Long-term impact of chemotherapy-induced ovarian failure on bone mineral density (BMD) in premenopausal breast cancer patients. The effect of adjuvant clodronate treatment

Lack of evidence for fracture prevention in early breast cancer bisphosphonate trials: a meta-analysis

OBJECTIVES

Recent data suggest that fractures might affect quality of life and survival in early breast cancer patients. Bisphosphonates are effective in treatment and prevention of cancer treatment-induced bone loss, but their value in the prevention of fractures is still investigational. Our aim was to evaluate the fracture rate in breast cancer patients receiving adjuvant bisphosphonates compared with those receiving no treatment or placebo.

METHODS

Our study is a systematic review and meta-analysis of randomized clinical trials. Trials were located through PubMed, ISI, Cochrane Library and major cancer scientific meetings searches. We identified 21 potentially eligible trials. Of these, 14 studies reported fracture data and were included in the analyses. Overall, 7461 early breast cancer patients were randomized, 3691 received bisphosphonates and 3770 received either placebo or no treatment.

RESULTS

Adjuvant breast cancer treatment with bisphosphonates did not reduce the fracture rate compared to placebo or no use either in intent to treat analysis (12 trials, OR=0.99, 95% CI=0.73-1.34, p=0.932) and in comprehensive analysis (all 14 trials included, OR=0.84, 95% CI=0.65-1.09 p=0.197). Treatment with bisphosphonates was not beneficial in postmenopausal patients (7 trials, OR=0.82, 95% CI=0.55-1.20 p=0.298) and in patients receiving aromatase inhibitors (6 trials, OR=0.79, 95% CI=0.53-1.17 p=0.242).

CONCLUSION

Our meta-analysis provides substantial evidence that bisphosphonates in the adjuvant setting among women with breast cancer do not decrease the number of fractures compared with placebo or no treatment.

New results from the use of bisphosphonates in cancer patients

PURPOSE OF REVIEW

Metastatic bone disease results from cancer-bone cell interactions in the bone marrow microenvironment rather than direct destruction by cancer cells. Additionally, cancer treatments may have adverse effects on bone health. Therefore, a clear rationale exists for bone-targeted therapies to prevent skeletal complications and potentially modify the underlying disease.

RECENT FINDINGS

Studies in metastatic disease have focused on refining treatment, largely through the use of bone metabolism markers. Use of bisphosphonates in early cancer has become increasingly important to prevent bone loss. Recent results, notably with zoledronic acid, indicate that bone mineral density can be maintained and increased bone turnover normalized. Bisphosphonates are potent inhibitors of bone osteolysis and may impede both the development of bone metastases and survival of dormant cells in the marrow microenvironment. Additionally, bisphosphonates may have direct effects on tumour cells, especially in combination with chemotherapy. Clinical trial results in breast cancer with clodronate were inconclusive, but recent data with zoledronic acid suggest that bisphosphonates may indeed modify the course of the disease.

SUMMARY

The roles of bisphosphonates in metastatic bone disease and the prevention of cancer treatment induced bone loss have been defined. However, results from ongoing metastasis prevention trials are required before routine adjuvant bisphosphonates can be recommended.

Adjuvant bisphosphonates in endocrine-responsive breast cancer: what is their place in therapy?

Recent advances in the treatment of early breast cancer have improved clinical outcomes and prolonged survival, especially in women with endocrine-responsive disease. However, cancer therapies including cytotoxic chemotherapy, ovarian suppression, and aromatase inhibitors can drastically reduce circulating estrogen, increasing bone loss and fracture risk. Because most women with early breast cancer will live for many years, it is important to protect bone health during cancer therapy. Several recent clinical trials combining adjuvant endocrine therapy with bisphosphonates have demonstrated efficacy for preventing cancer treatment-induced bone loss in pre- and postmenopausal women with early breast cancer. The largest body of evidence supporting the use of adjuvant bisphosphonates comes from studies with zoledronic acid; however, studies with risedronate, ibandronate, and denosumab (a biologic agent) have also demonstrated efficacy for preventing bone loss. Adding zoledronic acid to endocrine therapy prevents bone loss and improves bone mineral density (BMD). In addition, preclinical studies suggest that bisphosphonates have direct and indirect antitumor activity, such as inducing tumor cell apoptosis, reducing tumor cell adhesion and invasion, reducing angiogenesis, activating immune responses, and synergy with chemotherapy agents, among others. Clinical trials have demonstrated significantly improved disease-free survival in patients receiving adjuvant endocrine therapy plus zoledronic acid compared with endocrine therapy alone. Ongoing studies will further define the role of adjuvant bisphosphonates in maintaining bone health and improving clinical outcomes. The available evidence suggests that pre- and postmenopausal patients may receive clinical benefit from including bisphosphonates as part of their adjuvant treatment regimen for endocrine-responsive early breast cancer.

The influence of chemotherapy on bone mineral density, quantitative ultrasonometry and bone turnover in pre-menopausal women with breast cancer

INTRODUCTION

The effects of doxorubicin/cyclophosphamide (A/C; 6 cycles) chemotherapy on bone mineral density (BMD), quantitative ultrasonography (QUS) and bone turnover markers in pre-menopausal women with oestrogen receptor-negative breast cancer (BC) were compared with age-matched controls.

METHODS

Among 106 women (BC=53, controls=53), BMD (spine and hip), QUS (calcaneus and phalanges) and bone marker levels were measured at baseline, 6 and 12 months. Correlations between parameters were determined by Spearman's rho.

RESULTS

All BC patients became amenorrhoeic after chemotherapy and remained so for the duration of treatment. BC patients had significant bone loss at all sites (P.005) and significant increases in bone turnover (P.05). There were significant correlations between BMD, QUS and bone markers (P.05).

CONCLUSIONS

Results confirm A/C's deleterious influence on bone health in pre-menopausal women with BC and established QUS's utility for monitoring bone effects. Large-scale longitudinal studies are needed to further understand and prevent bone changes following chemotherapy.

Adverse bone effects during pharmacological breast cancer therapy

The improved survival and cure rate of breast cancer patients leads to increased diagnosis of later occurring side effects to therapy such as osteoporosis. Conventional chemotherapies such as CMF and CEF are known to induce premature menopause, which increases bone loss but these therapies have additional detrimental effects on bone. The loss in bone mass during chemotherapy is substantial and may lead to increased fracture risk. The influence of taxanes on bone is less well known. Whereas tamoxifen has a slight protective effect on bone loss the opposite is true for aromatase inhibitors. Adverse effect reportings show, that adjuvant treatment with aromatase inhibitors in postmenopausal women increases the risk of clinical fractures as compared to tamoxifen. The Danish Bone Society suggests that all women with operable breast cancer have their fracture risk evaluated including a BMD measurement prior to initiation of adjuvant aromatase inhibitor therapy as a part of the standard examination program. If osteoporosis is diagnosed, anti-osteoporosis therapies should be considered. Moreover, all women undergoing adjuvant chemotherapy and endocrine therapy should be informed of the risk of bone loss and should receive life style advice of how to preserve bone. Adjuvant regimens in breast cancer patients improve survival and cure rates. Therefore it is preferable to use such therapies although they increase risk of side effects such as osteoporosis.

Treatment Options for Breast Cancer and Bone Metastases

The most common destination for breast cancer metastases is bone. If bone metastases are detected, treatment algorithms should include the continuation of cytoreductive therapy with the addition of treatment to counter skeletal-related events, including bone pain. The range of current treatment options includes bisphosphonates, surgical intervention to improve structural integrity and palliative focal radiotherapy. This article focuses on the role of bisphosphonate therapy in metastatic breast cancer. Bisphosphonate therapy significantly reduces the impact of skeletal-related events, reduces bone pain and increases patient quality of life. Our current understanding is that bisphosphonates may also disrupt the metastatic process and reduce the development of bone lesions. Ultimately, this may lead to further expansion of bisphosphonate-based therapy in the future.

The evolving role of zoledronic acid in early breast cancer

Most women with early breast cancer (BC) have an excellent prognosis and will remain disease-free for many years after treatment. However, bone-specific side effects of cancer therapies can have a negative effect on patients' long-term bone health. The accelerated bone loss associated with BC therapies, especially endocrine therapy, can put women at risk for osteoporosis and fractures later in life. Recent treatment guidelines have now begun to address the need for bone-preserving measures to be included in adjuvant therapy regimens. Bisphosphonates have long been used to treat osteoporosis, as well as bone metastases in patients with advanced cancers. Furthermore, in the adjuvant BC setting, the intravenous bisphosphonate zoledronic acid has emerged to play an important role. Several large, randomized phase III trials involving a total of approximately 4,000 premenopausal and postmenopausal women with early BC demonstrated the bone-protective effects of adjuvant zoledronic acid (4 mg every 6 months). Additionally, these same trials also showed significant improvement in disease-free survival for patients receiving adjuvant endocrine therapy plus zoledronic acid that was over and above the benefit achieved with endocrine therapy alone. The results of these zoledronic acid trials will be reviewed herein, and evidence supporting the antitumor effects of adjuvant zoledronic acid will be discussed.

Cancer treatment-induced bone loss in breast and prostate cancer

PURPOSE

Bone loss resulting from the treatment of breast and prostate cancer is an emerging problem. Bisphosphonates have a potential role in the prevention of this cancer treatment-induced bone loss (CTIBL).

METHODS

Studies evaluating the incidence and prevalence of CTIBL in early breast and prostate cancer patients and trials evaluating the preventative role of bisphosphonates were identified by a search of the PubMed and Cochrane Library databases through the end of March 2008. Reference lists from retrieved articles were cross referenced, and further information was obtained from relevant scientific meetings.

RESULTS

Several therapies commonly used in the treatment of women and men with breast and prostate cancers, in particular the aromatase inhibitors (AIs) for breast cancer and androgen deprivation therapy (ADT) for prostate cancer, are associated with significant bone loss and with an increase in fracture risk. The use of bisphosphonates seems to attenuate the bone loss, although the long-term impact remains unclear because of insufficient follow-up.

CONCLUSION

Adjuvant endocrine therapy with an AI or androgen deprivation can be considered a risk factor for the development of osteopenia, osteoporosis, and bone fracture, which can be mitigated by appropriate bisphosphonate therapy. Clear identification of risk factors for osteoporosis in individual patients should aid treatment decisions about whether to use bisphosphonates when starting or switching to an AI or ADT. Patients need to be educated about this risk and other measures to avoid this complication, including lifestyle modifications that may benefit their general and bone health.

Ten-year follow-up of 3 years of oral adjuvant clodronate therapy shows significant prevention of osteoporosis in early-stage breast cancer

PURPOSE

We have previously reported that 3-year adjuvant clodronate treatment prevents bone loss in breast cancer patients. Here we report the 10-year follow-up data of clodronate in the prevention of treatment-related osteoporosis in women with early-stage breast cancer.

PATIENTS AND METHODS

Two hundred sixty-eight pre- and postmenopausal, node-positive breast cancer patients were randomly assigned to clodronate, 1.6 g orally administered daily, or to control groups for 3 years. Premenopausal women were treated with adjuvant CMF chemotherapy; and postmenopausal women were treated with antiestrogens, either 20 mg tamoxifen or 60 mg toremifene, for 3 years. The bone mineral density (BMD) of the lumbar spine and hip was measured before treatment and at 1, 2, 3, 5, and 10 years after therapy.

RESULTS

Eighty-nine disease-free patients were included in the analyses of osteoporosis-free survival. During the 10-year period, 24 of 89 patients were diagnosed with osteoporosis. Fourteen patients developed spinal osteoporosis (three of 41 in the clodronate group, and 11 of 48 in the control group), and 14 of 89 patients were diagnosed with hip osteoporosis (seven of 41 in the clodronate group, and seven of 48 in the control group). The 10-year spinal, osteoporosis-free survival rate was 92.7% in the clodronate group, and 77.0% in the control group (P = .035). No difference was seen in the frequency of hip osteoporosis (85.4% v 82.9%; P = .92). Baseline BMD measurement had a predictive value of 18 of 24 patients (75%) who developed osteoporosis had osteopenia of the lumbar spine at baseline.

CONCLUSION

Three years of clodronate therapy significantly reduces the incidence of lumbar spine osteoporosis. Patients at risk of developing osteoporosis are among those who have pretreatment osteopenia, that is, baseline BMD measurement has predictive value.

Bone mineral density and bone turnover in postmenopausal women treated for breast cancer

Chemotherapy and endocrine treatments for breast cancer are believed to increase risk of osteoporosis by causing early menopause in premenopausal women and by further depleting estrogen levels in postmenopausal women. Multivariate analyses were used to evaluate the contributions of 7 predictors (age, body mass index [BMI], family history of osteoporosis, months since menopause, past use of chemotherapy, and current use of tamoxifen or aromatase inhibitors) in explaining variability in bone mineral density (BMD) at the hip and the spine and bone turnover in 249 postmenopausal women who are breast cancer survivors. This report was an analysis of baseline data from a federally funded (1 R01 NR07743-01A1) intervention study on osteoporosis prevention. Mean age of the women was 58.5 years, and average BMI was 26.7 kg/m; 98% were white. All had measurable bone loss, 167 had chemotherapy, 76 were on tamoxifen, and 21 were on aromatase inhibitors. Women with higher BMI had higher BMD at the hip (P < .001) and the spine (P = .004). Women on tamoxifen had lower measures of bone formation (Alkphase B) (P < .001), suggesting less bone turnover, and higher BMD at the hip (P = .035). There was a trend for women who had received chemotherapy to have lower BMD at the spine (P = .06). The implications of these findings are discussed in the article.

Cancer treatment-induced bone loss: pathophysiology and clinical perspectives

Hormone-ablative therapies for breast or prostate cancer can cause marked and rapid reductions in circulating estrogen or testosterone levels, resulting in significant effects on bone metabolism and cancer treatment-induced bone loss (CTIBL). Most patients with cancer are over the age of 65 and are already at risk for osteoporosis. Thus, accelerated bone loss from CTIBL is especially concerning in this population. Although there are currently no approved therapies for the treatment or prevention of CTIBL, oral bisphosphonates have been used in settings other than oncology to treat bone loss. New-generation i.v. bisphosphonates have demonstrated promising activity in preventing CTIBL in patients receiving hormonal therapy for breast or prostate cancer. In particular, zoledronic acid not only prevents CTIBL in both breast and prostate cancer patients but also increases bone mineral density above baseline. Such agents have the potential to delay or prevent CTIBL in patients receiving hormonal therapies.

Risedronate prevents bone loss in breast cancer survivors: a 2-year, randomized, double-blind, placebo-controlled clinical trial

PURPOSE

Limited data are available on the efficacy of oral bisphosphonate therapy in breast cancer survivors. Our goal was to examine prevention of breast cancer-related bone loss in this cohort.

PATIENTS AND METHODS

Eighty-seven postmenopausal women after chemotherapy for breast cancer were randomly assigned to once-weekly risedronate 35 mg or placebo for 24 months. Outcomes included bone mineral density (BMD) and turnover markers.

RESULTS

At study initiation, 13% of patients were on an aromatase inhibitor (AI). After 24 months, there were differences of 1.6 to 2.5% (P < .05) at the spine and hip BMD between the placebo and risedronate groups. At study completion, 44% were on an AI. Adjusting for an AI, women on placebo plus AI had a decrease in BMD of (mean +/- SE) 4.8% +/- 0.8% at the spine and 2.8% +/- 0.5% at the total hip (both P < .001). In women on risedronate + AI, the spine decreased by 2.4% +/- 1.1% (P < .05) and was stable at the hip. Women in the placebo group not on an AI, maintained BMD at the spine, and had a 1.2% +/- 0.5% loss at the total hip (P < .05). Women who received risedronate but no AI had the greatest improvement in BMD of 2.2% +/- 0.9% (P < .05) at the total hip. Bone turnover was reduced with risedronate. There were no differences in adverse events between the groups.

CONCLUSION

We conclude that in postmenopausal women with breast cancer with or without AI therapy, once-weekly oral risedronate was beneficial for spine and hip BMD, reduced bone turnover, and was well tolerated.

[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.

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.

Bisphosphonates for Breast Cancer: Questions Answered, Questions Remaining

Bone is an important organ that is essential to adult hematopoiesis, electrolyte balance, and locomotion. Individuals who have metastatic breast cancer involving the bone are at increased risk for skeletal complications and those who have a history of early-stage breast cancer may be at increased risk for fragility fractures. Maintaining bone integrity is critical to control the morbidity and mortality associated with fractures and other skeletal complications. The bisphosphonates have been shown to be efficacious in decreasing the risk for skeletal complications in cancer and in osteoporosis. The article reviews the use of bisphosphonates in patients who have breast cancer.

Endocrine Effects of Breast Cancer Treatment

OBJECTIVES

To discuss long-term physical effects of treatment for breast cancer including effects on reproductive, bone, sexual health, and related women's issues.

DATA SOURCES

Research articles, abstracts, literature reviews.

CONCLUSION

Long-term effects of treatment have become increasingly prevalent in breast cancer survivors. The most common are effects on reproductive, bone, and sexual health.

IMPLICATIONS FOR NURSING PRACTICE

Long-term effects of treatment can have a significant negative impact on the long-term health and QOL of women with breast cancer. Oncology nurses are well-positioned to anticipate and address the reproductive and endocrine consequences of breast cancer treatment.

Prevention of bone loss in survivors of breast cancer: A randomized, double-blind, placebo-controlled clinical trial

BACKGROUND

Few data are available on the safety and efficacy of once-weekly oral bisphosphonate therapy in breast cancer survivors.

OBJECTIVE

Our objective was to determine whether risedronate, 35 mg weekly, is efficacious and safe in preventing bone loss associated with chemotherapy-induced menopause.

DESIGN

The study was a randomized, double-blind, placebo-controlled clinical trial over 12 months.

SETTING AND PARTICIPANTS

Participants included 87 newly postmenopausal women with status post chemotherapy, recruited from a breast cancer clinic in an academic medical center.

INTERVENTION

Participants were randomly assigned to receive risedronate 35 mg/wk or placebo.

MAIN OUTCOME MEASURES

The primary outcomes were the 12-month changes in spine and hip bone mineral density. Secondary outcomes included changes in markers of bone resorption (urine N-telopeptide cross-linked collagen type I) and formation (osteocalcin, N-terminal propeptide of type I procollagen, and bone-specific alkaline phosphatase).

RESULTS

After 12 months, bone mineral density increased by 1.2% at the spine and 1.3% at the hip in women on risedronate vs. significant decreases for women in the placebo group of 0.9% at the spine and 0.8% at the hip (P < 0.01, difference between groups). N-telopeptide cross-linked collagen type I, a marker of bone resorption, decreased by 19.3%, and N-terminal propeptide of type I procollagen, a marker of bone formation, decreased by 26.6% in participants on active therapy compared with increases in the control group. Risedronate was well tolerated, and the retention rate was 95% at 1 yr.

CONCLUSIONS

Risedronate once weekly prevented bone loss and reduced bone turnover in women with breast cancer treated with chemotherapy. Early measures to prevent bone loss should be considered in this cohort of breast cancer survivors.

Skeletal complications of breast cancer therapies

Nonsurgical treatment options, such as hormonal therapy, chemotherapy, radiation, and bisphosphonate therapy, are undoubtedly improving outcomes for women with breast cancer; however, these therapies also carry significant skeletal side effects. For example, adjuvant hormonal treatments, such as aromatase inhibitors that disrupt the estrogen-skeleton axis, have the potential to cause decreased bone mineral density. Similarly, chemotherapy often induces primary ovarian failure in premenopausal women, resulting in decreased levels of circulating estrogen and subsequent osteopenia. In both cases, women receiving these therapies are at an increased risk for the development of osteoporosis and skeletal fracture. Furthermore, women undergoing radiation therapy to the upper body may have an increased incidence of rib fracture, and those receiving bisphosphonates may be vulnerable to the development of osteonecrosis of the jaw. Therefore, women with breast cancer who are undergoing any of these therapies should be closely monitored for bone mineral loss and advised of skeletal health maintenance strategies.

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.

Tamoxifen treatment after adjuvant chemotherapy has opposite effects on bone mineral density in premenopausal patients depending on menstrual status

PURPOSE

Adjuvant chemotherapy followed by tamoxifen is a standard treatment option for women with intermediate or high-risk hormone receptor-positive breast cancer. Premenopausal women treated with chemotherapy often develop early menopause and thus, enter a period of accelerated bone loss. We conducted a prospective study of the effect of sequential adjuvant therapy with chemotherapy followed by tamoxifen on bone mineral density (BMD) in premenopausal patients.

PATIENTS AND METHODS

One hundred eleven premenopausal women with early breast cancer were treated with adjuvant chemotherapy. Patients with hormone receptor-positive tumors went on to tamoxifen 6 months after the beginning of the chemotherapy (tamoxifen group), while those with hormone receptor-negative tumors received no further therapy (control group). The effect of tamoxifen and menstrual status on BMD was studied.

RESULTS

Tamoxifen treatment and menopausal status correlated significantly with the changes in lumbar spine BMD (P < .0001). A significant bone loss was noted in those tamoxifen-treated patients who continued to menstruate after chemotherapy. At 3 years of follow-up, menstruating patients on tamoxifen had lost -4.6% of their baseline BMD values, while a modest gain of +0.6% was noted in the control group. In contrast, bone loss was reduced among tamoxifen-treated women as compared with controls in patients who developed chemotherapy-induced early menopause. In amenorrheic patients, the lumbar spine BMD values decreased -6.8% in tamoxifen users and -9.5% in the controls, respectively.

CONCLUSION

We conclude that tamoxifen usage was associated with bone loss in patients who continued to menstruate after adjuvant chemotherapy. On the contrary, tamoxifen decreased bone loss in those women who developed chemotherapy-induced amenorrhea.

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.

Bisphosphonates as adjuvant therapy for breast cancer

Great strides have been made over the last 20 years in the treatment of breast cancer and despite an increasing incidence, the number of deaths has fallen sharply since the late 1980s. The advent of new therapies, including taxanes and aromatase inhibitors, and exciting results announced recently using trastuzumab in the adjuvant treatment of HER2-positive patients should decrease this even further. However, although most patients present with disease that appears to be localized to the breast, a significant proportion of women will eventually develop metastatic breast cancer. Therefore, the detection and treatment of micrometastatic disease represents perhaps the most important remaining challenge in breast cancer management, and is the focus of extensive ongoing research. Bone is the most frequent site of distant relapse, accounting for approximately 40% of all first recurrences. In addition to the well recognized release of bone cell-activating factors from the tumor, it is now appreciated that the release of bone-derived growth factors and cytokines from resorbing bone can attract cancer cells to the bone surface and facilitate their growth and proliferation. Bisphosphonates are potent inhibitors of bone osteolysis and the inhibition of bone resorption could therefore have an effect on the development and progression of metastatic bone disease. They could represent an adjuvant therapeutic strategy of potential importance. Clinical trial results with the early bisphosphonate, clodronate, have proved inconclusive. A large, randomized, controlled trial has recently completed accrual and should provide the definitive answer to the question of the role of clodronate in this setting. More potent second- and third-generation bisphosphonates have also shown enhanced antitumor effects in preclinical evaluation and further studies are required to determine whether this antitumor potential of bisphosphonates translates to the clinical setting. Adjuvant bisphosphonates are, therefore, currently only recommended in the research setting and clinical trials evaluating the adjuvant use of these newer compounds are currently recruiting or being established. This article will review in more detail the rationale for the adjuvant use of bisphosphonates, the results of early trials, the progress of the later trials and the potential future role of bisphosphonates in the adjuvant treatment of breast cancer. In addition, it is increasingly acknowledged that many cancer treatments have detrimental effects on bone and can increase the risk of fracture. The increasing use of aromatase inhibitors, in particular, will become a major cause of treatment-induced bone loss. This bone loss can be prevented with bisphosphonate treatment and this will also be discussed.

Bone loss and the aromatase inhibitors

The increasing use of systemic adjuvant therapies has considerably improved the prognosis from early breast cancer. However, some of these therapies affect bone metabolism, resulting in osteoporosis. Aromatase inhibitors lower circulating oestrogen levels to almost unrecordable levels in postmenopausal women, predisposing them to bone loss with an increase in fracture risk. Ongoing clinical trials are favouring the use of the aromatase inhibitors over tamoxifen and this may advocate greater use of these drugs in the future. Strategies for the identification and management of treatment-induced bone loss are currently being defined.

Changes on Bone Mineral Density after Adjuvant Treatment in Women with Non-metastatic Breast Cancer

PURPOSE

. Adjuvant therapies have prolonged survival of non-metastatic breast cancer (NMBC) patients, but they also decrease bone mineral density (BMD). We have analyzed the effects of chemotherapy, hormone therapy with tamoxifen or both, on BMD of women with NMBC.

PATIENTS AND METHODS

We prospectively included 168 women with NMBC (stage I-III) referred to the Medical Oncology Service of University Hospital of Canary Islands between 1997 and 2001 (55 +/- 12 years; 37% premenopausal; 43 +/- 13 months of follow-up). We measured lumbar and hip BMD (g/cm2) at diagnosis, after chemotherapy and after 12 months of tamoxifen. If a low BMD was detected, women were treated with bisphosphonates.

RESULTS

BMD after chemotherapy (n = 83) significantly decreased at lumbar (1.014 +/- 0; 0.995 +/- 0, p = 0.0001), trochanter (0.701 +/- 0; 0.690 +/- 0, p = 0.001), intertrochanter (1.095 +/- 0; 1.078 +/- 0, p = 0.0001) and total hip (0.924 +/- 0; 0.915 +/- 0, p = 0.046) areas. Although 60% of the premenopausal women suffered amenorrhea after chemotherapy, there were not significant differences in BMD between them and women who retained menses. BMD of women who received 12 months of tamoxifen after chemotherapy increased--total hip (0.907 +/- 0; 0.922 +/- 0, p = 0.005) and intertrochanter (1.071 +/- 0; 1.091 +/- 0, p = 0.003)--or remained stable--lumbar, femoral neck, trochanter, and Ward's triangle (n = 39). When tamoxifen was the only adjuvant treatment, BMD after 12 months (n = 22) increased in trochanter area (0.644 +/- 0; 0.663 +/- 0, p = 0.011), and remained stable in all other sites. 50 (30%) patients were treated with bisphosphonates because of osteopenia.

CONCLUSION

Women with NMBC are affected by early bone loss after adjuvant chemotherapy. This bone loss is attenuated by one year of tamoxifen treatment.

Three-year oral clodronate treatment does not impair mineralization of newly formed bone--a histomorphometric study

Bisphosphonates have been used successfully in the treatment of malignant hypercalcemia and skeletal metastases. Recently, clodronate has been studied in adjuvant settings in primary breast cancer. However, long-term effect of adjuvant clodronate on bone histology has not been reported, whereas bone mineral density studies have been published. The aim of this study was to examine the effect and safety of long-term clodronate treatment on bone quality as measured by histomorphometric techniques from bone biopsies. A total of 299 patients with early stage breast cancer were randomized to receive adjuvant oral clodronate (1.6 g/day) or to a control group for 3 years. All patients had adjuvant treatment: premenopausal women had six cycles of chemotherapy and postmenopausal women had antiestrogen for 3 years. Trabecular bone quality was examined in transiliac bone biopsy specimens by using histomorphometric techniques in 28 clodronate treated and 35 control patients who were disease-free at 3 years and who allowed the biopsy specimen to be obtained. No statistically significant differences were found in the values of osteoid, mineral apposition rate, or mineralization lag time in bone biopsies between the clodronate and the control groups. Postmenopausal women who received two antiresorptive drugs, antiestrogen and clodronate, developed features of secondary hyperparathyroidism with increased eroded surface and osteoclast number. In premenopausal, women clodronate with adjuvant chemotherapy, which induced early menopause and rapid bone loss in most of the patients, seemed to conduct slight depression in bone formation. Three-year oral clodronate treatment does not impair mineralization of newly formed bone: however, clodronate with different adjuvant breast cancer treatments has a diverse impact on bone histomorphometry depending on the type of therapy.

Approaches to managing bone metastases from breast cancer: The role of bisphosphonates

Conventional management of metastatic bone disease involves local and systemic therapies in various combinations, along with symptomatic management to provide optimal care. In recent years, it has become clear that adding bisphosphonates to these treatments reduces the incidence and severity of skeletal complications. Bisphosphonates can also relieve metastatic bone pain and improve quality of life, although the extent to which they have demonstrated these effects may differ between agents. While bisphosphonates are the standard of care for the treatment of bone metastases, clinical trials are investigating additional indications for these agents, including the use of intensive dosing regimens for the relief of severe or opioid-resistant metastatic bone pain and adjuvant treatment for the prevention of bone metastases and cancer treatment-induced bone loss. Current and future indications demand effective, well-tolerated and convenient bisphosphonates, and the benefits of different drugs must be balanced against their limitations. The cost-effectiveness of bisphosphonate treatment is also a consideration, given the high economic burden of metastatic bone disease from breast cancer.

Strategies to Prevent Chemotherapy-Induced Bone Loss in Women with Breast Cancer

Treatment-induced osteoporosis is an increasing problem for women diagnosed with breast cancer. As more women receive adjuvant endocrine therapy and chemotherapy, and breast cancer survival improves, the impact of cancer treatment on bone health and the morbidity associated with chemotherapy-induced bone loss becomes more of a significant medical concern. Endocrine agents like aromatase inhibitors and luteinizing hormone-releasing hormone agonists decrease the production of ovarian and adrenal estrogens and are widely used in the adjuvant and metastatic settings for treatment of women with hormone receptor-positive breast cancer. Estrogen is important for bone health. It stimulates osteoblasts and maintains bone integrity. As bone density decreases, the risk of fracture increases. This can include fractures of the wrist, femur, and vertebrae. Several potent bisphosphonates have been developed to prevent or treat cancer treatment-induced bone loss.

Bone mineral density and adjuvant therapy in breast cancer survivors

Compared to mean values from a US database, premenopausal breast cancer survivors (BCS) had significantly higher whole body bone mineral density (BMD) compared to age and ethnicity matched referents; higher whole body BMD was present in all premenopausal BCS, including those who received chemotherapy, tamoxifen+chemotherapy, or no adjuvant therapy. Postmenopausal BCS who had received no adjuvant therapy also had higher whole body BMD compared to similarly aged women. In contrast, hip and lumbar spine BMD values in BCS were similar to those of the population-based database.

Perspectives on the future of bisphosphonate use in breast cancer patients

Bisphosphonates are effective for reducing the skeletal complications of metastatic breast cancer. Current treatment guidelines tend to recommend starting bisphosphonates at the time of diagnosis of bone metastases and continuing indefinitely or until the patients' performance status declines substantially. While meta-analyses of clinical trials have suggested that treatment should continue for at least 6 months to reduce skeletal-related events, few data exist on alternative strategies to optimize therapy. Other indications for bisphosphonates in the management of breast cancer include managing reduced bone mineral density in patients with early stage disease. In addition, because of considerable preclinical and clinical evidence that they may have direct antitumor actions, bisphosphonates are being tested as adjuvant therapy for early stage breast cancer in a number of large clinical trials.

Short-Term Intermittent Intravenous Clodronate in the Prevention of Bone Loss Related to Chemotherapy-Induced Ovarian Failure

Chemotherapy-induced ovarian failure causes rapid bone loss in premenopausal women with early breast cancer. The aim of the present study was to investigate the effect of intravenous intermittent clodronate during adjuvant chemotherapy in prevention of this rapid bone loss. 45 premenopausal women with early stage breast cancer were treated with adjuvant chemotherapy. In addition, all women were randomly allocated to receive either seven cycles of intravenous clodronate infusions (1500 mg each) parallel to the chemotherapy or no further therapy. The mean bone loss in the lumbar spine at 6 months was -0.5% in the clodronate group and -1.4% in the control group (p = 0.22) and, at 12 months, -3.9% and -3.6%, respectively (p = 0.62). Type I collagen metabolite PINP levels at six months were significantly lower in the clodronate group than in the control group: 22.6 microg/l (range 15.7-55.8 microg/l) and 44.0 microg/l (range 12.5-91.9 microg/l), respectively (p = 0.0001). At 12 months, no difference between the PINP levels in clodronate and control groups were seen. In conclusion, in this small study a short-term intermittent intravenous clodronate treatment did not seem to prevent clinically significantly the bone loss related to chemotherapy-induced ovarian failure in premenopausal women with early stage breast cancer, even though a significant reduction of a biochemical marker of bone turnover (PINP) was seen during the therapy.

Managing cancer-related skeletal events with bisphosphonates

Bone metastases cause considerable morbidity. This article discusses the benefits of bisphosphonates, which are now well established in the treatment of skeletal complications across a wide range of tumour types.

Osteopenia and osteoporosis in women with breast cancer

Osteopenia and osteoporosis are prevalent in women. Epidemiologic studies show that the risk of breast cancer is greater in postmenopausal women with higher bone mineral density (BMD). Standard treatments for breast cancer such as adjuvant chemotherapy or hormonal therapy can increase bone loss, and hence may increase the risk of osteoporosis. Premenopausal women treated with standard adjuvant chemotherapy frequently develop permanent ovarian failure, or early menopause. Ovarian failure is associated with accelerated bone loss, and bisphosphonates may mitigate this bone loss in women treated with adjuvant chemotherapy. Tamoxifen preserves BMD in postmenopausal women; however, in premenopausal women tamoxifen may increase bone loss. Anastrazole, an aromatase inhibitor, is approved for adjuvant treatment of postmenopausal women with early-stage, estrogen receptor-positive breast cancer. With a follow-up duration of less than 5 years, anastrazole-treated women experience increased fractures relative to those treated with tamoxifen. The management of osteopenia and osteoporosis in women with breast cancer generally does not differ from women without breast cancer. Adequate dietary calcium and vitamin D intake, encouraging weight-bearing exercise, and counseling about the relationship between smoking and alcohol and bone loss are all prudent recommendations for overall health and may lessen bone loss and the risk of subsequent osteoporosis. BMD should be measured in women with chemotherapy-induced ovarian failure, and in those on aromatase inhibitors. Bisphosphonates reduce the bone loss associated with chemotherapy-induced ovarian failure, and clinical trials evaluating third-generation bisphosphonates in women with chemotherapy-induced ovarian failure are underway. As many women with breast cancer will be long-term survivors, increasing recognition of maintaining skeletal health is important.

A case of gonadal dysgenesis, breast development, Graves' disease, and low bone mass

OBJECTIVE

To describe a case of XY gonadal dysgenesis with Tanner stage 4 breast development in the absence of a hormone-producing gonadal neoplasm and with Graves' disease and low bone mass.

METHODS

The clinical features, laboratory results, and cytogenetic findings in the patient are presented, and the potential mechanisms of breast development are discussed. A MEDLINE search was performed, and related articles in the English-language literature published between 1955 and 2001 were reviewed.

RESULTS

A 23-year-old African American woman was referred to the University of Louisville Hospital for evaluation of hyperthyroidism. About 4 months before this referral, hyperthyroidism was diagnosed, and treatment with methimazole was initiated. She continued to have thyrotoxicosis. Additionally, systemic review disclosed a history of primary amenorrhea. Physical examination revealed a tall phenotypic female patient with Tanner stage 4 breast development. Pelvic examination showed normal findings except for sparse pubic hair. Laboratory evaluation confirmed the diagnosis of Graves' disease as well as primary gonadal failure. Pelvic ultrasonography revealed a small uterus and bilateral adnexal masses (0.9 by 0.6 cm). On chromosomal analysis, a 46,XY karyotype was found. Further analysis of Y-DNA by polymerase chain reaction confirmed the presence of an intact Y chromosome, and no microdeletions were identified. Dual-energy x-ray absorptiometry demonstrated a Z-score of -4.7 and -4.2 at the lumbar spine and right hip, respectively. Graves' disease was successfully treated with (131)I. Laparoscopy was performed to resect streak gonads. On histologic examination, no typical ovarian, testicular, or neoplastic tissue was identified. The breast development in this patient remains unexplained.

CONCLUSION

To the best of our knowledge, this is the first case report of a tall XY female patient with breast development in the absence of a hormone-producing gonadal neoplasm and without clearly identifiable gonads. Breast development was most likely related to estrogens, possibly produced by either streak gonads at the time of puberty or peripheral conversion of androgens, or to increased sensitivity of breast tissue to estrogens. Graves' disease is likely coincidental and could contribute to bone loss in such subjects.