Department of Health Sciences, Mayo Clinic College of Medicine, Rochester, Minnesota, 55905, USA.
Clin Cancer Res. 2013 Apr 15;19(8):2144-53. doi: 10.1158/1078-0432.CCR-12-2789. Epub 2013 Mar 6.
Mammographic breast density (MBD) is decreased by tamoxifen, but the effect of aromatase inhibitors is less clear.
We enrolled early-stage postmenopausal patients with breast cancer initiating adjuvant aromatase inhibitor therapy and ascertained mammograms before and at an average 10 months of aromatase inhibitor therapy. We matched cases to healthy postmenopausal women (controls) from a large mammography screening cohort on age, baseline body mass index, baseline MBD, and interval between mammograms. We estimated change in MBD using a computer-assisted thresholding program (Cumulus) and compared differences between cases and matched controls.
In predominantly White women (96%), we found 14% of the 387 eligible cases had a MBD reduction of at least 5% after an average of 10 months of aromatase inhibitor therapy. MBD reductions were associated with higher baseline MBD, aromatase inhibitor use for more than 12 months, and prior postmenopausal hormone use. Comparing each case with her matched control, there was no evidence of an association of change in MBD with aromatase inhibitor therapy [median case-control difference among 369 pairs was -0.1% (10th and 90th percentile: -5.9%, 5.2%) P = 0.51]. Case-control differences were similar by type of aromatase inhibitor (P's 0.41 and 0.56); prior use of postmenopausal hormones (P = 0.85); baseline MBD (P = 0.55); and length of aromatase inhibitor therapy (P = 0.08).
In postmenopausal women treated with aromatase inhibitors, 14% of cases had a MBD reduction of more than 5%, but these decreases did not differ from matched controls. These data suggest that MBD is not a clinically useful biomarker for predicting the value of aromatase inhibitor therapy in White postmenopausal women.
他莫昔芬可降低乳腺密度（MBD），但芳香化酶抑制剂的作用尚不清楚。
我们招募了开始接受辅助芳香化酶抑制剂治疗的早期绝经后乳腺癌患者，并在接受芳香化酶抑制剂治疗前和平均 10 个月时确定了乳房 X 光片。我们根据年龄、基线体重指数、基线 MBD 和乳房 X 光片之间的间隔，将病例与来自大型乳房 X 光筛查队列的健康绝经后女性（对照组）相匹配。我们使用计算机辅助阈值程序（Cumulus）估计 MBD 的变化，并比较病例和匹配对照组之间的差异。
在以白种人为主的女性（96%）中，我们发现 387 名符合条件的病例中有 14%在接受芳香化酶抑制剂治疗平均 10 个月后 MBD 至少降低了 5%。MBD 降低与较高的基线 MBD、芳香化酶抑制剂使用超过 12 个月以及绝经后激素使用有关。将每个病例与其匹配的对照进行比较，没有证据表明 MBD 变化与芳香化酶抑制剂治疗有关[369 对中病例对照差异的中位数为-0.1%（第 10 和第 90 个百分位数：-5.9%，5.2%），P=0.51]。病例对照差异与芳香化酶抑制剂类型（P 值分别为 0.41 和 0.56）、绝经后激素使用史（P=0.85）、基线 MBD（P=0.55）和芳香化酶抑制剂治疗时间（P=0.08）无关。
在接受芳香化酶抑制剂治疗的绝经后妇女中，14%的病例 MBD 降低超过 5%，但与匹配的对照组没有差异。这些数据表明，MBD 不是预测白种绝经后妇女芳香化酶抑制剂治疗价值的临床有用的生物标志物。
