Ravdin P M, Green S, Dorr T M, McGuire W L, Fabian C, Pugh R P, Carter R D, Rivkin S E, Borst J R, Belt R J
University of Texas Health Science Center, San Antonio.
J Clin Oncol. 1992 Aug;10(8):1284-91. doi: 10.1200/JCO.1992.10.8.1284.
Southwest Oncology Group (SWOG) protocol 8228 is a prospective trial designed to investigate the prognostic significance of progesterone receptor (PgR) levels in estrogen receptor (ER)-positive breast cancer patients who were treated with tamoxifen. This study was undertaken because the value of PgR measurements in advanced breast cancer had been assessed previously only in studies that were small, retrospective, or included heterogeneously treated patients.
Receptor assays were performed only in the laboratories that met strict quality control guidelines. Of the 398 patients entered, 342 patients were eligible and assessable for the study end points of objective clinical response, time to treatment failure, and overall survival.
Multivariate analysis shows that elevated PgR levels significantly and independently correlated with increased probability of response to tamoxifen, longer time to treatment failure, and longer overall survival. Overall response rate (defined as complete response [CR], partial response [PR], or stable disease [SD] for greater than 6 months) in this trial was 54%. Response rates to tamoxifen were 43%, 53%, and 61% in subsets of patients with less than 10, 10 to 99, and more than 100 fmol/mg PgR, respectively. Exploratory subset analysis using PgR and other prognostic variables identified ER-positive patient subsets with response rates to tamoxifen ranging from 24% (premenopausal patients) to 86% (postmenopausal patients with ER greater than 38 and PgR greater than 329 fmol/mg). No groups of ER-positive patients were identified who had such a low response rate as to absolutely preclude considering the use of tamoxifen. Multivariate analysis showed the independent, statistically significant predictors were: for response to tamoxifen, menopausal status, PgR, and ER; for time to treatment failure, menopausal status, disease-free interval (DFI), PgR, and ER; and for overall survival DFI, PgR, ER, site of disease, and history of adjuvant therapy.
We conclude that knowledge of PgR levels together with other clinical information can improve the pretreatment assessment of ER-positive breast cancer patients with metastatic disease.
西南肿瘤协作组（SWOG）8228号方案是一项前瞻性试验，旨在研究在接受他莫昔芬治疗的雌激素受体（ER）阳性乳腺癌患者中，孕激素受体（PgR）水平的预后意义。开展这项研究是因为此前仅在规模较小、回顾性或纳入了异质性治疗患者的研究中评估过PgR检测在晚期乳腺癌中的价值。
仅在符合严格质量控制指南的实验室进行受体检测。在入组的398例患者中，342例患者符合条件并可评估客观临床反应、治疗失败时间和总生存等研究终点。
多变量分析显示，PgR水平升高与对他莫昔芬反应的概率增加、治疗失败时间延长及总生存时间延长显著且独立相关。本试验的总缓解率（定义为完全缓解[CR]、部分缓解[PR]或疾病稳定[SD]超过6个月）为54%。PgR低于10、10至99、超过100 fmol/mg的患者亚组对他莫昔芬的缓解率分别为43%、53%和61%。使用PgR和其他预后变量进行的探索性亚组分析确定，ER阳性患者亚组对他莫昔芬的缓解率范围为24%（绝经前患者）至86%（ER大于38且PgR大于329 fmol/mg的绝经后患者）。未发现ER阳性患者组的缓解率低到绝对排除考虑使用他莫昔芬的情况。多变量分析显示，具有统计学意义的独立预测因素为：对于他莫昔芬反应，为绝经状态、PgR和ER；对于治疗失败时间为绝经状态、无病间期（DFI）、PgR和ER；对于总生存为DFI、PgR、ER、疾病部位和辅助治疗史。
我们得出结论，了解PgR水平及其他临床信息可改善对转移性疾病的ER阳性乳腺癌患者的预处理评估。
