Letrozole suppresses plasma estradiol and estrone sulphate more completely than anastrozole in postmenopausal women with breast cancer
Letrozole suppresses plasma estradiol and estrone sulphate more completely than anastrozole in postmenopausal women with breast cancer
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DOI：
10.1200/jco.2007.13.9279
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发表时间：
2008-04-01
影响因子：
45.3
通讯作者：
Dowsett, Mitch
中科院分区：
文献类型：
--
作者：
Dixon, J. Michael;Renshaw, Lorna;Dowsett, Mitch
目的比较阿那曲唑和来曲唑对血浆雌二醇（E2）和硫酸雌酮（E1S）水平的影响。患者和方法54名绝经后雌激素受体阳性乳腺癌患者接受芳香化酶抑制剂（AIs）作为辅助治疗的一部分，随机分配接受3个月的阿那曲唑（1mg）和3个月的来曲唑（2.5 mg），每天口服一次，或3个月的相反顺序。于用药前、用药后3个月，于患者每周同一天、同一时间采血，采用高灵敏度放射免疫法测定血浆E2、E1S水平。结果每组27例。患者平均年龄63岁（49 ~ 83岁）。E2基线水平从3pmol /L到91pmol /L，平均值为25.7pmol/L。54例患者中只有1例（2%）接受来曲唑治疗后E2值>= 3pmol / L，而54例患者中有20例（37%）接受阿那曲唑治疗后E2值>= 3pmol / L （P < 0.001）。外推法显示，阿那曲唑治疗后E2水平平均为2.71 pmol/ L（范围为2.38至3.08 pmol/ L）。来曲唑之后为1.56 pmol/ L（范围为1.37 ~ 1.78 pmol/ L）。阿那曲唑的平均残留E2为10.1%，来曲唑为5.9%。阿那曲唑组E1S残留量为4.6%，来曲唑组为2.0% （P = 0.001）。结论来曲唑对雌激素受体阳性乳腺癌患者血浆E2和E1S水平的降低作用明显大于阿那曲唑。
Purpose To compare the effects of anastrozole and letrozole on plasma estradiol (E2) and estrone sulfate (E1S) levels.Patients and Methods Fifty-four postmenopausal women with estrogen receptor-positive breast cancer receiving aromatase inhibitors (AIs) as part of their adjuvant therapy were randomly assigned to receive either 3 months of anastrozole (1 mg) followed by 3 months of letrozole (2.5 mg), both given orally once daily, or 3 months of the opposite sequence. Blood was taken at the same time and the same day of the week from each patient, before and after 3 months of each drug, and plasma levels of E2 and E1S were determined using highly sensitive radioimmunoassays.Results There were 27 patients in each group. The mean age of the patients was 63 years (range, 49 to 83 years). Baseline E2 levels ranged from 3 pmol/L to 91 pmol/L with a mean of 25.7pmol/L. Only one of 54 (2%) patients had an E2 value >= 3 pmol/ L after receiving letrozole, versus 20 of 54 (37%) patients after receiving anastrozole (P < .001). Extrapolation revealed a mean E2 level after anastrozole treatment of 2.71 pmol/ L (range, 2.38 to 3.08 pmol/ L). Following letrozole, it was 1.56 pmol/ L (range, 1.37 to 1.78 pmol/ L). Mean residual E2 was 10.1% for anastrozole and 5.9% for letrozole. Residual E1S levels were 4.6% for anastrozole and 2.0% for letrozole (P = .001).Conclusion Letrozole reduces plasma E2 and E1S levels to a significantly greater extent than anastrozole in postmenopausal women taking AIs as part of their adjuvant therapy for hormone receptor-positive breast cancer.