<?xml version="1.0" encoding="UTF-8"?><OAI-PMH xmlns="http://www.openarchives.org/OAI/2.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd"><responseDate>2026-10-19T01:04:19Z</responseDate><request verb="GetRecord" identifier="oai:ebyu-rdlopen.rawdatalibrary.net:ebyu/12053" metadataPrefix="oai_dc">https://ebyu-rdlopen.rawdatalibrary.net/oai/request</request><GetRecord><record><header><identifier>oai:ebyu-rdlopen.rawdatalibrary.net:ebyu/12053</identifier><datestamp>2026-10-18T20:39:22Z</datestamp><setSpec>openaire</setSpec><setSpec>driver</setSpec><setSpec>com_ebyu_10000</setSpec><setSpec>col_ebyu_10001</setSpec></header><metadata><oai_dc:dc xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd"><dc:title>Comparison of HER2-zero and HER2-low in terms of clinicopathological factors and survival in early-stage breast cancer: A systematic review and meta-analysis</dc:title><dc:creator>Ergun, Yakup</dc:creator><dc:creator>Ucar, Gokhan</dc:creator><dc:creator>Akagunduz, Baran</dc:creator><dc:subject>Breast cancer</dc:subject><dc:subject>HER2-low</dc:subject><dc:subject>HER2-zero</dc:subject><dc:subject>Hormone receptor</dc:subject><dc:subject>Meta-analysis</dc:subject><dc:subject>Prognosis</dc:subject><dc:subject>Breast Neoplasms</dc:subject><dc:subject>Disease-Free Survival</dc:subject><dc:subject>Female</dc:subject><dc:subject>Humans</dc:subject><dc:subject>Proportional Hazards Models</dc:subject><dc:subject>Receptor, ErbB-2</dc:subject><dc:subject>Retrospective Studies</dc:subject><dc:subject>antineoplastic agent</dc:subject><dc:subject>epidermal growth factor receptor 2</dc:subject><dc:subject>bibliographic database</dc:subject><dc:subject>breast cancer molecular subtype</dc:subject><dc:subject>cancer grading</dc:subject><dc:subject>cancer prognosis</dc:subject><dc:subject>cancer risk</dc:subject><dc:subject>cancer staging</dc:subject><dc:subject>cancer surgery</dc:subject><dc:subject>cancer survival</dc:subject><dc:subject>clinical feature</dc:subject><dc:subject>clinical outcome</dc:subject><dc:subject>confidence interval</dc:subject><dc:subject>correlation analysis</dc:subject><dc:subject>data extraction</dc:subject><dc:subject>data quality assessment</dc:subject><dc:subject>disease free survival</dc:subject><dc:description>Background: The prognostic differences between HER2-zero and HER2-low breast cancer (BC) remain unclear. Purpose of this meta-analysis is to investigate the differences between HER2-low and HER2-zero in terms of clinicopathological factors and survival outcomes in early-stage BC. Methods: We searched major databases and congress proceedings until November 1, 2022 to identify studies comparing HER2-zero and HER2-low in early-stage BC. HER2-zero immunohistochemically (IHC) was defined as score 0, while HER2-low was defined as IHC 1+ or 2+/in situ hybridization negative. Result: A total of 23 retrospective studies involving 636,535 patients were included. HER2-low rate was 67.5% in the hormone receptor (HR)-positive group, while this rate was 48.6% in the HR-negative group. In the analysis of clinicopathological factors by HR status, the proportion of premenopausal patients within the HR-positive group was greater in the HER2-zero arm (66.5% vs 61.8%), whereas grade 3 tumors (74.2% vs 71.5%), patients younger than 50 years of age (47.3% vs 39.6%), and T3-T4 tumors (7.7% vs 6.3%) within the HR-negative group was higher in the HER2-zero arm. In both the HR-positive and HR-negative groups, the HER2-low arm showed significantly improved results for disease-free survival (DFS) and overall survival (OS). The hazard ratios for DFS and OS in the HR-positive group were 0.88 (95% CI 0.83–0.94) and 0.87 (95% CI 0.78–0.96), respectively. In the HR-negative group, the hazard ratios for DFS and OS were 0.87 (95% CI 0.79–0.97) and 0.86 (95% CI 0.84–0.89), respectively. Conclusion: In early-stage BC, HER2-low is associated with better DFS and OS compared to HER2-zero, regardless of HR status. © 2023 Elsevier Ltd</dc:description><dc:publisher>W.B. Saunders Ltd</dc:publisher><dc:date>2023</dc:date><dc:type>Review Article</dc:type><dc:identifier>https://rdlopen.rawdatalibrary.net/r/ebyu/12053</dc:identifier><dc:identifier>https://doi.org/10.1016/j.ctrv.2023.102538</dc:identifier><dc:identifier>0305-7372</dc:identifier><dc:language>en</dc:language><dc:relation>Cancer Treatment Reviews</dc:relation><dc:rights>info:eu-repo/semantics/openAccess</dc:rights><dc:type>info:eu-repo/semantics/review</dc:type><dc:identifier>https://ebyu-rdlopen.rawdatalibrary.net/tr/items/ebyu/12053</dc:identifier></oai_dc:dc></metadata></record></GetRecord></OAI-PMH>