Immunohistochemically detected expression of breast tumor-associated glycoprotein (323/A3) in breast cancer

Breast carcinomas were studied to determine the association between expression of breast tumor-associated glycoprotein (BTAG or 323/A3) and clinical parameters such as estrogen receptor status, lymph node status, histological grade and menopausal status. In addition, the relationship between BTAG expression and other tumor markers namely, estrogen receptor- related protein (ERRP or p29), cathepsin-D, c-erbB2, epidermal growth factor receptor (EGFR), Ha-ras, p53 and c-myc was investigated. A series of 59 patients with primary breast carcinomas comprising of nine ductal carcinoma in situ (DCIS), forty-five invasive ductal carcinomas, three colloid carcinomas and one each of medullary and invasive lobular carcinoma were available. An immunohistochemical method was used to evaluate the expression of BTAG which was expressed in 66% of primary breast carcinomas including 66% ductal carcinoma in situ, 64% invasive ductal carcinomas, 67% colloid carcinomas, all medullary and invasive lobular carcinomas. BTAG was not significantly correlated with estrogen receptor status, lymph node status, histological grade and menopausal status but it was significantly (p<0.05) associated with EGFR, c-erbB2 and c-myc, but weakly associated with cathepsin-D. BTAG expression appears not to be an independent prognostic marker but may be useful in identifying tumors with aggressive behavior.