Division of Cancer Prevention and Genetics, European Institute of Oncology, Milan, Italy.
Ann Oncol. 2010 May;21(5):949-54. doi: 10.1093/annonc/mdp408. Epub 2009 Oct 25.
Tamoxifen's cost-benefit ratio for breast ductal intraepithelial neoplasia (DIN) is unclear. Since low-dose tamoxifen showed a favorable modulation of breast cancer biomarkers in phase II trials, a monoinstitutional cohort of women with DIN treated with low-dose tamoxifen or no systemic treatment was analyzed.
A total of 309 patients with DIN received low-dose tamoxifen as part of institutional guidelines and were compared with 371 patients with DIN who received no systemic treatment after surgery.
Women with estrogen receptor (ER)/progesterone receptor (PgR) >50% DIN who were not treated had a higher incidence of breast events than women on tamoxifen [hazard ratio (HR) 1.76; 95% confidence interval (CI) 1.00-3.12] or women with ER/PgR <50% DIN (HR 1.72; 95% CI 1.14-2.58). Among untreated patients with ER >50% DIN, recurrence was higher in PgR > or =50% DIN than in PgR <50% DIN, whereas it was similar among low PgR (<50%) DIN against which tamoxifen had no effect. No difference in endometrial cancer incidence was noted.
High ER and especially high PgR expression is a significant adverse prognostic indicator of DIN, and low-dose tamoxifen appears to be an active treatment. Women with low-expression ER or PgR DIN do not seem to benefit from tamoxifen. A definitive clinical trial is warranted.
他莫昔芬治疗乳腺导管上皮内瘤变（DIN）的成本效益比尚不清楚。由于低剂量他莫昔芬在 II 期临床试验中显示出对乳腺癌生物标志物的有利调节作用，因此分析了一组接受低剂量他莫昔芬或无系统治疗的 DIN 女性的单机构队列。
共有 309 名患有 DIN 的患者接受了低剂量他莫昔芬治疗，作为机构指南的一部分，并与 371 名手术后未接受系统治疗的患有 DIN 的患者进行了比较。
未接受治疗的 ER/PgR > 50% 的 DIN 女性的乳房事件发生率高于接受他莫昔芬治疗的女性[风险比（HR）1.76；95%置信区间（CI）1.00-3.12]或 ER/PgR < 50% 的 DIN 女性（HR 1.72；95% CI 1.14-2.58）。在未接受治疗的 ER > 50%的 DIN 患者中，PgR > = 50%的 DIN 比 PgR < 50%的 DIN 更易复发，而在 PgR 较低（<50%）的 DIN 中，他莫昔芬无作用，复发情况相似。子宫内膜癌的发病率无差异。
高 ER，尤其是高 PgR 表达是 DIN 的一个重要不良预后指标，低剂量他莫昔芬似乎是一种有效的治疗方法。低表达 ER 或 PgR 的 DIN 女性似乎不能从他莫昔芬中获益。需要进行一项明确的临床试验。
