Effect of adjuvant endocrine therapy on hormonal levels in premenopausal women with breast cancer: the ProBONE II study.

Endocrine therapy (ET) is a key treatment modality in hormone receptor positive (HR+) early breast cancer (BC) patients. Although the anticancer activity of adjuvant ET + zoledronic acid (ZOL) has been investigated, the potential effects of ET ± ZOL on endocrine hormones in premenopausal women with HR+ early BC are not well understood. ProBONE II was prospective, double-blind, randomized controlled trial. Premenopausal patients with histologically confirmed invasive BC with no evidence of metastases and a T score >-2.5 received ET ± ZOL 4 mg every 3 months for 2 years. Serum levels of estradiol (E2), follicle-stimulating hormone, anti-muellerian hormone (AMH), inhibins A and B, sex hormone-binding globulin, parathyroid hormone, total testosterone, and vitamin D were evaluated at baseline and at every scheduled visit. Of 71 women enrolled, 70 were evaluable (n = 34, ZOL; n = 36, placebo). No statistically significant differences were observed in hormone levels, except E2 and AMH, which showed minor differences. These included decreases in serum E2 levels, which reached a nadir after 3 and 9 months in placebo and ZOL groups, respectively, and decrease in serum AMH levels throughout the study with ZOL, but remained constant with placebo after 6 months. Adverse events in ZOL-treated group were influenza-like illness (32.4 %), bone pain (32.4 %), chills (20.6 %), and nausea (23.5 %). ET ± ZOL was well tolerated. This study showed no influence of ZOL on hormonal level changes that accompany ET, supporting inclusion of ZOL in adjuvant therapy for premenopausal women with HR + BC.

Effects of a low-dose oral estrogen only treatment on bone mineral density and quantitative ultrasonometry in postmenopausal women.

INTRODUCTION: The aim of this study was to evaluate an oral low-dose estrogen therapy on bone mineral density (BMD) and quantitative ultrasonometry (QUS) in osteopenic postmenopausal women. MATERIAL AND METHODS: This prospective, open-label cohort study investigated 120 postmenopausal hysterectomized women. Forty-seven women had been treated with 0.3 mg conjugated equine estrogen daily (ET). Primary end point was the change in BMD at the spine after 24 months. Secondary end points were among other changes in QUS at the os calcis and phalanges. RESULTS: After matching 42 participants in the ET group, 42 controls were analyzed. The change in BMD differed significantly after 24 months (p = 0.019). Women on ET showed significant increase of spine and hip Z-score, whereas controls showed significant decreases in spine and total hip BMD. In QUS of the os calcis and the phalanges, a number of variables showed a significant improvements with ET. CONCLUSION: Our results comprised a positive effect of an oral low-dose estrogen therapy on BMD. Limitations of the study are the small sample size and the open-label, non-randomized cohort study design. The findings are in accordance to the common literature and support the use of ET in the primary prevention of postmenopausal bone loss.