Osteoporosis after adjuvant treatment for early-stage breast cancer.

INTRODUCTION: Adjuvant treatment of early-stage breast cancer has been associated with bone loss in randomised trials, but evidence from unselected populations is needed. In a single-center study, we assessed the annual percentage change in bone mineral density (∆BMDt) and risk of osteoporosis from two to five years after adjuvant chemotherapy in patients with oestrogen-receptor-positive and oestrogen-receptor-negative tumours. METHODS: Dual energy X-ray absorptiometry (DXA) was performed in 241 recurrence-free Danish breast cancer patients, among whom 157 had a prior DXA scan within two years of chemotherapy ("early"). Linear regression was used to assess ∆BMDt in spine and hip according to age, different health-related variables and time since early DXA. RESULTS: Based on 157 patients, we observed annual decreases in spine BMD of 1.73% (95% confidence interval (CI): -2.01--1.44, p less than 0.001) and hip BMD of 1.30% (95% CI: -1.51--1.09, p less than 0.001). Patients aged less than 50 years at diagnosis had a significant decrease in mean spine BMD of 2.23% (95% CI: -2.78--1.68), whereas the decline was more limited in patients aged 50-59 years and patients aged 60 years or older with a mean spine BMD of 1.70% (95% CI: -2.07--1.34) and 0.81% (95% CI: -1.42--0.20), respectively. The results persisted in multivariable analyses. Osteoporosis was diagnosed in 9% of patients, all postmenopausal. CONCLUSIONS: Adjuvant anthracycline-taxane-based chemotherapy followed by endocrine therapy caused bone loss, especially in younger compared with older patients with early-stage breast cancer, confirming the results from randomised trials. FUNDING: This work was supported by the Region of Southern Denmark (grant number 13/7078); the University of Southern Denmark (grant number 00-101-000); the Danish Cancer Society (grant number R90-A6210-14-52); the Department of Oncology and Department of Endocrinology, Odense University Hospital; and the Consultant Council Scholarship, Odense University Hospital. TRIAL REGISTRATION: The study was approved by the Ethics Committee in Region of Southern Denmark (Project ID S-20140142) and the Danish Data Protection Board (ID 2008-58-0035).

Change in bone mineral density during adjuvant chemotherapy for early-stage breast cancer.

PURPOSE: Adjuvant chemotherapy has been associated with loss of bone mineral density (BMD) either as a direct effect or due to glucocorticoids used as supportive care medication. A prospective cohort study was conducted to evaluate changes in BMD from baseline to right after completion of chemotherapy, i.e., 4 months. METHODS: Dual-imaging X-ray absorptiometry (DXA) was performed at baseline and after completing anthracycline- and taxane-based chemotherapy to measure BMD in the spine, hip, and forearm in early-stage breast cancer patients. High-dose prednisolone was used at three weekly intervals to reduce nausea and vomiting. Patients were advised a daily calcium/vitamin D supplement. Linear regression was used to assess mean percentage change in BMD and 95 % confidence intervals (95 % CI) according to doses of prednisolone, menopausal status, smoking, and BMI. RESULTS: Eight patients were excluded: seven because of initiation of bisphosphonate treatment due to osteoporosis at baseline, and one had non-interpretable DXA. The final cohort included 97 patients with a mean age of 53 years (range 34-72). Mean cumulative prednisolone dose was 1308 mg (95 % CI 1255; 1362). BMD increased 1.36 % (95 % CI 0.7; 2.0, p < 0.001) in the spine and 1.27 % (95 % CI 0.9; 1.7, p < 0.001) in the hip. Forearm BMD did not change. Postmenopausal women had increases in spine BMD of 2.35 % (95 % CI 1.1; 3.6, p < 0.001) compared to premenopausal women. The spine BMD of current smokers decreased 1.67 % (95 % CI -3.3; -0.1, p = 0.04) compared to never/former smokers. CONCLUSIONS: Adjuvant chemotherapy supplemented with prednisolone was not associated with loss of BMD. Postmenopausal women gained bone mass, whereas current smokers lost bone mass.