Apolipoprotein A1 as a novel urinary biomarker for diagnosis of bladder cancer: A systematic review and meta-analysis

Introduction: The emergence of urinary biomarkers for bladder cancer diagnosis could provide a reliable and less invasive diagnostic method. It could be also used as an adjuvant to the current gold standards of cytology and cystoscopy to improve diagnostic accuracy and decrease the percentage of false positives. Methods: We searched PubMed, SCOPUS, and Web of Science up to March 18, 2020. We selected four studies that assessed the diagnostic accuracy of urinary apolipoprotein A1 (ApoA-1) in detecting bladder cancer and met the inclusion and exclusion criteria. Two authors independently extracted the data and performed quality assessment of the studies. Results: Four studies with 771 participants were selected; 417 were bladder cancer patients and 354 were controls. Bladder cancer was either transitional cell carcinoma or squamous cell carcinoma, the stages varied between Ta to T3, and the grades varied between G1 and G3. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 90.7%, 90%, 9.478, 0.1, and 99.424, respectively. Summary receiver operating characteristic curve showed an area under the curve of 0.9544 and QFNx01 index of 0.8965. Conclusions: ApoA-1 showed high sensitivity and specificity, so it could be a useful biomarker in diagnosis of bladder cancer.