Neoadjuvant chemotherapy for triple-negative and Her2 +ve breast cancer: striving for the standard of care

Breast Cancer Res Treat. 2024 Jul;206(2):227-244. doi: 10.1007/s10549-024-07282-1. Epub 2024 Apr 27.

Abstract

Purpose: Neoadjuvant chemotherapy (NAC) for triple-negative (TN) and Her2-positive (HER2) breast cancers is supported by international guidelines as it can decrease extent of surgery, provide prognostic information, and allow response-driven adjuvant therapies. Our goal was to describe practice patterns for patients with TN and HER2-positive breast cancer and identify the factors associated with the receipt of NAC versus surgery as initial treatment.

Methods: A retrospective population-based cohort study of adult women diagnosed with stage I-III TN or HER2-positive breast cancer (2012-2020) in Ontario was completed using linked administrative datasets. The primary outcome was NAC as first treatment. The association between NAC and patient, tumor, and practice-related factors was examined using multivariable logistic regression models.

Results: Of 14,653 patients included, 23.9% (n = 3500) underwent NAC as first treatment. Patients who underwent NAC were more likely to be younger and have larger tumors, node-positive disease, and stage 3 disease. Of patients who underwent surgery first, 8.8% were seen by a medical oncologist prior to surgery. On multivariable analysis, increasing tumor size (T2 vs T1/T0: 2.75 (2.31-3.28)) and node-positive (N1 vs N0: OR 3.54 (2.92-4.30)) disease were both associated increased odds of receiving NAC.

Conclusion: A considerable proportion of patients with TN and HER2-positive breast cancer do not receive NAC as first treatment. Of those, most were not assessed by both a surgeon and medical oncologist prior to initiating therapy. This points toward potential gaps in multidisciplinary assessment and disparities in receipt of guideline-concordant care.

Keywords: Breast; Chemotherapy; Her2 positive; Neoadjuvant; Triple negative.

MeSH terms

  • Adult
  • Aged
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use
  • Breast Neoplasms / drug therapy
  • Breast Neoplasms / metabolism
  • Breast Neoplasms / pathology
  • Chemotherapy, Adjuvant / methods
  • Female
  • Humans
  • Middle Aged
  • Neoadjuvant Therapy* / methods
  • Neoplasm Staging
  • Ontario / epidemiology
  • Prognosis
  • Receptor, ErbB-2* / metabolism
  • Retrospective Studies
  • Standard of Care
  • Triple Negative Breast Neoplasms* / drug therapy
  • Triple Negative Breast Neoplasms* / pathology

Substances

  • Receptor, ErbB-2
  • ERBB2 protein, human