Osteoporosis due to cancer treatment: pathogenesis and management

Women's health, breast health: a review of the gynecologic effects of breast cancer

Breast cancer is very common and seen in both premenopausal and postmenopausal women. Research into prevention, better screening, and more effective treatments is occurring continually, and changes are translated into clinical practice relatively quickly. It is important for women's health care providers to have an understanding of breast cancer treatments and the gynecologic side effects. For premenopausal women interested in fertility, options should be discussed prior to chemotherapy. Issues pertaining to pregnancy after breast cancer should be discussed in a multidisciplinary fashion, involving the obstetrician/gynecologist, breast surgeon, and oncologist. Ovarian suppression is often used as part of breast cancer treatment in premenopausal women with hormone positive disease, and menopausal symptoms may be severe. Hormonal therapies including tamoxifen and the aromatase inhibitors are used in the treatment of hormone positive breast cancers. Each of these drugs has a variety of gynecologic implications. Understanding the options for treatment for menopausal complaints in breast cancer patients is important for women's health providers. Although most breast cancers are sporadic, a small percentage will be due to mutations in the BRCA genes. It is important for women's health providers to take an appropriate family history and refer to genetic counselors for possible testing when hereditary cancer is suspected. This review focuses on the various women's health issues pertaining to breast cancer and treatment.

Long-term follow-up of testicular cancer patients shows no predisposition to osteoporosis

Most patients with testis cancer are cured with treatment. However, the incidence of osteoporosis after prolonged follow-up is unknown. This study investigates the incidence of osteoporosis in 39 testis cancer patients with follow-up from 5 to 28 years. There was no increased incidence of osteoporosis. These initial data are reassuring but require further investigation.

INTRODUCTION

The majority of patients with testis cancer are cured with either a unilateral orchidectomy alone or orchidectomy and chemotherapy. However, the long-term incidence of osteoporosis following treatment for testicular cancer has not been established.

METHOD

This was a single-centre cross-sectional study, where bone mineral density (BMD) measurements were performed in male patients who were previously treated for testicular cancer. BMD measurements were made by dual-energy X-ray scanning (DXA) using a HOLOGIC imaging bone densitometer. The World Health Organisation criteria were used to define osteoporosis and osteopenia. Blood samples were taken from each patient at the time of the DXA scan. Statistical analyses were performed in STATA10.

RESULTS

Neither orchidectomy alone nor orchidectomy and chemotherapy together predisposed to osteoporosis [p value = 0.4 (95%CI -0.1-0.8) and p value = 0.2 (95%CI -0.2-0.7), respectively]. Analysis also showed no evidence of an association between cases of osteopenia and length of follow-up (assessed by logistic regression).

CONCLUSION

This work found no association between treatment for testis cancer and the development of osteoporosis. Screening the whole population of testis cancer survivors for osteoporosis in the long term is not necessary; however, targeting specific patients with risk factors may be warranted.

An osteoporotic hip fracture in a 14-year-old girl undergoing chemotherapy and operated for knee osteosarcoma

Non-weight-bearing, pre- and postsurgical immobilization, neoadjuvant and adjuvant chemotherapy are known to act on bone turnover, causing osteoporosis over short and long time periods. Treatment of fracture insurgence is very difficult because it really depends on being able to choose the right time (i.e., when immunodeficiency is less important). We report a case of spontaneous neck femur fracture during adjuvant chemotherapy in a young girl treated with resection and prosthesis reconstruction for distal femur osteosarcoma. Possible prevention and the correct approach and surgical timing are emphasized considering immunodeficiency following chemotherapy.

Markers of bone metabolism in women receiving aromatase inhibitors for early-stage breast cancer

The aromatase inhibitors have been widely incorporated into the adjuvant breast cancer care of postmenopausal women with estrogen and/or progesterone receptor-positive breast cancer. Aromatase inhibitor use is associated with an increased risk of lowering bone mineral density and accelerating the risk of fragility fractures. Optimizing bone health includes appropriate nutrition and exercise, as well as screening for and treatment of low bone mass. Assessment of an individual's risk of fracture typically includes measuring the bone mineral density and other clinical risk factors, and there are evolving data as to the potential added information obtained by measuring biochemical markers of bone metabolism.

Denosumab treatment of prostate cancer with bone metastases and increased urine N-telopeptide levels after therapy with intravenous bisphosphonates: results of a randomized phase II trial

PURPOSE

Patients with bone metastases have high rates of RANKL driven bone resorption and an increased risk of skeletal morbidity. Osteoclast mediated bone resorption can be assessed by measuring urine N-telopeptide and can be inhibited by denosumab, a fully human antibody against RANKL.

MATERIALS AND METHODS

Eligible patients (111) had bone metastases from prostate cancer, other solid tumors or multiple myeloma, 1 or more bone lesions and urine N-telopeptide greater than 50 nM bone collagen equivalents per mM creatinine (urine N-telopeptide greater than 50) despite the use of intravenous bisphosphonates. Patients were stratified by cancer type and screening urine N-telopeptide, and randomized to continue intravenous bisphosphonates every 4 weeks or receive 180 mg subcutaneous denosumab every 4 weeks or 180 mg every 12 weeks. The primary end point was the proportion of patients with urine N-telopeptide less than 50 at week 13. We report the efficacy results for the subset of patients with prostate cancer.

RESULTS

Patients with prostate cancer represented 45% (50 of 111) of the study population. At week 13, 22 of 32 (69%) patients in the denosumab arms had urine N-telopeptide less than 50 vs 3 of 16 (19%) in the intravenous bisphosphonates cohort. At week 25, 22 of 32 (69%) denosumab treated patients continued to have urine N-telopeptide less than 50 vs 5 of 16 (31%) treated with intravenous bisphosphonates. Grade 4, asymptomatic, reversible hypophosphatemia, possibly related to denosumab, was reported in 1 patient.

CONCLUSIONS

In patients with prostate cancer related bone metastases and increased urine N-telopeptide despite intravenous bisphosphonate treatment, denosumab normalized urine N-telopeptide levels more frequently than ongoing intravenous bisphosphonates.

NCCN Task Force Report: Bone Health in Cancer Care

Bone health and maintenance of bone integrity are important components of comprehensive cancer care in both early and late stages of disease. Risk factors for osteoporosis are increased in patients with cancer, including women with chemotherapy-induced ovarian failure, those treated with aromatase inhibitors for breast cancer, men receiving androgen-deprivation therapy for prostate cancer, and patients undergoing glucocorticoid therapy. The skeleton is a common site of metastatic cancer recurrence, and skeletal-related events are the cause of significant morbidity. The National Comprehensive Cancer Network (NCCN) convened a multidisciplinary task force on Bone Health in Cancer Care to discuss the progress made in identifying effective screening and therapeutic options for management of treatment-related bone loss; understanding the factors that result in bone metastases; managing skeletal metastases; and evolving strategies to reduce bone recurrences. This report summarizes presentations made at the meeting.

Skeletal sequelae of cancer and cancer treatment

INTRODUCTION

Survivors of cancer may experience lingering adverse skeletal effects such as osteoporosis and osteomalacia. Skeletal disorders are often associated with advancing age, but these effects can be exacerbated by exposure to cancer and its treatment. This review will explore the cancer and cancer treatment-related causes of skeletal disorders.

METHODS

We performed a comprehensive search, using various Internet-based medical search engines such as PubMed, Medline Plus, Scopus, and Google Scholar, for published articles on the skeletal effects of cancer and cancer therapies.

RESULTS

One-hundred-forty-two publications, including journal articles, books, and book chapters, met the inclusion criteria. They included case reports, literature reviews, systematic analyses, and cohort reports. Skeletal effects resulting from cancer and cancer therapies, including hypogonadism, androgen deprivation therapy, estrogen suppression, glucocorticoids/corticosteroids, methotrexate, megestrol acetate, platinum compounds, cyclophosphamide, doxorubicin, interferon-alpha, valproic acid, cyclosporine, vitamin A, NSAIDS, estramustine, ifosfamide, radiotherapy, and combined chemotherapeutic regimens, were identified and described. Skeletal effects of hyperparathyroidism, vitamin D deficiency, gastrectomy, hypophosphatemia, and hyperprolactinemia resulting from cancer therapies were also described.

DISCUSSION/CONCLUSIONS

The publications researched during this review both highlight and emphasize the association between cancer therapies, including chemotherapy and radiotherapy, and skeletal dysfunction.

IMPLICATIONS FOR CANCER SURVIVORS

These studies confirm that cancer survivors experience a more rapid acceleration of bone loss than their age-matched peers who were never diagnosed with cancer. Further studies are needed to better address the skeletal needs of cancer survivors.

Adjuvant bisphosphonate therapy for breast cancer patients: Standard of care or future direction?

Bone is the most common site of metastatic spread in breast cancer patients. The use of bisphosphonates (BPs) in women with bone metastases from breast cancer has been shown to reduce the incidence, and delay the onset of, skeletal-related events. Indeed, BPs are now an established standard of care in treating patients with bone metastases. As with many new therapies, once efficacy in the metastatic setting is demonstrated, therapies are tested in the adjuvant setting. There are a number of trials that have tested the hypothesis that BP therapy in women with early breast cancer may not only reduce the development of skeletal metastases but also improve both disease-free and overall survival; recent randomized trials have demonstrated intriguing results regarding the possible anticancer effects of adjuvant BP therapy. Furthermore, interesting signals are filtering through from trials evaluating the role of BPs to prevent cancer-treatment induced bone loss. Many of these trials will be reported in the near future. In this article we review possible subgroups that may benefit from adjuvant treatment with BPs, and ongoing trials that may offer more definitive answers.

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.

Cancer therapy and osteoporosis: approach to evaluation and management

The incidences of osteoporosis and cancer increase with age, and these two diagnoses are often made in the same individual. Both increasing age and hypogonadism associated with aging, as well as cancer therapies, can lead to loss of bone mass and increased risk for fragility fractures. Advancing age carries an association with increased incidence of cancers. Thus, cancer and its therapies may predispose an individual to osteoporosis and its associated morbidity and mortality. Prevention of bone loss and its consequent fractures is critical in the care of aging patients. This article reviews the mechanisms of bone metabolism and the principles of management of bone health in the older population with a history of cancer.

Cancer treatment-related bone disease

Bone health may be impaired in many patients being treated for cancer. Primary tumors that reside in or form metastases to bone can result in compromised skeletal integrity. It has also been increasingly recognized that patients undergoing therapies for treatment of cancer are at higher risk of bone loss. These include androgen-deprivation therapy for prostate cancer and aromatase inhibitor therapy for breast cancer, among others. Hypogonadism induced by many of these cancer treatments results in bone loss and increases the risk of osteoporosis and fractures. Progress has been made in identifying the role of oral and intravenous bisphosphonates to prevent bone loss in these patients. This review discusses bone loss associated with cancer treatments, with a focus on breast cancer, prostate cancer, and survivors of childhood malignancies.

Management of complications from estrogen deprivation in breast cancer patients

In the United States today, more than 2 million women live as breast cancer survivors. As the number of cancer survivors grows, the unique long-term side effects of cancer treatment and aging play an increasingly prominent role in the routine care of these patients. Of special concern are the short- and long-term effects of sex hormone deprivation. This article reviews current issues surrounding the acute and late effects associated with hormone deprivation in breast cancer survivors and summarizes the scientific and therapeutic discoveries to date to identify optimal nonestrogenic treatments for symptom control in individual patients.

Adjuvant Endocrine Therapy in Early Postmenopausal Breast Cancer

Five years of adjuvant tamoxifen treatment has been the gold standard for women with early hormone-responsive breast cancer. Results from two large phase III, adjuvant studies have indicated that the third-generation aro-matase inhibitors (AIs) letrozole and anastrozole offer greater protection against recurrence than tamoxifen in upfront substitution strategies in the first 5 years. Similarly, changeover to an AI (exemestane or anastrozole) after 2-3 years of tamoxifen has been more efficient to prevent recurrence than 5 years of tamoxifen. Most early breast cancer recurrences occur 5 or more years after surgery. Letrozole has been shown to offer greater protection against recurrence than placebo in the 5 years after a standard course of tamoxifen. The optimal adjuvant use (duration and sequencing) of AIs requires further investigation. Safety implications of treatment with these AIs for 5 years or more are closely monitored. The anticipated effects of estrogen deprivation on bone health may be treatable with bisphosphonates. Effects on the cardiovascular system, and other estrogen-sensitive systems such as the central nervous system, are currently examined. The AIs letrozole, anastrozole, and ex-emestane have recently replaced tamoxifen as the recommended adjuvant endocrine therapy, on the basis of greater efficacy and better tolerability.

Effect of risedronate on hip structural geometry: a 1-year, double-blind trial in chemotherapy-induced postmenopausal women

INTRODUCTION

Chemotherapy-induced menopause is associated with bone loss. The effect on structural geometry is unknown. Our objective was to determine if oral bisphosphonate therapy could maintain or improve femoral geometry in breast cancer patients with chemotherapy-induced menopause.

METHODS

This preplanned 1 year interim, secondary analysis of the Risedronate's Effect on Bone loss in Breast CAncer Study (REBBeCA Study) examined hip structure analysis (HSA), i.e. changes in the bone cross-sectional area (bone CSA), section modulus (SM: measure of bending strength), cortical thickness (CT) and buckling ratio (BR: index of cortical bone stability), in a double-blind trial of 87 newly postmenopausal, nonmetastatic breast cancer patients, randomized to risedronate, 35 mg once weekly (RIS) versus placebo (PBO).

RESULTS

After 12 months, intertrochanteric parameters demonstrated percentage improvement (RIS vs. PBO) from baseline in bone CSA (mean+/-SD: 4.25+/-6.29 vs. 0.60+/-5.99%), SM (3.97+/-6.40 vs. 0.80+/-7.08%), and CT [5.20+/-6.98 vs. 1.13+/-6.87% (all p-values <0.05 except SM p=0,0643)]. Similar improvements were observed at the femoral shaft [bone CSA: 2.24+/-5.74 vs. -0.78+/-5.73%; SM: 1.62+/-6.23 vs. -1.39+/-7.06%; CT: 3.79+/-7.84 vs. -0.17+/-7.90% (all p-values <0.05, RIS vs. PBO, except SM p= p =0.0568)]. At both sites, the BR had significant decreases consistent with improved strength.

CONCLUSION

We conclude that RIS improves measures of hip structural geometry in women with breast cancer following chemotherapy.

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.

Bone loss in patients with breast cancer receiving aromatase inhibitors and associated treatment strategies

Hormone-receptor-positive breast cancer in postmenopausal women is treated increasingly with aromatase inhibitors because of increased efficacy and reduced incidence of endometrial cancer compared with tamoxifen. However, aromatase inhibitor therapy increases bone turnover as a result of nearly complete oestrogen depletion, leading to increases in bone loss and fragility fractures that erode patients' functional independence and quality of life. Management of patients with aromatase inhibitor-associated bone loss (AIBL) is currently evolving and intervention strategies are under investigation. Although no treatments are specifically approved for AIBL, bisphosphonates are currently the intervention of choice for patients with low bone mineral density or evidence of rapid bone turnover, along with adequate calcium and vitamin D supplementation and a healthy lifestyle. In this setting, the majority of information available regarding bisphosphonate efficacy is from studies of intravenous zoledronic acid (4 mg) every 6 months. Data from four large international studies (three of identical design in postmenopausal women and one in premenopausal women) indicate that zoledronic acid is effective in the management of AIBL. Treatment algorithms based on risk factors and bone mineral density are under development, and the results of ongoing studies should help define optimal bone health management for patients undergoing aromatase inhibitor treatment for early breast cancer.

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.

Bone mineral density deficits in pediatric patients treated for sarcoma

BACKGROUND

Children treated for sarcoma are at risk of treatment-associated deficits in bone mineral density (BMD). We investigated the severity of risk factors for BMD deficits in this patient population.

PROCEDURE

Using signed-rank test and logistic regression analysis, we retrospectively analyzed the relation of treatment variables and other potential risk factors to BMD (using quantitative computed tomography (QCT)) of 99 patients treated for pediatric sarcoma who had completed therapy at least 1 year previously.

RESULTS

The study group (38% rhabdomyosarcoma (RMS), 25% osteosarcoma (OS), 24% Ewing-family tumors, and 12% non-rhabdomyosarcoma soft-tissue sarcoma (NRSTS)) represented 22% of the sarcoma survivors treated between 1982 and 2003 who remained in follow-up at St. Jude. These patients underwent QCT between July 1, 1997 and February 5, 2003. Their median age was 8.7 years (range, 0.2-21.3 years) at diagnosis and 17.4 years (range, 3.3-30.2 years) at the time of BMD measurement; 58% were male and 82% Caucasian. Median BMD Z-score was -0.75 (range, -3.33-3.02), and median BMD was 168.0 mg/cc (range, 89.2-264.8 mg/cc). Risk of BMD deficit increased significantly with younger age at diagnosis (P = 0.044) and higher cumulative cyclophosphamide dose (P = 0.007). Patients with lower extremity primary disease had a significantly lower risk of BMD deficits than others. We found no association between BMD and body habitus, primary disease, lifestyle factors, or endocrinopathy.

CONCLUSION

A significant subset of sarcoma survivors are at risk of BMD deficits warranting prospective study of BMD to verify our results and refine risk factors contributing to BMD deficits.

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.

Significance of sagittal reformations in routine thoracic and abdominal multislice CT studies for detecting osteoporotic fractures and other spine abnormalities

The purpose was to assess osteoporotic vertebral fractures and other spinal lesions in sagittal reformations obtained from routine multidetector computed tomography (MDCT) studies of the thorax and abdomen, to compare sagittal reformations with axial images in detecting these lesions and to investigate how frequently they were missed in the official radiology report. Routine abdominal or thoracoabdominal MDCT using a standard protocol was performed in 112 postmenopausal women. Axial images and sagittal reformations were analyzed separately by two radiologists in consensus and were compared in order to evaluate how often spinal lesions could be detected. In addition the official radiology reports were assessed to determine how many of those abnormalities were identified. Spine abnormalities were visualized in 101/112 postmenopausal women. In 27 patients osteoporotic vertebral deformities were found; 6 of these were shown in the axial images, but none of these were diagnosed in the official radiology report. Additional abnormalities included degenerative disc disease, osteoarthritis of the facet joints, scoliosis, hemangiomas and bone metastases. In only 9/101 patients spine abnormalities were mentioned in the radiology report. Sagittal reformations of standard MDCT images provide important additional information on spinal abnormalities; in particular, osteoporotic vertebral deformities are substantially better detected.

Some musculo-skeletal sequelae in cancer survivors

This paper deals with some of the musculo-skeletal complication that can occur after cancer treatment. In particular, we focus on Cancer Treatment Induced Bone Loss (CTIBL) and the musculo-skeletal complications that can occur in patients treated for extremity sarcoma. In addition we discuss peripheral neuropathy, musculo-skeletal pain and briefly mention some of the complications related to radiotherapy. CTIBL is mostly studied in breast cancer and prostate cancer survivors. The cause in these groups is mainly due to treatment induced hypogonadism. Other causes of CTIBL are indirect or direct cause of chemotherapy, physical inactivity and inadequate intake of vitamin D and calcium. Treatment of CTIBL consists of diet and lifestyle changes and pharmacological intervention. Extremity bone sarcomas constitute a special group since they often experience mutilating surgery and heavy combination chemotherapy. The treatment results in worse function than the normal population and the amputated usually have lower physical functioning than patients treated with limb sparing surgery (LSS). However, most studies fail to show differences in quality of life between the amputated and LSS. Most of the studies performed on musculo-skeletal sequelae have been done on survivors of childhood cancer, breast cancer or prostate cancer. More studies among the other cancer groups are needed to reveal the extent and prevalence of these complications.

Guidance on the use of bisphosphonates in solid tumours: recommendations of an international expert panel

Bisphosphonates (BP) prevent, reduce, and delay cancer-related skeletal complications in patients, and have substantially decreased the prevalence of such events since their introduction. Today, a broad range of BP with differences in potency, efficacy, dosing, and administration as well as approved indications is available. In addition, results of clinical trials investigating the efficacy of BP in cancer treatment-induced bone loss (CTIBL) have been recently published. The purpose of this paper is to review the current evidence on the use of BP in solid tumours and provide clinical recommendations. An interdisciplinary expert panel of clinical oncologists and of specialists in metabolic bone diseases assessed the widespread evidence and information on the efficacy of BP in the metastatic and nonmetastatic setting, as well as ongoing research on the adjuvant use of BP. Based on available evidence, the panel recommends amino-bisphosphonates for patients with metastatic bone disease from breast cancer and zoledronic acid for patients with other solid tumours as primary disease. Dosing of BP should follow approved indications with adjustments if necessary. While i.v. administration is most often preferable, oral administration (clodronate, IBA) may be considered for breast cancer patients who cannot or do not need to attend regular hospital care. Early-stage cancer patients at risk of developing CTIBL should be considered for preventative BP treatment. The strongest evidence in this setting is now available for ZOL. Overall, BP are well-tolerated, and most common adverse events are influenza-like syndrome, arthralgia, and when used orally, gastrointestinal symptoms. The dose of BP may need to be adapted to renal function and initial creatinine clearance calculation is mandatory according to the panel for use of any BP. Subsequent monitoring is recommended for ZOL and PAM, as described by the regulatory authority guidelines. Patients scheduled to receive BP (mainly every 3-4 weeks i.v.) should have a dental examination and be advised on appropriate measures for reducing the risk of jaw osteonecrosis. BP are well established as supportive therapy to reduce the frequency and severity of skeletal complications in patients with bone metastases from different cancers.

Bone mineral density deficits in survivors of childhood cancer: long-term follow-up guidelines and review of the literature

The development of curative therapy for most pediatric malignancies has produced a growing population of childhood cancer survivors who are at increased risk for a variety of health problems resulting from their cancer or its treatment. Because of the fact that many treatment-related sequelae may not become clinically apparent until the survivor attains maturity or begins to age, the ability of primary care providers to anticipate late effects of treatment is essential for providing timely interventions that prevent or correct these sequelae and their adverse effects on quality of life. Altered bone metabolism during treatment for childhood cancer may interfere with attainment of peak bone mass, potentially predisposing to premature onset of and more severe complications related to osteopenia and osteoporosis. Bone mineral deficits have been reported after treatment for a variety of pediatric malignancies and represent morbidity that can be reduced or prevented through lifestyle changes and attention to other common cancer-related sequelae such as hypogonadism. The Children's Oncology Group long-term follow-up guidelines for survivors of childhood, adolescent, and young adult cancers provide risk-based surveillance recommendations that are based on expert opinion and review of the scientific literature for potential late effects of pediatric cancer therapy including osteopenia. This review summarizes the existing literature that has defined characteristics of cancer survivors at risk for bone mineral deficits and contributed to the surveillance and counseling recommendations outlined in the Children's Oncology group long-term follow-up guidelines.

Prolonged efficacy of a single dose of the bisphosphonate zoledronic acid

PURPOSE

Bisphosphonates play a central role in the management of bone loss due to a range of disorders, including metastatic bone disease, cancer treatment-induced bone loss, and postmenopausal osteoporosis. With potent bisphosphonates, such as zoledronic acid, it may be possible to maintain efficacy with relatively infrequent administration.

EXPERIMENTAL DESIGN

Sixty-six patients who were osteopenic at >1 year following curative cancer therapy received a single i.v. 4 mg dose of the bisphosphonate zoledronic acid. Bone mineral density (BMD) was measured using double-beam X-ray absorptiometry scan and the bone resorption marker N-telopeptide of type II collagen was determined using a chemiluminescence ELISA assay.

RESULTS

The single dose of zoledronic acid induced mean increases in bone BMD at the lumbar spine of 3.1%, 5.2%, and 5.3% and at the total hip of 2.7%, 3.5%, and 4.3% after 12, 24, and 36 months of follow-up, respectively (P < 0.001 at all time points). By 36 months, 84% of patients had achieved increase in BMD at the spine and 90% at the hip. The mean percentage decrease in the bone resorption marker N-telopeptide was approximately 58% at 6 weeks and 42%, 33%, and 31% at 12, 24, and 36 months, respectively (P < 0.001).

CONCLUSIONS

A single dose of zoledronic acid in patients with low BMD results in a sustained increase in BMD and a corresponding decrease in bone resorption. Very infrequent administration of zoledronic acid may have clinical benefits in terms of convenience, reduced toxicity, improved compliance, and cost.

Cancer treatment-induced bone loss

PURPOSE OF REVIEW

Patients treated for cancer may be at risk for osteoporosis and fracture. Evaluation and treatment of patients with cancer treatment-induced bone loss should lead to fewer fractures. This review will help clinicians learn to identify, evaluate and treat cancer patients at risk.

RECENT FINDINGS

Survivors of childhood cancers and patients made hypogonadal by treatment for breast or prostate cancer are clearly at risk for osteoporosis and fracture. Use of aromatase inhibitors rather than tamoxifen for breast cancer will likely lead to more osteoporosis. Bisphosphonates prevent bone loss in many patients at risk.

SUMMARY

For many cancer patients, treatment with calcium, vitamin D, and bisphosphonates will likely decrease the consequences of cancer treatment-induced bone loss, namely fractures.

[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.

Management of cancer treatment-induced bone loss in early breast and prostate cancer -- a consensus paper of the Belgian Bone Club

Cancer treatment-induced bone loss (CTIBL) is one of the most important side effects of adjuvant antineoplastic treatment in hormone-dependent neoplasms. Chemotherapy, GnRH analogs and tamoxifen can induce marked bone loss in premenopausal women with early breast cancer. Aromatase inhibitors (AIs) are replacing tamoxifen as the preferred treatment for postmenopausal women. As a class effect, steroidal (exemestane) and non-steroidal (anastrozole and letrozole) AIs increase bone turnover and cause bone loss (4%-5% over 2 years). When compared to tamoxifen, the risk of getting a clinical fracture under AI treatment is increased by 35%-50%. In patients with prostate cancer, androgen deprivation therapy (ADT) increases bone turnover, reduces bone mass (4%-5% per year) and increases the fracture rate depending on the duration of therapy. Zoledronic acid can prevent accelerated bone loss induced by goserelin in premenopausal women, by letrozole in postmenopausal women and by ADT in men. More limited data indicate that weekly alendronate or risedronate could also be effective for preventing CTIBL. Initiation of therapy early, prior to the occurrence of severe osteoporosis, rather than after, may be more effective. Bisphosphonate treatment should be considered in osteoporotic but also in osteopenic patients if other risk factor(s) for fractures are present.

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.

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.

Bisphosphonate therapy for reduced bone mineral density during treatment of acute lymphoblastic leukemia in childhood and adolescence: a report of preliminary experience

BACKGROUND

Osteopenia is a common consequence of the treatment of acute lymphoblastic leukemia (ALL) in children and adolescents, due predominantly to glucocorticosteroid therapy. The pathogenesis relates to an imbalance of resorption over formation of bone.

METHODS

Alendronate (Fosamax), an inhibitor of osteoclastic bone resorption, was administered for at least 6 months to 15 children with ALL during maintenance chemotherapy, after the diagnosis of osteopenia/osteoporosis by dual energy x-ray absorptiometry. The height velocity was also measured during the administration of alendronate and again 2 years later.

RESULTS

Areal bone mineral density Z scores of the lumbar spine had a median value of -1.32 before administration of alendronate and a median gain of +0.64, with 14/15 children showing improvement. There was no adverse effect of alendronate on height velocity, and the drug was well tolerated with no short-term toxicity.

CONCLUSIONS

This preliminary experience suggests a potential value in the use of alendronate for the treatment of osteopenia/osteoporosis in children with ALL and points to the need for a randomized controlled trial of this intervention.

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.

Bone mineral status after treatment of malignant lymphoma in childhood and adolescence

The relationship between bone mineral mass and cumulative dose of corticosteroids (CDC) was investigated in 42 children and adolescents treated for Hodgkin disease (HD; n = 22) and non-Hodgkin lymphoma (NHL; n = 20). The median age at the time of the study was 24.1 years for HD survivors and 14.1 years for NHL survivors. Dual-energy X-ray absorptiometry [bone mineral density of the lumbar spine (LS-BMD) expressed as Z-scores] and peripheral quantitative computed tomography at the distal radius [trabecular volumetric BMD (vBMD-trab)] were undertaken. Osteopenia (Z-score < -1.00) was found in 9/22 patients with HD and 10/20 with NHL, while 34% (HD = 6, NHL = 8) had a vBMD-trab below the normal range. The CDC correlated inversely with LS-BMD Z-score (r =-0.41, P = 0.007). There was a statistically significantly higher vBMD-trab in patients who received low (1-4 g/m(2)) compared with high (>or=20 g/m(2)) CDC (P = 0.031). Treatment of malignant lymphoma with high CDC is a risk factor for development of osteopenia.

High body mass index increases the risk for osteonecrosis in children with acute lymphoblastic leukemia

PURPOSE

The aim of the study was to determine the incidence of and clinical risk factors for radiographic osteonecrosis (ON) in children treated for acute lymphoblastic leukemia (ALL) using the Nordic ALL protocols.

PATIENTS AND METHODS

Ninety-seven consecutive patients with childhood ALL were studied prospectively by magnetic resonance imaging (MRI) of the lower extremities at the end of the treatment.

RESULTS

Twenty-three (24%) of the 97 patients had ON. Seven of the patients (30%) were symptomatic, and three patients (13%) required surgical interventions. Multiple logistic regression analysis showed that high body mass index (BMI; P = .04), female sex (P = .01), older age at diagnosis (P < .001), and higher cumulative dexamethasone dose (P = .03) were independent risk factors for radiographic ON. The cumulative prednisone dose did not differ significantly between the patients with and without ON. The incidence of radiographic ON decreased significantly, from 36% to 7%, when the duration of dexamethasone exposure during the delayed-intensification phase was shortened from 3 to 4 weeks to 2 weeks with a taper (P = .001).

CONCLUSION

ON as determined by MRI was found to be a common complication in children and adolescents after treatment with the Nordic ALL protocols. Revision of the ALL protocols by shortening the single exposure to dexamethasone has diminished the risk for ON remarkably. High BMI was identified as a new significant risk factor for ON.

Volumetric quantitative CT of the spine and hip derived from contrast-enhanced MDCT: conversion factors

OBJECTIVE

The purposes of this study were to perform volumetric quantitative CT (QCT) of the spine and hip using nondedicated contrast-enhanced standard MDCT data sets and to derive a conversion factor for bone mineral density (BMD) assessment based on dedicated volumetric QCT data sets.

SUBJECTS AND METHODS

Forty postmenopausal women with a mean +/- SD age of 71 +/- 9 years underwent routine contrast-enhanced abdominal and pelvic MDCT. Before this imaging examination, standard volumetric QCT of the spine (L1-L3, n = 40) and hip (n = 21) was performed. Relations between QCT and contrast-enhanced MDCT findings were assessed with linear regression analysis.

RESULTS

Mean lumbar BMD was 84.1 +/- 35.8 mg/mL, and mean femoral BMD was 0.62 +/- 0.12 g/cm2, as determined with QCT. Contrast-enhancement values with MDCT were on average 30.3% higher than those of QCT in the spine and 2.3% higher in the proximal femur (p < 0.05). Based on linear regression, a correlation coefficient of r = 0.98 was calculated for lumbar BMD with the equation BMD(QCT) = 0.96xBMD(MDCT) - 20.9 mg/mL. A coefficient of r = 0.99 was calculated for the proximal femur with the equation BMD(QCT) = 0.99xBMD(MDCT) - 12 mg/cm2 (p < 0.01). In 17 of 40 patients, 33 vertebral fractures were found. The dedicated QCT and enhanced MDCT data sets did not show a significant difference (p > 0.05) between patients with fractures and those without fractures.

CONCLUSION

With the conversion factors, reliable volumetric BMD measurements can be calculated for the hip and the spine from routine abdominal and pelvic MDCT data sets.

Reduced incidence of distant metastases and lower mortality in 1072 patients with breast cancer with a history of hormone replacement therapy

OBJECTIVE

Substitution of estrogens (hormone replacement therapy [HRT]) is the most common therapy and prophylaxis of postmenopausal complaints. However, in most studies, long-term HRT has been associated with an increased risk for breast cancer, but the influence on a prognosis of breast cancer has been examined rarely.

STUDY DESIGN

For further investigation, we analyzed 1072 patients aged 45-70 years at the time of first diagnosis of breast cancer with and without preoperative HRT with regard to the incidence of distant metastases and overall survival. Of these, 279 women were premenopausal (mean, 47.8 +/- 3.2 years); 793 women were postmenopausal (mean, 54.5 +/- 3.5 years); 320 women had received HRT over a minimum of 1 year (mean, 5.5 +/- 4.0 years; group HRT+); and 473 women had not received HRT (group HRT-). The median follow-up time was 73.2 months.

RESULTS

Although body mass index, tumor size, and grading of group HRT- were significantly higher than in group HRT+, nodal status, S-phase fraction, hormone-receptor status, and local recurrence showed no significant differences. In regard to the incidence of distant metastases, women without HRT have significantly (P < .001) more metastases to bone (68 vs 20 women), lung (47:13 women), and liver (47:13 women). Overall survival was significantly lower in the HRT- group.

CONCLUSION

We were able to show that the use of HRT before the diagnosis of breast cancer results in more favorable primary tumors, with a lower incidence of recurrences and a better overall survival rate. This might be due to normalized bone metabolism by the use of HRT, which may lower the conditions of tumor cell seeding.

The late effects of childhood cancer therapy

In this article the difficulties that face survivors of childhood cancer therapy are presented, and the late effects of such therapy, separated into nonmalignant and malignant late effects, are discussed according to organ system. Recommendations for monitoring the late effects are set forth. A table listing radiation-therapy site and chemotherapeutic agents and selected late effects that result from their use is provided. Finally, a brief recommendation regarding the establishment of a late-effects clinic is also presented.

Metabolic bone disease in gastrointestinal illness

Metabolic bone disease is often silent, often undiagnosed, and occurs frequently in patients with chronic gastrointestinal illnesses. Potentially modifiable risk factors, such as malnutrition, malabsorption, prolonged use of glucocorticoids, and a sedentary lifestyle, can lead to low bone mass, an increased rate of bone loss, and debilitating bone disease. This article explores common gastrointestinal illnesses that place patients at risk for developing metabolic bone disease. Concepts are presented to assist the practitioner in identifying patients at risk; clinical evaluation and diagnostic test selection are discussed, and therapeutic options for the prevention and treatment of metabolic bone disease in gastrointestinal illness are presented.

Bone loss and fracture risk associated with cancer therapy

BACKGROUND

Cancer patients experience osteoporosis resulting from accelerated loss of bone mineral density (BMD) caused by their treatment. Such bone loss greatly increases the risk for fracture and can have other serious effects on quality of life.

METHODS

In the current report, the author focuses on studies of cancer therapy-associated bone loss, its prevalence and pathogenesis, and resulting clinical impact. Options for management and prevention are also reviewed, including treatment guidelines where available.

RESULTS

A variety of cancer therapies, including hormonal therapy, chemotherapy, and glucocorticoids, affect gonadal hormone production, which increases bone resorption and decreases BMD. Such bone loss occurs more rapidly and to a greater degree than normal age-related osteoporosis, increases the risk for fracture and other morbidities, and decreases survival. Regular BMD screening and early intervention can prevent further decline in bone density and bone quality. Pharmacologic therapy with oral and i.v. bisphosphonates has been shown to slow bone loss in patients receiving cancer therapy, and the i.v. bisphosphonate zoledronic acid can increase BMD in patients with cancer treatment-related bone loss. Lifestyle changes, including supplementation with calcium and vitamin D, diet, and proper exercise, can also slow the rate of bone loss.

CONCLUSIONS

Bone loss associated with various cancer therapies significantly affects bone health. Early initiation of bisphosphonates, when indicated, and lifestyle modification can improve patient outcomes. Education of patients and health care professionals regarding the importance of this complication and effective treatment options is essential.

Use of inhaled and oral glucocorticoids, severity of inflammatory disease and risk of hip/femur fracture: a population-based case-control study

BACKGROUND

Patients using higher dosages of inhaled or oral glucocorticoids (GCs) have an increased risk of hip/femur fractures. The role of the underlying disease in the aetiology of this increased risk has not been widely studied.

OBJECTIVE

To evaluate the contribution of the underlying disease to the risk of hip/femur fracture in patients using inhaled or oral GCs.

DESIGN AND SUBJECTS

A case-control study within the Dutch PHARMO-RLS database was conducted. Cases (n = 6763) were adult patients with a first hip/femur fracture during enrolment. Each case was matched to four controls by age, gender and region.

RESULTS

The risk of hip/femur fracture increased with current use of inhaled GCs (crude OR 1.30, 95% CI:1.16-1.47) and with current use of oral GCs (crude OR 1.66, 95% CI: 1.46-1.90). After adjustment for disease severity, the risk of hip/femur fracture was no longer statistically significantly increased in inhaled GC users (adjusted OR 1.08, 95% CI: 0.91-1.27), whilst it remained elevated in oral GC users (adjusted OR 1.43, 95% CI: 1.22-1.67). Patients using inhaled GCs without any exposure to oral GCs had no increased risk of fracture (adjusted OR 0.98, 95% CI: 0.79-1.22).

CONCLUSION

Inhaled GC users had no increased risk of femur/hip fracture after adjustment for underlying disease severity. Our data suggest that, even at higher dosages, inhaled GC use is not an independent risk factor for fracture. In contrast, oral GC use was associated with an increased risk of fracture, which was not fully explained by the underlying disease severity.

Effect of chemotherapy on skeletal health in male survivors from testicular cancer and lymphoma

PURPOSE

There are concerns over the late effects of cancer therapy, including accelerated bone loss leading to increased risk of osteoporosis. Treatment-related bone loss is well recognized in breast and prostate cancer, due to overt hypogonadism, but there has been little evaluation of the skeletal effects of chemotherapy alone in adults. This study assesses the extent of bone loss due to previous chemotherapy in men.

EXPERIMENTAL DESIGN

The bone mineral density (BMD) of men who had received previously chemotherapy with curative intent for lymphoma or testicular cancers was compared with that of an age-matched population of men from a cancer control population that had not received chemotherapy. BMD was measured by dual-energy X-ray scanning. Additionally, measurement of sex hormones and the bone turnover markers N-telopeptide fragment of type I collagen and bone-specific alkaline phosphatase were done. All statistical tests were two sided.

RESULTS

One hundred fifteen chemotherapy-treated patients and 102 cancer controls were recruited. There was no statistical difference in BMD between the chemotherapy and control groups at either spine or hip and the mean BMD values in both groups were no lower than that of a reference population. There were no significant differences in estradiol, luteinizing hormone, and testosterone, but follicle-stimulating hormone values were significantly higher in the chemotherapy group (P=0.011). The mean values of NH2-terminal telopeptide fragment of type I collagen and bone-specific alkaline phosphatase were within the reference ranges.

CONCLUSIONS

The absence of accelerated bone loss following chemotherapy is reassuring and suggests that standard dose cytotoxic chemotherapy has no lasting clinically important direct effects on bone metabolism.

Aromatase Inhibitors in the Adjuvant Treatment of Postmenopausal Women with Early Breast Cancer: Putting Safety Issues into Perspective

Tamoxifen has been the gold standard adjuvant therapy for the treatment of postmenopausal women with hormone-receptor-positive (HR+) early breast cancer for many years. Tamoxifen treatment is limited to 5 years because of the development of de novo and acquired resistance, and an ongoing risk of adverse events, including endometrial cancer, thromboembolic events, and gynecological symptoms with long-term use. The third-generation aromatase inhibitors (AIs), letrozole, anastrozole, and exemestane, are displacing tamoxifen as the first-choice therapy for HR+ early breast cancer, and are now recommended as the preferred therapy by national and international guidelines. Recent randomized trials have demonstrated that the AIs are more effective than tamoxifen in preventing disease recurrence when used in substitution and sequential strategies in the early adjuvant setting, and letrozole has been shown to be more effective than placebo in the extended adjuvant setting (after 5 years of tamoxifen therapy). Trial safety data show that the overall tolerability of AIs is similar to that of tamoxifen, with adverse events being predictably characteristic of estrogen deprivation; however, some important differences in adverse event profiles between tamoxifen and the AIs have been demonstrated. In addition to antiestrogenic effects, tamoxifen acts as an estrogen agonist in some tissues, which can lead to serious side effects not associated with the AIs, which prevent estrogen biosynthesis. A lower incidence of gynecological and thromboembolic events is observed in patients taking AIs, and fewer cases of endometrial cancer are seen compared with tamoxifen. Adverse events that are more frequent with adjuvant AI therapy compared with tamoxifen include arthralgia and myalgia, bone loss, and effects on the cardiovascular system and blood lipids. The effects of AIs on bone are predictable and may be easily managed, where necessary, with bisphosphonates. Studies examining the effects of AIs on the cardiovascular system and lipid profiles, including in the extended adjuvant setting, suggest that these adverse events may be due to the absence of a protective effect of tamoxifen rather than true AI toxicity. Further studies are required to determine the long-term safety of AI therapy in postmenopausal women with HR+ early breast cancer.

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.