cancer progression.

Advances in the Treatment of Bone Metastases

The skeleton is the third most common site for cancer to spread to after the liver and lungs. Malignancies that can cause destruction of skeletal bones include multiple myeloma and metastatic disease of the breast, prostate, and lung. Bone metastases are problematic for patients with cancer because accelerated bone breakdown occurs with many associated complications. One or more of the following problems may occur: pain, hypercalcemia, pathologic fractures, myelosuppression, and spinal cord compression with subsequent progressive immobility. Quality of life is affected negatively, and associated feelings of fear, grief, anger, despair, anxiety, and depression can occur. Management of malignancies of the bone involves a multimodal approach. Therapies include analgesia, hormone therapy, chemotherapy, surgery, radiation therapy, and the use of bisphosphonates. Nurses can be instrumental in promoting positive outcomes for patients with bone metastases.

Bone Related Events in High Risk Prostate Cancer

PURPOSE

We provide recommendations for defining and treating bone related events in high risk prostate cancer.

MATERIALS AND METHODS

A focused literature review was done.

RESULTS

Men with prostate cancer often have osteoporosis and osteopenia even before initiating androgen deprivation therapy. After starting androgen deprivation therapy they experience accelerated bone loss. Bone mineral density is the most common tool to assess the degree of bone loss, although the use of bone turnover markers for this purpose is being actively explored. Bisphosphonates are effective for increasing bone mineral density and treating osteoporosis. The benefits derived from bisphosphonates should be weighed against the adverse effects, including the risk of osteonecrosis of the jaw. Treatment is indicated in patients with prostate cancer with osteoporosis and it may be considered in patients with osteopenia and/or additional risk factors. The time of initiation of therapy and duration of treatment have not been conclusively established.

CONCLUSIONS

Prolonged androgen deprivation therapy results in bone loss and it has a potential to impact quality of life. Additional research is needed to characterize patients who would benefit from therapy and optimize strategies to prevent osteoporosis.

The addition of bicalutamide 150 mg to radiotherapy significantly improves overall survival in men with locally advanced prostate cancer

PURPOSE

Castration therapy adjuvant to radiotherapy can significantly improve overall survival compared with radiotherapy alone in patients with locally advanced prostate cancer. Although many of the adverse effects of castration therapy are manageable, they can have a detrimental effect on quality of life. Here we evaluate the efficacy and tolerability of the non-castration-based therapy bicalutamide ('Casodex') 150 mg adjuvant to radiotherapy in patients with T1-4, M0, any n prostate cancer.

METHODS

The subset of patients within the early prostate cancer (EPC) program who received radiotherapy with curative intent (n = 1,370) were included in the analysis. These patients were randomized to receive oral bicalutamide 150 mg once daily (n = 699) or placebo (n = 671).

RESULTS

The median follow-up for patients included in this analysis was 7.2 years. In patients with locally advanced disease (n = 305), bicalutamide adjuvant to radiotherapy significantly improved: progression-free survival (PFS), reducing the risk of objective progression by 44% compared with radiotherapy alone [hazard ratio (HR) 0.56; 95% confidence interval (CI) 0.40, 0.78; P < 0.001). Prostate-specific antigen (PSA)-PFS, reducing the risk of PSA progression by 59% compared with radiotherapy alone (HR 0.41; 95% CI 0.30, 0.55; P < 0.001). Overall survival, reducing the risk of death by 35% compared with radiotherapy alone (HR 0.65; 95% CI 0.44, 0.95; P = 0.03). This significant overall survival benefit for bicalutamide was driven by a lower risk of prostate cancer-related deaths (16.1 vs 24.3%, respectively). There was no significant difference in PFS or overall survival in patients with localized disease (n = 1,065).

CONCLUSIONS

In patients with locally advanced disease, bicalutamide 150 mg adjuvant to radiotherapy demonstrates significant clinical benefits in terms of overall survival, PFS and PSA-PFS compared with radiotherapy alone. The overall survival benefit in these patients is consistent with prior studies evaluating castration-based therapies adjuvant to radiotherapy (Bolla et al. in Lancet 360:103-108, 2002; Pilepich et al. in Int J Radiat Oncol Biol Phys 61:1285-1290, 2005). In addition, the clinical benefit of bicalutamide 150 mg in locally advanced patients, but not in those with localized disease, is consistent with the overall results from the EPC program (McLeod et al. BJU Int 97:247-254, 2006). Given the quality-of-life advantages of bicalutamide relative to castration, bicalutamide 150 mg adjuvant to radiotherapy is an attractive alternative for men with locally advanced prostate cancer.

Cancer-treatment-induced bone loss, part 1

PURPOSE

The pathophysiology, frequency, sequelae, diagnosis, and treatment of cancer-treatment-induced bone loss (CTIBL) are discussed.

SUMMARY

CTIBL is a long-term complication associated with cancer therapies that can directly or indirectly affect bone metabolism. Although CTIBL can occur in any patient receiving a cancer therapy known to cause bone loss, CTIBL is most common in patients with breast or prostate cancer who receive chemotherapy, hormone therapy, or surgical castration, as these can cause hypogonadism and induce bone loss. CTIBL causes bone fragility and an increased susceptibility to fractures; therefore, prevention, early diagnosis, and treatment of CTIBL are essential to decrease the risk of fracture. Bone loss occurs more rapidly and tends to be more severe in patients with CTIBL compared with those with normal age-related bone loss. Fractures of the hip, vertebra, and wrist are the fractures most commonly associated with bone loss. CTIBL is diagnosed by measuring bone mass using bone densitometry. Treatment of CTIBL consists of changing diet and lifestyle such as optimizing calcium and vitamin D intake, exercising, modifying behaviors known to increase the risk of CTIBL and pharmacologic therapy with hormone replacement therapy (HRT), selective estrogen-receptor modifiers (SERMs), calcitonin, or a bisphosphonate.

CONCLUSION

Early identification and treatment of CTIBL are essential to prevent fractures. Patients should be instructed to optimize calcium and vitamin D intake, exercise regularly, and modify lifestyle behaviors known to cause bone loss. Patients with CTIBL should be treated with an oral or i.v. bisphosphonate; SERMs or HRT may be an option in some patients if contraindications do not exist.

Optimizing outcomes and quality of life in the hormonal treatment of prostate cancer

We review the effectiveness of androgen-deprivation therapy (ADT) in the management of prostate cancer, and the effect that this treatment has on a patient's quality of life (QoL), based on discussions held at a European symposium on the management of prostate cancer. The overall QoL is reduced in asymptomatic men, and there are known decreases in cognitive function, self-esteem, libido and sexual function. Hot flashes are also a frequent problem. Prolonged ADT can lead to osteoporosis and subsequently fractures. Various effective methods exist to manage and minimize these side-effects; some are specific to the side-effect, whereas other more general methods include lifestyle changes, specific drugs and added hormonal manipulations. Intermittent ADT for patients taking luteinizing hormone-releasing hormone agonists offers a promising method to reduce adverse effects, and possibly increases the time to androgen independence. Initial studies indicate that prostate-specific antigen-based progression with intermittent ADT is similar to that seen with continuous ADT, but there is a reduction in side-effects, leading to an improvement in QoL.

The diagnosis and treatment of osteoporosis in men on androgen deprivation therapy for advanced carcinoma of the prostate

PURPOSE

Androgen deprivation therapy (ADT) for advanced prostate cancer increases the risk of osteoporosis. Thus, the practicing urologist should be aware of the appropriate assessment and management. In this article we review the tests designed to diagnose osteoporosis as well as treatment options. We also review methods to monitor the response to therapy and make recommendations for management.

MATERIALS AND METHODS

We performed a MEDLINE (1966 to 2004) search for the terms male, osteoporosis, bone mineral density, prostate cancer, androgen deprivation therapy, bisphosphonates, estrogen and the combinations thereof. We then constructed a management algorithm based on the best evidence available.

RESULTS

Dual energy x-ray absorptiometry of the hip is the gold standard test for osteoporosis. Biochemical markers of bone turnover are not suitable for diagnosis but they have been shown to be useful for monitoring the response to treatment. Smoking cessation, weight bearing exercise, and vitamin D and calcium have been shown to help improve bone mineral density (BMD). Bisphosphonates have been demonstrated to increase BMD and decrease fracture risk in men with osteoporosis. Estrogens have also recently been shown to decrease bone turnover and increase BMD in men on ADT.

CONCLUSIONS

Hip dual energy x-ray absorptiometry should be performed in all men who are anticipated to be on long-term ADT. In addition, all men on ADT should receive vitamin D and calcium supplementation, and perform regular weight bearing exercise. The value of smoking cessation cannot be overstated. In men who have osteopenia or osteoporosis bisphosphonate therapy should be initiated. Estrogen therapy has shown promise but specific recommendations cannot be made at this time.

Bisphosphonates for malignancy-related bone disease: current status, future developments

This review relates to the efficacy and safety of bisphosphonates in metastatic bone disease. It discusses practical recommendations and possible future indications for bisphosphonate therapy. The current aims of bisphosphonates for metastatic bone disease are to prevent skeletal-related events (SREs), reduce bone pain and improve quality of life. Phase III clinical trials of clodronate and pamidronate have established their efficacy against bone complications in patients with breast cancer and multiple myeloma, while randomized trials have shown SRE reductions with zoledronic acid in patients with breast cancer and multiple myeloma, prostate cancer, and lung and other solid tumors. These bisphosphonates also have some effect on metastatic bone pain. Ibandronate is a new aminobisphosphonate, available in more than 40 countries outside of the US as intravenous and oral formulations for the prevention of skeletal events in patients with breast cancer and bone metastases. Phase III studies have shown that both intravenously and orally administered ibandronate have efficacy for the prevention of skeletal events and for the reduction of metastatic bone pain. In addition to efficacy, the long-term tolerability of bisphosphonates in metastatic bone disease influences drug selection. Besides their use in patients with established bone metastases, recent and ongoing research suggests that bisphosphonates also have clinical benefit in the adjuvant setting, and for the treatment of cancer-treatment-induced bone loss. Such interesting new developments may underpin a new era of bisphosphonate use sometime in the near future.

Open-label trial evaluating the safety and efficacy of zoledronic acid in preventing bone loss in patients with hormone-sensitive prostate cancer and bone metastases

OBJECTIVES

To evaluate the efficacy and safety of zoledronic acid in preventing bone loss in patients with hormone-sensitive prostate cancer and bone metastases who were receiving androgen deprivation therapy.

METHODS

Patients received zoledronic acid 4 mg as a 15-minute infusion every 3 weeks for 1 year. Bone mineral density of the lumbar spine (L2 to L4) and total hip was measured by dual-energy x-ray absorptiometry at baseline and 12 months. Biochemical markers of bone turnover (N-telopeptide and bone alkaline phosphatase) and serum creatinine levels were evaluated at baseline and during the study. Skeletal-related events were assessed at each study visit.

RESULTS

Of the 221 enrolled patients, 202 and 221 patients were included in the efficacy and safety analyses, respectively. The mean increase in bone mineral density of the lumbar spine and total hip was 7.7% (P <0.001) and 3.6% (P <0.001), respectively. Decreases in N-telopeptide and bone alkaline phosphatase levels were significant and sustained. The median time to the first skeletal-related event was not reached; 11.9% of patients had a skeletal-related event. Arthralgia (20.4%), nausea (14%), fatigue (14%), and back pain (12.2%) were the most common adverse events. Adverse events due to renal function deterioration were infrequent. The mean maximal change in serum creatinine level from baseline was 0.3 mg/dL.

CONCLUSIONS

Zoledronic acid administration for 1 year to patients with hormone-sensitive prostate cancer and bone metastases who were receiving androgen deprivation therapy was safe and prevented bone loss, as demonstrated by significant increases in bone mineral density and sustained suppression of biochemical markers of bone turnover.

Intermittently administered parathyroid hormone 1-34 reverses bone loss and structural impairment in orchiectomized adult rats

Male osteoporosis is emerging as a central theme in bone research. As in females, hypogonadism appears as a principal risk factor in men that leads to bone loss and increased fracture incidence. Intermittently administered parathyroid hormone (PTH) reverses bone loss in sex hormone-deprived women and female animals and increases bone mass in elderly men and normal male animals. This study was carried out to assess whether the PTH anabolic activity is also effective in adult castrated males and to gain insight into the underlying tissue processes. Bilateral orchiectomy (ORX) or sham-ORX was performed in 13-week old rats. Five weeks later, the ORX rats were treated intermittently with human PTH(1-34), 80 microg/kg/day or vehicle for 6 weeks. Femora were evaluated by quantitative micro-computed tomography followed by dynamic histomorphometry. The trabecular bone volume density showed 40% and 56% ORX-induced loss in the distal metaphysis at 6 weeks and 12 weeks post-ORX, respectively. PTH(1-34) induced supraphysiologic recovery of this bone loss (155% recovery) consequent to a vast increase in trabecular thickness (174% over sham-ORX controls) and a partial reversal (62%) of the decrease in trabecular number. As compared with the results in 12-week, orchiectomized vehicle-administered rats, the PTH(1-34) treatment induced a significant decrease in osteoclast number (20%) and twofold increase in bone formation rate. While ORX did not affect the femoral diaphysis, PTH(1-34) induced marked cortical thickening via the stimulation of endosteal mineral appositional rate (154% over ORX rats). These data portray PTH(1-34) as a highly potent bone anabolic agent in adult ORX rats, mainly by increasing both the trabecular and cortical thicknesses through its effect on osteoblasts and osteoclasts. The adult ORX rat is useful for investigating the processes involved in bone anabolic activity in castrated osteoporotic males and for the development of bone anabolic agents for treating this condition.

Cancer treatment-induced bone loss in patients with breast or prostate cancer

PURPOSE/OBJECTIVES

To review the prevalence, consequences, pathophysiology, diagnosis, and treatment of cancer treatment-induced bone loss (CTIBL) in patients with breast or prostate cancer.

DATA SOURCES

Published articles, abstracts, book chapters, electronic resources, and manufacturer information.

DATA SYNTHESIS

CTIBL is a long-term complication associated with cancer therapies that cause hypogonadism in patients with breast or prostate cancer. Early diagnosis and treatment of CTIBL is essential to prevent bone fractures. CTIBL treatment includes modification of lifestyles that increase the risk of developing bone loss and fractures and includes the use of bone loss therapies (e.g., bisphosphonates, selective estrogen receptor modifiers, calcitonin).

CONCLUSIONS

CTIBL is becoming more common as patients with breast or prostate cancer survive longer. Identifying and treating CTIBL early are important because once bone is lost, damaged bone becomes more difficult to repair; early diagnosis and treatment also may prevent fractures.

IMPLICATIONS FOR NURSING

Nurses must be knowledgeable about CTIBL to identify high-risk patients and educate patients and their families about CTIBL, bone loss therapies, and lifestyle modifications.

HIP FRACTURES IN MEN WITH PROSTATE CANCER TREATED WITH ORCHIECTOMY

PURPOSE

Androgen deprivation therapy increases the risk of osteoporosis related fractures. This issue is of increasing importance in men with prostate cancer as increasingly more undergo androgen deprivation therapy and therapy is administered sooner following diagnosis. Data directly addressing the long-term fracture risk in men diagnosed with prostate cancer are limited.

MATERIALS AND METHODS

Using population based registries in Sweden we studied the incidence of hip fractures in 17,731 men diagnosed with prostate cancer from 1964 to 1996 who were treated with bilateral orchiectomy within 6 months of diagnosis. The fracture incidence was compared to the incidence in 43,230 men diagnosed with prostate cancer but not treated with orchiectomy and in 362,354 of similar age who were randomly selected from the general population.

RESULTS

Men treated with orchiectomy were at increased risk for hip fracture. The estimated relative risk comparing men who underwent orchiectomy to population controls was 2.11 (95% CI 1.94 to 2.29) for femoral neck fractures and 2.16 (95% CI 1.97 to 2.36) for intertrochanter fractures. An increased risk of hip fracture was observed as early as 6 months after orchiectomy and the relative risk remained fairly constant up to 15 years following orchiectomy.

CONCLUSIONS

Hip fracture risk increases almost immediately following orchiectomy and the excess risk persists for at least 15 years. This side effect should be considered when assessing the merits of androgen deprivation therapy, particularly in symptom-free men diagnosed with localized prostate cancer. Measures to prevent osteoporosis should be considered in men undergoing androgen deprivation therapy.

Toward New Horizons: The Future of Bisphosphonate Therapy

Bisphosphonate therapy has become a standard of care for patients with malignant bone disease. In addition, preclinical and preliminary clinical data suggest that bisphosphonates may prevent cancer-treatment-induced bone loss (CTIBL) and the development of malignant bone disease in patients with early-stage cancer. Patients who receive adjuvant hormonal therapy for breast cancer or androgen-deprivation therapy for prostate cancer are at an especially high risk for CTIBL because of reduced estrogenic signaling. Oral clodronate (Bonefos; Anthra Pharmaceuticals; Princeton, NJ), oral risedronate (Actonel; Proctor and Gamble Pharmaceuticals, Inc.; Cincinnati, OH), and i.v. zoledronic acid (Zometa; Novartis Pharmaceuticals Corp.; East Hanover, NJ) have all demonstrated promise in preventing CTIBL in patients receiving hormonal therapy for breast cancer. Zoledronic acid has demonstrated efficacy with the longest between-treatment interval (3-6 months) and is currently being investigated in the Zometa/Femara Adjuvant Synergy Trials (Z-FAST and ZO-FAST in the United States and Europe, respectively). In patients receiving androgen-deprivation therapy for prostate cancer, i.v. pamidronate (Aredia; Novartis Pharmaceuticals Corp.) and i.v. zoledronic acid both have demonstrated significant benefits over placebo, but only zoledronic acid produced significant increases in bone mineral density compared with baseline values. Additionally, bisphosphonates have demonstrated antitumor activities in preclinical models, and clinical trials with oral clodronate suggest that bisphosphonates might prevent or delay bone metastasis in patients with early-stage breast cancer. Clinical trials are investigating the effect of zoledronic acid on disease progression in patients with breast cancer, prostate cancer, and non-small cell lung cancer. The results of these clinical trials should further define the clinical benefit of bisphosphonates in the oncology setting.

Understanding treatments for bone loss and bone metastases in patients with prostate cancer: a practical review and guide for the clinician

Prostate cancer patients are at risk for developing bone loss and bone metastases. Clinicians prescribing ADT should appreciate the potential effects of ADT on BMD as well as the morbidity and mortality that can result from osteoporotic fractures. Measures to address the evaluation of patients and when to treat patients with significant bone loss have been discussed. Bisphosphonates effectively prevent loss of BMD in prostate cancer patients. Treatment of prostate cancer patients with established bone metastases with zoledronic acid should be considered strongly based on the results of the Saad study and other studies of patients with bone metastases with other malignancies. Zoledronic acid is approved by the US FDA for use in men with metastatic hormone-refractory prostate cancer and in the European Union for any patient with bone metastases, including prostate cancer patients,because of the beneficial impact of zoledronic acid on skeletal-related events. There is no validated method to determine which patients might benefit most from bisphosphonate therapy in this setting. Many questions about the use of bisphosphonate therapy in men with prostate cancer must be addressed, both in terms of the use in bone loss and bone metastases. These questions include: What is the optimal timing of therapy? Which bisphosphonate is best? What is the best dose and dose schedule? Do bisphosphonates effectively decrease skeletal fracture rates in patients with osteoporosis? How long should patients receive therapy? Are bisphosphonate "holidays" warranted? What are the long-term skeletal and renal toxicities? Is there a role for sequencing bisphosphonate therapy either before or after chemotherapy? Is bisphosphonate therapy synergistic with certain chemotherapy or other bone-targeted therapies? Which patients are the most likely to benefit from bisphosphonate therapy? What are clinically significant endpoints of bisphosphonate trials in patients with metastatic disease? Does inhibiting bone turnover also inhibit formation of bone metastases? Preliminary work in these areas has been completed, but more questions than answers are available. Given the rising costs of health care, it is imperative that these questions be addressed to best use the health care dollar while offering high-risk patients the best available therapy. At present, no data suggest that bisphosphonates should be used routinely to prevent BMD loss in men with normal BMD or to prevent the development of bone metastases in men with biochemical relapse. Continuing trials may give us guidance in the future.

Exploring the effects of luteinizing hormone-releasing hormone agonist therapy on bone health: implications in the management of prostate cancer

Osteoporosis is a complication that may be associated with long-term androgen deprivation therapy (ADT) in men with prostate cancer. Androgen deprivation increases bone resorption, thereby leading to a more rapid decrease of bone mineral density (BMD) at multiple skeletal sites as compared with age-matched healthy men. ADT has been associated with an increased risk of skeletal fracture in several retrospective analyses. The role of androgens in maintaining bone health appears to be mediated indirectly through their conversion to estrogens, although testosterone may be an important factor in bone formation. Physicians need to be aware of the potential for osteoporosis and should inform patients of appropriate lifestyle and diet modifications, such as calcium and vitamin D supplementation, and exercise at the initiation of ADT. Evaluating BMD may become the accepted norm. Several studies suggest that bisphosphonates may be beneficial in preventing and treating osteoporosis in patients with prostate cancer. The overall benefit of ADT in men with prostate cancer will continue to improve as potential side effects, such as osteoporosis, are recognized and addressed successfully.