Slamon DJ, Clark GM, Wong SG, Levin WJ, Ullrich A, McGuire WL. Human breast Cancer: correlation of Relapse and Survival with amplification of the HER-2/Neu Oncogene. New York. 1987;235(4785):177–82.

Article  CAS  Google Scholar 

Slamon DJ, Leyland-Jones B, Shak S, Fuchs H, Paton V, Bajamonde V. Use of chemotherapy plus a monoclonal antibody against HER2 for metastatic breast cancer that overexpresses HER2. N Engl J Med. 2001;344(11):783–92.

Article  CAS  PubMed  Google Scholar 

Valero V, Forbes J, Pegram MD, Pienkowski T, Eiermann W, von Minckwitz G, et al. Multicenter phase III randomized trial comparing docetaxel and trastuzumab with docetaxel, carboplatin, and trastuzumab as first-line chemotherapy for patients with HER2-gene-amplified metastatic breast cancer (BCIRG 007 study): two highly active therapeutic regimens. J Clin Oncol. 2011;29(2):149–56.

Article  CAS  PubMed  Google Scholar 

Gianni L, Lladó A, Bianchi G, Cortes J, Kellokumpu-Lehtinen P-L, Cameron DA, et al. Open-label, phase II, multicenter, randomized study of the efficacy and safety of two dose levels of Pertuzumab, a human epidermal growth factor receptor 2 dimerization inhibitor, in patients with human epidermal growth factor receptor 2-negative metastatic breast cancer. J Clin Oncol. 2010;28:1131–7.

Article  CAS  PubMed  PubMed Central  Google Scholar 

Fehrenbacher L, Cecchini RS, Geyer CE Jr, Rastogi P, Costantino JP, Atkins JN, et al. NSABP B-47/NRG oncology phase III randomized trial comparing adjuvant chemotherapy with or without trastuzumab in high-risk invasive breast cancer negative for HER2 by FISH and with IHC 1 + or 2. J Clin Oncol. 2020;38:444–53.

Article  CAS  PubMed  Google Scholar 

Wolff AC, Hammond MEH, Allison KH, Harvey BE, Mangu PB, Bartlett JMS, et al. Human epidermal growth factor receptor 2 testing in breast Cancer: American Society of Clinical Oncology/College of American Pathologists Clinical Practice Guideline Focused Update. J Clin Oncol. 2018;36(20):2105–22.

Article  CAS  PubMed  Google Scholar 

Modi S, Jacot W, Yamashita T, Sohn J, Vidal M, Tokunaga E, et al. Trastuzumab Deruxtecan in previously treated HER2-low advanced breast cancer. N Engl J Med. 2022;387:9–20.

Article  CAS  PubMed  PubMed Central  Google Scholar 

Hurvitz SA, Wang LS, Chan D, Phan V, Lomis T, McAndrew NP, et al. TRIO-US B-12 TALENT: phase II neoadjuvant trial evaluating trastuzumab deruxtecan with or without anastrozole for HER2-low, HR + early-stage breast cancer. J Clin Oncol. 2022;40(16suppl):TPS623.

Article  Google Scholar 

Schettini F, Chic N, Brasó-Maristany F, Paré L, Pascual T, Conte B, et al. Clinical, pathological, and PAM50 gene expression features of HER2-low breast cancer. NPJ Breast Cancer. 2021;7(1):1.

Article  CAS  PubMed  PubMed Central  Google Scholar 

Rosso C, Voutsadakis LA, Characteristics. Clinical differences and outcomes of breast Cancer patients with negative or low HER2 expression. Clin Breast Cancer. 2022;22(4):391–7.

Article  CAS  PubMed  Google Scholar 

Denkert C, Seither F, Schneeweiss A, Link T, Blohmer JU, Just M, et al. Clinical and molecular characteristics of HER2-low-positive breast cancer: pooled analysis of individual patient data from four prospective, neoadjuvant clinical trials. Lancet Oncol. 2021;22:1151–61.

Article  CAS  PubMed  Google Scholar 

Tarantino P, Hamilton E, Tolaney SM, Cortes J, Morganti S, Ferraro E, et al. HER2-Low breast Cancer: pathological and clinical Landscape. J Clin Oncol. 2020;38:1951–62.

Article  CAS  PubMed  Google Scholar 

de Moura Leite L, Cesca MG, Tavares MC, Santana DM, Saldanha EF, Guimarães PT, et al. HER2-low status and response to neoadjuvant chemotherapy in HER2 negative early breast cancer. Breast Cancer Res Treat. 2021;190(1):155–63.

Article  PubMed  Google Scholar 

Tan R, Ong WS, Lee KH, Lim AH, Park S, Park YH, et al. HER2 expression, copy number variation and survival outcomes in HER2-low non-metastatic breast cancer: an international multicentre cohort study and TCGA-METABRIC analysis. BMC Med. 2022;20:105.

Article  CAS  PubMed  PubMed Central  Google Scholar 

Xu HC, Han YQ, Wu Y, Wang Y, Li Q, Zhang P, et al. Clinicopathological characteristics and prognosis of HER2-Low early-stage breast Cancer: a single-Institution experience. Front Oncol. 2022;12:906011.

Article  CAS  PubMed  PubMed Central  Google Scholar 

Kang S, Lee SH, Lee HJ, Jeong H, Jeong JH, Kim JE, et al. Pathological complete response, long-term outcomes, and recurrence patterns in HER2-low versus HER2-zero breast cancer after neoadjuvant chemotherapy. Eur J cancer. 2022;11:30–40.

Article  Google Scholar 

Zhou SL, Liu T, Kuang XY, Zhen TT, Shi HJ, Lin Y, et al. Comparison of clinicopathological characteristics and response to neoadjuvant chemotherapy between HER2-low and HER2-zero breast cancer. Breast. 2023;67:1–7.

Article  CAS  PubMed  Google Scholar 

Alves FR, Gil L, Vasconcelos de Matos L, Baleiras A, Vasques C, Neves MT, et al. Impact of human epidermal growth factor receptor 2 (HER2) low status in response to Neoadjuvant Chemotherapy in early breast Cancer. Cureus. 2022;14(2):e22330.

PubMed  PubMed Central  Google Scholar 

Di Cosimo S, La Rocca E, Ljevar S, De Santis MC, Bini M, Cappelletti V, et al. Moving HER2-low breast cancer predictive and prognostic data from clinical trials into the real world. Front Mol Biosci. 2022;9:996434.

Article  PubMed  PubMed Central  Google Scholar 

Shao YB, Yu Y, Luo ZF, Guan HJ, Zhu FY, He YN, et al. Clinical, Pathological Complete Response, and prognosis characteristics of HER2-Low breast Cancer in the Neoadjuvant Chemotherapy setting: a retrospective analysis. Ann Surg Oncol. 2022;29(13):8026–34.

Article  PubMed  Google Scholar 

Page MJ, McKenzie JE, Bossuyt PM, Boutron I, Hoffmann TC, Mulrow CD, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ. 2021;372:n71.

Article  PubMed  PubMed Central  Google Scholar 

Slim K, Nini E, Forestier D, Kwiatkowski F, Panis Y, Chipponi J, et al. Methodological index for non-randomized studies (MINORS): development and validation of a new instrument. ANZ J Surg. 2003;73:712–6.

Article  PubMed  Google Scholar 

Armitage P, Berry G, Matthews J. Analysing means and proportions. Statistical methods in Medical Research. Oxford: Blackwell Science; 2002. pp. 83–146.

Book  Google Scholar 

Begg CB, Mazumdar M. Operating characteristics of a rank correlation test for publication bias. Biometrics. 1994;50(4):1088e101.

Article  Google Scholar 

Domergue C, Martin E, Lemarié C, Jézéquel P, Frenel JS, Augereau P, et al. Impact of HER2 status on pathological response after Neoadjuvant Chemotherapy in Early Triple-negative breast Cancer. Cancers (Basel). 2022;14(10):2509.

Article  CAS  PubMed  PubMed Central  Google Scholar 

Qiao WQ, Guo WY, Liu QP, Guo X, Deng XM. Pathological complete response and prognosis after neoadjuvant chemotherapy in patients with HER2-low breast cancer. Ann Diagn Pathol. 2023;64:152125.

Article  PubMed  Google Scholar 

Li YJ, Maimaitiaili A, Qu FJ, Li GF, Shi BH, Wang YD, et al. Effect of HER2-low-positive status on neoadjuvant chemotherapy and survival outcome of breast cancer: a 10-year dual-center retrospective study. Am J Cancer Res. 2023;13(8):3571–81.

PubMed  PubMed Central  Google Scholar 

Pöschke P, Fasching PA, Adler W, Rübner M, Beckmann MW, Hack CC, et al. Clinical characteristics and prognosis of HER2-0 and HER2-Low-positive breast Cancer patients: real-World Data from patients treated with Neoadjuvant Chemotherapy. Cancers (Basel). 2023;15(19):4678.

Article  PubMed  Google Scholar 

Li JJ, Yu Y, Ge J. HER2-low-positive and response to NACT and prognosis in HER2-negative non-metastatic BC. Breast Cancer. 2023;30(3):364–78.

Article  CAS  PubMed  Google Scholar 

Zhong GS, Song DJ, Lou WY, Wei BJ, Chen YM, Cui HD, et al. Pathological complete response rate and clinical outcome after neoadjuvant therapy of HER2-low breast cancer: a National Cancer Database Analysis. Eur J Surg Oncol. 2023;49(11):106970.

Article  PubMed  Google Scholar 

Zhang SC, Liu Y, Liu X, Liu YX, Zhang J. Prognoses of patients with hormone receptor-positive and human epidermal growth factor receptor 2-Negative breast Cancer receiving neoadjuvant chemotherapy before surgery: a retrospective analysis. Cancers (Basel). 2023;15(4):1157.

Article  CAS  PubMed  Google Scholar 

Eiger D, Agostinetto E, Saúde-Conde R, de Azambuja E. The exciting new field of HER2-low breast cancer treatment. Cancers (Basel). 2021;13(5):1015.

Article  CAS  PubMed  Google Scholar 

Agostinetto E, Rediti M, Fimereli D, Debien V, Piccart M, Aftimos P, et al. HER2-low breast cancer: molecular characteristics and prognosis. Cancers (Basel). 2021;13(11):2824.

Article  CAS  PubMed  Google Scholar 

Yi XL, Hu SS, Ma ML, Huang DS, Zhang Y. Effect of HER2-low expression on neoadjuvant efficacy in operable breast cancer. Clin Transl Oncol. 2023;13.

Wolff AC, Somerfield MR, Dowsett M, Hammond MEH, Hayes DF, McShane LM, et al. Human epidermal growth factor receptor 2 testing in breast Cancer: ASCO-College of American Pathologists Guideline Update. J Clin Oncol. 2023;41(22):3867–72.

Article  CAS  PubMed  Google Scholar 

Liu XX, Zhu YF, Li CX, Fang YY, Chen JN, Xu F, et al. Single-cell HER2 quantification via instant signal amplification in microdroplets. Anal Chim Acta. 2023;22:1251.

Google Scholar 

Baehner FL, Achacoso N, Maddala T, Shak S, Quesenberry CP, Goldstein LC, et al. Human epidermal growth factor receptor 2 assessment in a case-control study: comparison of fluorescence in situ hybridization and quantitative reverse transcription polymerase chain reaction performed by central laboratories. J Clin Oncol. 2010;28(28):4300–6.

Article  PubMed