Expression and prognostic value of HER-2/neu in primary breast cancer with sentinel lymph node metastasis

Abstract

The present study explores the correlation of human epidermal growth factor receptor-2 (HER-2) protein expression with sentinel lymph node (SLN) metastasis and prognosis of breast cancer. The breast cancer tissues and adjacent tissues were obtained from patients with primary breast cancer. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to detect the mRNA level of HER-2. Spearman correlation analysis was used to analyze the correlation of HER-2 expression with SLN metastasis. The disease-free survival (DFS) and overall survival (OS) of breast cancer patients were investigated. Univariate and multivariate analyses were performed to explore factors influencing SLN metastasis and prognosis of breast cancer. Compared with adjacent tissues, HER-2 expression was significantly up-regulated in breast cancer tissues. HER-2 expression was correlated with the pathological type, tumor node metastasis (TNM) staging, histological grade, blood vessel invasion, SLN metastasis, estrogen receptor (ER), and progesterone receptor (PR). The expression level of HER-2 was positively related to the SLN metastasis (r=0.548). Median DFS and OS were longer in patients with negative HER-2 expression than in patients with positive HER-2 expression. TNM staging, SLN metastasis, and expression levels of HER-2 and ER were independent factors for DFS of breast cancer patients, while TNM staging, blood vessel invasion, histological grade, SLN metastasis, and expression levels of HER-2 and PR were independent factors for OS of breast cancer patients. Our study suggests that high expression of HER-2 promoted SLN metastasis. HER-2 expression and SLN metastasis were the independent factors for the prognosis of breast cancer.

Keywords: breast cancer; disease-free survival; human epidermal growth factor receptor-2; overall survival; prognosis; sentinel lymph node metastasis.

Figure 1. HER-2 expression in breast cancer tissues and adjacent tissues (SP ×200)

(A) HER-2 expression in breast cancer tissues detected by SP. (B) HER-2 expression in adjacent tissue detected by SP. (C) The histogram of positive rate of HER-2 in breast cancer tissues and adjacent tissues. *P<0.05, compared with the adjacent tissues.

Figure 2. Kaplan–Meier survival curves of patients with different HER-2 expression and SLN metastasis

(A) DFS survival curve of HER-2, with P<0.05 examined by Log-rank test. (B) OS survival curve of HER-2, with P<0.05 examined by Log-rank test. (C) DFS survival curve of SLN metastasis, with P<0.05 examined by Log-rank test. (D) OS survival curve of SLN metastasis, with P<0.05 examined by Log-rank test.