Predictors of nodal metastases in early stage HER2+ breast cancer: Deciding on treatment approach with neoadjuvant chemotherapy vs. upfront surgery

Eur J Surg Oncol. 2023 Aug;49(8):1411-1416. doi: 10.1016/j.ejso.2023.03.226. Epub 2023 Mar 31.

Abstract

Background: The purpose of this study is to evaluate preoperative predictors of nodal metastases in patients with early-stage, HER2-positive (HER2+) breast cancer.

Methods: The SEER Database was queried to identify women with a first diagnosis of stage I-II (T1-T2) HER2-positive breast cancer treated with upfront surgery in 2018. Multivariable logistic regression was used to identify clinical characteristics independently associated with nodal involvement.

Results: Overall, 3333 women with stage I-II HER2+ breast cancer met inclusion criteria and were included in the study. The median age at diagnosis was 59 years (IQR, 51-69 years). Most patients underwent breast-conserving surgery (60.9%), with a median of 3 (IQR 2-4) axillary lymph nodes removed. On final pathology, 762 (22.9%) of T1-T2 HER2+ patients were node positive; 2.7% pN0[i+], 3.7% pN1mi, 15.1% pN1, and 1.4% pN2. Women less than 40 years and those between 40 and 49 years showed the highest proportion of axillary lymph node metastasis, in 33.7% and 30.7% respectively, and declining with age (p < 0.001). Patients with triple-positive breast cancer had the highest rates of nodal involvement (24.8%), compared to 20.7% ER+/PR-/HER2+ and 19.6% of HER2-enriched patients (p = 0.006). On adjusted analysis, age, biologic subtype, tumour size, and type of surgery remained independent predictors of nodal involvement. On subgroup analysis, women under age 50 with T1c HER2-enriched or triple-positive breast cancer had a 33% and 35% incidence of nodal involvement, which declined with age.

Conclusions: The likelihood of pathologic nodal involvement in early-stage HER2+ breast cancer is contingent on age, ER/PR status, and tumour size.

Keywords: Axillary lymph nodes; Breast neoplasms; Neoadjuvant chemotherapy.

MeSH terms

  • Aged
  • Axilla / pathology
  • Breast Neoplasms* / pathology
  • Female
  • Humans
  • Lymph Node Excision
  • Lymph Nodes / pathology
  • Lymphatic Metastasis / pathology
  • Middle Aged
  • Neoadjuvant Therapy
  • Receptor, ErbB-2

Substances

  • Receptor, ErbB-2