ETS-1 oncoprotein expression is decreased in aggressive papillary transitional cell carcinoma of the urinary bladder: An immunohistochemical study

Abstract

Introduction: ETS-1 proto-oncogene is a transcription factor that plays multiple roles in the process of oncogenesis and helps in the process of tumor invasion. ETS-1 oncoprotein correlation with high grade and invasive tumors is controversial; as it is found to be upregulated with some tumors and down regulated with others. Expression of ETS-1 in urinary bladder carcinoma (UBC) and its correlation with tumor differentiation and invasiveness are still under-investigated. So far, there is no reliable prognostic marker has been proved for detection of the tumor progression and recurrence.

Objectives: To analyze the correlation between ETS-1 oncoprotein immunohistochemical expression and the different stages and grades of the primary papillary transitional cell carcinoma of the urinary bladder.

Patients and methods: This is a retrospective cross sectional study that included archival material from 150 cancer cases and 24 control biopsies.

Results: There was a decreased ETS-1 oncoprotein expression with increasing stage and grade of the tumor with a highly significant statistical correlation (P = 0.001). With the quantitative assessment of the immunohistochemical results and using ROC (receiver operating characteristics) curve, cut-off values were found, that were associated with high grade and muscle invasive tumors (≤30% and ≤20%, respectively).

Conclusion: ETS-1 oncoprotein is down regulated with high grade and highly invasive urinary bladder papillary transitional cell carcinomas. This oncoprotein may be used as an independent prognostic marker to predict the aggressive papillary transitional carcinomas with high invasive potential. More studies are needed to confirm our results.

Keywords: Papillary transitional cell carcinoma; ETS-1; Prognostic marker; Immunohistochemical; Stage; Grade