Quantitative Biomarkers, Genomic Assays, and Demographics Associated with Breast-Conserving Surgery Following Neoadjuvant Therapy in Early-Stage, Hormone Receptor-Positive, HER-Negative Breast Cancer

Ann Surg Oncol. 2024 Dec;31(13):8829-8842. doi: 10.1245/s10434-024-16160-5. Epub 2024 Sep 9.

Abstract

Background: Given increased neoadjuvant therapy use in early-stage, hormone receptor (HR)-positive/HER2-negative breast cancer, we sought to quantify likelihood of breast-conserving surgery (BCS) after neoadjuvant chemotherapy (NACT) or endocrine therapy (NET) as a function of ER%/PR%/Ki-67%, 21-gene recurrence scores (RS), or 70-gene risk groups.

Methods: We analyzed the 2010-2020 National Cancer Database. Surgery was categorized as "mastectomy/BCS." Logistic regression was performed. Adjusted odds ratios (AOR) were per 10-unit increase in ER%/PR%/Ki-67%.

Results: Overall, 42.3% underwent BCS after NACT, whereas 64.0% did after NET. Increasing ER% (AOR = 0.96, 95% confidence interval [CI] 0.94-0.97) or PR% (AOR=0.98, 95% CI 0.96-0.99) was associated with lower odds of BCS after NACT. Increasing Ki-67% was associated with greater odds of BCS (AOR = 1.07, 95% CI 1.04-1.10). Breast-conserving surgery rates increased by ~20 percentage points, with Ki-67% ≥15 or RS >20. Patients with a low (43.0%, AOR = 0.50, 95% CI 0.29-0.88) or intermediate (46.4%, AOR = 0.58, 95% CI 0.41-0.81) RS were less likely than patients with a high RS (65.0%) to undergo BCS after NACT. Increasing ER% was associated with higher odds of BCS after NET (AOR = 1.09, 95% CI 1.01-1.17). Breast-conserving surgery rates increased by ~20 percentage points between ER <50% and >80%. In both cohorts, the odds of BCS were similar between 70-gene low-risk and high-risk groups. Asian or uninsured patients had lower odds of BCS.

Conclusions: Neoadjuvant chemotherapy is unlikely to downstage tumors with a low-intermediate RS, higher ER%/PR%, or lower Ki-67%. Breast-conserving surgery after NET was most dependent on ER%. Findings could facilitate treatment decision-making based on tumor biology and racial/socioeconomic disparities and improve patient counseling on the likelihood of successful BCS.

Keywords: Breast-conserving surgery; Early-stage breast cancer; Genomic assays; National Cancer Database; Neoadjuvant therapy; Quantitative biomarkers; Racial disparities.

MeSH terms

  • Adult
  • Aged
  • Biomarkers, Tumor* / genetics
  • Biomarkers, Tumor* / metabolism
  • Breast Neoplasms* / drug therapy
  • Breast Neoplasms* / genetics
  • Breast Neoplasms* / metabolism
  • Breast Neoplasms* / pathology
  • Breast Neoplasms* / surgery
  • Breast Neoplasms* / therapy
  • Female
  • Follow-Up Studies
  • Genomics
  • Humans
  • Mastectomy, Segmental* / statistics & numerical data
  • Middle Aged
  • Neoadjuvant Therapy*
  • Neoplasm Recurrence, Local / genetics
  • Neoplasm Recurrence, Local / metabolism
  • Neoplasm Recurrence, Local / pathology
  • Neoplasm Staging
  • Prognosis
  • Receptor, ErbB-2* / metabolism
  • Receptors, Estrogen* / metabolism
  • Receptors, Progesterone* / metabolism

Substances

  • Receptors, Estrogen
  • Receptors, Progesterone
  • Receptor, ErbB-2
  • Biomarkers, Tumor
  • ERBB2 protein, human