Breast Center, CePO, University Hospital, Lausanne.
Ann Oncol. 2012 Jun;23(6):1474-81. doi: 10.1093/annonc/mdr448. Epub 2011 Oct 14.
The risk of osteoporosis and fracture influences the selection of adjuvant endocrine therapy. We analyzed bone mineral density (BMD) in Swiss patients of the Breast International Group (BIG) 1-98 trial [treatment arms: A, tamoxifen (T) for 5 years; B, letrozole (L) for 5 years; C, 2 years of T followed by 3 years of L; D, 2 years of L followed by 3 years of T].
Dual-energy X-ray absorptiometry (DXA) results were retrospectively collected. Patients without DXA served as control group. Repeated measures models using covariance structures allowing for different times between DXA were used to estimate changes in BMD. Prospectively defined covariates were considered as fixed effects in the multivariable models.
Two hundred and sixty-one of 546 patients had one or more DXA with 577 lumbar and 550 hip measurements. Weight, height, prior hormone replacement therapy, and hysterectomy were positively correlated with BMD; the correlation was negative for letrozole arms (B/C/D versus A), known osteoporosis, time on trial, age, chemotherapy, and smoking. Treatment did not influence the occurrence of osteoporosis (T score < -2.5 standard deviation).
All aromatase inhibitor regimens reduced BMD. The sequential schedules were as detrimental for bone density as L monotherapy.
骨质疏松症和骨折风险会影响辅助内分泌治疗的选择。我们分析了瑞士乳腺癌国际集团（BIG）1-98 试验患者的骨密度（BMD）[治疗组：A，他莫昔芬（T）治疗 5 年；B，来曲唑（L）治疗 5 年；C，T 治疗 2 年，L 治疗 3 年；D，L 治疗 2 年，T 治疗 3 年]。
回顾性收集双能 X 射线吸收法（DXA）结果。未行 DXA 的患者作为对照组。采用协方差结构重复测量模型，允许 DXA 之间的时间不同，以估计 BMD 的变化。前瞻性定义的协变量被认为是多变量模型中的固定效应。
546 例患者中有 261 例接受了一次或多次 DXA 检查，共进行了 577 次腰椎和 550 次髋关节测量。体重、身高、激素替代治疗和子宫切除术与 BMD 呈正相关；与来曲唑组（B/C/D 与 A）、已知骨质疏松症、试验时间、年龄、化疗和吸烟呈负相关。治疗并未影响骨质疏松症的发生（T 评分<-2.5 个标准差）。
所有芳香化酶抑制剂方案均降低了 BMD。序贯方案对骨密度的损害与来曲唑单药治疗相当。
