Immunohistochemical comparison between GCDFP-15 and estrogen and progesterone receptors in the diagnosis of metastatic carcinoma of the breast

Background: in the workup of tumors of unknown primary origin in women, a frequent consideration is breast carcinoma, because it is common and may initially present as metastasis. Objective: describe and compare the immunohistochemical profile of hormonal receptors (estrogen receptor and progesterone receptor) and GCDFP-15 in lymph node metastatic breast carcinoma according the histological grade. Methods: retrospective study analyzing 30 patients with identified primary breast cancer and lymph node metastasis. The cases were divided in three groups: grade I (well differentiated), grade II (moderately differentiated) and grade III (poorly differentiated). We used three antibodies (estrogen receptor, progesterone receptor and GCDFP-15) in the lymph node and compare the expression according the histological grade. Results: in metastatic lymph node from grade I breast carcinomas the hormone receptors were 100% positive and GCDFP-15 was 80% positive. In grade II, estrogen receptor and progesterone receptor were positive in 90 and 40% respectively, and GCDFP-15 was positive in 80%. In grade III, estrogen receptor and progesterone receptor were positive in 30 and 50% respectively, and GCDFP-15 in 60%. Conclusions: the immunohistochemical expression of hormonal receptors and GCDFP-15 in metastatic breast carcinoma is related to histological grade in the breast.