Analysis of the immunohistochemical expression of mammaglobin A in primary breast carcinoma and lymph node metastasis.

Mammaglobin A is a specific marker of the normal and neoplastic mammary tissue that usually is detected by RT-PCR. Few data are available about the immunohistochemical expression of this marker in mammary carcinoma and about the significance of the positive reaction. Our purpose was to investigate the sensitivity of the mammaglobin expression in breast cancer and to determine its correlations with conventional prognostic parameters. There were investigated 47 patients with breast carcinoma, and slides from paraffin blocks were stained with an antibody against mammaglobin. The immunohistochemical reaction was scored based on the percentage of positive tumor cells in both primary tumors and lymph node metastasis. Positive reaction for mammaglobin was found in the normal mammary tissue adjacent to the tumor in all cases, in 78.72% primary breast carcinoma, and in 58.06% of cases with lymph node metastases. A significant correlation was found between the mammaglobin expression in the primary tumor, grade, and lymph node status, but not with the age of the patient, pathologic subtype of carcinoma and stage of the tumor. The ductal in situ carcinoma associated to the invasive tumor did not influence significantly the prognostic value of mammaglobin expression. Out results suggest that mammaglobin is a sensitive marker of breast carcinoma, it defines a subgroup of patients with better prognosis and is a useful method to detect breast cancer metastases.