Expression patterns of ER, HER2, and NM23-H1 in breast cancer patients with different menopausal status: correlations with metastasis

This study was designed to analyze expression patterns of estrogen receptor (ER), human epidermal growth factor receptor-2 (HER2/ERBB2), and nonmetastatic protein 23 (NM23-H1/NME1) proteins in patients with invasive ductal carcinoma and different menopausal status to identify their relationships with axillary lymph node metastasis.

213 pre-menopausal and 177 post-menopausal women diagnosed with invasive ductal carcinoma were evaluated for ER, HER2, and NM23-H1 protein expression by immunohistochemistry. When HER2 immunoreactivity was equivocal (category 2+), specimens were confirmed by fluorescence in situ hybridization.

ER expression showed no correlation with menopausal status or lymph node metastasis (each p > 0.05). However, expression of ER was associated with negative expression of HER2 (r = -0.214, p < 0.05) and positive expression of NM23-H1 (r = 0.137, p < 0.05) in the pre-menopausal group. Over-expression of HER2 was correlated with menopausal status (r = -0.107, p < 0.05) and lymph node metastasis in the ER-negative post-menopausal group (r = 0.222, p < 0.05). NM23-H1 was associated with less lymph node metastasis in the ER-positive pre-menopausal group (r = -0.237, p < 0.05).

Our results indicated that expression patterns of ER, NM23-H1, and HER2 in primary breast cancer lesions warn that cells might have metastatic potential, which could assist clinicians to provide a more accurate prognosis and tailor therapeutic management for individual patients.