A urine-based liquid biopsy for detection of upper tract urothelial carcinoma: a self-matched study

Background To establish the pathological diagnosis of UTUC before treatment is profitable. At present, the conventional pathological diagnostic methods have certain problems. Besides, the urine-based DNA methylation test have been already utilized to detect bladder cancer. Objective To evaluate the sensitivity and specificity of DNA methylation plus 17 genes mutation test and compare the combined test with cytology. Materials and methods We included 45 patients from April 2019 to May 2022, all of whom underwent radical nephroureterectomy (RNU), nephrectomy, diagnostic ureteroscopy or tissue biopsy. Before surgery, the urine samples were collected for DNA methylation plus 17 genes mutation test and cytology. The test performance was calculated, and comparative ROC curves were drawn. Results The median age of the patients was 67 years. The Kappa value of the DNA methylation plus 17 genes mutation test and tissue pathology was 0.59 (p<0.001). The sensitivity/specificity/PPV/NPV of DNA methylation plus 17 genes mutation test was 86/80/94/62% compared with 29/100/100/29% for cytology. The AUC of DNA methylation plus 17 genes mutation test was 0.829 (p<0.001).The mutated gene proportion of UTUC patients was 51.43% for TERT and 25.71% for TP53. Conclusion The test performance of DNA methylation plus 17 genes mutation test was satisfactory, which may replace cytology in the future. Further multicenter studies with larger samples are needed to confirm the clinical value of this promising method. Novelty & impact statements We evaluated the diagnostic efficacy of a urine-based liquid biopsy for the detection of UTUC and compared the combined test with cytology. We found satisfactory results and concluded that the test could partly replace cytology. Further studies are needed.