Comparative Analysis of Trps-1 Expression in Breast and Urothelial Carcinomas

Carcinoma of unknown primary origin is a diverse group of carcinomas that is defined by the presence of metastatic disease with no identified primary tumor at initial presentation. This group comprises 2 to 5% of all carcinoma cases. GATA3 and CK7 are markers which are positive in both breast carcinoma as well as urothelial carcinoma. Trichorhinophalangeal syndrome type 1 (TRPS1), a member of the GATA family, is overexpressed in breast carcinoma. The aim of the study is to compare the expression of TRPS-1 gene in breast carcinoma and urothelial carcinomas for its potential use in differentiating breast carcinoma metastasis from that of urothelial carcinoma in cases of carcinoma of unknown primary, especially when routine markers for breast carcinoma are negative and GATA-3 is positive. The present study was an observational cross-sectional study conducted over a period of 4 years (2020-2023) on 150 cases each of breast and urothelial carcinoma, wherein the expression of TRPS-1 was studied. In the present study, a majority of urothelial carcinoma cases 92.7% (139/150) were negative with a score of 0. Eleven cases were positive (7.3%) with weak to intermediate score while all the cases of breast carcinoma (150/150; 100%) expressed TRPS-1 with intermediate to high scores. It was concluded that TRPS1 is 100% sensitive and 92.66% specific for breast carcinoma and can be included in the panel for search of unknown primary at metastatic site.