Aneuploidy in bladder cancers: the utility of fluorescent in situ hybridization in clinical practice

Urine Biopsy-Liquid Gold for Molecular Detection and Surveillance of Bladder Cancer

With recent advancements in a non-invasive approach to cancer diagnosis and surveillance, the term "liquid biopsy" has gained traction but is currently limited by technological challenges in identifying and isolating circulating tumor cells (CTCs), proteins, cell-free DNA (cfDNA), or other nucleic acids. Tumor tissue biopsy, especially in genitourinary (GU) system is sometimes inadequate and requires invasive surgical options, especially for upper tract urothelial cancer. Urine can prove to be "liquid gold" since it may be a more abundant source of tumor-derived material without the background noise; however, urine DNA (uDNA) may be associated with low mutant allele fraction (MAF). Molecular detection of mutations in uDNA requires a sensitive and accurate method of analysis that allows a high depth of sequencing while minimizing artifacts. Several sequencing approaches to address this hurdle using enhanced library preparation techniques such as Tagged amplicon deep sequencing (TAm-Seq), Safe-SeqS, FAST-SeqS, and CAPP-Seq approaches have been developed. Urine biopsy utilizing next-generation sequencing (NGS) can prove useful at all stages of urologic malignancy care, where urine can be collected to aid in clinical decision making through the identification of commonly known mutations, and potentially reduce or avoid all forms of invasive procedures.

Bladder Cancer Diagnosis and Follow-Up: The Current Status and Possible Role of Extracellular Vesicles

Diagnostic methods currently used for bladder cancer are cystoscopy and urine cytology. Cystoscopy is an invasive tool and has low sensitivity for carcinoma in situ. Urine cytology is non-invasive, is a low-cost method, and has a high specificity but low sensitivity for low-grade urothelial tumors. Despite the search for urinary biomarkers for the early and non-invasive detection of bladder cancer, no biomarkers are used at the present in daily clinical practice. Extracellular vesicles (EVs) have been recently studied as a promising source of biomarkers because of their role in intercellular communication and tumor progression. In this review, we give an overview of Food and Drug Administration (FDA)-approved urine tests to detect bladder cancer and why their use is not widespread in clinical practice. We also include non-FDA approved urinary biomarkers in this review. We describe the role of EVs in bladder cancer and their possible role as biomarkers for the diagnosis and follow-up of bladder cancer patients. We review recently discovered EV-derived biomarkers for the diagnosis of bladder cancer.

The frequencies of micronuclei, nucleoplasmic bridges and nuclear buds as biomarkers of genomic instability in patients with urothelial cell carcinoma

Bladder urothelial cell carcinoma (UCC) is an increasingly prevalent cancer worldwide, and thus, gaining a better understanding of its identifiable risk factors is a global priority. This study addressed this public health need with the understanding that cancer-initiating events, such as chromosome breakage, loss and rearrangement, can be reasonably used as biomarkers to evaluate an individual’s cancer risk. Overall, forty bladder cancer patients and twenty controls were evaluated for genomic instability. To the best of the investigators’ knowledge, this is the first study to perform micronucleus (MN) assays simultaneously in urothelial exfoliated cells (UEC), buccal exfoliated cells (BEC), and peripheral blood lymphocytes (PBL) in first-diagnosed, non-smoker bladder UCC patients. Additionally, the frequency of nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs) in PBL was evaluated. The MN frequencies in UEC, BEC, and PBL, as well as the frequencies of NPBs and NBUDs, were significantly higher in patients than in controls. In conclusion, MN assays, particularly in UEC, may be used to identify individuals who are at high risk of developing UCC, as single or as additional triage test to UroVysion FISH test. Our results further validate the efficacy of biomarkers, such as MN, NPBs, and NBUDs, as predictors of genomic instability.

Diagnostic Value Comparison of Urothelium Carcinoma Among Urine Exfoliated Cells Fluorescent In Situ Hybridization (FISH) Examination, Computerized Tomography (CT) Scan, and Urine Cytologic Examination

BACKGROUND This study aimed to compare the clinical effectiveness of urine exfoliated cells FISH examination, CT scan, and urine cytologic examination on the diagnosis of upper urinary tract urothelium carcinoma with hematuresis symptom. MATERIAL AND METHODS A total of 30 patients with suspicious upper urinary tract urothelium carcinoma between Aug 2010 and Aug 2011 were enrolled, including 23 males and 7 females. All the subjects received urine exfoliated cells FISH examination, CT scan, and urine cytologic examination. Twenty-one cases were diagnosed as urothelium carcinoma, including 14 cases of carcinoma of renal pelvis and 7 cases of carcinoma of ureter. There were 6 cases in stage Ta/T1, 12 cases in stage T2, and 3 cases in T3/T4. The other 9 cases consisted of 1 case of neuroendocrine carcinoma of the renal pelvis, 2 cases of nephrotuberculosis, and 6 cases of renal clear cell carcinoma. RESULTS The total sensitivity of FISH examination, CT scan, and urine cytologic examination on upper urinary tract urothelium carcinoma was 85.7%, 66.7%, and 28.6%, respectively (P<0.05). The tumor staging detection on Ta/T1, T2, and T3/T4 by FISH was 66.7%, 91.7%, 100%; by CT scan 33.3%, 75.0%, 100%; and by urine cytologic examination 0%, 25.0%, and 100%. Their diagnostic specificities were 88.9%, 77.8%, and 100%, respectively (P<0.05). CONCLUSIONS The diagnostic sensitivity on upper urinary tract urothelium carcinoma was highest in FISH examination, followed by CT scan and urine cytologic examination. FISH technique obviously improves the diagnosis of upper urinary tract urothelium carcinoma.

Detection of Bladder Cancer in Urine Sediments by a Novel Multicolor Fluorescence In Situ Hybridization (Quartet) Test

BACKGROUND

Bladder cancer is among the common human malignancies that show a heavy mutational load and copy number variations of numerous chromosomes, which makes them a target for diagnostic explorations.

OBJECTIVE

We aimed to design a multicolor fluorescence in situ hybridization (FISH) test referred to as the quartet test for the detection of bladder cancer in urine.

DESIGN, SETTING, AND PARTICIPANTS

We performed genome-wide copy number variation analysis on cohorts from the University of Texas MD Anderson Cancer Center (n=40) and The Cancer Genome Atlas (n=129), and identified the most frequently amplified chromosomal regions. These data were used to select four of the amplified regions to design a multicolor FISH test, referred to as the quartet test. Assay validation was performed on urine samples from 98 patients with bladder cancer: 56 with low-grade papillary, 42 with high-grade invasive disease, and 48 benign controls.

INTERVENTION

The quartet test can be used in clinical practice for noninvasive detection of bladder cancer.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We initially analyzed samples using a fraction of abnormal cell scores and then by the quantitative score, which included not only the proportion of cells with abnormal copy numbers, but also the proportion of cells with numbers of altered copies and degree of amplification. We used receiver operator characteristic (ROC) curves to identify cutoff values for the scores at which performances of sensitivity and specificity were maximized.

RESULTS AND LIMITATIONS

The copy number status assessed by probes detected in voided urine reflected the amplification status of the primary tumor. An ROC curve summarizing the proportion of assayed cells with any abnormal copy numbers gave specificity of 93.8% and sensitivity of 78.6% using the proportion of cells with abnormal copy numbers. The quantitative score giving extra weight to cells with multiple simultaneous amplifications provided 95.8% specificity and 76.8% sensitivity. Both percentage of abnormal cells and quantitative scores were highly effective for assessing the grade of the tumor. The full spectrum of potential clinical applications was not explored in the current study, and further validation studies are needed.

CONCLUSIONS

The quartet test shows promising specificity and sensitivity results, but it requires validation on a larger multi-institutional cohort of samples.

PATIENT SUMMARY

The quartet test can be used for noninvasive detection of bladder cancer in voided urine. It can also be used to assess the grade of the tumor and tumor recurrence as well as post-treatment effects.

Combined morphologic and fluorescence in situ hybridization analysis of voided urine samples for the detection and follow-up of bladder cancer in patients with benign urine cytology

BACKGROUND

Bladder cancer is among the 5 most common malignancies worldwide. Patients with bladder cancer are closely followed with periodic cystoscopies and urine cytology analyses due to the significant risk of tumor recurrence. The UroVysion fluorescence in situ hybridization (FISH) test demonstrated higher sensitivity over urine cytology in detecting bladder cancer by most comparative studies.

METHODS

In the current study, the diagnostic usefulness of a combined cytology and FISH analysis approach was tested using the Duet automatic scanning system in patients with benign urine cytology who were being monitored for recurrent urothelial carcinoma or being assessed for various urologic symptoms.

RESULTS

By combining the benefits of conventional cytology with molecular diagnostics, a more sensitive detection of bladder cancer was attained. All patients who had positive cystoscopy concomitantly with urine sampling were detected by combined analysis. Additional patients that developed transitional cell carcinoma during a follow-up period of 24 months had a previous positive result on combined analysis. Only 2 patients with a negative combined analysis result presented with late disease recurrence (20 months and 22 months, respectively, after the negative test). Therefore, negative combined analysis was found to be predictive of a lack of disease recurrence for at least 12 months. In this timeframe, the overall sensitivity, specificity, negative predictive value (NPV), and positive predictive values of the combined analysis test were 100%, 65%, 100%, and 44%, respectively.

CONCLUSIONS

Given the absolute sensitivity and NPV of the combined analysis test, the management of patients with a negative combined analysis result might be revised and allow for more flexible assessment and management of bladder cancer patients relying more on urine bound tests.

UroVysion FISH test for detecting urothelial cancers: meta-analysis of diagnostic accuracy and comparison with urinary cytology testing

OBJECTIVES

Since the introduction of the UroVysion test for detecting urothelial cancers in urine, its reported performance has varied. This article systematically analyzed reported results.

METHODS

Articles in English conforming to the Oxford EBM criteria were included, with the evaluation focused on cancers that were histologically confirmed at the time of testing rather than on any cancers that might develop later. Where applicable, samples with no cells were reclassified as negative so as to further improve the actual estimation of test performance. Where available, cytology data were also analyzed. Meta-DiSc software was used for the statistical analyses.

RESULTS

We identified 14 studies involving 2477 FISH tests. The overall prevalence of urothelial cancers was 35%. The pooled sensitivity and specificity of all studies were 72% (69%-75%) and 83% (82%-85%), respectively. Cytology data were available from 12 studies, with the overall sensitivity and specificity being 42% (38%-45%) and 96% (95%-97%). Excluding Ta tumors, the sensitivity was 86% (82%-89%) for UroVysion and 61% (56%-66%) for cytology. The overall performance was higher for UroVysion than for cytology: diagnostic odds ratio, 16.8 and 14.1; AUC, 0.867 (SE 0.021) and 0.626 (SE 0.091). These differences in overall test performance measures almost disappeared when superficial cancer cases were excluded from the analysis.

CONCLUSIONS

The published trials suggest that for a general mix of cases, cytology results are highly specific. However, a negative cytology result does not meaningfully change the post-test probability of the presence of urothelial cancer. UroVysion FISH test results should not be considered to provide conclusive evidence for the presence or absence of urothelial cancer, but both positive and negative results do moderately influence the post-test probability of disease.

Exposure to the tobacco smoke constituent 4-aminobiphenyl induces chromosomal instability in human cancer cells

The relationships between environmental factors and the genetic abnormalities that drive carcinogenesis are supported by experimental and epidemiologic evidence but their molecular basis has not been fully elucidated. At the genomic level, most human cancers display either chromosomal (CIN) or microsatellite (MIN) instability. The molecular mechanisms through which normal cells acquire these forms of instability are largely unknown. The arylamine 4-aminobiphenyl (4-ABP) is a tobacco smoke constituent, an environmental contaminant, and a well-established carcinogen in humans. Among others, bladder, lung, colon, and breast cancers have been associated with 4-ABP. We have investigated the effects of 4-ABP and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) on genetically stable colorectal (HCT116) and bladder (RT112) cancer cells. Cells were treated with carcinogens to generate resistant clones that were then subjected to genetic analysis to assess whether they displayed either CIN or MIN. We found that 50% to 60% of cells treated with 4-ABP developed CIN but none developed MIN as confirmed by their ability to gain and lose chromosomes. In contrast, all MNNG-treated clones (12/12) developed MIN but none developed CIN as shown by the microsatellite assay. The mismatch repair protein expression analysis suggests that the acquired mechanism of MIN resistance in the HCT116 MNNG-treated cells is associated with the reduction or the complete loss of MLH1 expression. By providing a mechanistic link between exposure to a tobacco constituent and the development of CIN, our results contribute to a better understanding of the origins of genetic instability, one of the remaining unsolved problems in cancer research.