INTRODUCTION

Traditional prognostic markers such as tumour grade and stage have a limited role in predicting outcomes in bladder cancer (BCa). Inositol polyphosphate-4-phosphatase, type II (INPP4B) is a tumour suppressor gene, and loss of INPP4B is associated with a poor prognosis in prostate and breast cancer with limited evidence in BCa.

PATIENT & METHODS

A tissue microarray (TMA) of 105 patients with stage IV (pT4b or N1/2) or metastatic BCa who had stable disease after chemotherapy was stained for INPP4B. All patients did not have radical treatment. Light microscopy was used to examine TMA cores. Primary end point was overall survival (OS).

RESULTS

Median follow-up was 17.4 months (range: 1.4-45.5, IQR: 7.1-20.1). INPP4B was positive in 56 patients (66.7%) while 28 patients (33.3%) had low/ negative INPP4B expression. INPP4B negative patients were significantly associated with shorter OS (HR: 1.97, 95% CI: 1.09- 3.57; p=0.022).

CONCLUSION

Loss of INPP4B was associated with shorter OS in BCa patients with stage IV or metastatic disease. Further work is needed to determine if INPP4B is a prognostic marker for response to chemotherapy.