Trophoblast Cell Surface Antigen 2 Expression in Human Tumors: A Tissue Microarray Study on 18,563 Tumors.

INTRODUCTION

Trophoblast cell surface antigen 2 (TROP2) is the target of sacituzumab govitecan, an antibody-drug conjugate approved for treatment of triple negative breast cancer and urothelial carcinoma.

METHODS

A tissue microarray containing 18,563 samples from 150 different tumor types and subtypes as well as 608 samples of 76 different normal tissue types was analyzed by TROP2 immunohistochemistry.

RESULTS

TROP2 positivity was found in 109 tumor categories, including squamous cell carcinomas of various origins, urothelial, breast, prostate, pancreatic, and ovarian cancers (>95% positive). High TROP2 expression was linked to advanced stage (p = 0.0069) and nodal metastasis (p < 0.0001) in colorectal cancer as well as to nodal metastasis in gastric adenocarcinoma (p = 0.0246) and papillary thyroid cancer (p = 0.0013). Low TROP2 expression was linked to advanced stage in urothelial carcinoma (p < 0.0001), high pT (p = 0.0024), and high grade (p < 0.0001) in breast cancer, as well as with high Fuhrmann grade (p < 0.0001) and pT stage (p = 0.0009) in papillary renal cell carcinomas.

CONCLUSION

TROP2 is expressed in many epithelial neoplasms. TROP2 deregulation can be associated with cancer progression in a tumor-type dependent manner. Since anti-TROP2 cancer drugs have demonstrated efficiency, they may be applicable to a broad range of tumor entities in the future.