The diagnostic significance of immunohistochemical expression of SOX10 and TRPS1 in triple negative breast cancer.

Triple negative breast cancer (TNBC) usually exhibits heterogeneous morphological features. The absence of a specific targeted marker for the breast origin of TNBC makes the diagnosis of metastatic TNBC challenging. TRPS1 is regarded as a diagnostic marker for breast cancer of various subtypes, including the basal type of TNBC. SOX10 has been recorded in to be highly expressed in TNBCs. Our cohort study aimed to: first, assess the diagnostic value of TRPS1 and SOX10 immunohistochemical (IHC) expression in TNBC; second, investigate if any of these two markers are related to the established pathological factors of prognostic significance. The study cohort comprised 84 TNBC cases subjected to TRPS1 and SOX10 IHC staining. TRPS1 expression was demonstrated in 86.9 % of the cases. It was expressed in 85.9 %, 83.3 %, and 100 % of invasive breast carcinoma-no special type (IBC-NST), metaplastic carcinomas, and IBC with medullary pattern, respectively. SOX10 expression was identified in 61.9 % of the cases. Most (85.7 %) of IBC with medullary pattern and 83.3 % of metaplastic carcinomas showed positive SOX10 expression. Evaluation of the combined expression of both markers revealed that 52.4 %, 34.5 %, 9.5 %, and 3.6 % of TNBC cases were SOX10+/TRPS1+, SOX10-/TRPS1+, SOX10+/TRPS1-, and SOX10-/TRPS1-, respectively. TRPS1 and SOX10 are fairly sensitive markers for the diagnosis of TNBC. Accordingly, they may be of help in the detection of metastatic TNBC. However, additional studies are required to evaluate these markers on non-breast tumor tissue to further investigate their specificity.