Comparing the Diagnostic Outcomes of Staining Various Breast Lesions with Either Anti-CK 5/6 or Anti-CK 5

Anti-CK5/6 monoclonal antibodies have an established role in breast disease diagnosis. Anti-CK5 monoclonal antibodies have recently become commercially available. There has been growing interest in the staining characteristics of anti-CK5 and its potential diagnostic role in place of anti-CK5/6. We aim to compare and contrast the staining characteristics of anti-CK5/6 vs anti-CK5.   58 tissue blocks containing 122 different lesions were selected from tissue archives. Two specimens (groups) were taken from each lesion One (group) was stained with anti-CK5 and the other (group) with anti-CK5/6 monoclonal antibodies, using the Streptavidin-biotin immuno-peroxidase method. The two groups of slides were compared and contrasted for lesion staining pattern and for intensity, using light microscopy. Results showed that the diagnostic staining pattern was exactly the same in both anti-CK5 and anti-CK5/6 groups, and also showed that anti-CK5, stained most of the lesions more intensely than anti-CK5/6. Anti-CK5 performed at least as well (for lesion-pattern staining), and better (for lesion staining intensity) than did anti-CK5/6 in the diagnosis of a wide range of breast tissues and lesions. It may be justified to safely replace anti-CK5/6 with anti-CK5 in future routine clinical use, with resultant diagnostic and economic benefits.