Clinical value of urine nuclear matrix protein 22 (NMP22) quantitative test in the diagnosis of bladder cancer in a schistosoma endemic region

Abstract
Background: Bladder cancer is the ninth commonest cancer and the 13th most common cause of mortality worldwide. Its early diagnosis poses a great challenge therefore the need to identify biomarkers which may improve the current diagnostic practice. Methods: This is a prospective study of patients managed for bladder cancer at the urology unit, department of surgery, Usmanu Danfodiyo University Teaching Hospital, Sokoto, Nigeria between April 2019 to June 2020. Urine cytology, urine nuclear matrix protein 22 (NMP22) quantitative test and histology of the bladder biopsy specimens were done at the Histopathology and Chemical Pathology laboratory respectively of the Usmanu Danfodiyo University Teaching Hospital, Sokoto. Data was collected using a structured proforma and analyzed using statistical package for social sciences (SPSS) version 20.0. Results: Eighty-three patients enrolled in the study however 46 of them with features of bladder carcinoma participating in the study group and 37 in the control group. The study and control groups' mean age and age range are (49.70±11.45,18-69) and (51.84±13.75,18-78) years, respectively. The sensitivity, specificity, PPV, NPV and AUC of urine NMP22 and urine cytology in the study were (78.3% vs. 58.7%), (32.4% vs. 100.0%), (59.0% vs. 100.0%), (54.6% vs. 66.1%), (0.207 vs. 0.538) respectively for the diagnosis of bladder cancer. Conclusions: Urine NMP22 quantitative test shows high sensitivity, low specificity and a low AUC compared to urine cytology and thus of poor clinical value in the diagnosis of bladder cancer in our region.