RESUMO
PURPOSE: The ARIBON trial is a double blind, randomised, placebo controlled study designed to evaluate the impact of ibandronate on bone mineral density (BMD) in women taking anastrozole for adjuvant treatment of breast cancer. METHODS: 131 postmenopausal women with early breast cancer were recruited to the study. Of these, 13 had osteoporosis, 50 osteopenia and 68 normal BMD. Patients with osteoporosis at baseline were treated with monthly oral ibandronate 150 mg for 5 years; osteopenic patients were randomised to receive either ibandronate or placebo for two years and offered open label ibandronate depending upon the results of their 2-year BMD result. RESULTS: Of the 20 patients with osteopenia who were randomised to ibandronate and evaluable at the 2 year visit, 17/20 were not offered a bisphosphonate and the improvements in BMD accrued during the first 2 years were lost both at the LS (-3.21%) and TH (-5.0%). Of the 16 patients randomised to placebo 8/16 with high rates of bone loss during years 0-2 received ibandronate over the next 3 years with improvements in BMD of +5.01 and +1.19 at the LS and TH respectively. The 8 patients who were not offered a bisphosphonate experienced relatively little change in BMD throughout the 5 years of the study (LS +0.15%, TH -2.72%). BMD increased steadily in the 9/13 patients initially identified as having osteoporosis (LS +9.65%, TH +2.72%). CONCLUSIONS: Monthly oral ibandronate provides an option to clinicians considering use of a bisphosphonate to prevent bone loss during aromatase inhibitor therapy.
RESUMO
Relationships between the rate of bone resorption (measured by urinary N-telopeptide (Ntx) excretion) and a range of skeletal complications have been evaluated in patients with metastatic bone disease. A total of 121 patients had monthly measurements of Ntx during treatment with bisphosphonates. All skeletal-related events, plus hospital admissions for bone pain and death during the period of observation, were recorded. Data were available for 121 patients over the first 3-month period of monitoring (0-3 months) and 95 patients over the second 3-month period (4-6 months). N-telopeptide levels were correlated with the number of skeletal-related events and/or death (r=0.62, P<0.001 for 0-3 months and r=0.46, P<0.001 for 4-6 months, respectively). Patients with baseline Ntx values > or =100 nmol mmol(-1) creatinine (representing clearly accelerated bone resorption) were 19.48 times (95% CI 7.55, 50.22) more likely to experience a skeletal-related event/death during the first 3 months than those with Ntx <100 (P<0.001). In a multivariate logistic regression model, Ntx was highly predictive for events/death. This study is the first to indicate a strong correlation between the rate of bone resorption and the frequency of skeletal complications in metastatic bone disease. N-telopeptide appears useful in the prediction of patients most likely to experience skeletal complications and thus benefit from bisphosphonate treatment.