Preventive effect of risedronate on bone loss and frailty fractures in elderly women treated with anastrozole for early breast cancer

Osteoporotic Vertebral Fractures as Part of Systemic Disease

Our understanding of the genetic control of skeletogenesis and bone remodeling is expanding, and normally, bone resorption and bone formation are well balanced through regulation by hormones, growth factors, and cytokines. Osteoporosis is considered a systemic disease characterized by low bone mass and microarchitectural deterioration of bone tissue. Consequent increased bone fragility results in higher fracture risk. The most common osteoporotic fractures are located in the spine, and they form a significant health issue. A large variety of systemic diseases are associated with risk of osteoporotic vertebral fractures, illustrating its multifactorial etiology. Prevalences of these conditions vary from common to extremely rare, and incidence peaks differ according to etiology. This review appreciates different aspects of osteoporotic vertebral fractures as part of systemic disease, including genetic, immunologic, inflammatory, metabolic, and endocrine pathways. It seems impossible to be all-comprehensive on this topic; nevertheless, we hope to provide a reasonably thorough overview. Plenty remains to be elucidated in this field, identifying even more associated diseases and further exposing pathophysiological mechanisms underlying osteoporotic vertebral fractures.

Serum uric acid and incident osteoporotic fractures in old people: The PRO.V.A study

PURPOSE

Although high serum uric acid (SUA) levels are associated with negative outcomes in older people, recent studies reported that hyperuricemia could help protect against the onset of bone fractures. We consequently examined whether baseline SUA levels were associated with risk of incident osteoporotic fractures in a representative group of elderly people with no fractures or other bone-modifying conditions or drugs at the baseline.

METHODS

Among 3099 people aged ≥ 65 years initially involved in the PRO.V.A. study, 1586 participants with no prior diagnosis of osteoporotic fractures, and no conditions or medication affecting bone metabolism at the baseline were followed up for 4.4 ± 1.2 years. Baseline SUA levels were classified in gender-specific quintiles. Incident osteoporotic fractures were considered as any new fractures occurring at the usual sites of osteoporotic fractures.

RESULTS

At the baseline, participants with higher SUA levels had significantly less osteoporosis and lower serum beta cross-laps levels, but higher serum parathormone concentrations irrespective of gender. Over a 4.4-year follow-up, 185 subjects were diagnosed with a new osteoporotic fracture, giving rise to an incidence of 25 events per 1,000 person-years. Cox's regression analysis, adjusted for potential baseline and follow-up confounders, revealed no relationship between high SUA levels and incident fractures during the follow-up in the sample as a whole (p for trend=0.46) or by gender (p for trend=0.14 in males and 0.64 in females).

CONCLUSIONS

Baseline SUA concentrations were not associated with the onset of new osteoporotic fractures over a 4.4-year follow-up in our sample of community-dwelling older men and women.

Prevention of bone loss with risedronate in breast cancer survivors: a randomized, controlled clinical trial

In postmenopausal women with low bone mass and hormone-receptor-positive breast cancer on an aromatase inhibitor, risedronate maintained skeletal health assessed by bone density and turnover markers. Women with the greatest decreases in bone turnover markers at 12 months had the greatest increases in bone density at 24 months.

INTRODUCTION

Aromatase inhibitors (AIs), adjuvant endocrine therapy for postmenopausal women with hormone-receptor-positive breast cancer, are associated with bone loss and fractures. Our objectives were to determine if (1) oral bisphosphonate therapy can prevent bone loss in women on an AI and (2) early changes in bone turnover markers (BTM) can predict later changes in bone mineral density (BMD).

METHODS

We conducted a 2-year double-blind, placebo-controlled, randomized trial in 109 postmenopausal women with low bone mass on an AI (anastrozole, letrozole, or exemestane) for hormone-receptor-positive breast cancer. Participants were randomized to once weekly risedronate 35 mg or placebo, and all received calcium plus vitamin D. The main outcome measures included BMD, BTM [carboxy-terminal collagen crosslinks (CTX) and N-terminal propeptide of type 1 procollagen (P1NP)], and safety.

RESULTS

Eighty-seven percent completed 24 months. BMD increased more in the active treatment group compared to placebo with an adjusted difference at 24 months of 3.9 ± 0.7 percentage points at the spine and 3.2 ± 0.5 percentage points at the hip (both p < 0.05). The adjusted difference between the active treatment and placebo groups were 0.09 ± 0.04 nmol/LBCE for CTX and 23.3 ± 4.8 μg/mL for P1NP (both p < 0.05). Women with greater 12-month decreases in CTX and P1NP in the active treatment group had a greater 24-month increase in spinal BMD (p < 0.05). The oral therapy was safe and well tolerated.

CONCLUSION

In postmenopausal women with low bone mass and breast cancer on an AI, the oral bisphosphonate risedronate maintained skeletal health.

Changes in bone mineral density at 3 years in postmenopausal women receiving anastrozole and risedronate in the IBIS-II bone substudy: an international, double-blind, randomised, placebo-controlled trial

BACKGROUND

Aromatase inhibitors prevent breast cancer in postmenopausal women at high risk of the disease but are associated with accelerated bone loss. We assessed effectiveness of oral risedronate for prevention of reduction in bone mineral density (BMD) after 3 years of follow-up in a subset of patients in the IBIS-II trial.

METHODS

The double-blind IBIS-II trial recruited 3864 healthy, postmenopausal women at increased risk of breast cancer and randomly allocated them oral anastrozole (1 mg/day) or matched placebo. 1410 (36%) postmenopausal women were then enrolled in a bone substudy and stratified at baseline according to their lowest baseline T score at spine or femoral neck (stratum I: T score at least -1·0; stratum II: T score at least -2·5 but less than -1·0; stratum III: T score less than -2·5 but greater than -4·0). Women in stratum I were monitored only; women in stratum III were all given risedronate (35 mg/week). Women in stratum II were randomly assigned (1:1) to risedronate (35 mg/week) or matched placebo by use of a block randomisation schedule via a web-based programme. The primary outcome of this per-protocol analysis (done with all women with a baseline and 3 year DXA assessment) was the effect of risedronate versus placebo for osteopenic women in stratum II randomly allocated to anastrozole (1 mg/day). Secondary outcomes included effect of anastrozole (1 mg/day) on BMD in women not receiving risedronate (strata I and II) and in osteoporotic women who were all treated with risedronate (stratum III). The trial is ongoing, but no longer recruiting. This trial is registered, number ISRCTN31488319.

FINDINGS

Between Feb 2, 2003, and Sept 30, 2010, 150 (58%) of 260 women in stratum II who had been randomly allocated to anastrozole and either risedronate or placebo had baseline and 3 year assessments. At the lumbar spine, 3 year mean BMD change for the 77 women receiving anastrozole/risedronate was 1·1% (95% CI 0·2 to 2·1) versus -2·6% (-4·0 to -1·3) for the 73 women receiving anastrozole/placebo (p<0·0001). For the total hip, 3 year mean BMD change for women receiving anastrozole/risedronate was -0·7% (-1·6 to 0·2) versus -3·5% (-4·6 to -2·3) for women receiving anastrozole/placebo (p=0·0001). 652 (65%) of 1008 women in strata I and II who were not randomly allocated to risedronate had both baseline and 3 year assessments. Women not receiving risedronate in stratum I and II who received anastrozole (310 women) had a significant BMD decrease after 3 years of follow-up compared with women who received placebo (342 women) at the lumbar spine (-4·0% [-4·5 to -3·4] vs -1·2% [-1·7 to -0·7], p<0·0001) and total hip (-4·0% [-4·4 to -3·6] vs -1·8% [-2·1 to -1·4], p<0·0001). 106 (79%) of 149 women in stratum III had a baseline and a 3 year assessment. The 46 women allocated to anastrozole had a modest BMD increase of 1·2% (-0·1 to 2·6) at the spine compared with a 3·9% (2·6 to 5·2) increase for the 60 women allocated to placebo (p=0·006). For the total hip, a small 0·3% (-0·9 to 1·5) increase was noted for women allocated anastrozole compared with a 1·5% (0·5 to 2·5) increase for women allocated placebo, but the difference was not significant (p=0·12). The most common adverse event reported was arthralgia (stratum I: 94 placebo and 114 anastrozole; stratum II: 39 placebo/placebo, 25 placebo/risedronate, 34 anastrozole/placebo, and 34 anastrozole/risedronate; stratum III: 21 placebo/risedronate, 17 anastrozole/risedronate). Other adverse events included hot flushes, alopecia, abdominal pain, and back pain.

INTERPRETATION

Risedronate counterbalances the effect of anastrozole-induced bone loss in osteopenic and osteoporotic women and might be offered in combination with anastrozole treatment to provide an improved risk-benefit profile.

FUNDING

Cancer Research UK (C569/A5032), National Health and Medical Research Council Australia (GNT300755, GNT569213), Sanofi-Aventis, and AstraZeneca.

Calcium and vitamin D supplementation and loss of bone mineral density in women undergoing breast cancer therapy

An unintended consequence of breast cancer therapies is an increased risk of osteoporosis due to accelerated bone loss. We conducted a systematic review of calcium and/or vitamin D (Ca±D) supplementation trials for maintaining bone mineral density (BMD) in women with breast cancer using the "before-after" data from the Ca±D supplemented comparison group of trials evaluating the effect of drugs such as bisphosphonates on BMD. Whether Ca±D supplements increase BMD in women undergoing breast cancer therapy has never been tested against an unsupplemented control group. However, results from 16 trials indicate that the Ca±D doses tested (500-1500mg calcium; 200-1000IU vitamin D) were inadequate to prevent BMD loss in these women. Cardiovascular disease is the main cause of mortality in women with breast cancer. Because calcium supplements may increase cardiovascular disease risk, future trials should evaluate the safety and efficacy of Ca±D supplementation in women undergoing breast cancer therapy.

Randomized controlled trial of zoledronic acid for treatment of osteoporosis in women

Objective

To assess the effect of zoledronic acid (ZOL) on bone mineral density (BMD) and fracture risk at the L1–L4 vertebrae, femoral neck, hip and trochanter in Chinese women with osteoporosis.

Methods

A randomized controlled trial was conducted in female patients with osteoporosis, randomized to receive one 5-mg ZOL intravenous infusion per year or placebo equivalent. Facture risk and BMD were measured over a 2-year follow-up period.

Results

A statistically significant reduction in the risk of fracture was observed at the trochanter in the ZOL group ( n = 242) compared with the placebo group ( n = 241); (odds ratio 0.54 [95% confidence interval 0.29, 0.98]): BMD was 0.24, 0.28, 0.31 and 0.22 greater at the L1–L4 vertebrae, total hip, femoral neck and trochanter, respectively, in the ZOL group. The incidence of adverse events was comparable between treatment groups.

Conclusions

This study indicated that ZOL could increase BMD and reduce fracture risk in women with osteoporosis over a 2-year follow-up period, and was not associated with any serious drug-related adverse effects.