Application of tissue microarrays for receptor immunohistochemistry in breast carcinoma

The current treatment of breast cancer, the most frequent malignancy found in females, requires the study of biomarkers. The standard set of these includes at least an estrogen receptor, a progesterone receptor and a HER2 receptor, although many other factors have been shown to contribute to the prognosis. Tissue microarrays have been introduced to decrease costs and workload of immunohistochemistry applied to large collections of samples. The aim of the study was to test the performance of this technology on three basic biomarkers of breast carcinoma in 106 cases of invasive breast carcinoma. Tissue microarrays composed of 3 cores sized 0.6 mm per case were constructed and stained by standard immunohistochemistry. The results were assessed on virtual slides created with an Aperio scanner. A sensitivity and specificity of 0.83 and 0.88 was obtained for the estrogen receptor, 0.76 and 0.88 for the progesterone receptor, 0.69 and 0.96 for HER2. In conclusion, TMA technology may give results comparable to the diagnosis based on whole sections, and the clinicopathologic correlations for the immunohistochemistry performed by both methods are fairy similar.