Institute of Clinical Medicine, University of Oslo, Faculty Division at Akershus University Hospital, Sykehusveien 27, Lørenskog N-1478, Norway.
Br J Cancer. 2011 Mar 29;104(7):1059-66. doi: 10.1038/bjc.2011.58. Epub 2011 Mar 1.
Aromatase inhibition is the gold standard for treatment of early and advanced breast cancer in postmenopausal women suffering from an estrogen receptor-positive disease. The currently established group of anti-aromatase compounds comprises two reversible aromatase inhibitors (anastrozole and letrozole) and on the other hand, the irreversible aromatase inactivator exemestane. Although exemestane is the only widely used aromatase inactivator at this stage, physicians very often have to choose between either anastrozole or letrozole in general practice. These third-generation aromatase inhibitors (letrozole/Femara (Novartis Pharmaceuticals, Basel, Switzerland) and anastrozole/Arimidex (AstraZeneca, Pharmaceuticals, Macclesfield, Cheshire, UK)), have recently demonstrated superior efficacy compared with tamoxifen as initial therapy for early breast cancer improving disease-free survival. However, although anastrozole and letrozole belong to the same pharmacological class of agents (triazoles), an increasing body of evidence suggests that these aromatase inhibitors are not equipotent when given in the clinically established doses. Preclinical and clinical evidence indicates distinct pharmacological profiles. Thus, this review focuses on the differences between the non-steroidal aromatase inhibitors allowing physicians to choose between these compounds based on scientific evidence. Although we are waiting for the important results of a still ongoing head-to-head comparison in patients with early breast cancer at high risk for relapse (Femara Anastrozole Clinical Evaluation trial; 'FACE-trial'), clinicians have to make their choices today. On the basis of available evidence summarised here and until FACE-data become available, letrozole seems to be the best choice for the majority of breast cancer patients whenever a non-steroidal aromatase inhibitor has to be chosen in a clinical setting. The background for this recommendation is discussed in the following chapters.
芳香酶抑制是治疗绝经后雌激素受体阳性疾病的早期和晚期乳腺癌的金标准。目前建立的一组抗芳香酶化合物包括两种可逆的芳香酶抑制剂（阿那曲唑和来曲唑）和另一方面，不可逆的芳香酶失活剂依西美坦。虽然依西美坦是现阶段唯一广泛使用的芳香酶失活剂，但在一般实践中，医生经常不得不选择阿那曲唑或来曲唑。这些第三代芳香酶抑制剂（来曲唑/Femara（诺华制药，巴塞尔，瑞士）和阿那曲唑/Arimidex（阿斯利康制药，麦克尔斯菲尔德，柴郡，英国）），最近与他莫昔芬相比，作为早期乳腺癌的初始治疗，改善了无病生存率，显示出更高的疗效。然而，尽管阿那曲唑和来曲唑属于同一类药理学药物（三唑类），越来越多的证据表明，这些芳香酶抑制剂在临床应用的剂量下并不具有同等效力。临床前和临床证据表明它们具有不同的药理学特征。因此，这篇综述重点介绍了非甾体芳香酶抑制剂之间的差异，使医生能够根据科学证据在这些化合物之间进行选择。虽然我们正在等待一项仍在进行的高危复发早期乳腺癌患者（Femara Anastrozole Clinical Evaluation 试验；'FACE 试验）头对头比较的重要结果，但临床医生今天必须做出选择。基于这里总结的现有证据，并且在 FACE 数据可用之前，对于大多数乳腺癌患者来说，在临床环境中需要选择非甾体芳香酶抑制剂时，来曲唑似乎是最佳选择。以下章节将讨论这一建议的背景。
