Evaluation of TRPS1 as a Diagnostic Marker for Breast Carcinoma

Abstract Background Breast cancer (BC) is a very important health challenge worldwide. It is the leading cause of global cancer incidence and the leading cause for cancer related mortality in women. BC is a disease with high metastatic potential always a suspect in the differential diagnoses of metastatic carcinoma of unknown primary. Based on the expression of ER, PR, Her2 BC is categorized into molecular subtypes as luminal (A&B), Her2-postive and triple negative (TNBC) subtypes. TNBC is the most aggressive form with high tendency for metastasis and overall poorer clinical behavior. Diagnosis of metastatic TNBC breast cancer is usually a diagnostic dilemma due to absence of sensitive and specific immunohistochemical marker for breast origin. Trichorhinophalangeal syndrome-1 (TRPS1) is a recently discovered breast marker with high expression in different molecular groups especially TNBC, making it a potential useful tool for diagnosis of BC. Objective To evaluate the immunohistochemical expression of TRPS1 in breast carcinoma as a highly sensitive and specific marker for breast carcinoma, especially for TNBC. Methods The current study was conducted retrospectively on 80 cases of invasive breast carcinoma as archived formalin fixed paraffin embedded blocks obtained the Pathology Department lab of Ain Shams University Hospitals (2019-2023). The cases included in the current study were divided into 3 groups; Group 1: included 25 Luminal cases, Group 2: included 20 Her-2 positive cases and Group 3: included 35 TNBC cases. Data concerned with gender, age and type of procedure were obtained from the electronically archived reports. The histopathological data were re-examined microscopically by at least two authors. After then, the expression of TRPS1 was evaluated in different molecular groups, followed by statistical evaluation of the obtained results. Results TRPS1 was expressed in 88.8% of the studied cases. No statistically significant relationship between TRPS1 expression and the histopathological subtype, tumor size, tumor grade, lymph node status nor in-situ duct component. TRPS1 high score was detected in 66.3% of the studied cases. TRPS1 showed high expression in different molecular groups, as it was detected in 96% of luminal group, 85% of Her2-positive group and 85.7% of TNBC group. These differences were not statistically significant. Conclusion TRPS1 is a sensitive marker for all molecular subtypes of breast cancer. It might be a valuable addition to determine breast origin in clinical practice especially for TNBC.