AI-related BMD variation in actual practice conditions: A prospective cohort study

Changes in bone mineral density during 5 years of adjuvant treatment in premenopausal breast cancer patients

PURPOSE

Adjuvant treatment for breast cancer in postmenopausal women is a risk factor for bone loss. However, the association between bone mineral density (BMD) changes in premenopausal breast cancer patients and various adjuvant treatment regimens is not well characterized. In this study, we evaluated the changes in BMD according to adjuvant treatment in premenopausal women with breast cancer.

METHODS

Between 2006 and 2010, BMD data of 910 premenopausal women with breast cancer before operation and 1, 2, 3.5, and 5 years post-operation were retrospectively analyzed. The patients were divided according to the type of treatment: observation (O), tamoxifen (T), chemotherapy (C), C followed by T (C → T), and gonadotropin-releasing hormone (GnRH) agonist with T (G + T).

RESULTS

After 5 years of follow-up, BMD changes were similar between the T and O groups (all p > 0.05). Within 1 year of treatment, the C group showed the most significant BMD loss. The C → T and G + T groups showed more significant BMD loss in the lumbar spine and femur than the O and T groups (both p < 0.001, both). After 1 year of treatment, BMD loss in the lumbar spine was significantly greater in the C → T and G + T groups than in the T group; this tendency was maintained for 5 years of treatment (all p < 0.005).

CONCLUSION

Premenopausal women who received adjuvant treatment which induced menopause showed significant bone loss which lasted for 5 years. Although no significant difference was observed between the O and T groups, tamoxifen treatment during chemotherapy or GnRH agonist treatment might prevent bone loss.

Bone health evaluation one year after aromatase inhibitors completion

INTRODUCTION

Breast cancer patients treated with aromatase inhibitors (AIs) experience increased bone loss during their treatment. However, there is little information about bone mineral density (BMD) after completing AI-treatment. The present study aimed to assess BMD changes one year after AI-therapy completion.

METHODS

Data were collected from 864 postmenopausal women treated with AI during 5 years (5y-AI group), or during 2-3 years after taking tamoxifen therapy (pTAM-AI group). Participants with osteoporosis were treated with oral bisphosphonates (BP). BMD changes in lumbar spine (LS), femoral neck (FN) and total hip (TH) between baseline, end of treatment, and at one year post-treatment were assessed using repeated-measures ANOVA.

RESULTS

At the end of AI-treatment, 382 patients had available BMD values and 316 also had post-treatment BMD values. As expected, BMD levels were decreased at AI-completion in non-BP treated patients. After one year, LS BMD increased in both groups (5y-AI: +2.11% [95%CI: 1.55 to 2.68], p < 0.001; pTAM-AI: +1.00% [95%CI: 0.49 to 1.51], p < 0.001) compared with the end of AI-therapy, while values at FN and TH remained stable. On the other hand, BMD values of BP-treated patients were increased or maintained at the end of AI-treatment and also at post-treatment.

CONCLUSIONS

At one year after AI-completion, FN and TH BMD remained reduced in non-BP treated women, while LS BMD was recovered in the 5y-AI group and partially recovered in the pTAM-AI group. BP treatment increased or maintained BMD values at the end of therapy and at one year post-treatment.

Management of Aromatase Inhibitor-Associated Bone Loss (AIBL) in postmenopausal women with hormone sensitive breast cancer: Joint position statement of the IOF, CABS, ECTS, IEG, ESCEO IMS, and SIOG

BACKGROUND

Several guidelines have been reported for bone-directed treatment in women with early breast cancer (EBC) for averting fractures, particularly during aromatase inhibitor (AI) therapy. Recently, a number of studies on additional fracture related risk factors, new treatment options as well as real world studies demonstrating a much higher fracture rate than suggested by randomized clinical controlled trials (RCTs). Therefore, this updated algorithm was developed to better assess fracture risk and direct treatment as a position statement of several interdisciplinary cancer and bone societies involved in the management of AI-associated bone loss (AIBL).

PATIENTS AND METHODS

A systematic literature review identified recent advances in the management of AIBL. Results with individual agents were assessed based on trial design, size, follow-up, and safety.

RESULTS

Several fracture related risk factors in patients with EBC were identified. Although, the FRAX algorithm includes fracture risk factors (RF) in addition to BMD, it does not seem to adequately address the effects of AIBL. Several antiresorptive agents can prevent and treat AIBL. However, concerns regarding compliance and long-term safety remain. Overall, the evidence for fracture prevention is strongest for denosumab 60 mg s.c. every 6 months. Additionally, recent studies as well as an individual patient data meta-analysis of all available randomized trial data support additional anticancer benefits from adjuvant bisphosphonate treatment in postmenopausal women with a 34% relative risk reduction in bone metastasis and 17% relative risk decrease in breast cancer mortality that needs to be taken into account when advising on management of AIBL.

CONCLUSIONS

In all patients initiating AI treatment, fracture risk should be assessed and recommendation with regard to exercise and calcium/vitamin D supplementation given. Bone-directed therapy should be given to all patients with a T-score<-2.0 or with a T-score of <-1.5 SD with one additional RF, or with ≥2 risk factors (without BMD) for the duration of AI treatment. Patients with T-score>-1.5 SD and no risk factors should be managed based on BMD loss during the first year and the local guidelines for postmenopausal osteoporosis. Compliance should be regularly assessed as well as BMD on treatment after 12 - 24 months. Furthermore, because of the decreased incidence of bone recurrence and breast cancer specific mortality, adjuvant bisphosphonates are recommended for all postmenopausal women at significant risk of disease recurrence.