Copy number variation of urine exfoliated cells by low-coverage whole genome sequencing for diagnosis of prostate adenocarcinoma: a prospective cohort study

• Published in: BMC medical genomics Vol. 15; no. Suppl 2; p. 104
• Main Authors: Guan, Youyan, Wang, Xiaobing, Guan, Kaopeng, Wang, Dong, Bi, Xingang, Xiao, Zhendong, Xiao, Zejun, Shan, Xingli, Hu, Linjun, Ma, Jianhui, Li, Changling, Zhang, Yong, Shou, Jianzhong, Wang, Baiyun, Qian, Ziliang, Xing, Nianzeng
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 05-05-2022; BioMed Central; BMC
• Subjects: Adenocarcinoma; Adenocarcinoma - diagnosis; Adenocarcinoma - genetics; Adenocarcinoma - pathology; Aneuploidy; Biomarkers; Biopsy; Cancer; Cancer screening; Cell division; Chromosomes; Cohort analysis; Copy number; Copy number variations; Deoxyribonucleic acid; Diagnosis; DNA; DNA Copy Number Variations; DNA sequencing; Early Detection of Cancer; Genetic aspects; Genomes; Genomic instability; Genotyping; Health aspects; Humans; Hypertrophy; Male; Medical prognosis; Methods; Mortality; Mutation; Nucleotide sequencing; Patients; Prospective Studies; Prostate - pathology; Prostate cancer; Prostate-Specific Antigen - genetics; Prostatic Hyperplasia - diagnosis; Prostatic Hyperplasia - genetics; Prostatic intraepithelial neoplasia; Prostatic Neoplasms - diagnosis; Prostatic Neoplasms - genetics; Prostatic Neoplasms - pathology; Software; Tumors; Urine; Whole Genome Sequencing; China; United States > US
• ISSN: 1755-8794; 1755-8794
• DOI: 10.1186/s12920-022-01253-5

Non-invasive, especially the urine-based diagnosis of prostate cancer (PCa) remains challenging. Although prostate cancer antigen (PSA) is widely used in prostate cancer screening, the false positives may result in unnecessary invasive procedures. PSA elevated patients are triaged to further evaluation of free/total PSA ratio (f/t PSA), to find out potential clinically significant PCa before undergoing invasive procedures. Genomic instability, especially chromosomal copy number variations (CNVs) were proved much more tumor specific. Here we performed a prospective study to evaluate the diagnostic value of CNV via urine-exfoliated cell DNA analysis in PCa.
We enrolled 28 PSA elevated patients (≥ 4 ng/ml), including 16 PCa, 9 benign prostate hypertrophy (BPH) and 3 prostatic intraepithelial neoplasia (PIN). Fresh initial portion urine was collected after hospital admission. Urine exfoliated cell DNA was analyzed by low coverage Whole Genome Sequencing, followed by CNV genotyping by the prostate cancer chromosomal aneuploidy detector (ProCAD). CNVs were quantified in absolute z-score (|Z|). Serum free/total PSA ratio (f/t PSA) was reported altogether.
In patients with PCa, the most frequent CNV events were chr3q gain (n = 2), chr8q gain (n = 2), chr2q loss (n = 4), and chr18q loss (n = 3). CNVs were found in 81.2% (95% Confidence Interval (CI) 53.7-95.0%) PCa. No CNV was identified in BPH patients. A diagnosis model was established by incorporating all CNVs. At the optimal cutoff of |Z|≥ 2.50, the model reached an AUC of 0.91 (95% CI 0.83-0.99), a sensitivity of 81.2% and a specificity of 100%. The CNV approach significantly outperformed f/t PSA (AUC = 0.62, P = 0.012). Further analyses showed that the CNV positive rate was significantly correlated with tumor grade. CNVs were found in 90.9% (95% CI 57.1-99.5%) high grade tumors and 60.0% (95% CI 17.0-92.7%) low grade tumors. No statistical significance was found for patient age, BMI, disease history and family history.
Urine exfoliated cells harbor enriched CNV features in PCa patients. Urine detection of CNV might be a biomarker for PCa diagnosis, especially in terms of the clinically significant high-grade tumors.