乳がん再発リスクの低下（Abstract #: LBA4）

ゾレドロン酸は術後ホルモン療法を受けている早期乳がん患者の再発リスクを軽減する
Zoledronic acid reduces risk for recurrence when given to patients with early-stage breast cancer who are receiving postoperative hormone therapy
ゾレドロン酸は、術後卵巣機能抑制およびホルモン療法を受けている閉経前早期乳がん患者の再発リスクを軽減する、とAmerican Society of Clinical Oncology学会で発表された。このphase IIIトライアルでは、ゴセレリンを用いた術後卵巣抑制療法を受けているstage IまたはIIの患者を、タモキシフェンまたはアナストロゾールのいずれかにゾレドロン酸を追加または追加なしの4群のいずれかに無作為に割り付けた。一次エンドポイントは無増悪生存期間であった。追跡期間中央値の60ヵ月後、ホルモン療法とゾレドロン酸の併用によりホルモン療法単独と比較し再発リスクが35%低下した2つのホルモン療法群の間に有意な差はなかった。4つの治療群全てにおいて忍容性は良好であり予想外の副作用は認められなかった。
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Zoledronic acid reduces risk for recurrent breast cancer in premenopausal patients with early-stage disease who have undergone surgery and are receiving ovarian suppression and hormone therapy, according to a presentation at the annual meeting of the American Society of Clinical Oncology.

All women in the multicenter phase III trial had cancer that was positive for estrogen receptors, progesterone receptors, or both.

?"It's very exciting to find that in addition to preventing bone loss in women undergoing adjuvant endocrine therapy for breast cancer, zoledronic acid can also reduce the likelihood that breast cancer will return in some women," said Michael Gnant, MD, a professor of surgery at the Medical University of Vienna, the president of the Austrian Breast and Colorectal Cancer study group, and the study's lead author.

"Future research will focus on optimizing the administration schedule and the dose, and determining which patients will benefit the most from treatment with zoledronic acid."

The study randomized 1,803 patients with stage I or II disease who were receiving postoperative ovarian suppression using goserelin to one of four arms: treatment with tamoxifen or anastrozole with or without zoledronic acid.

The study's primary endpoint was disease-free survival. After a median follow-up of 60 months, hormone therapy plus zoledronic acid reduced the risk of relapse by 35 percent compared with hormone therapy alone. There was not a significant difference between the two hormone therapies. Treatment was well tolerated in all four groups and there were no unexpected side effects.