The potential use of urine cell free DNA as a marker for cancer

Fragmentation patterns of cell-free DNA and somatic mutations in the urine of metastatic breast cancer patients

BACKGROUND

Urinary cell-free deoxyribonucleic acid (DNA) (ucfDNA) holds promise as a biomarker; however, its potential remains largely unexplored. We examined the fragmentation pattern of ucfDNA and identified somatic mutations within urine samples from metastatic breast cancer (MBC) patients.

METHODS

Urine and blood specimens were collected before treatment from 45 MBC patients and posttreatment urine samples from 16 of the 45 patients at the China National Cancer Center. Somatic mutations and tumor mutational burden (TMB) in the urine and plasma of 10 patients were analyzed by next-generation sequencing (NGS). Fragmentation patterns of cfDNA were displayed using electropherograms. Differences in the extracted amount of cfDNA, length of cfDNA fragments, and TMB between urine and plasma were compared using a Wilcoxon test.

RESULTS

The fragmentation patterns of ucfDNA were categorized as follows: (1) profile A (n = 26) containing a short peak (100-200 bp) and a long peak (>1500 bp); (2) profile B (n = 8) containing only a long peak; and (3) profile C (n = 11) containing flat pattern. For profile A patients, the short-peaked ucfDNA circulating in the bloodstream was much shorter compared with plasma cfDNA (149 vs. 171 bp, Wilcoxon test, P = 0.023). The fragmentation patterns in lung metastasis patients exhibited a higher propensity toward profile C ( P = 0.002). After treatment, 87.5% of the patients exhibited consistent fragmentation patterns. The concordance rate for somatic mutations in the plasma and urine was 30%, and the median TMB of urine and plasma was not significantly different.

CONCLUSIONS

This study established a fragmentation pattern for ucfDNA and detected somatic mutations in the urine of MBC patients. These results suggest the potential application of ucfDNA as a biomarker for MBC.

Circulating and urinary tumour DNA in urothelial carcinoma - upper tract, lower tract and metastatic disease

Precision medicine has transformed the way urothelial carcinoma is managed. However, current practices are limited by the availability of tissue samples for genomic profiling and the spatial and temporal molecular heterogeneity observed in many studies. Among rapidly advancing genomic sequencing technologies, non-invasive liquid biopsy has emerged as a promising diagnostic tool to reproduce tumour genomics, and has shown potential to be integrated in several aspects of clinical care. In urothelial carcinoma, liquid biopsies such as plasma circulating tumour DNA (ctDNA) and urinary tumour DNA (utDNA) have been investigated as a surrogates for tumour biopsies and might bridge many shortfalls currently faced by clinicians. Both ctDNA and utDNA seem really promising in urothelial carcinoma diagnosis, staging and prognosis, response to therapy monitoring, detection of minimal residual disease and surveillance. The use of liquid biopsies in patients with urothelial carcinoma could further advance precision medicine in this population, facilitating personalized patient monitoring through non-invasive assays.

Circulating Biomarkers for the Early Diagnosis and Management of Hepatocellular Carcinoma with Potential Application in Resource-Limited Settings

Hepatocellular carcinoma (HCC) is among the world's third most lethal cancers. In resource-limited settings (RLS), up to 70% of HCCs are diagnosed with limited curative treatments at an advanced symptomatic stage. Even when HCC is detected early and resection surgery is offered, the post-operative recurrence rate after resection exceeds 70% in five years, of which about 50% occur within two years of surgery. There are no specific biomarkers addressing the surveillance of HCC recurrence due to the limited sensitivity of the available methods. The primary goal in the early diagnosis and management of HCC is to cure disease and improve survival, respectively. Circulating biomarkers can be used as screening, diagnostic, prognostic, and predictive biomarkers to achieve the primary goal of HCC. In this review, we highlighted key circulating blood- or urine-based HCC biomarkers and considered their potential applications in resource-limited settings, where the unmet medical needs of HCC are disproportionately highly significant.

The Role of Cell-Free DNA in Cancer Treatment Decision Making

The aim of this review is to evaluate the present status of the use of cell-free DNA and its fraction of circulating tumor DNA (ctDNA) because this year July 2022, an ESMO guideline was published regarding the application of ctDNA in patient care. This review is for clinical oncologists to explain the concept, the terms used, the pros and cons of ctDNA; thus, the technical aspects of the different platforms are not reviewed in detail, but we try to help in navigating the current knowledge in liquid biopsy. Since the validated and adequately sensitive ctDNA assays have utility in identifying actionable mutations to direct targeted therapy, ctDNA may be used for this soon in routine clinical practice and in other different areas as well. The cfDNA fragments can be obtained by liquid biopsy and can be used for diagnosis, prognosis, and selecting among treatment options in cancer patients. A great proportion of cfDNA comes from normal cells of the body or from food uptake. Only a small part (<1%) of it is related to tumors, originating from primary tumors, metastatic sites, or circulating tumor cells (CTCs). Soon the data obtained from ctDNA may routinely be used for finding minimal residual disease, detecting relapse, and determining the sites of metastases. It might also be used for deciding appropriate therapy, and/or emerging resistance to the therapy and the data analysis of ctDNA may be combined with imaging or other markers. However, to achieve this goal, further clinical validations are inevitable. As a result, clinicians should be aware of the limitations of the assays. Of course, several open questions are still under research and because of it cfDNA and ctDNA testing are not part of routine care yet.

Microfluidics-Based Urine Biopsy for Cancer Diagnosis: Recent Advances and Future Trends

Urine biopsy, allowing for the detection, analysis and monitoring of numerous cancer-associated urinary biomarkers to provide insights into cancer occurrence, progression and metastasis, has emerged as an attractive liquid biopsy strategy with enormous advantages over traditional tissue biopsy, such as noninvasiveness, large sample volume, and simple sampling operation. Microfluidics enables precise manipulation of fluids in a tiny chip and exhibits outstanding performance in urine biopsy owing to its minimization, low cost, high integration, high throughput and low sample consumption. Herein, we review recent advances in microfluidic techniques employed in urine biopsy for cancer detection. After briefly summarizing the major urinary biomarkers used for cancer diagnosis, we provide an overview of the typical microfluidic techniques utilized to develop urine biopsy devices. Some prospects along with the major challenges to be addressed for the future of microfluidic-based urine biopsy are also discussed.

Liquid biopsy: a step closer to transform diagnosis, prognosis and future of cancer treatments

Over the past decade, invasive techniques for diagnosing and monitoring cancers are slowly being replaced by non-invasive methods such as liquid biopsy. Liquid biopsies have drastically revolutionized the field of clinical oncology, offering ease in tumor sampling, continuous monitoring by repeated sampling, devising personalized therapeutic regimens, and screening for therapeutic resistance. Liquid biopsies consist of isolating tumor-derived entities like circulating tumor cells, circulating tumor DNA, tumor extracellular vesicles, etc., present in the body fluids of patients with cancer, followed by an analysis of genomic and proteomic data contained within them. Methods for isolation and analysis of liquid biopsies have rapidly evolved over the past few years as described in the review, thus providing greater details about tumor characteristics such as tumor progression, tumor staging, heterogeneity, gene mutations, and clonal evolution, etc. Liquid biopsies from cancer patients have opened up newer avenues in detection and continuous monitoring, treatment based on precision medicine, and screening of markers for therapeutic resistance. Though the technology of liquid biopsies is still evolving, its non-invasive nature promises to open new eras in clinical oncology. The purpose of this review is to provide an overview of the current methodologies involved in liquid biopsies and their application in isolating tumor markers for detection, prognosis, and monitoring cancer treatment outcomes.

Liquid biopsy: the value of different bodily fluids

Liquid biopsies have gained an increasing interest in the last years among medical and scientific communities. Indeed, the value of liquid effusions, while less invasive and more accurate techniques, has been markedly highlighted. Peripheral blood comprises the most often analyzed sample, but recent evidences have pointed out the huge importance of other bodily fluids, including pleural and peritoneal fluids, urine, saliva and cerebrospinal fluid in the detection and monitoring of different tumor types. In face to these advances, this review aims to provide an overview of the value of tumor-associated mutations, detectable in different effusions, and how they can be used in clinical practice, namely in prognosis assessment and early disease and minimal disease recurrence detection, and in predicting the treatment response or acquired-resistance development.

Diving into the Pleural Fluid: Liquid Biopsy for Metastatic Malignant Pleural Effusions

Simple Summary

Malignant pleural effusion is a common complication arising as the natural progression of many tumors, such as lung cancer. When this occurs, the common protocol consists of analyzing the pleural fluid for the presence of malignant cells. However, on many occasions no malignant cells are found despite a clear suspicion of cancer. Thus, the current diagnostic methodology is imperfect and more precise methods for the identification of malignancy are needed. Nonetheless, these methods are often invasive, which may be counterproductive, especially for patients with poor health condition. These concerns have made clinicians consider alternative non-invasive strategies to diagnose cancer using the generally abundant pleural fluid (e.g., liquid biopsy). Thus, a liquid sample can be analyzed for the presence of cancer footprints, such as circulating malignant cells and tumor nucleic acids. Herein, we review the literature for studies considering pleural fluid as a successful source of liquid biopsy.

Abstract

Liquid biopsy is emerging as a promising non-invasive diagnostic tool for malignant pleural effusions (MPE) due to the low sensitivity of conventional pleural fluid (PF) cytological examination and the difficulty to obtain tissue biopsies, which are invasive and require procedural skills. Currently, liquid biopsy is increasingly being used for the detection of driver mutations in circulating tumor DNA (ctDNA) from plasma specimens to guide therapeutic interventions. Notably, malignant PF are richer than plasma in tumor-derived products with potential clinical usefulness, such as ctDNA, micro RNAs (miRNAs) and long non-coding RNAs (lncRNAs), and circulating tumor cells (CTC). Tumor-educated cell types, such as platelets and macrophages, have also been added to this diagnostic armamentarium. Herein, we will present an overview of the role of the preceding biomarkers, collectively known as liquid biopsy, in PF samples, as well as the main technical approaches used for their detection and quantitation, including a proper sample processing. Technical limitations of current platforms and future perspectives in the field will also be addressed. Using PF as liquid biopsy shows promise for use in current practice to facilitate the diagnosis and management of metastatic MPE.

Urine as a Source of Liquid Biopsy for Cancer

Simple Summary

Tissue biopsy is essential for diagnosis and characterization of a tumor. Recently circulating tumor cells and other tumor-derived nucleic acid can be detected from blood, which is called liquid biopsy. Now this concept has been expanded to many other body fluids including urine. Urine is the least invasive method to obtain a liquid biopsy and can be done anywhere, which allows longitudinal repeated sampling. Here, we review the latest update on urine liquid biopsy in urological and non-urological cancers.

Abstract

Tissue biopsy is the gold standard for diagnosis and morphological and immunohistochemical analyses to characterize cancer. However, tissue biopsy usually requires an invasive procedure, and it can be challenging depending on the condition of the patient and the location of the tumor. Even liquid biopsy analysis of body fluids such as blood, saliva, gastric juice, sweat, tears and cerebrospinal fluid may require invasive procedures to obtain samples. Liquid biopsy can be applied to circulating tumor cells (CTCs) or nucleic acids (NAs) in blood. Recently, urine has gained popularity due to its less invasive sampling, ability to easily repeat samples, and ability to follow tumor evolution in real-time, making it a powerful tool for diagnosis and treatment monitoring in cancer patients. With the development and advancements in extraction methods of urinary substances, urinary NAs have been found to be closely related to carcinogenesis, metastasis, and therapeutic response, not only in urological cancers but also in non-urological cancers. This review mainly highlights the components of urine liquid biopsy and their utility and limitations in oncology, especially in non-urological cancers.

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

AIM

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).

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Urinary Biomarkers in Tumors: An Overview

Recent reports suggest that urine is a useful noninvasive tool for the identification of urogenital tumors, including bladder, prostate, kidney, and other nonurological cancers. As a liquid biopsy, urine represents an important source for the improvement of new promising biomarkers, a suitable tool to identify indolent cancer and avoid overtreatment. Urine is enriched with DNAs, RNAs, proteins, circulating tumor cells, exosomes, and other small molecules which can be detected with several diagnostic methodologies.We provide an overview of the ongoing state of urinary biomarkers underlying both their potential utilities to improve cancer prognosis, diagnosis, and therapeutic strategy and their limitations.

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.

Detection of colorectal cancer in urine using DNA methylation analysis

Colorectal cancer (CRC) is the second leading cause for cancer-related death globally. Clinically, there is an urgent need for non-invasive CRC detection. This study assessed the feasibility of CRC detection by analysis of tumor-derived methylated DNA fragments in urine. Urine samples, including both unfractioned and supernatant urine fractions, of 92 CRC patients and 63 healthy volunteers were analyzed for DNA methylation levels of 6 CRC-associated markers (SEPT9, TMEFF2, SDC2, NDRG4, VIM and ALX4). Optimal marker panels were determined by two statistical approaches. Methylation levels of SEPT9 were significantly increased in urine supernatant of CRC patients compared to controls (p < 0.0001). Methylation analysis in unfractioned urine appeared inaccurate. Following multivariate logistic regression and classification and regression tree analysis, a marker panel consisting of SEPT9 and SDC2 was able to detect up to 70% of CRC cases in urine supernatant at 86% specificity. First evidence is provided for CRC detection in urine by SEPT9 methylation analysis, which combined with SDC2 allows for an optimal differentiation between CRC patients and controls. Urine therefore provides a promising liquid biopsy for non-invasive CRC detection.

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 cells for 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.

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.

The therapeutic and prognostic implications of molecular biomarkers in urothelial carcinoma

Urothelial cell carcinoma (UCC) of the bladder and upper urinary tract is a heterogeneous disease with distinct biologic features resulting in different clinical behaviors. Bladder cancer (BC) is classified into non-muscle invasive BC (NMIBC) and muscle invasive BC (MIBC). NMIBC is associated with high recurrence rates and risk of progression to invasive disease, whereas MIBC is complicated by systemic recurrence after radical cystectomy because of the limited efficacy of available therapies. UCC of the upper urinary tract (UUT-UCC) is a rare but aggressive urologic cancer characterized by multifocality, local recurrence, and metastasis. Conventional histopathologic evaluation of UCC, including tumor stage and grade, cannot accurately predict the behavior of BC and UUT-UCC. Recent clinical and preclinical studies aimed at understanding the molecular landscape of UCC have provided insight into molecular subtyping, inter- or intratumoral heterogeneity, and potential therapeutic targets. Combined analysis of molecular markers and standard pathological features may improve risk stratification and help monitor tumor progression and treatment response, ultimately improving patient outcomes. This review discusses prognostic and therapeutic biomarkers for BC and UUT-UCC, and describes recent advances in molecular stratification that may guide prognosis, patient stratification, and treatment selection.

Urine cell-free DNA as a promising biomarker for early detection of non-small cell lung cancer

Background

While blood‐derived cell‐free DNA has been shown to be a candidate biomarker able to provide diagnostic and prognostic insight in cancer patients, little is known regarding the potential application of urine cell‐free DNA (ucfDNA) in diagnosis of cancer. Thus, the aim of this study was to investigate ucfDNA concentration and integrity index as potential biomarkers for early detection of non‐small‐cell lung cancer (NSCLC).

Methods

Urine samples were collected from 35 healthy controls and 55 NSCLC patients at various tumor node metastasis (TNM) stages. Two long interspersed nuclear element 1 (LINE1) fragments (LINE1‐97 and 266 bp) were quantified via quantitative real‐time PCR (qPCR). DNA integrity index was calculated as the ratio of LINE1‐266/LINE‐97.

Results

LINE1 fragments concentrations of ucfDNA (LINE1‐97, 266 bp) were significantly higher in NSCLC patients with stage III/IV than in stage I/II and in healthy controls. The receiver operating characteristic (ROC) curves for discriminating patients with stage III/IV from healthy controls had areas under the curves (AUC) of 0.84 and 0.886, respectively. Moreover, ucfDNA integrity LINE1‐266/97 was significantly higher in patients with stage III/IV than in stage I/II and in healthy controls. The AUC of ROC curve for discriminating patients with stage III/IV from healthy controls was 0.800. Furthermore, LINE1‐266 fragment concentration was significantly higher in lymph node metastasis (LNM)‐positive patients relative to LNM‐negative patients. The ROC curve for discriminating LNM‐positive from LNM‐negative patients had an AUC of 0.822.

Conclusion

UcfDNA could serve as a promising biomarker for early detection of NSCLC.

6-gene promoter methylation assay is potentially applicable for prostate cancer clinical staging based on urine collection following prostatic massage

The detection of prostate cancer (PCa) biomarkers in bodily fluids, a process known as liquid biopsy, is a promising approach and particularly beneficial when performed in urine samples due to their maximal non-invasiveness requirement of collection. A number of gene panels proposed for this purpose have allowed discrimination between disease-free prostate and PCa; however, they bear no significant prognostic value. With the purpose to develop a gene panel for PCa diagnosis and prognosis, the methylation status of 17 cancer-associated genes were analyzed in urine cell-free DNA obtained from 31 patients with PCa and 33 control individuals using methylation-specific polymerase chain reaction (MSP). Among these, 13 genes indicated the increase in methylation frequency in patients with PCa compared with controls. No prior association has been reported between adenomatosis polyposis coli 2 (APC2), homeobox A9, Wnt family member 7A (WNT7A) and N-Myc downstream-regulated gene 4 protein genes with PCa. The 6-gene panel consisting of APC2, cadherin 1, forkhead box P1, leucine rich repeat containing 3B, WNT7A and zinc family protein of the cerebellum 4 was subsequently developed providing PCa detection with 78% sensitivity and 100% specificity. The number of genes methylated (NGM) value introduced for this panel was indicated to rise monotonically from 0.27 in control individuals to 4.6 and 4.25 in patients with highly developed and metastatic T₂/T₃ stage cancer, respectively. Therefore, the approach of defining the NGM value may not only allow for the detection of PCa, but also provide a rough evaluation of tumor malignancy and metastatic potential by non-invasive MSP analysis of urine samples.

Utility of liquid biopsy using urine in patients with pancreatic ductal adenocarcinoma

In recent years, liquid biopsy for blood and body fluid in cancer patients has attracted attention. However, there have been few reports of liquid biopsy focusing on urine of pancreatic ductal adenocarcinoma (PDAC). In 56 patients with PDAC, DNA was extracted from urine and plasma prior to treatment, and KRAS mutations were analyzed with droplet digital PCR to examine the mutation detection rate. Our study showed that KRAS mutations were found in 27 cases (48%) in urine and 27 cases (48%) in plasma. The detection rate of urine KRAS mutations varied by renal functions. The rates were 70% (14/20) and 36% (13/36) in the creatinine clearance rate (CCr) < 70 mL/min group and in the CCr ≥ 70 mL/min group, respectively (P = .024). Whereas, no influence of the CCr was observed in the detection rates of plasma KRAS mutations. The rates were 50% (10/20) and 47% (17/36) in cases with the CCr < 70 mL/min group and the CCr ≥ 70 mL/min group, respectively. Although the sample size was small, this study clearly indicated a new possibility of less invasive urine liquid biopsy in PDAC patients.

Head and neck cancer: searching for genomic and epigenetic biomarkers in body fluids - the state of art

Head and neck squamous cell carcinoma (HNSCC) affects multiple sites of the upper aerodigestive tract and exhibited high incidence and mortality worldwide, being frequently diagnosed at advanced stage. Early detection of HNSCC plays a crucial role in a successful therapy. In the last years, the survival rates of these tumors have not improved significantly due to the late diagnosis and the lack of precise disease biomarkers and targeted therapies. The introduction in the clinical practice of body fluids to detect and analyze circulating tumor cells (CTCs), circulating tumor DNA (ctDNA) and exosomes provides a minimally or non-invasive method also called as liquid biopsy for diagnostic and prognostic biomarkers detection, representing a shift of paradigm in precision medicine through the revolution in the way to perform HNSCC diagnosis and to screen high risk population. Despite the use of body fluids being an emergent and up-to date issue to early diagnosis HNSCC and their recurrences, no strategy has yet proven to be consistently effective and able to be translated to clinical application in the routine clinical management of these patients. In this review we will discuss the recent discoveries using blood and saliva to identify biomarkers for the early detection and prognosis of HNSCC.

Urinary Cell-Free DNA: Isolation, Quantification, and Quality Assessment

Urine cell-free DNA is an important source of diagnostic markers for different diseases (e.g., cancer and prenatal diagnosis). It is important to achieve a simple and fast protocol to maximize the recovery of DNA from urine supernatant and to assess its quality. Here we describe a simple approach from urine collection to DNA quality assessment for downstream analyses.

Urinary Cell-Free DNA IQGAP3/BMP4 Ratio as a Prognostic Marker for Non-Muscle-Invasive Bladder Cancer

BACKGROUND

Disease monitoring in non-muscle-invasive bladder cancer (NMIBC) patients is crucial for early identification of disease recurrence and progression. High IQGAP3/BMP4 and IQGAP3/FAM107A ratios in urinary cell-free DNA (ucfDNA) are a diagnostic biomarker for bladder cancer. We aimed to investigate whether the levels of these biomarkers in ucfDNA can be used to monitor disease recurrence or progression in patients with NMIBC.

PATIENTS AND METHODS

A total of 103 patients with NMIBC (pTa-pT1) were enrolled. The IQGAP3/BMP4 and IQGAP3/FAM107A ratios in ucfDNA were measured by real-time PCR, and the results were compared with clinical outcome by Kaplan-Meier curves and Cox regression analyses.

RESULTS

Overall, 55 patients (53.4%) experienced recurrence and 29 (28.2%) experienced disease progression during a median follow-up of 42.7 months (range, 6.1-172.2 months). Kaplan-Meier analysis revealed that NMIBC patients with a high IQGAP3/BMP4 ratio had worse recurrence-free survival and progression-free survival (PFS) (P = .001 and < .001, respectively), and those with a high IQGAP3/FAM107A ratio had worse PFS (P = .006). Multivariate Cox regression analysis revealed that the IQGAP3/BMP4 ratio was independently associated with recurrence-free survival (hazard ratio, 2.462; P = .003) and PFS (hazard ratio = 3.871; P = .004), whereas the IQGAP3/FAM107A ratio was not an independent factor for PFS (P = .079).

CONCLUSION

The IQGAP3/BMP4 ratio in ucfDNA might be a valuable novel biomarker for predicting disease recurrence and progression in patients with NMIBC.

Detection of BRAFV600E Mutation in Melanoma Patients by Digital PCR of Circulating DNA

AIMS

About 50% of melanomas have the BRAFV600E mutation. This mutation is an attractive therapeutic target. The aims of our study were to detect BRAFV600E mutations within circulating cell-free DNA in plasma ("liquid biopsy") by a droplet digital PCR (ddPCR) method, and to investigate how well the Breslow-Clark score can be predicted by ddPCR.

MATERIALS AND METHODS

We analyzed 113 patients with malignant melanoma. ddPCR was performed using the QX200 system (BIO-RAD^®, Hercules). All samples were tested in duplicate. Besides the results of the liquid biopsy, we have collected data on gender and age of the patients, as well as the mitotic activity of the tumor; the tumor subtype and localization, and the Breslow-Clark score. The limit of detection (LoD) was determined by the method of Tzonev. The LoD was found to be five events per well.

RESULTS

The BRAFV600E mutation was detected in 37 of 113 samples. A moderate predictive accuracy of the Breslow-Clark score can be attained with the mitotic activity and the type of melanoma as the most important predictors.

CONCLUSION

Our results show that ddPCR is a highly sensitive method and could be used for a routine laboratory detection of the BRAFV600E mutation as well as for follow-up monitoring to determine the treatment response in patients with malignant melanomas.

[Urinary long non-coding RNA H19 may serve as a biomarker for early diagnosis of acute intestinal necrosis]

OBJECTIVE

To explore the value of urinary long non-coding RNA(lncRNA) H19 in the differential diagnosis of acute intestinal necrosis against other abdominal emergencies.

METHODS

Surgical specimens of necrotic intestinal tissues, adjacent normal intestinal tissues, and serum and urine samples were collected from 51 patients with acute intestinal necrosis, and analyzed along with the serum and urine samples from 51 healthy controls, patients with 10 different acute abdominal conditions(35 cases for each condition), and patients with breast cancer, gastric cancer, bladder cancer, acute myeloid leukemia, and lung cancer(10 cases for each malignancy). The expression levels of H19 were measured with quantitative PCR in the collected samples. Receiver-operating characteristic(ROC)curves were used to determine the diagnostic value of serum and urine H19 levels for acute intestinal necrosis.

RESULTS

The 51 patients with acute intestinal necrosis included 35 women and 26 men(mean age of 74.4 years) with arterial thrombosis as the dominant etiology(26 cases). Compared with that in normal intestinal tissues, H19 was significantly overexpressed by 11.2 times in necrotic intestinal tissues(P < 0.001). Serum and urine H19 expression levels did not differ significantly among the healthy controls, patients with other acute abdominal conditions and malignancies(P > 0.05). Serum and urine H19 levels were significantly up-regulated in patients with acute intestinal necrosis as compared with those in the other subjects included in the analysis(P < 0.001). In patients with acute intestinal necrosis, H19 levels in the necrotic intestinal tissue, serum and urine samples were significantly correlated with correlation coefficients of 0.974(tissue vs serum), 0.967(serum vs urine), and 0.917(tissue vs urine). In ROC curve analysis, the areas under curves(AUCs)of serum and urine H19 for diagnosis of acute intestinal necrosis were 0.951 and 0.915, respectively; their diagnostic sensitivities were 94% and 79.6%, respectively, and they both had a diagnostic specificity of 100%.

CONCLUSIONS

In patients with acute intestinal necrosis, H19 is overexpressed in necrotic intestinal tissues, from which it is released into the blood circulation and urine. Urinary H19 may serve as a novel and non-invasive biomarker that assists in early diagnosis of acute intestinal necrosis.

Kinetics of circulating cell-free DNA for biomedical applications: critical appraisal of the literature

Circulating cell-free DNA is considered as one of the major breakthroughs in the field of innovative diagnosis, used as a liquid biopsy. The kinetic parameters of a biomarker are mandatory to assess its usefulness as a diagnostic tool. Obtaining precise mathematical values for the kinetic parameters (e.g., half-life) is then crucial because it could be used for therapeutic monitoring as a prognostic factor. However, little is known about the intrinsic properties of circulating cell-free DNA, more especially, its kinetic properties within the organism. We summarized the basic principles that may affect the kinetics of circulating cell-free DNA within the organism in the light of biological and clinical evidence. We also meta-analyzed the reported data in the literature and the methodologies that have been used to study the kinetic parameters of human circulating cell-free DNA in vivo.

Circulating cell-free DNA as a biomarker was a major breakthrough in the field of diagnostics. Understanding the kinetic parameters of a biomarker is mandatory to assess its usefulness as a diagnostic tool, especially for therapeutic monitoring. However, at the present time little is known about its kinetic properties within the organism. This review provides an overview of the basic principles that may impact the kinetics of cell-free DNA within the organism and analyzes the reported data thus far.

Rapid preparation of self-assembled CdTe quantum dots used for sensing of DNA in urine

In this article, the authors report a systematic study of the self-assembly of CdTe quantum dots (QDs) stabilized by mercaptosuccinic acid (MSA) at laboratory temperature (25 °C) or after thermal treatment (90 °C).

Liquid Biopsy Analysis of FGFR3 and PIK3CA Hotspot Mutations for Disease Surveillance in Bladder Cancer

BACKGROUND

Disease surveillance in patients with bladder cancer is important for early diagnosis of progression and metastasis and for optimised treatment.

OBJECTIVE

To develop urine and plasma assays for disease surveillance for patients with FGFR3 and PIK3CA tumour mutations.

DESIGN, SETTING, AND PARTICIPANTS

Droplet digital polymerase chain reaction (ddPCR) assays were developed and tumour DNA from two patient cohorts was screened for FGFR3 and PIK3CA hotspot mutations. One cohort included 363 patients with non-muscle-invasive bladder cancer (NMIBC). The other cohort included 468 patients with bladder cancer undergoing radical cystectomy (Cx). Urine supernatants (NMIBC n=216, Cx n=27) and plasma samples (NMIBC n=39, Cx n=27) from patients harbouring mutations were subsequently screened using ddPCR assays.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Progression-free survival, recurrence-free survival, and overall survival were measured. Fisher's exact test, the Wilcoxon rank-sum test and Cox regression analysis were applied.

RESULTS AND LIMITATIONS

In total, 36% of the NMIBC patients (129/363) and 11% of the Cx patients (44/403) harboured at least one FGFR3 or PIK3CA mutation. Screening of DNA from serial urine supernatants from the NMIBC cohort revealed that high levels of tumour DNA (tDNA) were associated with later disease progression in NMIBC (p=0.003). Furthermore, high levels of tDNA in plasma samples were associated with recurrence in the Cx cohort (p=0.016). A positive correlation between tDNA levels in urine and plasma was observed (correlation coefficient 0.6). The retrospective study design and low volumes of plasma available for analysis were limitations of the study.

CONCLUSIONS

Increased levels of FGFR3 and PIK3CA mutated DNA in urine and plasma are indicative of later progression and metastasis in bladder cancer.

PATIENT SUMMARY

Urine and plasma from patients with bladder cancer may be monitored for diagnosis of progression and metastasis using mutation assays.