Urinary Cell-free DNA Research Articles

Dynamics of methylated cell-free DNA in the urine of non-small cell lung cancer patients

ABSTRACT High levels of methylated DNA in urine represent an emerging biomarker for non-small cell lung cancer (NSCLC) detection and are the subject of ongoing research. This study aimed to investigate the circadian variation of urinary cell-free DNA (cfDNA) abundance and methylation levels of cancer-associated genes in NSCLC patients. In this prospective study of 23 metastatic NSCLC patients with active disease, patients were asked to collect six urine samples during the morning, afternoon, and evening of two subsequent days. Urinary cfDNA concentrations and methylation levels of CDO1, SOX17, and TAC1 were measured at each time point. Circadian variation and between- and within-subject variability were assessed using linear mixed models. Variability was estimated using the Intraclass Correlation Coefficient (ICC), representing reproducibility. No clear circadian patterns could be recognized for cfDNA concentrations or methylation levels across the different sampling time points. Significantly lower cfDNA concentrations were found in males (p=0.034). For cfDNA levels, the between- and within-subject variability were comparable, rendering an ICC of 0.49. For the methylation markers, ICCs varied considerably, ranging from 0.14 to 0.74. Test reproducibility could be improved by collecting multiple samples per patient. In conclusion, there is no preferred collection time for NSCLC detection in urine using methylation markers, but single measurements should be interpreted carefully, and serial sampling may increase test performance. This study contributes to the limited understanding of cfDNA dynamics in urine and the continued interest in urine-based liquid biopsies for cancer diagnostics.

Characterizing the molecular composition and diagnostic potential of Mycobacterium tuberculosis urinary cell-free DNA using next-generation sequencing

BackgroundUrine cell-free DNA (cfDNA) is an attractive target for diagnosing pulmonary Mycobacterium tuberculosis (MTB) infection, but has not been thoroughly characterized as a biomarker. MethodsThis study was performed to investigate the size and composition of urine cfDNA from tuberculosis (TB) patients with minimal bias using next-generation sequencing (NGS). A combination of DNA extraction and single-stranded sequence library preparation methods demonstrated to recover short, highly degraded cfDNA fragments was employed. Urine cfDNA from 10 HIV-positive patients with pulmonary TB and two MTB-negative controls was examined. ResultsMTB-derived cfDNA was identifiable by NGS from all MTB-positive patients and was absent from negative controls. MTB cfDNA was significantly shorter than human cfDNA, with median fragment lengths of ≤19–52 bp and 42–92 bp, respectively. MTB cfDNA abundance increased exponentially with decreased fragment length, having a peak fragment length of ≤19 bp in most samples. In addition, we identified a larger fraction of short human genomic cfDNA, ranging from 29 to 53 bp, than previously reported. Urine cfDNA fragments spanned the MTB genome with relative uniformity, but nucleic acids derived from multicopy elements were proportionately over-represented. ConclusionsTB urine cfDNA is a potentially powerful biomarker but is highly fragmented, necessitating special procedures to maximize its recovery and detection.

Urine tumor DNA detection of minimal residual disease in muscle-invasive bladder cancer treated with curative-intent radical cystectomy: A cohort study.

BackgroundThe standard of care treatment for muscle-invasive bladder cancer (MIBC) is radical cystectomy, which is typically preceded by neoadjuvant chemotherapy. However, the inability to assess minimal residual disease (MRD) noninvasively limits our ability to offer bladder-sparing treatment. Here, we sought to develop a liquid biopsy solution via urine tumor DNA (utDNA) analysis.Methods and findingsWe applied urine Cancer Personalized Profiling by Deep Sequencing (uCAPP-Seq), a targeted next-generation sequencing (NGS) method for detecting utDNA, to urine cell-free DNA (cfDNA) samples acquired between April 2019 and November 2020 on the day of curative-intent radical cystectomy from 42 patients with localized bladder cancer. The average age of patients was 69 years (range: 50 to 86), of whom 76% (32/42) were male, 64% (27/42) were smokers, and 76% (32/42) had a confirmed diagnosis of MIBC. Among MIBC patients, 59% (19/32) received neoadjuvant chemotherapy. utDNA variant calling was performed noninvasively without prior sequencing of tumor tissue. The overall utDNA level for each patient was represented by the non-silent mutation with the highest variant allele fraction after removing germline variants. Urine was similarly analyzed from 15 healthy adults. utDNA analysis revealed a median utDNA level of 0% in healthy adults and 2.4% in bladder cancer patients. When patients were classified as those who had residual disease detected in their surgical sample (n = 16) compared to those who achieved a pathologic complete response (pCR; n = 26), median utDNA levels were 4.3% vs. 0%, respectively (p = 0.002). Using an optimal utDNA threshold to define MRD detection, positive utDNA MRD detection was highly correlated with the absence of pCR (p < 0.001) with a sensitivity of 81% and specificity of 81%. Leave-one-out cross-validation applied to the prediction of pathologic response based on utDNA MRD detection in our cohort yielded a highly significant accuracy of 81% (p = 0.007). Moreover, utDNA MRD–positive patients exhibited significantly worse progression-free survival (PFS; HR = 7.4; 95% CI: 1.4–38.9; p = 0.02) compared to utDNA MRD–negative patients. Concordance between urine- and tumor-derived mutations, determined in 5 MIBC patients, was 85%. Tumor mutational burden (TMB) in utDNA MRD–positive patients was inferred from the number of non-silent mutations detected in urine cfDNA by applying a linear relationship derived from The Cancer Genome Atlas (TCGA) whole exome sequencing of 409 MIBC tumors. We suggest that about 58% of these patients with high inferred TMB might have been candidates for treatment with early immune checkpoint blockade. Study limitations included an analysis restricted only to single-nucleotide variants (SNVs), survival differences diminished by surgery, and a low number of DNA damage response (DRR) mutations detected after neoadjuvant chemotherapy at the MRD time point.ConclusionsutDNA MRD detection prior to curative-intent radical cystectomy for bladder cancer correlated significantly with pathologic response, which may help select patients for bladder-sparing treatment. utDNA MRD detection also correlated significantly with PFS. Furthermore, utDNA can be used to noninvasively infer TMB, which could facilitate personalized immunotherapy for bladder cancer in the future.

Copy Number Signatures and Clinical Outcomes in Upper Tract Urothelial Carcinoma

Tumor staging of upper tract urothelial carcinomas (UTUCs) is relatively difficult to assert accurately before surgery. Here, we used copy number (CN) signatures as a tool to explore their clinical significance of molecular stratification in UTUC. CN signatures were extracted by non-negative matrix factorization from the whole-genome sequencing (WGS) data of 90 Chinese UTUC primary tumor samples. A validation UTUC cohort (n = 56) and a cohort from urinary cell-free DNA (cfDNA) of urothelial cancer patients (n = 94) and matched primary tumors were also examined. Survival analyses were measured using the Kaplan–Meier, and Cox regression was used for multivariate analysis. Here, we identified six CN signatures (Sig1–6). Patients with a high contribution of Sig6 (Sig6high) were associated with higher microsatellite instability level and papillary architecture and had a favorable outcome. Patients with a low weighted genome integrity index were associated with positive lymph node and showed the worst outcome. Sig6high was identified to be an independently prognostic factor. The predictive significance of CN signature was identified by a validation UTUC cohort. CN signatures retained great concordance between primary tumor and urinary cfDNA. In conclusion, our results reveal that CN signature assessment for risk stratification is feasible and provides a basis for clinical studies that evaluate therapeutic interventions and prognosis.

Abstract 547: Urine tumor DNA MRD detection and correlation with pathologic complete response in muscle-invasive bladder cancer treated with curative-intent radical cystectomy

Abstract Objective: Standard-of-care for muscle-invasive bladder cancer (MIBC) is neoadjuvant chemotherapy followed by radical cystectomy. The inability to assess molecular residual disease (MRD) noninvasively limits our ability to offer bladder-sparing treatment. We seek to develop a liquid biopsy solution via urine tumor DNA (utDNA) analysis. Methods: We applied uCAPP-Seq, a targeted next-generation sequencing method for detecting utDNA, to urine cell-free DNA samples acquired on the day of curative-intent radical cystectomy from 42 patients with non-metastatic bladder cancer, 30 of whom had a confirmed diagnosis of MIBC and 19 of whom received neoadjuvant chemotherapy. utDNA mutational calling was performed noninvasively without tumor tissue sequencing knowledge. The overall utDNA level for each patient was represented by the non-silent mutation with the highest duplex-supported variant allele fraction after removing germline variants. Urine was similarly analyzed from 15 healthy donors. The concordance between urine cell-free DNA and tumor tissue was determined for a subset of patients. Tumor mutational burden (TMB) in utDNA MRD-positive patients was inferred from the number of mutations detected in urine cell-free DNA by applying a linear relationship derived from TCGA whole-exome sequencing of 409 MIBC tumors. Results: utDNA analysis revealed a median utDNA level of 0% in healthy donors and 2.4% in non-metastatic bladder cancer patients. Concordance between urine- and tumor-derived mutations, determined in 5 MIBC patients, was 87%. When patients were classified as those who had residual disease detected in their surgical sample (n = 16) compared to those who achieved a pathologic complete response (n = 26), median utDNA levels were 4.3% vs. 0%, respectively (P = 0.002). The lack of utDNA MRD detection was highly correlated with pathologic complete response by Fisher's exact test (P = 0.0001) with Youden's index-determined sensitivity of 81% and specificity of 81%. Moreover, utDNA MRD-positive patients exhibited significantly worse progression-free survival compared to utDNA MRD-negative patients (HR = 7.2; P = 0.03) with a median follow-up time of 200 days. Leveraging data from TCGA, the median inferred TMB in utDNA MRD-positive patients was 198 mutations per exome. We suggest that 58% of these patients with inferred TMB ≥ this level might have been candidates for early immune checkpoint blockade. Conclusion: The lack of utDNA MRD detection prior to curative-intent radical cystectomy for muscle-invasive bladder cancer correlated significantly with pathologic complete response. utDNA MRD detection status also correlated significantly with progression-free survival. Furthermore, utDNA results can be used to noninvasively infer TMB, which may facilitate the targeted use of adjuvant immunotherapy. Citation Format: Kevin Chen, Pradeep S. Chauhan, Ramandeep K. Babbra, Wenjia Feng, Peter K. Harris, Katherine Dienstbach, Andrew Atkocius, Lenon Maguire, Faridi Qaium, Armaan Nallicheri, Brian C. Baumann, Melissa A. Reimers, Eric H. Kim, Zachary L. Smith, Vivek K. Arora, Aadel A. Chaudhuri. Urine tumor DNA MRD detection and correlation with pathologic complete response in muscle-invasive bladder cancer treated with curative-intent radical cystectomy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 547.

MO27-6 Clinical significance of urinary cell-free DNA in urothelial cancer

MO27-6 Clinical significance of urinary cell-free DNA in urothelial cancer

Clinical Features and Treatment Approaches in Patients with Rosai-Dorfman Disease: The Mayo Clinic Experience

IntroductionRosai-Dorfman disease (RDD) is a rare subtype of non-Langerhans cell histiocytosis that is classically characterized by lymphadenopathy and accumulation of CD68-positive, S100-positive, and CD1a-negative histiocytes with frequent emperipolesis in sinuses of lymph nodes and lymphatics of internal organs. In this series, we report on the clinical features, treatment strategies utilized and outcomes of a large cohort of RDD patients seen at one institution.MethodsWe retrospectively reviewed the medical records of patients with biopsy-proven RDD evaluated at the Mayo Clinic from January 1, 1994 to September 2, 2016. Data abstracted from the medical records included: demographic characteristics, symptoms at disease presentation, treatment, and outcomes. In addition, radiologic and molecular findings were collected when available.ResultsA total of 55 patients with confirmed RDD were included in our study. The median age at diagnosis was 50 years (range, 2-79), including 4 pediatric subjects. The median duration from symptom onset to diagnosis was 6.4 months (range, 0-128; mean 18 months). There was a female preponderance (male 1: female 1.5). The most common presenting signs and symptoms were painful or painless subcutaneous masses (40%), lymphadenopathy (13%), bone pain (11%), constitutional symptoms (fevers, chills, myalgia, or weight loss: 11%), and abdominal pain (11%). The organ systems involved with RDD based on either histopathological or radiological findings are shown in the Table. In our series, extranodal presentation in the soft tissue (55%) was more common than a nodal presentation (38%). Other rare extranodal sites included one case each involving the parotid gland, thyroid gland, testicles, and rectum. The median number of biopsies required to establish diagnosis was 2 (range, 1-6). Next generation sequencing was performed on 2 patient samples, and showed a CDC73 truncation in exon 5 in the first case and a KRAS K117N mutation in the second case. BRAF V600E mutation testing was negative in 2 patients: one by immunohistochemistry and one by urine cell-free DNA PCR.Treatment data were available for 46 patients. Of these, 13% patients were observed. The most common first line therapeutic modalities used were surgical excision (39%) and corticosteroids (35%). Other first-line systemic therapies included rituximab in 2 patients and vinblastine in 1 patient. Approximately 13 (28%) patients developed recurrent disease and were treated with other modalities: surgery (n=4), radiation therapy (n=3), and systemic therapies like cladribine (n=4), CVP (cyclophosphamide, vincristine, and prednisone; n=1), and 6-mercaptopurine with prednisone (n=1).The median duration of follow-up after diagnosis was 20 months (range, 0-188). At the time of last follow-up, 4 patients were deceased. Of the deceased, 3 patients died from other malignancies (acute myeloid leukemia, peripheral T-cell lymphoma, and metastatic gall bladder carcinoma) and the cause of death for 1 patient was unknown.ConclusionsRDD is a rare histiocytic disorder presenting with diverse clinical manifestations. The diagnosis is often delayed due to inconclusive biopsies, and in some instances, multiple biopsy attempts are necessary to secure a definitive diagnosis. Approximately one-third of patients may require second-line systemic therapies. Next generation sequencing might yield targetable mutations in RDD patients that relapse or have progressive multi-organ disease. [Display omitted] DisclosuresNowakowski:Morphosys: Consultancy, Research Funding; celgene: Consultancy, Research Funding; Genetech: Consultancy, Research Funding; Bayer: Consultancy, Research Funding; pharmacyclics: Consultancy; Abbvie: Consultancy; Nanostring: Research Funding. Sher:LAM Therapeutics, Inc: Research Funding. Parikh:Pharmacyclics: Honoraria; Pharmacyclics: Research Funding; AstraZeneca: Honoraria.

Tracking minimal residual disease with urine tumor DNA in muscle-invasive bladder cancer after neoadjuvant chemotherapy.

e16514 Background: Standard-of-care for muscle-invasive bladder cancer (MIBC) consists of neoadjuvant chemotherapy (NAC) followed by radical cystectomy. The inability to noninvasively assess minimal residual disease (MRD) after NAC limits our ability to offer bladder-sparing treatment. We perform urine tumor DNA (utDNA) analysis to identify pathologic complete response (pCR) at the time of cystectomy in patients receiving NAC. Methods: We applied CAPP-Seq to urine cell-free DNA samples acquired on the day of radical cystectomy from 19 MIBC patients treated with NAC. utDNA variant-calling was performed without prior tumor mutational knowledge using a panel of 49 consensus driver genes mutated in MIBC. The utDNA level for each patient was represented by the duplex-supported non-silent driver mutation with the highest variant allele fraction (vAF) after removing germline variants. We also serially tracked utDNA variants in two patients before, during, and after NAC. Results: Comparing patients with residual disease detected in their cystectomy specimen ( n = 10) to those who achieved a pCR ( n = 9), median utDNA levels were 2.4% vs. 0%, respectively ( P = 0.006). Using an optimal utDNA threshold to define MRD detection, positive utDNA MRD was highly correlated with the absence of pCR ( P = 0.003). Analysis of two patients’ serial urine samples revealed utDNA dynamics that were consistent with treatment responses in real-time. In one patient who ultimately achieved a pCR, four non-silent driver mutations were detectable pre-NAC, including ERCC2 N238S (7.8% vAF) associated with increased chemosensitivity. One week after starting NAC, ERCC2 N238S increased by 1.6-fold in urine, as did PIK3CA E726K which increased by 8.4-fold. Four weeks post-NAC, however, all mutations previously detected in this patient’s urine became undetectable, consistent with the patient’s pCR and long-term disease-free survival. Conversely, another patient harbored two non-silent driver mutations in PLEKHS1 (1.9% vAF) and KMT2D (4.9% vAF) pre-NAC. One week after starting NAC, both mutations decreased dramatically by 8.0- and 4.3-fold, respectively. By three weeks post-NAC, however, these mutations progressively increased by 5.2-fold on average, which correlated with a lack of pCR as well as post-treatment disease progression. Two newly detected non-silent driver mutations in ARID1A and ERBB2 also emerged on NAC and persisted following completion of chemotherapy , likely reflecting the development of treatment resistance. Conclusions: utDNA MRD after NAC but before radical cystectomy for MIBC correlated significantly with pathologic response, which could help personalize patient selection for bladder-sparing treatments in the future. Serial monitoring of utDNA variants during NAC can reveal dynamic mutational changes that reflect real-time treatment responses as well as ultimate disease-free survival.

Progress toward Developing Sensitive Non-Sputum-Based Tuberculosis Diagnostic Tests: the Promise of Urine Cell-Free DNA.

A highly accurate, non-sputum-based test for tuberculosis (TB) detection is a key priority for the field of TB diagnostics. A recent study in the Journal of Clinical Microbiology by Oreskovic and colleagues (J Clin Microbiol 59:e00074-21, 2021, https://doi.org/10.1128/JCM.00074-21) reports the performance of an optimized urine cell-free DNA (cfDNA) test using sequence-specific purification combined with short-target PCR to improve the accuracy of TB detection. Their retrospective clinical study utilized frozen urine samples (n = 73) from study participants diagnosed with active pulmonary TB in South Africa and compared results to non-TB patients in South Africa and the United States in an early-phase validation study. Overall, this cfDNA technique detected TB with a sensitivity of 83.7% (95% CI: 71.0 to 91.5) and specificity of 100% (95% CI: 86.2 to 100), which meet the World Health Organization's published performance criteria. Sensitivity was 73.3% in people without HIV (95% CI: 48.1 to 89.1) and 76% in people with smear-negative TB (95% CI: 56.5 to 88.5). In this commentary, we discuss the results of this optimized urine TB cfDNA assay within the larger context of TB diagnostics and pose additional questions for further research.

A novel urine cell-free DNA preservation solution and its application in kidney transplantation.

Urine cell-free DNA (cfDNA) is a new type of liquid biopsy biomarker used in tumours and allograft injury detection but is highly susceptible to degradation by the high nuclease activity of urine. This study presents a newly developed urine cfDNA preservation solution (AlloU), efficient for examining allograft injury in kidney transplant recipients (KTx). We established urine-preserve solution called AlloU based on the response-surface methodology, with two commercial collection reagents (Streck and K2 EDTA preservation solution) included for analysis. A total of 120 urine samples from KTx patients, including morning, nocturnal and random urine from specific storage time were subjected to investigation. The urine total cfDNA concentration was quantified by fluorometry, fragment distribution was analysed by qPCR, and donor-derived cfDNA (ddcfDNA) was detected by next-generation sequencing. Urine total cfDNA concentration and fragment size of samples preserved with AlloU and Streck did not change significantly within 5 days whereas the ddcfDNA also did not change significantly within 7 days. However, compared with EDTA, the total cfDNA concentration increased significantly on the third day. When compare with different urine types, it was found that samples preserved with AlloU showed no significant differences in total cfDNA concentration, fragment size, and ddcfDNA concentration, however, the SD for morning urine was significantly smaller in total cfDNA and ddcfDNA concentration. To the best of our knowledge, this is the first report to verify the dynamics of urine cfDNA in KTx, especially in the analysis impact of different urine types on cfDNA detection.

Toward urinary cell-free DNA-based treatment of urothelial carcinoma: a narrative review.

Liquid biopsy technique targeting urinary cell-free DNA (cfDNA) is getting a lot of attention to overcome limitations of the present treatment strategy for urothelial carcinoma, including urothelial bladder carcinoma (UBC) and upper tract urothelial carcinoma (UTUC). Analysis of tumor-derived DNA in urine focusing either on genomic or epigenomic alterations, holds great potential as a noninvasive method for the detection of urothelial carcinoma with high accuracy. It is also predictive of prognosis and response to drugs, and reveals the underlying characteristics of different stages of urothelial carcinoma. Although cfDNA methylation analyses based on a combination of several methylation profiles have demonstrated high sensitivity for UBC diagnosis, there have been few reports involving epigenomic studies of urinary cfDNA. In mutational analyses, frequent gene mutations (TERT promoter, TP53, FGFR3, PIK3CA, RAS, etc.) have been detected in urine supernatant by using remarkable technological innovations such as next-generation sequencing and droplet digital PCR. These methods allow highly sensitive detection of rare mutation alleles while minimizing artifacts. In this review, we summarize the current insights into the clinical applications of urinary cfDNA from patients with urothelial carcinoma. Although it is necessary to conduct prospective multi-institutional clinical trials, noninvasive urine biopsy is expected to play an important role in the realization of precision medicine in patients with urothelial carcinoma in the near future.

Diagnosing Pulmonary Tuberculosis by Using Sequence-Specific Purification of Urine Cell-Free DNA.

ABSTRACTTransrenal urine cell-free DNA (cfDNA) is a promising tuberculosis (TB) biomarker, but is challenging to detect because of the short length (<100 bp) and low concentration of TB-specific fragments. We aimed to improve the diagnostic sensitivity of TB urine cfDNA by increasing recovery of short fragments during sample preparation. We developed a highly sensitive sequence-specific purification method that uses hybridization probes immobilized on magnetic beads to capture short TB cfDNA (50 bp) with 91.8% average efficiency. Combined with short-target PCR, the assay limit of detection was ≤5 copies of cfDNA in 10 ml urine. In a clinical cohort study in South Africa, our urine cfDNA assay had 83.7% sensitivity (95% CI: 71.0 to 91.5%) and 100% specificity (95% CI: 86.2 to 100%) for diagnosis of active pulmonary TB when using sputum Xpert MTB/RIF as the reference standard. The detected cfDNA concentration was 0.14 to 2,804 copies/ml (median 14.6 copies/ml) and was inversely correlated with CD4 count and days to culture positivity. Sensitivity was nonsignificantly higher in HIV-positive (88.2%) compared to HIV-negative patients (73.3%), and was not dependent on CD4 count. Sensitivity remained high in sputum smear-negative (76.0%) and urine lipoarabinomannan (LAM)-negative (76.5%) patients. With improved sample preparation, urine cfDNA is a viable biomarker for TB diagnosis. Our assay has the highest reported accuracy of any TB urine cfDNA test to date and has the potential to enable rapid non-sputum-based TB diagnosis across key underserved patient populations.

00005 Urine tumor DNA detects minimal residual disease in muscle-invasive bladder cancer treated with curative-intent radical cystectomy

ABSTRACT IMPACT: Urine tumor DNA non-invasively detects minimal residual disease and infers tumor mutational burden in locally advanced bladder cancer prior to radical cystectomy, which may potentially enable the selection of patients for bladder-sparing treatment or facilitate personalized adjuvant immunotherapy. OBJECTIVES/GOALS: Standard-of-care treatment for muscle-invasive bladder cancer (MIBC) is radical cystectomy. The inability to assess minimal residual disease (MRD) non-invasively limits our ability to offer bladder-sparing treatment. We sought to develop a liquid biopsy solution via urine tumor DNA (utDNA) analysis. METHODS/STUDY POPULATION: We applied uCAPP-Seq, a targeted sequencing method for detecting utDNA, to urine cell-free DNA samples acquired on the day of radical cystectomy from 42 patients with bladder cancer. utDNA variant-calling was performed non-invasively without prior tumor mutational knowledge. The overall utDNA level for each patient was represented by the non-silent mutation with the highest variant allele fraction after removing germline variants. Urine was similarly analyzed from 15 healthy adults. Tumor mutational burden (TMB) was inferred from the number of non-silent mutations detected in urine cell-free DNA by applying a linear relationship derived from TCGA whole exome sequencing of 409 MIBC tumors. RESULTS/ANTICIPATED RESULTS: utDNA levels were significantly higher in patients with residual disease detected in their surgical pathology compared to those who achieved a pathologic complete response (P = 0.002). Using an optimal utDNA threshold to define MRD detection, positive utDNA MRD significantly predicted the absence of pathologic complete response with a sensitivity of 81% and specificity of 81%. Positive utDNA MRD also portended significantly worse progression-free survival (HR = 7.4; P = 0.03) compared to negative utDNA MRD. Furthermore, we applied a linear relationship (Pearson r = 0.84; P &lt; 0.0001) to identify patients with high inferred TMB who may have been candidates for early immune checkpoint blockade. DISCUSSION/SIGNIFICANCE OF FINDINGS: utDNA MRD analysis prior to surgery correlated significantly with pathologic response and progression-free survival, which may help select patients for bladder-sparing treatment. utDNA can also non-invasively infer TMB, which could facilitate personalized adjuvant therapy for patients in the future.

Ultrasensitive hybridization capture: Reliable detection of

Urine cell-free DNA (cfDNA) is a valuable non-invasive biomarker with broad potential clinical applications, but there is no consensus on its optimal pre-analytical methodology, including the DNA extraction step. Due to its short length (majority of fragments <100 bp) and low concentration (ng/mL), urine cfDNA is not efficiently recovered by conventional silica-based extraction methods. To maximize sensitivity of urine cfDNA assays, we developed an ultrasensitive hybridization method that uses sequence-specific oligonucleotide capture probes immobilized on magnetic beads to improve extraction of short cfDNA from large-volume urine samples. Our hybridization method recovers near 100% (95% CI: 82.6–117.6%) of target-specific DNA from 10 mL urine, independent of fragment length (25–150 bp), and has a limit of detection of ≤5 copies of double-stranded DNA (0.5 copies/mL). Pairing hybridization with an ultrashort qPCR design, we can efficiently capture and amplify fragments as short as 25 bp. Our method enables amplification of cfDNA from 10 mL urine in a single qPCR well, tolerates variation in sample composition, and effectively removes non-target DNA. Our hybridization protocol improves upon both existing silica-based urine cfDNA extraction methods and previous hybridization-based sample preparation protocols. Two key innovations contribute to the strong performance of our method: a two-probe system enabling recovery of both strands of double-stranded DNA and dual biotinylated capture probes, which ensure consistent, high recovery by facilitating optimal probe density on the bead surface, improving thermostability of the probe-bead linkage, and eliminating interference by endogenous biotin. We originally designed the hybridization method for tuberculosis diagnosis from urine cfDNA, but expect that it will be versatile across urine cfDNA targets, and may be useful for other cfDNA sample types and applications beyond cfDNA. To make our hybridization method accessible to new users, we present a detailed protocol and straightforward guidelines for designing new capture probes.

Superior molecular pathology of urothelial bladder cancer using urinary cell-free DNA.

491 Background: Both urinary and blood cell-free DNA (cfDNA) have been implicated in noninvasive detection and surveillance of urothelial bladder cancer (UBC). However, a direct comparison of their diagnostic performance in the real-world setting is lacking. Methods: 59 eligible cases with pathologically confirmed disease and accompanying tissue/urine pairs were prospectively enrolled and consented to Institutional Review Board-approved protocols. Baseline peripheral blood mononuclear cell (PBMC) and plasma specimens were collected during clinic visit. The 180-gene Predicine liquid biopsy assay was applied for ultra-deep targeted sequencing and somatic alteration identification in tumor tissue-based DNA (tDNA), urinary cfDNA (ucfDNA) and blood cfDNA (bcfDNA). Results: The 59 studied subjects constituted a natural UBC cohort of non-muscle invasive bladder cancer (NMIBC) and muscle invasive bladder cancer (MIBC), including 48 (81.4%) NMIBC and 42 (71.2%) male patients. Diverse quantitative metrics such as VAF (variant allele frequency) and TMB (tumor mutational burden) were invariably concordant between tDNA and ucfDNA, but not bcfDNA. The mutational landscape captured by tDNA or ucfDNA highly resembled each other and mirrored previously described genomic panorama of UBC, whereas a significant proportion of bcfDNA aberrations stemmed from clonal hematopoiesis. Using tDNA-informed variants as the ground truth, ucfDNA assays achieved a specificity of 99.3%, a sensitivity of 86.7%, a positive predictive value (PPV) of 67.2%, a negative predictive value (NPV) of 99.8%, and a diagnostic accuracy of 99.1%, which were generally lower in the case of bcfDNA analysis. Conclusions: Urine-based molecular pathology provides valid and complete genetic information about neoplastic lesions, and represents a faithful surrogate for genotyping and monitoring UBC.

Jagged Ends of Urinary Cell-Free DNA: Characterization and Feasibility Assessment in Bladder Cancer Detection.

Double-stranded DNA in plasma is known to carry single-stranded ends, called jagged ends. Plasma DNA jagged ends are biomarkers for pathophysiologic states such as pregnancy and cancer. It remains unknown whether urinary cell-free DNA (cfDNA) molecules have jagged ends. Jagged ends of cfDNA were detected by incorporating unmethylated cytosines during a DNA end-repair process, followed by bisulfite sequencing. Incorporation of unmethylated cytosines during the repair of the jagged ends lowered the apparent methylation levels measured by bisulfite sequencing and were used to calculate a jagged end index. This approach is called jagged end analysis by sequencing. The jagged end index of urinary cfDNA was higher than that of plasma DNA. The jagged end index profile of plasma DNA displayed several strongly oscillating major peaks at intervals of approximately 165 bp (i.e., nucleosome size) and weakly oscillating minor peaks with periodicities of approximately 10 bp. In contrast, the urinary DNA jagged end index profile showed weakly oscillating major peaks but strongly oscillating minor peaks. The jagged end index was generally higher in nucleosomal linker DNA regions. Patients with bladder cancer (n = 46) had lower jagged end indexed of urinary DNA than participants without bladder cancer (n = 39). The area under the curve for differentiating between patients with and without bladder cancer was 0.83. Jagged ends represent a property of urinary cfDNA. The generation of jagged ends might be related to nucleosomal structures, with enrichment in linker DNA regions. Jagged ends of urinary DNA could potentially serve as a new biomarker for bladder cancer detection.

Urinary Cell-Free DNA in Bladder Cancer Detection.

Urinary bladder cancer is a common urological cancer. Although flexible cystoscopy is widely employed in bladder cancer detection, it is expensive, invasive, and uncomfortable to the patients. Recently, urinary cell-free DNA (ucfDNA) isolated from urine supernatant has been shown to have great potential in bladder cancer detection and surveillance. Molecular features, such as integrity and concentration of ucfDNA, have been shown to be useful for differentiating bladder cancer patients from healthy controls. Besides, bladder cancer also exhibits unique genetic features that can be identified from sequencing and expression of ucfDNA. Apart from bladder cancer detection, ucfDNA is also useful for molecular classification. For example, ucfDNA exhibits significant differences, both molecularly and genetically, in non-muscle-invasive and muscle-invasive bladder cancers. There is no doubt that ucfDNA is a very promising tool for future applications in the field of bladder cancer.

Concentration and integrity indexes of urine cell-free DNA as promising biomarkers for early lung cancer diagnosis.

Aim: To explore the role of urine cell-free DNA (ucfDNA) concentration and integrity indexes as potential biomarkers for lung cancer diagnosis. Materials & methods: Quantitative real-time PCR targeting Arthrobacter luteus (ALU) repeats at three size fragments (ALU-60, 115 and 247 bp) was performed in 55 lung cancer patients and 35 healthy individuals. Results: ucfDNA concentration and integrity indexes were significantly higher in lung cancer patients than in healthy controls. The area under the receiver operating characteristiccurve for differentiating patients with stage I/II from healthy controls by ALU fragments concentration were 0.856, 0.909 and 0.932, respectively. In addition, the ucfDNA integrity indexes in patients with lymph node metastasis were significantly higher than in patients with non-metastatic. Conclusion: ucfDNA concentration and integrity indexes could serve as promising biomarkers for lung cancer diagnosis.

Mutational Analysis in Urinary Cell-Free DNA: KRAS in Colorectal Cancer.

Urinary cell-free DNA offers an important noninvasive source of material for genomic testing also for nonurological tumors. Its clinical utility in monitoring tumor evolution and treatment failure is promising. Here we describe a method to detect cancer mutations into urine from patients affected by colorectal cancer.

Urinary Cell-Free DNA Integrity Analysis.

Urine cell-free DNA is an important source of diagnostic markers for different diseases, especially for cancer. It could be important to achieve the urine cell-free DNA integrity to establish its provenience from cancer cells or dead inflammatory cellsfor necrosis in urine or from normal cells with the purpose to use it as an early diagnostic tool for urological cancers or other diseases. Here we describe a simple, noninvasive approach from urine collection to DNA integrity analysis using real-time PCR.