Comparison of GATA-3, Mammaglobin and GCDFP-15 Expression in Primary, Metastatic and Triple Negative Breast Carcinomas: An Indian Scenario

BACKGROUND AND OBJECTIVE: Mammaglobin and GCDFP-15 are traditional immunohistochemistry (IHC) markers utilized to recognize metastasis of breast carcinoma in an unknown primary. GATA-3 is increasingly being used as a marker of primary breast origin. This study was done to evaluate and compare GATA-3 with GCDFP-15 and Mammaglobin in invasive primary including metastatic and triple negative breast carcinomas. METHODS: Immunohistochemistry for GATA-3, GCDFP-15 and Mammaglobin was applied on 100 cases of primary breast carcinomas, including 20 triple negative cases and 30 cases of metastatic breast carcinomas. Staining scores were given for each marker by multiplying the percentage of positive tumor cells by the intensity of staining (1+, 2+ or 3+), with scores ranging from 0 to 300. Staining score of 1 or more was considered positive. RESULTS: GATA-3 was expressed in 92% of primary, 80% of metastatic and 60% of triple negative breast carcinomas, with an average staining score of 270. Mammaglobin was expressed in 68% of primary, 56.6% of metastatic and 25% of triple negative breast carcinomas, with an average staining score of 180. GCDFP-15 was expressed in 48% of primary, 26.6% of metastatic and 05% of breast carcinomas, with an average staining score of 60. GATA-3 demonstrated to have higher staining score (average of 270) than other two markers in maximum number of cases. CONCLUSION: GATA-3 has a higher sensitivity and increased staining scores in primary breast carcinomas, metastatic breast carcinomas as well as in triple negative breast carcinomas.