Breast cancer has a heterogeneous natur...

OBJECTIVE: To determine the frequency of the immunohistochemical profiles of a series of high-grade ductal carcinoma in situ of the breast. METHODS: One hundred and twenty-one cases of high-grade ductal carcinoma in situ, pure or associated with invasive mammary carcinoma, were identified from 2003 to 2008 and examined with immunohistochemistry for estrogen receptor, human epidermal growth factor receptor 2, cytokeratin 5, and epidermal growth factor receptor. The tumors were placed into five subgroups: luminal A, luminal B, HER2, basal-like, and ‘‘not classified’’. RESULTS: The frequencies of the immunophenotypes of pure ductal carcinoma in situ were the following: luminal A (24/42 cases; 57.1%), luminal B (05/42 cases; 11.9%), HER2 (07/42 cases; 16.7%), basal-like phenotype (00/42 cases; 0%), and ‘‘not classified’ ’ (06/42 cases; 14.3%). The immunophenotypes of ductal carcinoma in situ associated with invasive carcinoma were the following: luminal A (46/79 cases; 58.2%), luminal B (10/79 cases; 12.7%), HER2 (06/79 cases; 7.6%), basal-like (06/79 cases; 7.6%), and ‘‘not classified’ ’ (11/79 cases; 13.9%). There was no significant difference in the immunophenotype frequencies between pure ductal carcinoma in situ and ductal carcinoma in situ associated with invasive carcinoma (p.0.05). High agreement was observed in immunophenotypes between both components (kappa=0.867)