Up to 20% of breast cancer overexpress HER2 protein, making it a reliable target for antibody-based treatments. In early HER2-positive breast cancer avoiding anthracycline-based chemotherapy is a challenge. Based on the single-arm phase II APT trial results, adjuvant paclitaxel/trastuzumab is an accepted regimen for patients with stage I HER2-positive disease. In our retrospective study of 240 patients, the median tumor size was 12.0 mm (IQR 9 -15), and 204 (85%) had estrogen receptor-positive disease. After a median follow-up of 4.6 years, 3-year real-world disease-free survival, distant DFS, and overall survival were 98.8% (95% confidence interval (CI), 96.2-99.6), 99.2% (95% CI, 96.7-99.8), and 98.3% (95% CI, 96.2-99.6), respectively. In a real-world setting, an adjuvant paclitaxel/trastuzumab regimen was associated with low recurrence rates among women with stage I, HER2-positive breast cancer. Additionally, we reviewed other treatment optimization strategies attempted or ongoing in HER2-positive breast cancer., Competing Interests: Declaration of Competing Interest VD, MS, FJ, MM, MP, IS, WH: none. GNM: Travel grants for meetings from Roche and Bayer, outside the submitted work. EA: Speaking fee/consultancy: Eli Lilly, Sandoz, AstraZeneca. Support to attend medical conferences from Eli Lilly, Roche, Novartis, Genetics, Istituto Gentili, Daiichi Sankyo (all outside the present work). CM: receive fees from Novartis and Lilly outside the submitted work.Ugo De Giorgi received honoraria for advisory boards or speaker fees for Pfizer, BMS, MSD, PharmaMar, Astellas, Bayer, Ipsen, Roche, Novartis, Clovis, GSK, AstraZeneca, Institutional research grants from AstraZeneca, Sanofi and Roche all outside the submitted work. UDG: Advisory boards: Astellas, Bayer, BMS, Ipsen, MSD, Novartis, Pfizer, PharmaMar, Roche; Institutional research grant: AstraZeneca, Roche, Sanofi. AS: Advisory Board: BMS (BRISTOL-MYERS-SQUIBB), Servier,Gilead, Pfizer, Eisai, Bayer, MSD (MERCK SHARP & DOHME); Consultancy: Arqule, Sanofi, Incyte; Speaker’s Bureau: Takeda, BMS, Roche, Abbvie, Amgen, Celgene, Servier, Gilead, Astrazeneca, Pfizer, Arqule, Lilly, Sandoz, Eisai, Novartis, Bayer, MSD. DT: advisory board: Agendia, AstraZeneca, Daiichi Sankyo, Eli Lilly, Medscape, MSD, Novartis, Roche; Travel: AstraZeneca,Pfizer, Roche. FPD: Advisory Board: Amgen, AstraZeneca, Daiichi Sankyo, Gilead Sceince, Lilly, Novartis, Pfizer, Pierre Fabre, Roche, Seagen; Contracted Research: Fondation belge contre le cancer; Institutional grant: AstraZeneca. AB: Advisory board: Argen, BMS, Eli-Lilly, MSD, Novartis, Pfizer, Roche. GB: Advisory board: BMS, Eli Lilly, MSD, Novartis, Pfizer, Roche; Travel: BMS, Eli Lilly, MSD, Novartis, Pfizer, Roche. ML: reports advisory role for Roche, Lilly, Novartis, Astrazeneca, Pfizer, Seagen, Gilead, MSD and Exact Sciences; speaker honoraria from Roche, Lilly, Novartis, Pfizer, Sandoz, Libbs, Daiichi Sankyo and Takeda; Travel Grants from Gilead; Research funding (to the Institution) from Gilead outside the submitted work. EdA: Honoraria and/or advisory board from Roche/GNE, Novartis, SeaGen, Zodiac, Libbs, Pierre Fabre, Lilly, Astra-Zeneca; travel grants from Roche/GNE and Astra-Zeneca; Research grant to my institution from Roche/GNE, AstraZeneca, and GSK/Novartis. MP: Board Member (Scientific Board): Oncolytics; Consultant (honoraria): AstraZeneca, Camel-IDS/Precirix, Gilead, Immunomedics, Lilly, Menarini, MSD, Novartis, Pfizer, Roche-Genentech, Seattle Genetics, Immutep, Seagen, NBE Therapeutics, Frame Therapeutics; Research grants to my Institute: AstraZeneca, Immunomedics, Lilly, Menarini, MSD, Novartis, Pfizer, Radius, Roche-Genentech, Servier, Synthon., (Copyright © 2023 Elsevier B.V. All rights reserved.)