Open Access
CC BY 4.0 · Brazilian Journal of Oncology 2025; 21
DOI: 10.1055/s-0045-1807788
BREAST TUMORS
1928
POSTER PRESENTATION

Real-world validation of outcomes with adjuvant paclitaxel + trastuzumab (APT) in low-risk early-stage HER2 positive breast cancer

Authors

  • Christopher Lucas Negrete

  • Rafael Duarte Paes

  • Aline Coelho Gonçalves

  • Rafael Brant Costa

  • Flavia Rocha Paes

  • Daniel Gimenes

  • Luciana Castro Garcia Landeiro

  • Cristiano Augusto Andrade de Resende

  • Leandro Jonata de Carvalho Oliveira

  • Bruno Lemos Ferrari

  • Pedro Emanuel Rubini Liedke

  • Max Senna Mano

  • Rodrigo Dienstmann

Further Information
 
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    Keywords

    HER2-positive breast cancer - APT protocol - real world data (RWD)

    Introduction: Clinical trial data with APT protocol (paclitaxel + trastuzumab weekly for 12 weeks, followed by maintenance trastuzumab monotherapy for 9 months) has shown 98.7% invasive disease-free survival (iDFS) rate at 3 years, with a median follow-up of 48 months. Real World Data (RWD) may help us understand whether this favorable single arm clinical trial outcome can be reproduced within the Brazilian population.

    Objective: To characterize the population who received the APT regimen within the Oncoclínicas Group in recent years and determine iDFS rate at 3 years.

    Method: Retrospective observational study from all breast cancer patients who started the APT regimen between 2017 and 2022 in a private healthcare outpatient network of clinics. Data were extracted from the Oncoclínicas Electronic Health Records database using technology-based abstraction and human curation by ontology experts. iDFS was calculated from treatment start to recurrence or death from any cause using the Kaplan-Meier method.

    Results: From 6,380 HER2+ early breast cancer treated at OC in the study period, a total of 214 patients (3.4%) were eligible. Median age was 64 years (29-94). Most were treated in Southeastern region (71%) and the self-reported white race (61%). Pathological stage I comprised 82% of the population, and stage II the 18% remaining patients. With median follow-up of 40 months, iDFS rate at 3 years was 94.72% (95% CI 91.16% – 98.43%). Among the 10 iDFS events, 5 were disease recurrence/new primaries (age less than 50 years and stage II in 40%), and the other 5 events were deaths without clinical documentation of recurrence (all aged 74 years or older, 80% stage I).

    Conclusion: Our data show comparable iDFS outcomes with landmark clinical trial, reinforcing the effectiveness of this regimen in selected patients and the value of RWD to validate single arm trials. This is the largest published Brazilian cohort of early-stage HER2-positive patients treated with the APT protocol.

    Corresponding author: Christopher Lucas Negrete (e-mail: negrete.pharm@gmail.com).


     

    No conflict of interest has been declared by the author(s).

    Publication History

    Article published online:
    06 May 2025

    © 2025. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution 4.0 International License, permitting copying and reproduction so long as the original work is given appropriate credit (https://creativecommons.org/licenses/by/4.0/)

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    Bibliographical Record
    Christopher Lucas Negrete, Rafael Duarte Paes, Aline Coelho Gonçalves, Rafael Brant Costa, Flavia Rocha Paes, Daniel Gimenes, Luciana Castro Garcia Landeiro, Cristiano Augusto Andrade de Resende, Leandro Jonata de Carvalho Oliveira, Bruno Lemos Ferrari, Pedro Emanuel Rubini Liedke, Max Senna Mano, Rodrigo Dienstmann. Real-world validation of outcomes with adjuvant paclitaxel + trastuzumab (APT) in low-risk early-stage HER2 positive breast cancer. Brazilian Journal of Oncology 2025; 21.
    DOI: 10.1055/s-0045-1807788
      All articles of this category