Progressive decrease in bone density over 10 years of androgen deprivation therapy in patients with prostate cancer

Andropause: Symptom Management for Prostate Cancer Patients Treated With Hormonal Ablation

Andropause, or the age-related decline in serum testosterone, has become a popular topic in the medical literature over the past several years. Andropause includes a constellation of symptoms related to lack of androgens, including diminished libido, decreased generalized feeling of well-being, osteoporosis, and a host of other symptoms. The andropause syndrome is very prominent in men undergoing hormonal ablation therapy for prostate cancer. Most significant in this population are the side effects of hot flashes, anemia, gynecomastia, depression, cognitive decline, sarcopenia, a decreased overall quality of life, sexual dysfunction, and osteoporosis with subsequent bone fractures. The concept of andropause in prostate cancer patients is poorly represented in the literature. In this article, we review the current literature on the symptoms, signs, and possible therapies available to men who cannot take replacement testosterone.

Background to and management of treatment-related bone loss in prostate cancer

Prostate cancer is a common disease among older men. Androgen suppression by either orchiectomy or administration of luteinising hormone-releasing hormone (LHRH) analogues is the mainstay of treatment. Since the use of prostate-specific antigen (PSA) serum testing has become widespread, however, the timing of endocrine therapy has expanded considerably to include patients with limited involvement of extraprostatic sites and patients presenting an isolated elevation of PSA after radical treatments. These patients are expected to be treated for a long time, since they have a rather low risk of disease progression and there is no recommended time limit for LHRH analogue therapy. The long-term adverse effects of androgen deprivation therapy, therefore, deserve more attention than they have received in the past. Osteoporosis represents a special concern for men with prostate cancer receiving androgen deprivation therapy. The rate of bone loss in these men seems to markedly exceed that associated with menopause in women, and fractures occur more frequently than in the healthy elderly male population. Serial bone mineral density (BMD) evaluation could allow the detection of patients with prostate cancer who are at greater risk of osteoporosis and adverse skeletal events after androgen deprivation therapy, such as patients already osteopenic or osteoporotic at baseline and men with rapid bone loss during treatment. BMD evaluated during treatment could also be a potential surrogate parameter of antiosteoporotic therapeutic efficacy. Treatment of bone loss induced by androgen deprivation comprises general prevention measures, antiosteoporotic drugs and the use of alternative endocrine therapies. Optimising lifestyle and diet is important, although it cannot completely prevent bone loss. Patients with nonsevere bone disease may benefit from calcium and vitamin D supplements. Men who are osteoporotic before androgen deprivation or men becoming osteoporotic during treatment and/or experiencing adverse skeletal events may also require bisphosphonates. The effectiveness of these drugs in preventing fractures has been shown in a single randomised study involving patients with osteoporosis, but it has not yet been established in a prostatic cancer population without bone metastases given androgen deprivation therapy. Different forms of endocrine therapy such as low-dose estrogens, antiandrogens and intermittent androgen ablation are under investigation. They could offer the advantage of avoiding (or limiting) treatment-related bone loss. In our opinion, however, the data available so far are not robust enough to recommend these alternative endocrine therapies instead of standard androgen deprivation in routine clinical practice.

Leuprorelin: a leading role in advanced prostate cancer therapy

Leuprorelin is a luteinizing hormone-releasing hormone analogue, licensed in the UK for the treatment of advanced prostate cancer. This review highlights the efficacy and tolerance of this agent and the benefits provided for developing patient-centred therapy and optimizing patient quality of life.

Management of Vertebral Metastases in Prostate Cancer: A Retrospective Analysis in 119 Patients

The objectives of this study were to define clinical problems and treatment strategies in vertebral metastases of prostate cancer. The clinical files of 634 patients with prostate cancer seen in a comprehensive cancer center during a 4-year period were retrospectively reviewed. One hundred nineteen patients (18.8%) had 212 significant episodes of osseous spinal metastases. Pain was nearly universal (93%), and motor and bladder impairment occurred in 25% and 3.1% of patients, respectively. Bone scan and magnetic resonance imaging (MRI) were performed in 197 and 64 episodes, respectively. Fifteen episodes of spinal cord compression were treated surgically. Other treatments included hormonal therapy (163 episodes), chemotherapy (70 episodes), and radiation therapy (103 episodes). Osteolytic lesions were observed alone and in combination with osteoblastic pattern in 18% and 26% of episodes, respectively. Bone scan was the most effective screening procedure of vertebral involvement, and MRI effectively showed epidural involvement. Overall treatment led to improvements in pain and motor impairment in 77% and 50% of patients, respectively. However, clinical episodes were recurrent (1.78 episodes per patient; range, 1-8). Median survival after vertebral metastasis episode was 14 months compared with only 4 months after surgery for spinal cord compression. Vertebral metastases strongly alter quality of life in patients with prostate cancer. Pain and neurologic complications are the major problems. Careful early screening with bone scan and MRI may help to define better treatment strategy. However, further prospective studies of clinical management are needed to determine the optimal timing of radiation therapy, medical treatments, and surgery.

The role of bisphosphonates in the management of metastatic prostate cancer

Most men with advanced prostate cancer have primarily skeletal metastases, which are responsible for most of the morbidity and mortality of prostate cancer. Although bone lesions are osteoblastic in radiographic appearance, recent evidence has demonstrated that anti-osteoclast therapy with bisphosphonates reduces skeletal-related complications in hormone-refractory prostate cancer. This observation may be explained by the demonstration that osteoclast activity is greatly upregulated even in osteoblastic metastases. Furthermore, androgen deprivation therapy, the mainstay of treatment for advanced prostate cancer, leads to increased bone resorption and reduces bone mineral density. These effects can be ameliorated, and potentially completely prevented, by coadministration of bisphosphonates. These findings may point to a role for bisphosphonates in men with prostate cancer even prior to the development of skeletal metastases. Determination of whether such early therapy ultimately results in delayed time to skeletal progression or in improved survival will require large randomized studies.

Therapeutic benefit of bisphosphonates in the management of prostate cancer-related bone disease

A diversity of bone pathology is present in men with prostate cancer. Androgen deprivation therapy (ADT) can cause significant and progressive osteopoenia and osteoporosis. Bone is also the primary site for metastases leading to associated pain, skeletal fractures and hypercalcaemia. Bisphosphonate therapy decreases bone resorption, which may prevent or reverse loss of bone mineral density. Both pamidronate and zoledronic acid have proven efficacy in preventing ADT-induced bone loss. In a randomised, placebo-controlled trial, in men with hormone-refractory prostate cancer, there was a decreased incidence of skeletal- related adverse events in men receiving zoledronic acid. So far, randomised trials have failed to show improved pain control. Formalised guidelines are needed to help clinicians decide which patients should be treated with bisphosphonates, when to initiate therapy and for what duration.

Androgen deprivation in men with prostate cancer is associated with an increased rate of bone loss

The objective of this work was to determine the effect of androgen deprivation therapy (ADT) on rates of bone mineral density (BMD) loss in men with prostate cancer. It was a prospective study comparing men receiving ADT to age matched controls for 2 y. Subjects received a history, physical exam, bone mineral density measurement, and laboratory evaluation every 6 months. Thirty-nine subjects receiving continuous ADT for prostate cancer (subjects) were compared to 39 age-matched controls not receiving ADT (controls). Twenty-three subjects and 30 controls completed the study through 24 months. Men in the ADT group demonstrated greater rates of bone mineral density loss than men in the control group at every site except the lumbar spine. Twenty-four month per cent of bone mineral density loss is presented as mean+/-standard error (s.e.). At the distal forearm, the ADT group value was -9.4%+/-1.0% and -4.4%+/-0.3% for controls (P<0.0005). The ADT group femoral neck values were -1.9%+/-0.7% and 0.6%+/-0.5% in the control group (P=0.0016). The ADT group total hip value was -1.5%+/-1.0% and 0.8%+/-0.5% in the control group (P=0.0018). The ADT group trochanter value was -2.0%+/-1.3% and -0.1%+/-0.5% in the control group (P=0.0019). The ADT group lumbar spine value was -0.2%+/-0.8 % and 1.1%+/-0.6% in the control group (P=0.079). Our data demonstrate greater rates of bone mineral density loss in men receiving androgen deprivation therapy for prostate cancer.

Zoledronic Acid Significantly Reduces Pathologic Fractures in Patients with Advanced-Stage Prostate Cancer Metastatic to Bone

The skeletal complications of metastatic bone disease secondary to advanced prostate cancer result in significant morbidity. In particular, pathologic fractures often require clinical intervention and are independent predictors of mortality in men with advanced prostate cancer. Before the introduction of zoledronic acid, bisphosphonates had been shown to provide pain palliation in patients with prostate cancer and bone metastases but were not efficacious in preventing skeletal complications. Zoledronic acid is the first bisphosphonate to show efficacy in reducing skeletal complications associated with the predominantly osteoblastic bone lesions characteristic of prostate cancer. In a large phase III randomized trial, zoledronic acid 4 mg every 3 weeks for 15 months significantly reduced the percentage of men who experienced a skeletal complication and reduced the incidence of pathologic fractures. Additionally, zoledronic acid 4 mg significantly decreased the annual incidence of skeletal complications, including fractures, and provided better control of bone pain compared with placebo. Adverse events with zoledronic acid were primarily limited to the flu-like, acute-phase symptoms previously reported with intravenous bisphosphonates, namely fever, myalgia, nausea, and anemia. These adverse events were mild to moderate and easily managed with supportive care. Zoledronic acid is the first and only bisphosphonate shown to reduce skeletal morbidity, including fractures, in patients with advanced prostate cancer and bone metastases.

Severe symptomatic osteoporosis in patients on androgen deprivation therapy for prostatic carcinoma

We report 3 patients referred to the bone clinic after spinal fractures. Dual energy X-ray absorptiometry showed severe osteoporosis. Each patient was found to have a history of prostatic carcinoma and long-term treatment with goserelin. We suggest that all patients who have received androgen deprivation therapy for more than 1 year should be evaluated by bone densitometry.

Controversies surrounding androgen deprivation for prostate cancer

BACKGROUND

Management of metastatic prostate cancer continues to evolve. The widespread use of the prostate-specific antigen (PSA) assay has led to earlier diagnosis and earlier detection of recurrent disease. Debates continue regarding the proper use and timing of endocrine therapy with orchiectomy, estrogen agonists, luteinizing hormone-releasing hormone (LHRH) analogs, LHRH antagonists, and androgen antagonists.

METHODS

The authors reviewed the significant published materials of the last 20 years that have shaped hormonal management of metastatic and progressive prostate cancer. Major areas of controversy were also identified.

RESULTS

The present approach to hormonal management is summarized. Five potential pathways to the development of androgen-independent prostate cancer are described. Controversial topics of hormonal management, including immediate vs delayed hormonal therapy, monotherapy vs maximal androgen blockade (MAB), and intermittent hormonal therapy, are discussed.

CONCLUSIONS

Orchiectomy, estrogen agonists, and LHRH analogs have therapeutic equivalence. Patients who have a rising PSA after definitive treatment for prostate cancer and high risk of recurrent disease may warrant early androgen deprivation. MAB does not appear to be significantly better than single-agent LHRH analog therapy. Intermittent therapy may delay emergence of androgen independence and maintain or improve quality of life.

Increase of bone alkaline phosphatase after androgen deprivation therapy in patients with prostate cancer

OBJECTIVES

To evaluate the behavior of bone alkaline phosphatase (BAP) after androgen deprivation therapy in patients with prostate cancer.

METHODS

BAP was determined in the serum of 35 patients with nonmetastatic prostate cancer before maximal androgen blockade. During 5 years of follow-up, BAP was determined annually. A subset of 36 patients who underwent radical prostatectomy as the only treatment for prostate cancer was selected as a control group.

RESULTS

The mean pretreatment BAP serum concentration was similar in both groups (10.8 and 10.4 ng/mL, P >0.05). However, after 5 years, the mean BAP serum concentration increased 64.8% in the study group (from 10.8 to 17.6 ng/mL, P < 0.001); it remained stable in the control group (from 10.4 to 10.4 ng/mL). The increase of serum BAP in patients receiving androgen deprivation was 32.4% during the first year (from 10.8 to 14.3 ng/ml), 16.7% during the second (from 14.3 to 16.1 ng/mL), 7.4% during the third (from 16.1 to 16.9 ng/mL), 5.5% during the fourth (from 16.9 to 17.3 ng/mL), and 2.8% during the fifth year (from 17.3 to 17.6 ng/mL).

CONCLUSIONS

Androgen deprivation produces an increase in the BAP serum concentration. A major increase seems to be produced during the first year of follow-up and thereafter this increase is reduced around 50% annually.