American Society of Clinical Oncology 2003 update on the role of bisphosphonates and bone health issues in women with breast cancer

Management of bisphosphonate treatment in clinical practice

Bisphosphonates have become important tools for the treatment of bone lesions from various solid tumors or from multiple myeloma. Management of bone health in patients with malignant bone disease from breast cancer, prostate cancer, lung cancer, and multiple myeloma was discussed in clinical case workshops held during the ZENITH meeting (April 2007, Prague, Czech Republic). Physicians in attendance were generally in agreement that bisphosphonate therapy is recommended for treatment of bone metastases and that treatment should be sustained over the duration of disease progression. Consensus is still evolving regarding the optimal duration of therapy and the emerging role of bisphosphonates in the management of bone loss in the adjuvant setting. Bisphosphonates have proven efficacy in reducing and delaying skeletal-related events in patients with bone metastases, and play a key role in preserving patient functional independence and quality of life. Furthermore, bisphosphonate therapy is a cost-effective strategy in the care of patients with bone metastases compared with the cost of treatment for fractures and other skeletal complications. Finally, communication with patients is critical to increase awareness of the benefits of bisphosphonate therapy. Increased patient involvement with treatment decisions will likely encourage patient compliance and thereby maximize clinical benefit from bisphosphonate therapy.

Reducing the risk of cancer treatment-associated bone loss in patients with breast cancer

Women with breast cancer, especially those receiving aromatase inhibitors, are at higher risk for bone loss and fracture. Postmenopausal women may already have multiple risk factors for fracture, and breast cancer therapies compound these risks. Current guidelines for bone health management in women with breast cancer are based on bone mineral density (BMD) measurements; however, many risk factors for fracture are independent of bone mineral density. Thus, consideration of other risk factors for fracture, including cancer therapies, aromatase inhibitor therapy, and age, may be necessary to accurately identify patients at high risk for bone loss. Bisphosphonates, inhibitors of osteoclast-mediated osteolysis, may be efficacious for the prevention of aromatase inhibitor-associated bone loss. Several clinical trials evaluating zoledronic acid in this setting have produced favorable results. In the Austrian Breast and Colorectal Cancer Study Group (ABCSG)-12 trial, patients receiving anastrozole or tamoxifen plus goserelin experienced significant bone loss, and zoledronic acid treatment prevented bone loss in both groups. Results from the parallel studies Z-FAST, ZO-FAST, and E-ZO-FAST indicate that upfront zoledronic acid treatment increases BMD in patients receiving letrozole. These preliminary results are encouraging and suggest that zoledronic acid is an effective preventative therapy for bone loss in breast cancer patients receiving aromatase inhibitors.

Can computerised tomography replace bone scintigraphy in detecting bone metastases from breast cancer? A prospective study

BACKGROUND

The aim of this study was to determine whether bone scans (BS) can be avoided if pelvis was included in CT thorax and abdomen to detect bony metastases from breast cancer.

MATERIALS AND METHODS

Results of 77 pairs of CT (thorax, abdomen, and pelvis) and BS in newly diagnosed patients with metastatic breast cancer (MBC) were compared prospectively for 12 months. Both scans were blindly assessed by experienced radiologists and discussed at multidisciplinary team meetings regarding the diagnosis of bone metastases.

RESULTS

CT detected metastatic bone lesions in 43 (98%) of 44 patients with bone metastases. The remaining patient had a solitary, asymptomatic bony metastasis in shaft of femur. BS was positive in all patients with bone metastases. There were 11 cases of false positive findings on BS.

CONCLUSION

Our findings suggest routine BS of patients presenting with MBC is not required if CT (thorax, abdomen, and pelvis) is performed.

Bisphosphonate treatment and radiotherapy in metastatic breast cancer

Patients with advanced breast cancer frequently develop metastasis to bone. Bone metastasis results in intractable pain and high risk of pathologic fractures due to osteolysis. The treatment of breast cancer patients with bone metastases requires a multidisciplinary approach. Radiotherapy is an established treatment for metastatic bone pain. It may be delivered either as a localized low dose treatment for localized bone pain or systemically for more widespread symptoms. Bisphosphonates have been shown to reduce morbidity and bone pain from bone metastases when given to patients with metastatic bone disease. In vivo studies indicate that early bisphosphonates administration in combination with radiotherapy improves remineralization and restabilization of osteolytic bone metastases in animal tumor models. This review focused on a brief discussion about biology of bone metastases, the effects of radiotherapy and bisphosphonate therapy, and possible mechanisms of combination therapy in metastatic breast cancer patients.

Safely promoting breast-conserving surgery and preventing early relapses with an aromatase inhibitor

Neoadjuvant therapy improves patient outcomes substantially by increasing the rate of breast-conserving surgery. Following primary surgery, women with hormone-sensitive early breast cancer remain at risk for loco-regional and systemic recurrence. The most common relapse event, distant metastases, is associated with the poorest outcomes. As a neoadjuvant therapy, anastrozole, letrozole, and exemestane have been investigated in phase 3 studies and have shown efficacy in this setting. All three aromatase inhibitors (AIs) significantly improved the rate of breast-conserving surgery. As initial adjuvant therapy, the third-generation AIs anastrozole and letrozole more effectively reduce recurrence risk compared with tamoxifen following surgery, especially in the first 2 years, when the risk is greatest. Tamoxifen, once the standard initial therapy, is associated with improved disease-free survival but may be more effective at reducing loco-regional recurrence than distant metastases. Initial adjuvant letrozole therapy has also shown a pronounced reduction in the risk of distant metastases early on in the course of therapy. If AIs are not used upfront, sequential use of exemestane or anastrozole following tamoxifen provides greater protection against relapse than continuing on tamoxifen. Side effects associated with estrogen deprivation of AIs are less serious than those of tamoxifen and are easily managed. Various molecular markers are under study as surrogates to predict response to neoadjuvant therapy, which may in turn predict responsiveness to adjuvant therapy. Surgeons treating breast cancer patients and prescribing endocrine therapy should be aware of all treatment strategies, including neoadjuvant and adjuvant hormonal therapy, and inform their patients of the benefits and the potential side effects. Early and long-term-risk reduction with AI treatment should be discussed with patients, as should the management of common AI-associated adverse events.

Octreotide and the mTOR inhibitor RAD001 (everolimus) block proliferation and interact with the Akt-mTOR-p70S6K pathway in a neuro-endocrine tumour cell Line

BACKGROUND/AIM

The mode of action of the somatostatin analog octreotide on neuro-endocrine tumour proliferation is largely unknown. Overexpression of the proto-oncogene Akt/PKB (protein kinase B) has been demonstrated in certain neuro-endocrine tumours: Akt activates downstream proteins including mTOR and p70S6K, which play an important role in cell proliferation. RAD001 (everolimus) is a novel agent that is being trialled in the treatment of neuro-endocrine tumours, and is known to interact with mTOR. We explored the mechanism of action of octreotide, RAD001, and their combination on cell proliferation and kinase activation in a neuro-endocrine tumour cell line (rat insulinoma cell line, INS1).

METHODS

Proliferation assays were used to determine the effects of octreotide, RAD001, and their combination on cell proliferation. Western blotting was used to characterize the expression of phosphorylated Akt, phosphorylated TSC2, phosphorylated mTOR, and phosphorylated 70S6K.

RESULTS

Treatment with octreotide and RAD001 inhibited proliferation and attenuated phosphorylation of all downstream targets of Akt: TSC2, mTOR, and p70S6K.

CONCLUSIONS

In this cell model, octreotide and RAD001 appear to act through a similar pathway and inhibit the Akt-mTOR-p70S6 kinase pathway downstream of Akt. There may be some overlapping effects of the two inhibitors on the mTOR pathway, although it is likely that other additional effects may differentiate the two agents.

Zoledronic acid: a pharmacoeconomic review of its use in the management of bone metastases

Zoledronic acid (Zometa is a third-generation nitrogen-containing parenteral bisphosphonate indicated for the treatment of bone metastases due to solid tumours or multiple myeloma and for hypercalcaemia of malignancy (HCM). In patients with advanced breast or prostate cancer, zoledronic acid 4 mg every 3-4 weeks for up to 15 months significantly reduced the proportion of patients with > or =1 skeletal-related event (SRE), excluding HCM, compared with placebo. In patients with advanced breast cancer or multiple myeloma, the incidence of SREs was similar in patients treated with zoledronic acid 4 mg or pamidronic acid 90 mg every 3-4 weeks for up to 25 months but, in breast cancer patients, zoledronic acid reduced the risk of SREs, including HCM, by an additional 20% compared with pamidronic acid. In modelled cost-utility studies comparing direct costs based on efficacy and resource-use data from these and/or other trials, results have varied. In the most recent study performed from the perspective of the UK NHS and modelled over a 10-year treatment period in women with advanced breast cancer, intravenous zoledronic acid and oral ibandronic acid were dominant over no treatment. Intravenous zoledronic acid was the most cost effective, in terms of incremental costs per QALY gained, followed by oral ibandronic acid, intravenous pamidronic acid and intravenous ibandronic acid. Two other modelled analyses in patients with advanced breast cancer, also conducted from the perspective of the NHS, evaluated the cost utility of three bisphosphonate therapies in patients receiving hormonal therapy or intravenous chemotherapy. Analyses were modelled over 14.3 months (i.e. expected survival) and assumptions varied markedly from results in clinical breast cancer trials. Also, efficacy assumptions for zoledronic acid were not based on clinical trials with the drug. The results of these analyses suggest that oral ibandronic acid is more cost effective than intravenous zoledronic acid and intravenous pamidronic acid in terms of incremental cost per QALY gained. In a global, 15-month modelled cost-effectiveness analysis of patients with advanced prostate cancer, conducted from a third-party perspective, the incremental cost per QALY gained for zoledronic acid versus no treatment was $US159 200 (year 2000 value), which is about 3-fold greater than commonly accepted thresholds for cost effectiveness. In conclusion, a recent modelled economic analysis suggests that intravenous zoledronic acid 4 mg is dominant relative to no treatment in the management of bone metastases in patients with advanced breast cancer. In contrast, in patients with advanced prostate cancer, the incremental cost per QALY gained for zoledronic acid 4 mg versus no treatment was predicted to be higher than commonly accepted thresholds. Compared with other bisphosphonates in the setting of advanced breast cancer, intravenous zoledronic acid was more cost effective than oral or intravenous ibandronic acid and intravenous pamidronic acid in one study, but less cost effective than oral ibandronic acid in another. Further efficacy and economic data comparing intravenous zoledronic acid with oral ibandronic acid are needed. Meanwhile, zoledronic acid appears to be the most cost effective intravenous bisphosphonate for the management of bone metastases in patients with advanced breast cancer and possibly in patients with different types of advanced solid tumours.

Renal safety of intravenous bisphosphonates in the treatment of osteoporosis

Oral bisphosphonates are the mainstay of treatment for osteoporosis but cannot be used in some patients due to gastrointestinal contraindications, gastrointestinal intolerance, malabsorption or the inability to comply with dosing requirements. In such patients, intravenous bisphosphonates are a useful alternative. This review summarises the renal safety issues associated with the use of intravenous bisphosphonates for osteoporosis. Intravenous bisphosphonates are generally well tolerated, which may be a reflection of their selective activity in bone and metabolic stability. Adverse effects on renal function are primarily related to infusion rate and dose. Due to lack of data, no conclusions can be made regarding bisphosphonate safety in patients with intrinsic renal disease or an estimated glomerular filtration rate of < 30 ml/min.

Management of breast cancer in elderly individuals: recommendations of the International Society of Geriatric Oncology

Breast cancer is the most commonly diagnosed cancer and the leading cause of cancer mortality in women worldwide. Elderly individuals make up a large part of the breast cancer population, and there are important specific considerations for this population. The International Society of Geriatric Oncology created a task force to assess the available evidence on breast cancer in elderly individuals, and to provide evidence-based recommendations for the diagnosis and treatment of breast cancer in such individuals. A review of the published work was done with the results of a search on Medline for English-language articles published between 1990 and 2007 and of abstracts from key international conferences. Recommendations are given on the topics of screening, surgery, radiotherapy, (neo)adjuvant hormone treatment and chemotherapy, and metastatic disease. Since large randomised trials in elderly patients with breast cancer are scarce, there is little level I evidence for the treatment of such patients. The available evidence was reviewed and synthesised to provide consensus recommendations regarding the care of breast cancer in older adults.

Palliative care in orthopaedic surgical oncology

Hundreds of thousands of Americans are affected every year by skeletal complications of oncologic disease. Recent developments in medical oncology, radiation oncology and radiology, particularly with respect to the use of bisphosphonate medication and radiofrequency techniques, have served to greatly lessen the morbidity associated with metastatic skeletal disease. Similarly, there has been significant advancement in the field of orthopaedic oncology in the areas of internal fixation, endoprosthetic implant design, and minimally invasive kyphoplasty technology. Given the palliative intent of intervention in this patient population, the goal of treatment of skeletal metastases must be optimization of limb function and ultimately, quality of life.

Bone loss in patients with breast or prostate cancer

Cancers of the breast and prostate are very common in the general population, with breast cancer accounting worldwide for 23% of cancer cases in women and prostate cancer accounting for 12% of cases in men. During the past decade, the survival rates of patients with estrogen-dependent breast cancer and testosterone-dependent prostate cancer have improved. This improvement has been possible thanks to the introduction of hormone treatments that suppress the synthesis or antagonize the actions of gonadal steroids. However, estrogen and testosterone deficiencies are associated with excessive bone resorption that translates into damage of the bone microarchitecture, loss of bone mineral density, and predisposition to osteoporosis and fractures. Herein, we review the mechanisms of bone loss in breast and prostate cancer survivors, their clinical implications, and different available therapeutic modalities that may help to correct the damage of bone and prevent the development of fractures.

The what, why and how of aromatase inhibitors: hormonal agents for treatment and prevention of breast cancer

The third-generation aromatase inhibitors (AIs) anastrozole, exemestane and letrozole have largely replaced tamoxifen as the preferred treatment for hormone receptor - positive breast cancer in postmenopausal women. Approximately 185,000 new cases of invasive breast cancer are diagnosed yearly, and at least half of these women are both postmenopausal and eligible for adjuvant therapy with AIs. In addition, AIs are currently being tested as primary prevention therapy in large randomised trials involving tens of thousands of women at increased risk for breast cancer. Given the volume of use, internists will increasingly see postmenopausal women who are taking or considering treatment with AIs. Physicians need to be able to: (i) briefly discuss the pros and cons of using a selective estrogen receptor modulator such as tamoxifen or raloxifene vs. an AI for risk reduction and (ii) recognise and manage AI-associated adverse events. The primary purpose of this review is to help internists with these two tasks.

Medication-induced osteoporosis

Osteoporosis, a condition of low bone mass and microarchitectural deterioration, results in fractures with minimal trauma. Secondary osteoporosis is defined as bone loss resulting from either specific clinical disorders or medications. Some medications that can induce osteoporosis are discussed. Specifically, this article reviews the pathogenesis of glucocorticoid-induced bone loss and demonstrates the means to successfully manage the condition with a combination of calcium and vitamin D supplementation and, depending on the severity of the bone loss, bisphosphonates or parathyroid hormone. In addition, the pathophysiology of bone loss from aromatase inhibitors in women, gonadotropin-releasing hormone agonists in men, anticonvulsant medications, and proton pump inhibitors is outlined. Finally, this review offers suggestions on evaluation and management of bone health in individuals treated with these medications for prolonged times.

Bisphosphonates: reducing the risk of skeletal complications from bone metastasis

Women with advanced breast cancer often develop bone metastases that are associated with skeletal-related events (SREs), which reduce quality of life and increase the risk of death. Because patients who experience one SRE are more likely to experience subsequent events, the goal of therapy is to preserve quality of life by delaying the onset of the first SRE and reducing the incidence of subsequent SREs. Bisphosphonates are used for clinical management of malignant bone disease, and data suggest that early treatment (e.g., before bone pain) may confer additional clinical benefit. Furthermore, data from subsets of zoledronic acid trials suggest that long-term bisphosphonate therapy may provide sustained clinical benefit throughout the disease course. Bisphosphonates are generally safe and well tolerated; adverse events are more often mild and transient. Zoledronic acid has proven efficacy for reducing risk of SREs, and ongoing studies are under way to evaluate customized treatment schedules.

Pathologic fractures correlate with reduced survival in patients with malignant bone disease

BACKGROUND

Data from randomized, controlled trials of zoledronic acid were retrospectively analyzed to assess the effect of pathologic fractures on survival in patients with malignant bone disease.

METHODS

A Cox regression model was used to estimate the effect of fractures (time-dependent variable) on survival in patients with stage III multiple myeloma or bone metastases from solid tumors enrolled in 3 large trials. Patients were randomized to receive zoledronic acid, pamidronate, or placebo every 3-4 weeks for up to 24 months (prostate cancer, breast cancer, and multiple myeloma) or up to 21 months (lung and other solid tumors).

RESULTS

A total of 3049 patients with multiple myeloma (n = 513), breast (n = 1130), prostate (n = 640), or lung cancer or other solid tumors (n = 766) were included in this analysis. Patients with multiple myeloma had the highest fracture incidence (43%), followed by breast (35%), prostate (19%), and lung cancer (17%). In all tumor types except lung, pathologic fracture was associated with a significant increase in risk of death, and breast cancer patients had the greatest increased risk. After adjustment for baseline characteristics, including performance status and prior skeletal complications, breast cancer patients who developed a pathologic fracture on study had a significant 32% increased risk of death relative to patients without a fracture (hazard ratio = 1.32; P < .01); patients with multiple myeloma or prostate cancer had a >20% increased risk of death.

CONCLUSIONS

These results suggest that fractures are associated with increased risk of death in patients with malignant bone disease. Therefore, preventing fractures is an important goal of therapy.

[Osteoporosis in cancer survivors]

The detection of late sequelae in survivors of cancer has become increasingly important as developments in diagnostic and therapeutic methods have led to a more and long-term survival rates in tumoral patients. Osteoporosis is one of such problem that has been increasingly identified in patients with cancer. Significant bone loss and increased risk of fractures have been described in these patients. Medical problems associated with the malignancy or caused by the oncologic treatment are the main factors involved in bone loss. Therefore, patients at risk for bone loss should be undergo preventive or therapeutic interventions at an early enough stage to prevent fractures.

Prevention and management of osteoporosis in women with breast cancer and men with prostate cancer

Advances in cancer treatment have resulted in improved life expectancies for survivors of breast and prostate cancer. As the number of cancer survivors grows, the long-term side effects of treatment play an increasingly prominent role in the routine care of these patients. Due to similar management approaches, survivors of breast and prostate cancer are at increased risk for osteoporosis. This review summarizes the prevention and management of osteoporosis and osteopenia resulting from cancer treatment in survivors of breast and prostate cancer.

The influence of aging on the early detection, diagnosis, and treatment of breast cancer

Patterns of care for women with breast cancer vary substantially with patient age. Older patients with breast cancer frequently receive less than standard management, resulting in poorer outcome. At diagnosis, the health status of older women with breast cancer affects survival and treatment decisions. Age-related comorbidity may limit diagnostic tests, narrow treatment options, and significantly increase mortality not related to breast cancer. Yet, for healthy older women with early-stage breast cancer, stage-adjusted survival is similar to that of younger women. Calendar age is not sufficient to encompass the heterogeneity in health status of the elderly. Instead, management of older women with breast cancer should be based on anticipated survival, functional status, and the goals of the patient for treatment. In this review, we evaluate pertinent data and provide guidance for the management of older women with breast cancer.

Safety of aromatase inhibitors in the adjuvant setting

The third-generation aromatase inhibitors (AIs) letrozole, anastrozole, and exemestane are replacing tamoxifen as adjuvant therapy in most postmenopausal women with early breast cancer. Although AIs have demonstrated superior efficacy and better overall safety compared with tamoxifen in randomized controlled trials, they may not provide the cardioprotective effects of tamoxifen, and bone loss may be a concern with their long-term adjuvant use. Patients require regular bone mineral density monitoring, and prophylactic bisphosphonates are being evaluated to determine whether they may protect long-term bone health. AIs decrease the risks of thromboembolic and cerebrovascular events compared with tamoxifen, and the overall rate of cardiovascular events in patients treated with AIs is within the range seen in age-matched, non-breast-cancer populations. AIs are also associated with a lower incidence of endometrial cancer and fewer vaginal bleeding/discharge events than tamoxifen. Compared with tamoxifen, the incidence of hot flashes is lower with anastrozole and letrozole but may be higher with exemestane. Generally, adverse events with AIs are predictable and manageable, whereas tamoxifen may be associated with life-threatening events in a minority of patients. Overall, the benefits of AIs over tamoxifen are achieved without compromising overall quality of life.

Bisphosphonate-associated osteonecrosis of the jaw: report of a task force of the American Society for Bone and Mineral Research

ONJ has been increasingly suspected to be a potential complication of bisphosphonate therapy in recent years. Thus, the ASBMR leadership appointed a multidisciplinary task force to address key questions related to case definition, epidemiology, risk factors, diagnostic imaging, clinical management, and future areas for research related to the disorder. This report summarizes the findings and recommendations of the task force.

INTRODUCTION

The increasing recognition that use of bisphosphonates may be associated with osteonecrosis of the jaw (ONJ) led the leadership of the American Society for Bone and Mineral Research (ASBMR) to appoint a task force to address a number of key questions related to this disorder.

MATERIALS AND METHODS

A multidisciplinary expert group reviewed all pertinent published data on bisphosphonate-associated ONJ. Food and Drug Administration drug adverse event reports were also reviewed.

RESULTS AND CONCLUSIONS

A case definition was developed so that subsequent studies could report on the same condition. The task force defined ONJ as the presence of exposed bone in the maxillofacial region that did not heal within 8 wk after identification by a health care provider. Based on review of both published and unpublished data, the risk of ONJ associated with oral bisphosphonate therapy for osteoporosis seems to be low, estimated between 1 in 10,000 and <1 in 100,000 patient-treatment years. However, the task force recognized that information on incidence of ONJ is rapidly evolving and that the true incidence may be higher. The risk of ONJ in patients with cancer treated with high doses of intravenous bisphosphonates is clearly higher, in the range of 1-10 per 100 patients (depending on duration of therapy). In the future, improved diagnostic imaging modalities, such as optical coherence tomography or MRI combined with contrast agents and the manipulation of image planes, may identify patients at preclinical or early stages of the disease. Management is largely supportive. A research agenda aimed at filling the considerable gaps in knowledge regarding this disorder was also outlined.

Biology of bone metastases: causes and consequences

Breast cancer is a highly osteotropic neoplasm, and as many as 75% of patients with metastatic disease will have involvement of the bony skeleton. On radiologic examination, these metastases are predominantly osteolytic but can be osteoblastic or mixed. The mechanisms by which metastases are formed are complex, involving many steps that include angiogenesis, invasion, and proliferation in the bone microenvironment. Tumor cells in the bone microenvironment produce a large number of cytokines that stimulate osteoclastic activity. Increased osteoclastic activity, in turn, leads to production of a variety of lymphokines and growth factors that can increase tumor cell proliferation. Thus, a cytokine network is established, which results in an imbalance of the processes of bone formation and bone resorption. As tumor burden in bone increases, osteoclast-mediated bone resorption is accelerated, resulting in loss of bone strength, fractures, pain, and other morbidities. Tumor cells metastatic to bone can also secrete growth factors, leading to increased osteoblastic activity. Osteoblasts lay down an excess of new bone that is structurally weak. There is considerable crosstalk between osteoclasts, osteoblasts, macrophages, and other cellular elements within the bone environment. The increasing understanding of the biology of bone metastases has opened the door to improved management of this important clinical problem. Current treatment strategies include approaches to reduce tumor burden and developing treatments that directly inhibit osteoclast function. The bisphosphonates are a class of drugs that inhibit osteoclast recruitment and function. Several highly potent bisphosphonates are now available for clinical use and represent an important adjunct in the management of bone metastases from breast cancer, multiple myeloma, and several other types of malignancies. Some newer therapeutic approaches include agents designed to inhibit the osteoclast-osteoblast signaling interactions or alter processes of adhesion and invasion.

Efficacy and safety of intravenous bisphosphonates in patients with bone metastases caused by metastatic breast cancer

Solid tumors frequently metastasize to bone. This results in debilitating skeletal complications such as intractable bone pain, pathologic fractures, spinal cord compression, and hypercalcemia. Patients frequently require palliative radiation therapy or orthopedic surgery. Bisphosphonates have been shown to delay the incidence and decrease the frequency of skeletal-related events. Zoledronic acid is the only bisphosphonate that has provided benefits for patients with bone metastases secondary to a broad range of solid tumors. Among patients with metastatic breast or prostate cancer, zoledronic acid has demonstrated significant reductions in pain and skeletal morbidity compared with placebo. Zoledronic acid has also shown significant reductions in skeletal morbidity in patients with lung cancer or other solid tumors compared with placebo. Zoledronic acid is generally well tolerated. Flu-like symptoms which are manageable with standard treatment can occur. Renal monitoring is recommended, with dose reductions for patients with renal dysfunction. Osteonecrosis has been reported in patients receiving bisphosphonates and might be avoidable with appropriate dental care.

The use of bisphosphonates in cancer patients

Skeletal-related events resulting from bone metastases or osteoporosis can significantly contribute to morbidity and mortality in cancer patients. Expert opinion on the effectiveness of bisphosphonates in this setting is evolving. Here we review current evidence on the risks and benefits of bisphosphonate therapy for a wide variety of cancers, as well as clinical management of its adverse effects. A MEDLINE search of English-language literature (1966 through May 2006) was conducted using the terms bisphosphonate, cancer, multiple myeloma, malignancy, and randomized controlled clinical studies. Studies were selected based on clinical pertinence, with an emphasis on phase III clinical trials. We reviewed bibliographies for other relevant articles. Accumulating evidence reveals that bisphosphonate therapy has a significant effect in preventing skeletal complications in multiple myeloma, breast cancers, and prostate cancer, and in reducing skeletal complications in other metastatic bone malignancies. Emerging data indicate that bisphosphonates are useful for preventing bone loss resulting from cancer or its therapy. The efficacy of bisphosphonates for early-stage breast cancers remains controversial. Significant risks of bisphosphonate therapy include nephrotoxicity, electrolyte abnormalities, and osteonecrosis of the jaw. Bisphosphonate therapy has a clear role in the management of skeletal metastases associated with a variety of cancers. However, significant side effects require ongoing monitoring and treatment.

Reducing the risk of late recurrence in hormone-responsive breast cancer

Women with early breast cancer are exposed to an ongoing risk of relapse, even after successful surgical resection of the primary tumor and, where given, radiotherapy. Adjuvant chemotherapy and/or endocrine therapy can further help to prevent relapses by targeting metastatic disease deposits, which may be present but clinically undetectable. The benefits of adjuvant therapy are well documented, and millions of relapses have undoubtedly been prevented by treatment in this setting. Adjuvant tamoxifen has proven particularly effective in preventing relapses in hormone-receptor-positive (HR+) disease, and has been the standard treatment for affected women for over 30 years. However, long-term exposure to tamoxifen is associated with an unfavorable risk: benefit profile due to decreasing efficacy and an increasing incidence of harmful side effects. Although the risk of relapse is highest during the first 2-3 years after surgery, a residual risk remains indefinitely for those women who do not experience disease relapse in these early years, and the majority of all breast cancer recurrences and deaths occur after completion of 5 years of adjuvant tamoxifen. Hence, there is a great need for additional adjuvant therapies to reduce the considerable risk of late relapses in patients with HR+ disease: until recently no agent had been shown to provide a significant benefit over no further treatment. In 2003, upon publication of the first interim analysis of the MA.17 trial, letrozole became the first agent to be shown to significantly reduce relapses in women with HR+ early breast cancer who had completed 5 years of adjuvant tamoxifen. Subsequent analyses confirmed that letrozole significantly reduced recurrences, including distant metastases, and, in patients with node-positive disease, the agent also significantly improved overall survival, with the benefit of letrozole increasing with duration of therapy, at least up to 48 months. Preliminary results from a small, open-label study suggest that extended anastrozole therapy can also improve outcomes after completion of standard adjuvant tamoxifen. Ongoing analyses from MA.17, investigating how estrogen and progesterone receptor status and the length of time since finishing tamoxifen influence the effectiveness of letrozole, and studies evaluating the safety and efficacy of 10 years of extended aromatase inhibitor therapy, will help to optimize extended adjuvant therapy and improve outcomes for women with HR+ early breast cancer.

Safety profiles of tamoxifen and the aromatase inhibitors in adjuvant therapy of hormone-responsive early breast cancer

Adjuvant endocrine therapy plays an important role in the management of hormone-receptor-positive early breast cancer, and has increased life expectancy for millions of women. Many patients receive adjuvant treatment for at least 5 years following tumor resection, hence good long-term safety is important for endocrine agents to gain widespread acceptance. Tamoxifen has been used as adjuvant therapy for early breast cancer for many years, and safety data have been well documented, but a poor risk:benefit profile limits treatment duration to 5 years. Increased efficacy over tamoxifen and good tolerability have recently made the third-generation aromatase inhibitors (AIs) the first-choice agents for adjuvant endocrine therapy; however, it is currently not known whether AI therapy, like tamoxifen, will be limited to 5 years. Many side effects of endocrine therapy, such as hot flushes and mood disturbances, are related to estrogen deprivation and are common to tamoxifen and AIs, reflecting the mechanism of action of these drugs. In addition, tamoxifen has estrogenic effects that are beneficial in some tissues: tamoxifen lowers serum cholesterol levels and protects against bone loss and cardiovascular disease, but is also associated with potentially life-threatening side effects, such as endometrial cancer and thromboembolic disease. As AIs lack estrogenic activity, they are not associated with these serious adverse events. Clinical trials comparing AIs with tamoxifen in the adjuvant setting have shown that AIs are well tolerated and are associated with a lower incidence of gynecological symptoms and hot flushes than tamoxifen. However, AIs are associated with musculoskeletal side effects, such as arthralgia, myalgia and bone loss, but these events are preventable or manageable. The effects of AIs on lipid metabolism and the cardiovascular system are still debatable, but placebo-controlled trials provide no evidence to suggest that AIs adversely affect these systems. Furthermore, the AIs allow women to maintain a good quality of life, comparable with women receiving tamoxifen or placebo, and are a cost-effective therapeutic option. Ongoing trials will provide more information regarding the long-term effects of AI therapy and will provide comparative data on the efficacy and safety of the different AIs, thereby helping to determine the optimal treatment strategy for these highly effective and well-tolerated drugs.

Clinical management of adverse events in adjuvant therapy for hormone-responsive early breast cancer

Systemic adjuvant therapy has proven highly effective at reducing recurrences and deaths in patients who have received primary therapy for early breast cancer. However, as with all treatments, adjuvant therapy can cause unwanted side effects, and effective management of these events is essential to ensure that patients comply with, and continue, treatment. Adjuvant endocrine therapy is not associated with the more severe, acute toxicities of chemotherapy, and can therefore be taken for many years. At present, the standard duration of postoperative adjuvant endocrine therapy is 5 years. Prevention and treatment of adverse events associated with long-term endocrine therapy is particularly important in the adjuvant setting, where patients are clinically cancer free. In this situation, the efficacy benefits are not, therefore, obvious to the patient, but side effects may have a negative impact on daily life. Tamoxifen has been the gold standard endocrine therapy for hormone-receptor-positive early breast cancer for many years, and the long-term side effects of this agent are well documented. In recent years, the aromatase inhibitors (AIs) have begun to displace tamoxifen as the adjuvant therapy of choice, owing to greater efficacy and good tolerability. Predictably, the AIs and tamoxifen have partially overlapping side-effect profiles. Both therapies are associated with typical symptoms of estrogen deprivation; however, tamoxifen also has estrogenic activity in some tissues, which can cause either detrimental (genital tract) or beneficial (bone, cardiovascular system, lipids) effects that are not associated with AI use. To reduce treatment discontinuations, it is important that patients are made aware of the possible side effects of adjuvant therapy and the management strategies available to them, prior to starting therapy. The role of physical, alternative and pharmaceutical therapies in the management of adverse events associated with endocrine therapy has been investigated, and strategies are now available to alleviate symptoms and enable patients to benefit from adjuvant endocrine therapy without a significant adverse impact on quality of life.

A multidisciplinary approach to the management of breast cancer, part 2: therapeutic considerations

New approaches to breast cancer treatment have enhanced clinical outcomes and patient care. These approaches include advances in breast irradiation and hormonal and systemic adjuvant therapies. In addition to the identification of new drug targets and targeted therapeutics (eg, trastuzumab), there is renewed re-emphasis in the development of biomarkers for the prediction of response to therapy. One example is the pharmacogenetics of tamoxifen metabolism and the individualization of hormonal therapy. The current treatment of breast cancer continues to evolve rapidly, with new scientific and clinical achievements constantly changing the standard of care and leading to substantial reductions in breast cancer mortality. The goal of this article is to provide clinicians who care for women with breast cancer a multidisciplinary, state-of-the art approach to the treatment of these patients.

Cancer-associated bone disease

Patients with cancer are at risk for many events involving the skeleton, including metastatic disease of bone and treatment-related bone loss. Cancer-related therapies that can affect bone include hormonal therapy, chemotherapy, and the use of glucocorticoids. Screening for bone loss, with lifestyle modifications and the early use of anti-osteoporosis therapies such as bisphosphonates, may decrease bone loss and reduce the risk of fracture. This article reviews risk factors and mechanisms associated with cancer-related bone loss and metastases as well as strategies for the detection of bone-related complications of cancer and therapies to treat these complications. This article focuses on the more common cancers with adverse skeletal effects: breast cancer, prostate cancer, and multiple myeloma.

The breast cancer continuum in hormone-receptor-positive breast cancer in postmenopausal women: evolving management options focusing on aromatase inhibitors

There are now a number of highly effective options for the treatment of hormone-receptor-positive breast cancer. Although tamoxifen was the standard hormonal treatment for many years, we now have another option for postmenopausal women: the third-generation aromatase inhibitors (AIs) anastrozole, exemestane and letrozole. A number of trials have investigated the use of third-generation AIs compared with tamoxifen throughout the continuum of treatment settings for postmenopausal women with breast cancer. In the neoadjuvant setting, letrozole, given for 4 months, resulted in better overall clinical response and breast-conserving surgery rates than tamoxifen. The Immediate Preoperative Anastrozole Tamoxifen or Combined with Tamoxifen trial gave anastrozole for 3 months with no difference in clinical response but significantly improved breast-conserving surgery rates. Compared with tamoxifen, anastrozole and letrozole significantly improved disease-free survival as early adjuvant treatment for hormone-receptor-positive disease. Switching to anastrozole or exemestane after 2 to 3 years of adjuvant tamoxifen for a total of 5 years of therapy was also more effective than continued tamoxifen. All three agents are approved in the early adjuvant or switching setting in the USA. Letrozole following 5 years of tamoxifen as extended adjuvant treatment improved disease-free survival and, in the node-positive subgroup, overall survival when compared with placebo. Anastrozole and letrozole are both approved for the first-line treatment of hormone-sensitive advanced breast cancer in postmenopausal women; letrozole showed an improved response rate compared with tamoxifen. Anastrozole, letrozole and exemestane are all indicated for the second-line treatment of advanced breast cancer. In summary, third-generation AIs have been shown to have superior efficacy over tamoxifen in the metastatic, neoadjuvant and adjuvant settings and to improve outcome as extended adjuvant therapy following 5 years of tamoxifen. Ongoing studies will further define the role of sequential adjuvant treatment. Appropriate duration of treatment is another important area of investigation. This review will cover hormonal therapy for postmenopausal women with breast cancer and will not address the treatment of premenopausal women.

Bisphosphonates and osteonecrosis of the jaws: Science and rationale

Bisphosphonates as a group of drugs were introduced for the management of various conditions such as osteoporosis, Paget's disease, multiple myeloma, hypercalcemia of malignancy, breast cancer, prostate cancer, and other tumors. This group of drugs has improved the quality of life in many patients with proven efficacy in limiting pain and skeletal-related events. The controversy of osteonecrosis of the jaws and bisphosphonates is a recent and growing problem. Osteonecrosis of the jaws is recognized as a serious complication of bisphosphonate therapy, more commonly with the intravenous form of the drugs. However, there is limited scientific understanding about the association between osteonecrosis of the jaws and bisphosphonates. In the present article we discuss various mechanisms of action of bisphosphonates, the rationale for occurrence of osteonecrosis in the jaws, and treatment guidelines for the condition.

Computerized tomographic findings in bisphosphonate-associated osteonecrosis of the jaw in patients with cancer

OBJECTIVES

To study bisphosphonate-associated osteonecrosis of the jaw with respect to radiographic, demographic, and clinical features.

STUDY DESIGN

Thirty-two patients with painful exposed bone in the jaws subsequent to treatment with bisphosphonates for various neoplastic diseases were examined with both dental panoramic radiograph and multislice spiral computerized tomography (CT). Each case was assessed for the following radiologic signs: structural alteration of trabecular bone, cortical bone erosion, osteosclerosis, small sequestrum, extensive sequestrum, and presence of periosteal new bone. The McNemar, chi2, and Kruskall-Wallis tests were performed to analyze the association between radiologic signs, demographic data, clinical aspects of the lesion, and type and duration of bisphosphonate therapy. Hierarchical cluster analysis was used to group patients into categories on the basis of CT signs and dental panoramic radiograph signs. The agreement between CT and dental panoramic radiograph clusters was analyzed by kappa index.

RESULTS

Dental panoramic radiograph proved positive for features of osteonecrosis in 18 cases and CT in 30. Computerized tomography was far superior to dental panoramic radiograph in detecting all the radiologic signs. The cluster analysis applied to CT signs showed a classification of the 32 patients in 4 categories characterized by an increasing number of signs coherent with the clinical extension of the lesions. Structural alteration of trabecular bone and cortical bone erosion, a constant finding in the 30 positive CTs, could be sometimes differentiated only with difficulty from those due to recent extraction. Dental panoramic radiograph missed the correct diagnosis of sequestration in 15 cases. Intense periosteal reaction was often found. The most extensive maxillary lesions were associated with new bone formation in Schneider mucous membrane, never described previously, and oroantral communications.

CONCLUSIONS

Dental panoramic radiograph were found to be of limited use in assessing bisphosphonate-associated osteonecrosis of the jaw in patients for whom CT imaging was subsequently ordered.

The effects of medications on bone

Medications taken for the treatment of arthritis and psychotropic and epileptic disorders, as well as anticoagulants, antacids, bisphosphonates, corticosteroids, and antineoplastic drugs, can profoundly affect bone metabolism. In some scenarios (eg, osteoporosis), these effects are intended; in others (eg, rickets, osteomalacia secondary to antiepileptic drugs), potentially adverse side effects of medications on bone may occur. Nonsteroidal anti-inflammatory drugs appear to delay fracture healing and bone ingrowth, although these effects are reversible. Disease-modifying antirheumatic drugs do not appear to affect bone metabolism adversely when taken in the low dosages currently prescribed. Bisphosphonates are useful in restoring bone mass in cases of postmenopausal osteoporosis, glucocorticoid-induced osteoporosis, Paget's disease, and neoplastic conditions with bone loss and hypercalcemia. Corticosteroids and cancer chemotherapeutic agents generally affect bone adversely and increase fracture risk.