Alexander H.G. Paterson

Double-blind controlled trial of oral clodronate in patients with bone metastases from breast cancer.

PURPOSE Osteolytic metastases often give rise to hypercalcemia, fracture, and bone pain, and occur commonly in patients with recurrent breast cancer. We assessed the bisphosphonate, clodronate, which has proven to be a useful treatment for hypercalcemia and may be a potent inhibitor of tumor-induced osteolysis, for its effect on reducing the osseous complications of metastatic breast cancer. PATIENTS AND METHODS We studied 173 patients with bone metastases due to breast cancer in a randomized, double-blind, placebo-controlled trial of oral clodronate 1,600 mg/d (85 patients) compared with an identical placebo (88 patients). RESULTS The patients in each wing were comparable in their clinical, radiologic, and biochemical characteristics at trial entry. In patients who received clodronate, there was a significant reduction compared with placebo in the total number of hypercalcemic episodes (28 v 52; P < .01), in the number of terminal hypercalcemic episodes (seven v 17; P < .05), in the incidence of vertebral fractures (84 v 124 per 100 patient-years; P < .025), and in the rate of vertebral deformity (168 v 252 per 100 patient-years; P < .001). The combined rate of all morbid skeletal events was significantly reduced (218.6 v 304.8 per 100 patient-years; P < .001). Trends were seen in favor of clodronate for nonvertebral fracture rates and radiotherapy requirements for bone pain (particularly spinal pain). No significant survival differences and no significant differences in side effects were observed between the two groups. CONCLUSIONS These findings indicate that oral clodronate has a beneficial effect on the skeletal morbidity associated with breast cancer and should be considered as antiosteolytic therapy in affected patients. It deserves further investigation as an adjuvant therapy in operable breast cancer and in patients with nonosseous recurrence who are at high risk for bone metastases.

Randomized Active-Controlled Phase II Study of Denosumab Efficacy and Safety in Patients With Breast Cancer-Related Bone Metastases

PURPOSE Denosumab, a fully human monoclonal antibody to receptor activator of nuclear factor-kappaB ligand, suppresses bone resorption. In this study, we evaluated the efficacy and safety of five dosing regimens of denosumab in patients with breast cancer-related bone metastases not previously treated with intravenous bisphosphonates (IV BPs). PATIENTS AND METHODS Eligible women (n = 255) with breast cancer-related bone metastases were stratified by type of antineoplastic therapy received and randomly assigned to one of six cohorts (five denosumab cohorts [blinded to dose and frequency]; one open-label IV BP cohort). Denosumab was administered subcutaneously every 4 weeks (30, 120, or 180 mg) or every 12 weeks (60 or 180 mg). The primary end point was percentage of change in the bone turnover marker urine N-telopeptide corrected for urine creatinine (uNTx/Cr) from baseline to study week 13. The percentage of patients achieving more than 65% uNTx/Cr reduction, time to more than 65% uNTx/Cr reduction, patients experiencing one or more on-study skeletal-related events (SRE), and safety were also evaluated. RESULTS At study week 13, the median percent reduction in uNTx/Cr was 71% for the pooled denosumab groups and 79% for the IV BP group. Overall, 74% of denosumab-treated patients (157 of 211) achieved a more than 65% reduction in uNTx/Cr compared with 63% of bisphosphonate-treated patients (27 of 43). On-study SREs were experienced by 9% of denosumab-treated patients (20 of 211) versus 16% of bisphosphonate-treated patients (seven of 43). No serious or fatal adverse events related to denosumab occurred. CONCLUSION Subcutaneous denosumab may be similar to IV BPs in suppressing bone turnover and reducing SRE risk. The safety profile was consistent with an advanced breast cancer population receiving systemic therapy.

Current use of bisphosphonates in oncology. International Bone and Cancer Study Group.

PURPOSE The purpose of this article is to review the recent data on bisphosphonate use in oncology and to provide some guidelines on the indications for their use in cancer patients. DESIGN The group consensus reached by experts on the rationale for the use of bisphosphonates in cancer patients and their current indications for the treatment of tumor-induced hypercalcemia and metastatic bone pain in advanced disease and for the prevention of the complications of multiple myeloma and of metastatic bone disease are reviewed. RESULTS Bisphosphonates are potent inhibitors of tumor-induced osteoclast-mediated bone resorption. They now constitute the standard treatment for cancer hypercalcemia, for which we recommend a dose of 1,500 mg of clodronate or 90 mg of pamidronate; the latter compound is more potent and has a longer lasting effect. Intravenous bisphosphonates exert clinically relevant analgesic effects in patients with metastatic bone pain. Regular pamidronate infusions can also achieve a partial objective response by conventional International Union Against Cancer criteria and enhance the objective response rate to chemotherapy. In breast cancer, the prolonged administration of oral clodronate 1,600 mg daily reduces the frequency of morbid skeletal events by more than one fourth, whereas monthly pamidronate infusions of 90 mg for only 1 year in addition to chemotherapy reduce by more than one third the frequency of all skeletal-related events. The use of bisphosphonates to prevent bone metastases remains experimental. Last, bisphosphonates in addition to chemotherapy are superior to chemotherapy alone in patients with stages II and III multiple myeloma and can reduce the skeletal morbidity rate by approximately one half. CONCLUSION Bisphosphonate use is a major therapeutic advance in the management of the skeletal morbidity caused by metastatic breast cancer or multiple myeloma, although many questions remain unanswered, notably regarding the optimal selection of patients and the duration of treatment.

A high incidence of vertebral fracture in women with breast cancer

SummaryBecause treatment for breast cancer may adversely affect skeletal metabolism, we investigated vertebral fracture risk in women with non-metastatic breast cancer. The prevalence of vertebral fracture was similar in women at the time of first diagnosis to that in an age-matched sample of the general population. The incidence of vertebral fracture, however, was nearly five times greater than normal in women from the time of first diagnosis [odds ratio (OR), 4.7; 95% confidence interval (95% CI), 2.3–9.9], and 20-fold higher in women with soft-tissue metastases without evidence of skeletal metastases (OR, 22.7; 95% CI, 9.1–57.1). We conclude that vertebral fracture risk is markedly increased in women with breast cancer.

Clodronate Decreases the Frequency of Skeletal Metastases in Women with Breast Cancer

The aims of this study were to determine the effects of the bisphosphonate, clodronate, on the incidence of skeletal metastases and associated morbidity in women with advanced breast cancer. 133 women with recurrent breast cancer, but no evidence of skeletal metastases, were randomly allocated to receive clodronate 1600 mg daily by mouth or an identical placebo for 3 years under double-blind conditions at two clinical oncology centers in the UK and Canada. Main outcome measures included the occurrence of skeletal metastases, as judged by sequential bone scans and radiographs, and the morbidity associated with skeletal metastases comprising the incidence of hypercalcemia, vertebral, and nonvertebral fractures, and bone pain assessed by the requirements for skeletal radiotherapy. The number of patients developing skeletal metastases was lower in clodronate-treated patients than with placebo (15 vs. 19), but was not significantly different. The number of skeletal metastases was significantly lower with clodronate treatment than with placebo (32 vs. 63; p < 0.005). The complications of skeletal disease were fewer by 26% in clodronate-treated patients compared to controls (p < 0.01). Compared to placebo, significant effects in favor of clodronate were observed for vertebral deformities (29%) and nonvertebral fractures (75%), but the event frequency of each was low. There was a small (22%) but nonsignificant treatment effect on the requirements for radiotherapy and hypercalcemia (39%). There was no effect of clodronate on survival. We conclude that clodronate by mouth significantly decreases the number and complications of skeletal metastases in women with advanced breast cancer.

Reduction in bone relapse and improved survival with oral clodronate for adjuvant treatment of operable breast cancer [ISRCTN83688026]

IntroductionExperimental and clinical data show that the oral bisphosphonate clodronate (Bonefos®) can inhibit tumor-induced osteoclastic bone resorption. This randomized, double-blind, placebo-controlled, multicenter trial was designed to determine if the addition of oral clodronate to standard treatment for primary operable breast cancer could reduce the subsequent occurrence of bone metastases and thereby improve overall survival.Methods1,069 patients with primary operable stage I-III breast cancer were randomized to receive oral clodronate (1,600 mg/day) or placebo for 2 years, in conjunction with standard treatment for primary breast cancer including surgery, radiotherapy, adjuvant chemotherapy, and/or tamoxifen. All patients were assessed for bone metastases at two and five years and additionally when clinically indicated. Survival status was determined as of the close of the study on 30 June 2000 with a median follow up of 5.6 years. The treatment arms were compared using the unstratified log-rank test. Hazard ratios (HRs) with 95% confidence intervals were calculated.ResultsOral clodronate significantly reduced the risk of bone metastases in all patients over the 5 year study period (51 patients versus 73 patients with placebo; HR = 0.692, P = 0.043); the difference was also statistically significant over the 2 year medication period (19 patients versus 35 patients with placebo; HR = 0.546, P = 0.031). These differences were most pronounced in patients with stage II/III disease (39 patients versus 64 patients with placebo, HR = 0.592, P = 0.009 over 5 years; 16 patients versus 32 patients with placebo, HR= 0.496, P = 0.020 over 2 years). Survival data also favoured the clodronate arm (HR for all patients = 0.768, P = 0.048; HR for stage II/III disease = 0.743, P = 0.041), although this was not significant due to multiple analyses. Oral clodronate was well tolerated, with mild-to-moderate diarrhoea being the most frequently reported adverse event.ConclusionThese results confirm that oral clodronate will significantly improve the 5 year bone relapse free survival when used as a supplementary adjuvant treatment for patients receiving standard treatment for primary operable breast cancer.

Extended Efficacy and Safety of Denosumab in Breast Cancer Patients with Bone Metastases Not Receiving Prior Bisphosphonate Therapy

Purpose: Denosumab, a fully human monoclonal antibody to RANKL, suppresses bone resorption. This study evaluated the effects of denosumab in i.v. bisphosphonate (IV BP)–naïve patients with breast cancer-related bone metastases. Experimental Design: Eligible women (n = 255), stratified by type of antineoplastic therapy, were randomized to 1 of 5 blinded denosumab cohorts or an open-label IV BP cohort. Denosumab was administered s.c. every 4 weeks (30, 120, or 180 mg) or every 12 weeks (60 or 180 mg) through 21 weeks. Final efficacy results for up to 25 weeks are reported, including percentage change from baseline in urine N-telopeptide corrected for creatinine (uNTx/Cr) and incidence of skeletal-related events (SRE). Safety results are reported through the end of follow-up (up to 57 weeks). Results: At week 13 and 25, the median percent changes in uNTx/creatinine (Cr) among patients with measurable uNTx were −73% and −75% for the pooled denosumab groups and −79% and −71% for the IV BP group. Among patients with ≥1 postbaseline measurement of uNTx at week 25, 52% (109 of 208) of denosumab-treated patients and 46% (19 of 41) of IV BP–treated patients achieved >65% uNTx/Cr reduction. On-study SREs occurred in 12% (26 of 211) of denosumab-treated patients and 16% (7 of 43) of IV BP–treated patients. Overall rates of adverse events were 95% in denosumab and IV BP groups. No denosumab-related serious or fatal adverse events occurred. Conclusions: In IV BP–naïve breast cancer patients with bone metastases, denosumab suppresses bone turnover and seems to reduce SRE risk similarly to IV BPs, with a safety profile consistent with an advanced cancer population receiving systemic therapy.

Oral clodronate for adjuvant treatment of operable breast cancer (National Surgical Adjuvant Breast and Bowel Project protocol B-34): a multicentre, placebo-controlled, randomised trial

BACKGROUND Bisphosphonates are thought to act through the osteoclast by changing bone microenvironment. Previous findings of adjuvant clodronate trials in different populations with operable breast cancer have been mixed. The National Surgical Adjuvant Breast and Bowel Project (NSABP) protocol B-34 aims to ascertain whether oral clodronate can improve outcomes in women with primary breast cancer. METHODS NSABP B-34 is a multicentre, randomised, double-blind, placebo-controlled study in 3323 women with stage 1-3 breast cancer. After surgery to remove the tumour, patients were stratified by age, axillary nodes, and oestrogen and progesterone receptor status and randomly assigned in a 1:1 ratio to either oral clodronate 1600 mg daily for 3 years (n=1662) or placebo (1661). The primary endpoint was disease-free survival, analysed by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00009945. FINDINGS Median follow-up was 90·7 months (IQR 82·7-100·0) and 3311 patients had data for this period. Disease-free survival did not differ between groups (286 events in the clodronate group vs 312 in the placebo group; hazard ratio 0·91, 95% CI 0·78-1·07; p=0·27). Moreover, no differences were recorded for overall survival (0·84, 0·67-1·05; p=0·13), recurrence-free interval (0·83, 0·67-1·04; p=0·10), or bone metastasis-free interval (0·77, 0·55-1·07; p=0·12). Non-bone metastasis-free interval was slightly increased with clodronate (0·74, 0·55-1·00; p=0·047). Analyses in women age 50 years or older on study entry showed benefits of clodronate for recurrence-free interval (0·75, 0·57-0·99; p=0·045), bone metastasis-free interval (0·62, 0·40-0·95; p=0·027), and non-bone metastasis-free interval (0·63, 0·43-0·91; p=0·014), but not for overall survival (0·80, 0·61-1·04, p=0·094). Adherence to treatment at 3 years was 56% for the clodronate group and 60% for the placebo group. Grade 3 or higher liver dysfunction was noted in 23 of 1612 patients in the clodronate group and 12 of 1623 patients in the placebo group; grade 3-4 diarrhoea was noted in 28 patients in the clodronate group and in ten in the placebo group. There was one possible case of osteonecrosis of the jaw in the clodronate group. INTERPRETATION Findings of NSABP B-34 suggest that bisphosphonates might have anticancer benefits for older postmenopausal women. A meta-analysis of adjuvant bisphosphonate trials is suggested before recommendations for use in non-osteoporotic postmenopausal women with primary breast cancer are made. FUNDING National Cancer Institute, Bayer Oy (formerly Schering Oy).

Bisphosphonates and Bone Turnover in Premenopausal Women Receiving Adjuvant Chemotherapy

Awareness of cancer-induced bone loss (CIBL) and treatmentinduced bone loss has increased among clinicians. Premenopausal women who undertake chemotherapy for breast cancer may lose up to 7% or more of their bone mass in the first year postchemotherapy. Chemotherapy induces ovarian atrophy and estrogen decline at a rate depending on the regimen used, but is much faster than occurs with natural menopause. The bone loss after chemotherapy (and the luteinizing hormone-releasing hormone agonists) in the first year implies a rapid and profound switching to a net resorption pattern of bone turnover. That all this results in real morbidity was shown by Kanis et al, who reported a fourto five-fold increase in the first-year incidence of vertebral fractures in women with newly diagnosed breast cancer compared with an age-matched cohort of healthy women in the metropolitan London area. Attempts to ameliorate the unwanted side effect of CIBL have concentrated on the use of bisphosphonates, and it has sometimes been assumed that standard postmenopausal doses of bisphosphonates will be useful in this patient group. This may not be the case. Hines et al report in this issue of Journal of Clinical Oncology a phase III, placebo-controlled, randomized trial of the bisphosphonate risedronate for the prevention of bone loss in premenopausal women receiving adjuvant chemotherapy for primary breast cancer. This article has unexpected, but explainable, results. Two hundred and sixteen premenopausal women receiving chemotherapy were allocated to weekly oral risedronate or a placebo, and their bone mineral density (BMD) was measured at baseline and 1 year. The change in average BMD at 1 year in the lumbar spine was similar in both active and placebo groups; there was also little difference in the total hip and femoral neck bone mineral densities at 1 year. There was a nonsignificant numerical trend for patients receiving risedronate to have less bone loss at the lumbar spine, femoral neck, and total hip, as well as a numerical but nonsignificant trend for less osteopenia and osteoporosis in the risedronate group. Compliance was good, running at more than 86% in the risedronate arm, and tamoxifen and taxane usage was evenly spread in the two arms. All except two patients had systemic adjuvant chemotherapy, and most would be expected to undergo premature menopause. The results support the clinical impression that it is harder to suppress bone turnover and subsequent bone loss with standard postmenopausal osteoporosis dosing of bisphosphonates in premenopausal women undergoing chemotherapy-induced premature menopause than in older, postmenopausal women. Is this merely a question of inadequate drug dosing in the presence of a powerful wave of estrogen deprivation–induced bone resorption? Or does a preor perimenopausal state confer some kind of protection from the effects of bisphosphonates? Successful inhibition of bone turnover has been achieved in premenopausal women in several studies. Delmas et al have previously reported in JCO that risedronate was effective in the treatment of chemotherapy-induced bone loss in premenopausal women. In this smaller study, the patients (all of whom were premenopausal before adjuvant chemotherapy) were postmenopausal on entry to the trial with endocrine levels in the postmenopause range. Furthermore, patients were administered 30 mg risedronate orally daily for 2 weeks with a 10-week rest period for a total of eight cycles. This regime differs from the 35 mg weekly dose in this study (a standard dose for osteoporosis), and although the total amount of drug during 1 year is similar (1,680 mg in the Delmas et al study v 1,820 mg in the Hines et al study), the initial loading of 420 mg risedronate over 2 weeks may have been sufficient to inhibit bone turnover. However, using a 35 mg weekly dosing of residronate, van Londen et al have demonstrated improvement in hip structural geometry and BMD compared with a placebo group at 1 year. Powles et al reported BMD measurements at 1 and 2 years in women with breast cancer receiving oral clodronate versus placebo demonstrating inhibition of bone turnover in premenopausal women at 1 year ( 1.57% compared with 4.4%), although the effect was lost at 2 years ( 3.99% compared with 3.94%), possibly related to compliance. Postmenopausal women experienced a significant gain in BMD during the first and second years compared with the placebo group. Gnant et al showed the effectiveness of parenteral bisphosphonates in patients who were premenopausal on study entry. All received continuous goserelin for 3 years, thereby converting them to a biologic state similar to postmenopause. In that setting, intravenous zoledronic acid was effective in preventing the reduction in BMD seen in the untreated postmenopausal woman. Likewise, Hershman et al have shown a reduction of BMD loss with zoledronic acid in premenopausal women with CIBL. Estrogens have a beneficial effect on bone health by suppressing bone resorption and enhancing formation. Mechanisms for this effect JOURNAL OF CLINICAL ONCOLOGY E D I T O R I A L VOLUME 27 NUMBER 7 MARCH 1 2009

A double-blind, crossover trial of intravenous clodronate in metastatic bone pain

After a baseline symptom and laboratory assessment, 24 patients with metastatic bone disease and pain were randomized to receive either a 4-hr intravenous infusion of 2-dichloromethylene bisphosphonate (Cl2MDP), 600 mg in 500 mL of normal saline, or a 4-hr placebo infusion, 500 mL of normal saline. The administration was double blind. After 1 wk, the assessment was repeated and the patients were crossed over to the alternate treatment. After 1 more wk, a final assessment and blinded choice by the patient and investigator took place. Of the 21 evaluable patients, 12 (57%) chose the Cl2MDP and 4 (19%) chose the placebo; 5 (24%) patients did not have a specific preference (p = NS). The investigator chose the Cl2MDP in 14 (67%) cases, placebo in 6 (29%) cases and was unable to discern a difference in 1 (5%) case (p less than 0.05). The patients and investigator made similar selections in 16 (76%) instances. On the visual analogue scale assessments, a significant decrease in pain scores was observed following the Cl2MDP infusion (p less than 0.01) and an increase in activity scores was also demonstrated (p less than 0.01). No significant difference in the daily oral morphine equivalent analgesic requirement was demonstrated for either arm. No difference in clinical and laboratory parameters of toxicity was evident between the placebo and Cl2MDP arms of the trial. Our preliminary findings suggest that Cl2MDP is safe, and has analgesic properties that may prove to be useful in the management of metastatic bone pain.