Department of Surgery, Division of Breast and Melanoma Surgery, University of Virginia, Charlottesville, VA, USA.
Department of Pathology, University of Virginia, Charlottesville, VA, USA.
Ann Surg Oncol. 2023 Oct;30(10):6034-6040. doi: 10.1245/s10434-023-13892-8. Epub 2023 Jul 15.
The Pre-Operative Window of Endocrine Therapy to Inform Radiation Therapy Decisions (POWER, NCT04272801) trial aims to determine whether 3 months of preoperative endocrine therapy (pre-ET) informs adjuvant radiation therapy decisions among older women with early stage, ER-positive breast cancer. We propose the POWER Pathologic Assessment and Ki-67 (POWER-PAK) scoring system to characterize the histologic effects of pre-ET.
Histologic evaluation was performed on core biopsy and lumpectomy specimens from 37 POWER trial participants who completed pre-ET and surgery. The POWER-PAK score consists of tumor regression, decrease in Ki-67 expression, and ER expression, each ranging from 0 to 2. Scores were aggregated to create the POWER-PAK score with a range from 0 to 6. Participants with no residual tumor were labelled 6-NRT.
ER expression did not decrease after pre-ET. Ki-67 decreased from 13% in biopsy specimens to 5% in the lumpectomy specimens (p < 0.001). Cellularity decreased from 40% to 23% (p < 0.001). There was heterogeneity of POWER-PAK scores ranging from 2 to 6-NRT: score of 2, n = 2 (5.4%); 4, n = 8 (21.6%); 5, n = 4 (10.8%); 6, n = 16 (43.2%); and 6-NRT, n = 7 (18.9%). Participants with a score ≥ 5 were more likely to have smaller tumors after pre-ET compared with those with a score < 5 (p = 0.04).
The tumor responses following treatment with pre-ET are heterogenous. We propose that the POWER-PAK scoring system can be used to quantify response to pre-ET. Future studies will explore the use of POWER-PAK to support informed decision-making for adjuvant therapy options for older women with early stage breast cancer.
内分泌治疗前窗以告知放疗决策（POWER，NCT04272801）试验旨在确定 3 个月的术前内分泌治疗（术前 ET）是否能为早期 ER 阳性乳腺癌的老年女性提供辅助放疗决策信息。我们提出了 POWER 病理性评估和 Ki-67（POWER-PAK）评分系统，以描述术前 ET 的组织学效应。
对 37 名完成术前 ET 和手术的 POWER 试验参与者的核心活检和肿瘤切除术标本进行组织学评估。POWER-PAK 评分由肿瘤消退、Ki-67 表达下降和 ER 表达组成，每项评分范围为 0 至 2 分。评分汇总后，POWER-PAK 评分范围为 0 至 6 分。无残余肿瘤的患者标记为 6-NRT。
ER 表达在术前 ET 后没有下降。Ki-67 从活检标本中的 13%降至肿瘤切除术标本中的 5%（p<0.001）。细胞密度从 40%降至 23%（p<0.001）。POWER-PAK 评分范围从 2 到 6-NRT 不等，2 分者 2 例（5.4%），4 分者 8 例（21.6%），5 分者 4 例（10.8%），6 分者 16 例（43.2%），6-NRT 者 7 例（18.9%）。与评分<5 者相比，评分≥5 者的肿瘤在术前 ET 后更小（p=0.04）。
接受术前 ET 治疗后的肿瘤反应是异质的。我们提出，POWER-PAK 评分系统可用于量化对术前 ET 的反应。未来的研究将探索使用 POWER-PAK 来支持为早期乳腺癌老年女性提供辅助治疗方案的决策。
