HER-2/neu and p53 overexpression as biomarkers of breast carcinoma in women age 30 years and younger.

Abstract

Although p53 and HER-2/neu overexpression are found in 30% of breast carcinomas in women of all ages and are associated with high rates of lymph node metastases, their role in women age < 30 years has not been studied extensively. The institutional breast cancer data base was searched to identify young women (23-30 years) with breast carcinoma. An immunohistochemical analysis was performed to determine estrogen receptor and progesterone receptor expression and p53 and HER-2/neu overexpression. Positive staining for p53 was defined as nuclear staining in > 10% of tumor cells. HER-2/neu membranous staining was graded as 0, 1 (incomplete, faint staining in > 10% of cells), 2 (weak-to-moderate, complete staining in > 10% of cells), or 3 (complete, strong staining in > 10% of cells). Fluorescence in situ hybridization (FISH) was performed on all samples with > or = 2 and > or = 3 results, and only FISH-positive samples were classified as positive. The overexpression was correlated with clinicopathologic features. Among 44 patients, 1 patient had medullary carcinoma, and 1 had mixed ductal/lobular carcinoma. All remaining patients were diagnosed with invasive ductal carcinoma. The clinical stage was T1 in 5 patients, T2 in 24 patients, T3 in 10 patients, T4 in 4 patients, and unavailable in 1 patient. Positive p53 status was determined in 22 of 44 patients (50%), and positive HER-2/neu status was determined in 18 of 41 patients (44%). Tumors with lymph node metastasis had a significantly greater incidence of HER-2/neu overexpression (P=0.04). Frequent overexpression of HER-2/neu and p53 was found in the patient population. HER-2/neu overexpression was associated significantly with lymph node involvement and, thus, may be a marker for aggressive clinical behavior in patients with breast carcinoma age < or = 30 years.