Comparison of combined low-dose hormone therapy vs. tibolone in the prevention of bone loss.

OBJECTIVES: To compare the effects on bone mineral density (BMD) measured by dual-energy X-ray absorptiometry at the lumbar spine, the femoral neck and the total hip following 2 years of treatment with a low-dose combined hormone therapy (HT) comprised of 1 mg estradiol and 0.5 mg norethisterone acetate (E2/NETA) versus 2.5 mg tibolone in postmenopausal women. Additionally, quantitative ultrasonometry (QUS) of the os calcaneus and of the phalanges was performed. METHODS: Changes in BMD, QUS and side-effects were assessed at baseline, 6, 12 and 24 months in 50 postmenopausal women who received either E2/NETA (n = 26) or tibolone (n = 24) for 2 years. RESULTS: Compared to women on tibolone, women receiving E2/NETA showed a significant increase in BMD from baseline to 12 and 24 months at the lumbar spine (3.07%, 3.86%; p < 0.01 vs. 1.13%, 2.23%; p < 0.05), and at the total hip (1.33%, 1.69%; p < 0.01 vs. 0.76%, 0.70%) and at the femoral neck from baseline to 24 months (1.10%; p < 0.05). QUS indices only showed a significant change with the ultrasound bone profile index with E2/NETA at 6 months (-2.32%; p < 0.001). CONCLUSIONS: Low-dose E2/NETA showed a significantly higher increase in BMD compared to tibolone. QUS measurement was not considered to comprise beneficial effects in monitoring drug-induced bone changes.

Effects of zoledronic acid on bone mineral density in premenopausal women receiving neoadjuvant or adjuvant therapies for HR+ breast cancer: the ProBONE II study.

UNLABELLED: The effects of bisphosphonates on altered bone turnover marker (BTM) levels associated with adjuvant endocrine or chemotherapy in early breast cancer have not been systematically investigated. In ProBONE II, zoledronic acid decreased these elevated BTM levels and increased bone mineral density (BMD) during adjuvant therapy, consistent with its antiresorptive effects. INTRODUCTION: Adjuvant chemotherapy or endocrine therapy for early hormone receptor-positive breast cancer (HR(+) BC) is associated with rapid BMD loss and altered BTM levels. Adjuvant bisphosphonate studies demonstrated BMD increases, but did not investigate BTM effects. The randomized, double-blind, ProBONE II study investigated the effect of adjuvant zoledronic acid (ZOL) on BMD and BTM in premenopausal women with early HR(+) BC. METHODS: Seventy premenopausal women with early HR(+) BC received adjuvant chemotherapy and/or endocrine therapy plus ZOL (4 mg IV every 3 months) or placebo for 24 months. Primary endpoint was change in lumbar spine BMD at 24 months versus baseline. Secondary endpoints included femoral neck and total femoral BMD changes, changes in BTM, and safety. RESULTS: Lumbar spine BMD increased 3.14% from baseline to 24 months in ZOL-treated participants versus a 6.43% decrease in placebo-treated participants (P < 0.0001). Mean changes in T- and Z-scores, and femoral neck and total femoral BMD, showed similar results. Bone resorption marker levels decreased ∼ 55% in ZOL-treated participants versus increases up to 65% in placebo-treated participants (P < 0.0001 for between-group differences). Bone formation marker (procollagen I N-terminal propeptide) levels decreased ∼ 57% in ZOL-treated participants versus increases up to 45% in placebo-treated participants (P < 0.0001 for between-group differences). Adverse events were consistent with the established ZOL safety profile and included one case of osteonecrosis of the jaw after a tooth extraction. CONCLUSIONS: Adding ZOL to adjuvant therapy improved BMD, reduced BTM levels, and was well tolerated in premenopausal women with early HR(+) BC receiving adjuvant chemotherapy and/or endocrine therapy.

Effects of exemestane and tamoxifen on hormone levels within the Tamoxifen Exemestane Adjuvant Multicentre (TEAM) trial: results of a German substudy.

AIM: The aim of this study was to compare the effects of exemestane and tamoxifen on hormone levels in postmenopausal patients with hormone receptor-positive breast cancer within a Germany substudy of the Tamoxifen Exemestane Adjuvant Multinational (TEAM) trial. METHODS: Within the TEAM trial, patients were randomized to receive adjuvant treatment with exemestane for 5 years or tamoxifen for 2.5-3 years followed by exemestane for 2-2.5 years. Serum levels of testosterone, dehydroepiandrosterone sulfate (DHEAS), sex hormone binding globulin (SHBG), follicle stimulating hormone (FSH) and parathyroid hormone (PTH)-intact were measured at screening and after 3, 6 and 12 months of treatment. RESULTS: Data on hormone levels were available from 63 patients in the tamoxifen arm and 68 patients in the exemestane arm. Treatment with exemestane resulted in decreases from baseline in SHBG and PTH-intact levels, and increases from baseline in testosterone, DHEAS and FSH levels. Tamoxifen treatment resulted in increases from baseline in SHBG and PTH-intact, whereas levels of testosterone and FSH decreased and DHEAS levels did not change. At all time points assessed, the absolute change from baseline was significantly different between tamoxifen and exemestane for testosterone, SHBG, FSH and PTH-intact (all p < 0.0001). CONCLUSIONS: Exemestane and tamoxifen had statistically significantly different effects on hormone levels, including testosterone, SHBG, FSH and PTH-intact.