Gelmon K
BC Cancer Research Centre, 675 West 10th Avenue, Vancouver, BC Canada V5Z 1L3.
Breast. 2007 Oct;16(5):446-55. doi: 10.1016/j.breast.2007.04.002. Epub 2007 Jun 4.
The efficacy of 5 years of adjuvant tamoxifen in preventing disease recurrence in patients with breast cancer has been well established. Once patients have completed tamoxifen therapy, however, recurrence risk remains but treatment options are limited. Aromatase inhibitors such as letrozole are emerging as potential alternatives to tamoxifen therapy and as an option after tamoxifen. The pioneering MA-17 trial was designed to evaluate the efficacy and safety of letrozole in the extended adjuvant setting in postmenopausal women who remained disease-free after about 5 years of tamoxifen. The trial was unblinded at first interim analysis after letrozole proved more effective than placebo in improving disease-free survival. As such, the optimal duration of extended adjuvant letrozole was left in question. However, recent results from cohort analysis in MA-17 have shown an ongoing and increasing benefit of letrozole for up to 4 years after tamoxifen, suggesting that longer periods of extended adjuvant letrozole are safe and clinically beneficial.
5年他莫昔芬辅助治疗预防乳腺癌患者疾病复发的疗效已得到充分证实。然而，一旦患者完成他莫昔芬治疗，复发风险依然存在，但治疗选择却很有限。来曲唑等芳香化酶抑制剂正逐渐成为他莫昔芬治疗的潜在替代方案以及他莫昔芬治疗后的一种选择。开创性的MA-17试验旨在评估来曲唑在延长辅助治疗环境中对绝经后女性的疗效和安全性，这些女性在接受约5年他莫昔芬治疗后仍无疾病。在首次中期分析时试验未设盲，因为来曲唑在改善无病生存期方面被证明比安慰剂更有效。因此，延长辅助来曲唑的最佳疗程成了问题。然而，MA-17队列分析的最新结果显示，他莫昔芬治疗后长达4年来曲唑持续发挥且不断增加的益处，提示延长辅助来曲唑治疗更长时间是安全的且具有临床益处。
