The Effects of Low HER2/neu Expression on the Clinicopathological Characteristics of Triple-Negative Breast Cancer Patients

Abstract

Background: Triple-negative breast cancer (TNBC) is an aggressive type of breast cancer (BC), and its diagnosis is associated with negative expression of hormone receptors and HER2/neu. It consists of 10-20% of all BCs diagnosed. Methods and materials: This study focuses on three groups with different pathology: group one showed complete triple-negative HER2 expression with IHC of BC; groups two and three included patients with ER-, PR-, and HER2 1+ , and ER-, PR-, and HER2 2+ with a negative FISH test. These three groups were compared from the point of prognosis, which consisted of tumor size, patients' age, lymphatic, vascular and perineural invasion, organ metastasis, number of lymph nodes involvement, and the survival rate. Results: A total of 459 TNBC patients were enrolled, of which 268 were placed in the HER2 0 group, 146 in the HER2 1+ group, and 45 in the HER2 2+ group. Distant metastasis and recurrence rate were more common in HER2 0 patients, but bone metastasis was more common in patients with low HER2 expression. All patients with HER2 0 had a smaller tumor size at the time of BC diagnosis in comparison to patients in the low HER2 expression group. Patients with HER2 2+ had less lymphatic and vascular invasion as well as axillary lymph nodes involvement, but larger tumor size at presentation, resulting in a lower rate of recurrence and higher overall survival. Conclusion: The findings revealed that patients with HER2 2+ had better outcome in comparison to the patients with HER2 0 and HER2 1+. Furthermore, the results showed that many patients with HER2 2+ expression were not basal-like and had good prognosis amongst TNBC patients.

Clinical outcomes of de novo metastatic HER2-low breast cancer: a National Cancer Database Analysis

“…Consistent with most previous studies, this study found that tumors with HER2-low expression were more likely to be HR-positive and invasive ductal adenocarcinoma 14 , 17 – 19 . In addition, the results showed that HER2-low breast cancers had lower tumor grades and fewer visceral metastases.…”

“…Interestingly, they did not find a similar association in HR-negative breast cancers 17 . In contrast, Dehghani et al found that HER2 IHC2+/ISH negative tumors had less lymphovascular invasion and fewer basal-like subtypes than HER2-zero tumors in triple-negative breast cancers 14 . Due to the limitation of the NCDB dataset, we could not provide detailed molecular data such as KI-67, or genomic data of the metastatic HER-2 low tumors in this study.…”

“…A few singlecenter or regional observational studies yielded conflicting results. These studies only included a limited population with metastatic breast cancer [13][14][15][16][17][18] . In addition, these data may not represent the US patient population [14][15][16]18 .…”

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

“…To date, robust studies focusing on HER2-low breast cancer in China are lacking. Few studies from western countries combining HER2-low breast cancer patients from different datasets or clinical trials have yielded varying results (14)(15)(16). In this study, we aimed to characterize the clinicopathological features, survival, and prognosis of HER2-low tumors in metastatic breast cancer (MBC) based on the China National Cancer Center database and compare with HER2-zero tumors.…”

Clinicopathological features and prognosis of patients with HER2-low breast cancer

“…survived longer in the overall population and HR + subgroup [14]. Another study by Dehgani et al in TNBC obtained a similar result: patients with HER2 2 + had a lower rate of recurrence and longer overall survival (OS) [23]. In addition, other studies found no statistically signi cant difference in OS between patients with HER2-low and HER2-zero tumors [12,19].…”