The POWER-PAK Score Characterizes Tumor Response to 3 Months of Preoperative Endocrine Therapy.

Autor: Meneveau MO; Department of Surgery, Division of Breast and Melanoma Surgery, University of Virginia, Charlottesville, VA, USA., Crawford MP; Department of Pathology, University of Virginia, Charlottesville, VA, USA., Turkheimer LM; Department of Surgery, Division of Breast and Melanoma Surgery, University of Virginia, Charlottesville, VA, USA., Millard TA; Department of Medicine, Division of Hematology/Oncology, University of Virginia, Charlottesville, VA, USA., Atkins KA; Department of Pathology, University of Virginia, Charlottesville, VA, USA., Showalter SL; Department of Surgery, Division of Breast and Melanoma Surgery, University of Virginia, Charlottesville, VA, USA. snl2t@uvahealth.org.
Jazyk: angličtina
Zdroj: Annals of surgical oncology [Ann Surg Oncol] 2023 Oct; Vol. 30 (10), pp. 6034-6040. Date of Electronic Publication: 2023 Jul 15.
DOI: 10.1245/s10434-023-13892-8
Abstrakt: Background: 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.
Methods: 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.
Results: 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).
Conclusions: 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.
(© 2023. Society of Surgical Oncology.)
Databáze: MEDLINE
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