1. Ravdin PM, Chamness GC. The c-erbB-2 proto-oncogene as a prognostic and predictive marker in breast cancer: a paradigm for the development of other macromolecular markers-a review. Gene. 1995 Jun 14; 159(1): 19-27.
2. 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.
3. Denkert C, Seither F, Schneeweiss A, Link T, Blohmer J-U, 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. The Lancet Oncology. 2021; 22(8): 1151-61.
4. Rossi V, Sarotto I, Maggiorotto F, Berchialla P, Kubatzki F, Tomasi N, et al. Moderate immunohistochemical expression of HER-2 (2+) without HER-2 gene amplification is a Negative prognostic factor in early breast cancer. The Oncologist. 2012; 17(11): 1418-25.
5. Eggemann H, Ignatov T, Burger E, Kantelhardt EJ, Fettke F, Thomssen C, et al. Moderate HER2 expression as a prognostic factor in hormone receptor positive breast cancer. Endocrine-related cancer. 2015; 22(5): 725-33.
6. Ignatov T, Eggemann H, Burger E, Fettke F, Costa SD, Ignatov A. Moderate level of HER2 expression and its prognostic significance in breast cancer with intermediate grade. Breast Cancer Res Treat. 2015 Jun; 151(2): 357-64. doi: 10.1007/s10549-015-3407-2. Epub 2015 Apr 30. PMID: 25926338.
7. Horisawa N, Adachi Y, Takatsuka D, Nozawa K, Endo Y, Ozaki Y, Sugino K, Kataoka A, Kotani H, Yoshimura A, Hattori M. The frequency of low HER2 expression in breast cancer and a comparison of prognosis between patients with HER2-low and HER2-Negative breast cancer by HR status. Breast Cancer. 2022 Mar 1: 1-8.
8. Russo C, Voutsadakis IA. Characteristics, clinical differences and outcomes of breast cancer patients with Negative or low HER2 expression. Clinical breast cancer. 2022 Jun 1; 22(4): 391-7.
9. Almstedt K, Heimes AS, Kappenberg F, Battista MJ, Lehr HA, Krajnak S, Lebrecht A, Gehrmann M, Stewen K, Brenner W, Weikel W. Long-term prognostic significance of HER2-low and HER2-zero in node-Negative breast cancer. European Journal of Cancer. 2022 Sep 1; 173: 10-9.
10. Modi S, Jacot W, Yamashita T, Sohn J,
Vidal M, Tokunaga E, Tsurutani J, Ueno NT, Prat A, Chae YS, Lee KS. Trastuzumab deruxtecan in previously treated HER2-low advanced breast cancer. New England Journal of Medicine. 2022 Jul 7; 387(1): 9-20.
11. Won HS, Ahn J, Kim Y, Kim JS, Song JY, Kim HK, Lee J, Park HK, Kim YS. Clinical significance of HER2-low expression in early breast cancer: a nationwide study from the Korean Breast Cancer Society. Breast Cancer Research. 2022 Mar 21; 24(1): 22.
12. Sato A, Maeda Y, Matsumoto A, Ikeda T, Jinno H. Clinicopathological features and prognosis of breast cancer with low HER2 status evaluated by fluorescence in situ hybridization. Oncology Letters. 2024 Dec 6; 29(2): 92.
13. Zhou S, Liu T, Kuang X, Zhen T, Shi H, Lin Y, et al. Comparison of clinicopathological characteristics and response to neoadjuvant chemotherapy between HER2-low and HER2-zero breast cancer. The Breast. 2023; 67: 1-7.
14. Di Cosimo S, La Rocca E, Ljevar S, De Santis MC, Bini M, Cappelletti V, Valenti M, Baili P, de Braud FG, Folli S, Scaperrotta G. Moving HER2-low breast cancer predictive and prognostic data from clinical trials into the real world. Frontiers in Molecular Biosciences. 2022 Sep 26; 9: 996434.
15. De Moura Leite L, Cesca MG, Tavares MC, Santana DM, Saldanha EF, Guimarães PT, Sá DD, Simões MF, Viana RL, Rocha FG, Loose SK.
HER2-low status and response to neoadjuvant chemotherapy in HER2 Negative early breast cancer. Breast cancer research and treatment. 2021 Nov; 190(1): 155-63.
16. Xu H, Han Y, Wu Y, Wang Y, Li Q, Zhang P, Yuan P, Luo Y, Fan Y, Chen S, Cai R. Clinicopathological characteristics and prognosis of HER2-low early-stage breast cancer: a
single-institution experience. Frontiers in oncology. 2022 Jun 16; 12: 906011.
17. Mutai R, Barkan T, Moore A, Sarfaty M,
Shochat T, Yerushalmi R, et al. Prognostic impact of HER2-low expression in hormone receptor positive early breast cancer. The Breast. 2021; 60: 62-9.
18. Van den Ende NS, Smid M, Timmermans A, van Brakel JB, Hansum T, Foekens R, Trapman AM, Heemskerk-Gerritsen BA, Jager A, Martens JW, van Deurzen CH. HER2-low breast cancer shows a lower immune response compared to HER2-Negative cases. Scientific reports. 2022 Jul 28; 12(1): 12974.
19. Agostinetto E, Rediti M, Fimereli D, Debien V, Piccart M, Aftimos P, Sotiriou C, de Azambuja E. HER2-low breast cancer: molecular characteristics and prognosis. Cancers. 2021 Jun 5; 13(11): 2824.
20. Ergun Y, Ucar G, Akagunduz B. 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. Cancer treatment reviews. 2023 Apr 1; 115: 102538.
21. Tarantino P, Hamilton E, Tolaney SM, Cortes J, Morganti S, Ferraro E, et al. HER2-low breast cancer: pathological and clinical landscape. Journal of Clinical Oncology. 2020; 38(17): 1951-62.
22. Yang M, Sun J, Liu L, Kong X, Lin D, Zhou H, Gao J. Clinicopathological characteristics of HER2-low breast cancer: A retrospective study. Scientific reports. 2023 Jul 31; 13(1): 12382.
23. Molinelli C, Jacobs F, Agostinetto E,
Nader-Marta G, Ceppi M, Bruzzone M, Blondeaux E, Schettini F, Prat A, Viale G, Del Mastro L. Prognostic value of HER2-low status in breast cancer: a systematic review and meta-analysis. ESMO open. 2023 Aug 1; 8(4): 101592.
24. Wang W, Zhu T, Chen H, Yao Y. The impact of HER2-low status on response to neoadjuvant chemotherapy in clinically HER2-Negative breast cancer. Clinical and Translational Oncology. 2023 Jun; 25(6): 1673-81.
25. Zhang G, Ren C, Li C, Wang Y, Chen B, Wen L, Jia M, Li K, Mok H, Cao L, Chen X. Distinct clinical and somatic mutational features of breast tumors with high-, low-, or non-expressing human epidermal growth factor receptor 2 status. BMC medicine. 2022 Apr 29; 20(1): 142.
26. Chen M, Chen W, Liu D, Chen W, Shen K, Wu J, Zhu L. Prognostic values of clinical and molecular features in HER2 low-breast cancer with hormonal receptor overexpression: features of HER2-low breast cancer. Breast Cancer. 2022 Sep; 29(5): 844-53.
27. Shao Y, Yu Y, Luo Z, Guan H, Zhu F, He Y, Chen Q, Liu C, Nie B, Liu H. Clinical, pathological complete response, and prognosis characteristics of HER2-low breast cancer in the neoadjuvant chemotherapy setting: a retrospective analysis. Annals of surgical oncology. 2022 Dec; 29(13): 8026-34.
28. Burstein HJ, Curigliano G, Loibl S, Dubsky P, Gnant M, Poortmans P, et al. Estimating the benefits of therapy for early-stage breast cancer: the St. Gallen International Consensus Guidelines for the primary therapy of early breast cancer 2019. Annals of Oncology. 2019; 30(10): 1541-57.
29. De Moraes FC, de Castro Ribeiro CH, Pessôa FD, Chaves JR, de Souza AP, Di Felipe Ávila Alcantara D, Imbiriba MM, Magalhães MC, Burbano RM. Pathologic response rates in HER2-low versus HER2-zero early breast cancer patients receiving neoadjuvant therapy: a systematic review and meta-analysis. Breast Cancer Research. 2025 Mar 15; 27(1): 39.
