Frontiers in Oncology (Jan 2022)

In Real Life, Low-Level HER2 Expression May Be Associated With Better Outcome in HER2-Negative Breast Cancer: A Study of the National Cancer Center, China

  • Yiqun Li,
  • Nilupai Abudureheiyimu,
  • Hongnan Mo,
  • Xiuwen Guan,
  • Shaoyan Lin,
  • Zijing Wang,
  • Yimeng Chen,
  • Shanshan Chen,
  • Qiao Li,
  • Ruigang Cai,
  • Jiayu Wang,
  • Yang Luo,
  • Ying Fan,
  • Peng Yuan,
  • Pin Zhang,
  • Qing Li,
  • Fei Ma,
  • Binghe Xu

DOI
https://doi.org/10.3389/fonc.2021.774577
Journal volume & issue
Vol. 11

Abstract

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BackgroundTo characterize the clinical and pathological features and survival of patients with human epidermal growth factor receptor 2 (HER2)-low breast cancer in China.MethodsThe China National Cancer Center database was used to identify 1,433 metastatic breast cancer patients with HER2-negative disease diagnosed between 2005 and 2015. Clinicopathological features, survival, and prognosis information were extracted. Overall survival (OS) was estimated using the Kaplan–Meier method and compared using the log-rank test. Prognostic factors associated with OS were analyzed using Cox regression model with 95% confidence interval (95% CI).ResultsThere were 618 (43.1%) and 815 (56.9%) HER2-low and HER2-zero tumors out of 1,433 tumors, respectively. The proportion of hormone receptor (HR)-positive tumors was significantly higher in HER2-low tumors than in those with HER2-zero tumors (77.8% vs. 69.2%, p < 0.001). Patients with HER2-low tumors survived significantly longer than those with HER2-zero tumors in the overall population (48.5 months vs. 43.0 months, p = 0.004) and HR-positive subgroup (54.9 months vs. 48.1 months, p = 0.011), but not in the HR-negative subgroup (29.5 months vs. 29.9 months, p = 0.718). Multivariate regression analysis revealed that HER2-low tumors were independently associated with increased OS in HER2-negative population (HR: 0.85, 95% CI: 0.73–0.98, p = 0.026).ConclusionOur findings demonstrate that HER2-low tumors could be identified as a more distinct clinical entity from HER2-zero tumors, especially for the HR-positive subgroup. A more complex molecular landscape of HER2-low breast cancer might exist, and more precise diagnostic algorithms for HER2 testing could be investigated, thus offering new therapeutic targets for breast cancer treatment.

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