Diagnostic accuracy of NMP 22 and urine cytology for detection of transitional cell carcinoma urinary bladder taking cystoscopy as gold standard

摘要

Objective: To determine diagnostic accuracy of NMP 22 and urine cytology in the detection of transitionalcell carcinoma (TCC) urinary bladder taking cystoscopy as a gold standard in patients having provisionaldiagnosis of bladder cancer (BC).Methods: This cross sectional validational study enrolled 380 patients fulfilling selection criteria and wasconducted at Armed Forces Institute of Urology (AFIU) Rawalpindi, Pakistan form July 2018 to July 2019. Theurine sample collected underwent NMP22 and cytological analysis followed by rigid cystoscopy. Reports ofall three tests divided patients into positive or negative for malignancy as per defined criteria. Sensitivity,specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of NMP22, urine cytology and their combination was determined. Receiver operating characteristic (ROC) curveanalysis performed and area under the curve (AUC) compared among these tests.Results: The average age of patients was 53.08 ± 12.41 years having male to female ratio 3.75:1(300 malesand 80 females). NMP 22 had better sensitivity and comparable specificity to cytology (81.9 & 81.2% vs 54& 93.9%). Combination of NMP 22 / cytology outperformed both in terms of sensitivity (91.63 vs 81.83 vs53.96), NPV (87.59 vs 77.46 vs 61.02) and diagnostic accuracy (85.26 vs 81.58 vs 71.32) but at the cost ofspecificity (76.97 vs 81.21 vs 93.94) and PPV (83.83 vs 85.02 vs 92.06). ROC curve revealed statisticallysignificant higher AUC (0.843 vs .815 vs .73) for combination as compared to NMP 22 and Cytology (p0.001).Conclusion: NMP22 is a quick, point of care test having higher sensitivity, NPV and accuracy but similarspecificity and PPV to urine cytology for detection of TCC urinary bladder. Combination outperformed bothin terms of sensitivity while having modest specificity.