Objective: The purpose of this study was to investigate the value of GCDFP-15, ALA, CK7 and CK20 in the diagnosis and differential diagnosis of primary breast carcinoma and breast carcinoma metastases.

Material and Method: Tissues from 84 primary female breast carcinomas, 36 breast carcinoma metastases, 11 primary breast carcinomas and their metastases, and 10 primary male breast carcinomas were stained for GCDFP-15, ALA, CK7 and CK20 and the staining features were analyzed.

Results: GCDFP-15 was stained in 75%, 70% and 58% of the primary female breast cancer, male breast cancer, and metastatic breast cancer cases, respectively. ALA was stained in 87%, 100% and 77% of the primary female breast cancer, male breast cancer, and metastatic breast cancer cases, respectively. CK7 was stained in 87%, 80% and 86% of the primary female breast cancer, male breast cancer, and metastatic breast cancer cases, respectively. CK20 was stained in 5,4% and 10% of the primary female breast cancer and male breast cancer cases, respectively. When the staining levels of the immunohistochemical markers in all the primary and metastatic cancer cases were compared with each other, association between CK7 and CK20 (p=0.00), CK7 and GCDFP-15 (p=0.02), ALA and GCDFP-15 (p=0.02), ALA and CK20 (p=0.00), and CK20 and GCDFP-15 (p=0.00) were found statistically significant.

Conclusion: We suggest that it is useful to perform GCDFP-15 and ALA in addition to the hormone receptors in diagnosing primary breast carcinoma, metastatic carcinoma of unknown primary, and in differential diagnosis of other tumors that have various morphological appearances in the breast.