OBJECTIVE: To critically analyze the contribution of immunohistochemistry to the assessment of prognostic and predictive factors of breast cancer, to the search for micrometastases in sentinel lymph nodes, and to the differential diagnosis of mammary lesions. METHODS: An observational retrospective study was carried out reviewing all cases of mammary lesions submitted to immunohistochemistry at the Breast Pathology Laboratory of Federal University of Minas Gerais between 2001 and 2007. According to immunohistochemistry indication, the cases were classified into three categories: assessment of prognostic and predictive factors, search for epithelial metastatic cells in sentinel lymph nodes and differential diagnosis. RESULTS: Immunohistochemistry was performed in 1,294 cases, with 4,101 reactions using 21 different antibodies. In most cases, immunohistochemistry was conducted to assess predictive/prognostic factors (1,106 cases, 85.5%), followed by search for epithelial metastatic cells in sentinel lymph nodes (134 cases, 10.6%) and differential diagnosis of breast lesions (51 cases, 3.9%). Good quality reactions, with significant contribution to the immunohistochemistry study, were obtained in 1,247 cases (96.4%). In 47 cases (3.6%) the results were inconclusive due to fixation problems (autolysis) in the pre-analytical phase. CONCLUSION: Our data confirm that the immunohistochemical study is an important tool to the assessment of predictive and prognostic factors, search for micrometastases in sentinel lymph nodes, and differential diagnosis of mammary lesions. The widest use of immunohistochemistry was in the assessment of predictive and prognostic factors of breast cancer.
Breast; Carcinoma; Diagnosis; Pathology; Immunohistochemistry; Prognostic factors
