Perioperative search for circulating tumor cells in patients undergoing radical cystectomy for bladder cancer

Liquid biopsy in urothelial carcinoma: Detection techniques and clinical applications

The types of urothelial carcinoma (UC) include urothelial bladder cancer and upper tract urothelial carcinoma. Current diagnostic techniques cannot meet the needs of patients. Liquid biopsy is an accurate method of determining the molecular profile of UC and is a cutting-edge and popular technique that is expected to complement existing detection techniques and benefit patients with UC. Circulating tumor cells, cell-free DNA, cell-free RNA, extracellular vesicles, proteins, and metabolites can be found in the blood, urine, or other bodily fluids and are examined during liquid biopsies. This article focuses on the components of liquid biopsies and their clinical applications in UC. Liquid biopsies have tremendous potential in multiple aspects of precision oncology, from early diagnosis and treatment monitoring to predicting prognoses. They may therefore play an important role in the management of UC and precision medicine.

Liquid biopsies for detection, surveillance, and prognosis of urothelial cancer: a future standard?

INTRODUCTION

Liquid biopsies are used for the detection of tumor-specific elements in body fluid. Their application in prognosis and diagnosis of muscle/non-muscle invasive bladder cancer (MIBC/NMIBC) or upper tract urothelial cancer (UTUC) remains poorly known and rarely mentioned in clinical guidelines.

AREAS COVERED

Herein, we provide an overview of current data regarding the use of liquid biopsies in urothelial tumors.

EXPERT OPINION

Studies that were included analyzed liquid biopsies using the detection of circulating tumor cells (CTCs), deoxyribonucleic acid (DNA), ribonucleic acid (RNA), exosomes, or metabolomics. The sensitivity of blood CTC detection in patients with localized cancer was 35% and raised to 50% in patients with metastatic cancer. In NMIBC patients, blood CTC was associated with poor prognosis, whereas discrepancies were seen in MIBC patients. Circulating plasma DNA presented a superior sensitivity to urine and was a good indicator for diagnosis, follow-up, and oncological outcome. In urine, specific bladder cancer (BC) microRNA had an overall sensitivity of 85% and a specificity of 86% in the diagnosis of urothelial cancer. These results are in favor of the use of liquid biopsies as biomarkers for in urothelial cancer management.

Will the Use of Biomarkers Improve Bladder Cancer Radiotherapy Delivery?

Advances in the field of cancer biology and molecular techniques have led to a better understanding of the molecular underpinnings driving cancer development and outcomes. Simultaneously, advances in imaging have allowed for improved sensitivity in initial staging, radiotherapy planning and follow-up of numerous cancers. These two phenomena have led to the development of biomarkers that can guide therapy in multiple malignancies. In bladder cancer, there is extensive ongoing research into the identification of biomarkers that can help tailor personalised approaches for treatment based on the intrinsic tumour biology. However, the delivery of bladder cancer radiotherapy as part of trimodality therapy currently has a paucity of biomarkers to guide treatment. Here we summarise the existing literature and ongoing investigations into potential predictive and prognostic molecular and imaging biomarkers that may one day guide selection for utilisation of radiotherapy as part of trimodality therapy, guide selection of the radiosensitising agent, guide radiation dose and target, and guide surveillance for recurrence after trimodality therapy.

Tumor heterogeneity in muscle-invasive bladder cancer

Muscle-invasive bladder cancer (MIBC), a highly heterogeneous disease, shows genomic instability and a high mutation rate. Clinical outcomes are variable and responses to conventional chemotherapy differ among patients (due to inter-patient tumor heterogeneity and inter-tumor heterogeneity) and even within each individual tumor (intra-tumor heterogeneity). Emerging evidence indicates that tumor heterogeneity may play an important role in cancer progression, resistance to therapy, and metastasis. Comprehensive molecular subtyping classifies MIBC into distinct categories that have potential to guide prognosis, patient stratification, and treatment. Genomic characterization of time-series analyses at the single cell level, and of cell-free circulating tumor DNA or circulating tumor cells, are emerging technologies that enable dissection of the complex clonal architecture of MIBC. This review provides insight into the clinical significance of the molecular mechanisms underlying heterogeneity, focusing on inter- and intra-tumor heterogeneity, with special emphasis on molecular classification and methods used to analyze the complex patterns involved.

Liquid biopsy in the clinical management of bladder cancer: current status and future developments

Introduction: The use of liquid biopsy on the blood from solid malignancies provides a convenient way of detecting actionable mutations, monitoring treatment response, detecting early recurrence and prognosticating outcomes. The aim of this review is to discuss the current status and future direction of serum biomarkers in the clinical management of urinary bladder cancer.Areas covered: This review provides an overview of blood liquid biopsy and bladder cancer using methods of circulating tumors cells, circulating RNA, serum metabolites and cell-free DNA. Recent clinical studies and advances in methodology are emphasized. We performed a literature search using PMC/PubMed with keywords including 'liquid biopsy', 'circulating tumor DNA', 'cell-free DNA', 'biomarkers', 'bladder cancer' 'precision medicine'. Additional articles were obtained from the cited references of key articles. An emphasis was placed on recent studies published since 2018.Expert opinion: Liquid biopsies represent a potential biomarker using cell-free DNA, metabolomic profiles of altered cellular metabolism, circulating cancer cells and RNA. Despite displaying tremendous clinical promise, the current status of the blood liquid biopsies has not reached fruition. However, future investigations should lead the evolution of liquid biomarker into clinical utility for the management of bladder cancer.

Analysis of Circulating Tumor Cells in Patients with Non-Metastatic High-Risk Prostate Cancer before and after Radiotherapy Using Three Different Enumeration Assays

The characterization of circulating tumor cells (CTCs) can lead to a promising strategy for monitoring residual or relapsing prostate cancer (PCa) after local therapy. The aim of this study was to compare three innovative technologies for CTC enumeration in 131 high-risk patients with PCa, before and after radiotherapy, combined with androgen deprivation. The CTC number was tested using the FDA-cleared CellSearch^® system, the dual fluoro-EPISPOT assay that only detects functional CTCs, and the in vivo CellCollector^® technology. The highest percentage of CTC-positive patients was detected with the CellCollector^® (48%) and dual fluoro-EPISPOT (42%) assays, while the CellSearch^® system presented the lowest rate (14%). Although the concordance among methods was only 23%, the cumulative positivity rate was 79%. A matched-pair analysis of the samples before, and after, treatment suggested a trend toward a decrease in CTC count after treatment with all methods. CTC tended to be positivity correlated with age for the fluoro-EPISPOT assay and with PSA level from the data of three assays. Combining different CTC assays improved CTC detection rates in patients with non-metastatic high-risk PCa before and after treatment. Our findings do not support the hypothesis that radiotherapy leads to cancer cell release in the circulation.

Clinical applications of the CellSearch platform in cancer patients

The CellSearch® system (CS) enables standardized enrichment and enumeration of circulating tumor cells (CTCs) that are repeatedly assessable via non-invasive "liquid biopsy". While the association of CTCs with poor clinical outcome for cancer patients has clearly been demonstrated in numerous clinical studies, utilizing CTCs for the identification of therapeutic targets, stratification of patients for targeted therapies and uncovering mechanisms of resistance is still under investigation. Here, we comprehensively review the current benefits and drawbacks of clinical CTC analyses for patients with metastatic and non-metastatic tumors. Furthermore, the review focuses on approaches beyond CTC enumeration that aim to uncover therapeutically relevant antigens, genomic aberrations, transcriptional profiles and epigenetic alterations of CTCs at a single cell level. This characterization of CTCs may shed light on the heterogeneity and genomic landscapes of malignant tumors, an understanding of which is highly important for the development of new therapeutic strategies.

Clinical indications for, and the future of, circulating tumor cells

Circulating tumor cells (CTCs) are cells that have detached from the primary tumor and entered circulation with potential to initiate a site of metastasis. Currently, CTC detection using CellSearch is cleared by the Food and Drug Administration for monitoring metastatic breast, prostate, and colorectal cancers as a prognostic biomarker for progression-free and overall survival. Accumulating evidence suggests CTCs have similar prognostic value in other metastatic and non-metastatic settings. Current research efforts are focused on extending the utility of CTCs beyond a prognostic biomarker to help guide clinical decision-making. These include using CTCs as a screening tool for diagnosis, liquid biopsy for molecular profiling, predictive biomarker to specific therapies, and monitoring tool to assess response and guide changes to treatment. CTCs have unique advantages vs circulating tumor DNA in this endeavor. Indications for CTCs in daily practice will expand as isolation techniques improve and clinical studies validating their utility continue to grow.

The current status and clinical value of circulating tumor cells and circulating cell-free tumor DNA in bladder cancer

Urothelial carcinoma of the bladder (UCB) is a complex disease, which is associated with highly aggressive tumor biologic behavior, especially in patients with muscle-invasive and advanced tumors. Despite multimodal therapy options including surgery, radiotherapy and chemotherapy, UCB patients frequently suffer from poor clinical outcome. Indeed, the potential of diverse opportunities for modern targeted therapies is not sufficiently elucidated in UCB yet. To improve the suboptimal treatment situation in UCB, biomarkers are urgently needed that help detecting minimal residual disease (MRD), predicting therapy response and subsequently prognosis as well as enabling patient stratification for further therapies and therapy monitoring, respectively. To date, decision making regarding treatment planning is mainly based on histopathologic evaluation of biopsies predominantly derived from the primary tumors and on clinical staging. However, both methods are imperfect for sufficient outcome prediction. During disease progression, individual disseminated tumor cells and consecutively metastases can acquire characteristics that do not match those of the corresponding primary tumors, and often are only hardly assessable for further evaluation. Therefore, during recent years, strong efforts were directed to establish non-invasive biomarkers from liquid biopsies. Urine cytology and serum tumor markers have been established for diagnostic purposes, but are still insufficient as universal biomarkers for decision-making and treatment of UCB patients. To date, the clinical relevance of various newly established blood-based biomarkers comprising circulating tumor cells (CTCs), circulating cell-free nucleic acids or tumor-educated platelets is being tested in cancer patients. In this review we summarize the current state and clinical application of CTCs and circulating cell-free tumor DNA originating from blood as biomarkers in patients with different UCB stages.

Perioperative detection of circulating tumour cells in patients with lung cancer

Lung cancer is a leading cause of mortality and despite surgical resection a proportion of patients may develop metastatic spread. The detection of circulating tumour cells (CTCs) may allow for improved prediction of metastatic spread and survival. The current study evaluates the efficacy of the ScreenCell® filtration device, to capture, isolate and propagate CTCs in patients with primary lung cancer. Prior to assessment of CTCs, the present study detected cancer cells in a proof-of-principle- experiment using A549 human lung carcinoma cells as a model. Ten patients (five males and five females) with pathologically diagnosed primary non-small cell lung cancer undergoing surgical resection, had their blood tested for CTCs. Samples were taken from a peripheral vessel at the baseline, from the pulmonary vein draining the lobe containing the tumour immediately prior to division, a further central sample was taken following completion of the resection, and a final peripheral sample was taken three days post-resection. A significant increase in CTCs was observed from baseline levels following lung manipulation. No association was able to be made between increased levels of circulating tumour cells and survival or the development of metastatic deposits. Manipulation of the lung during surgical resection for non-small cell lung carcinoma results in a temporarily increased level of CTCs; however, no clinical impact for this increase was observed. Overall, the study suggests the ScreenCell® device has the potential to be used as a CTC isolation tool, following further work, adaptations and improvements to the technology and validation of results.

Clinical Significance of Early Changes in Circulating Tumor Cells from Patients Receiving First-Line Cisplatin-Based Chemotherapy for Metastatic Urothelial Carcinoma

Background: The therapeutic paradigm of metastatic urothelial carcinoma (UC) is rapidly shifting and new biomarkers are needed to enhance patient selection. Objective: Early identification of dynamic predictors of outcome may be a key to optimize the sequence of effective therapies in metastatic UC patients. Methods: Blood samples from patients receiving first-line MVAC chemotherapy were collected at baseline (T₀) and after 2 cycles (T₂). Samples were processed by immunomagnetic beads (AdnaTest ProstateCancerSelect kit) and the expression of EPCAM, MUC1 and ERBB2 was studied using multiplex-PCR. Circulating tumor cell (CTC) positivity and cutoffs, obtained by receiver operator characteristic (ROC) curve analysis in healthy donors, were: ≥1 positive marker among EPCAM (≥0.40 ng/μl), MUC1 (≥0.10 ng/μl) and ERBB2 (≥0.20 ng/μl). CTC variation (T₀/T₂) was split in favorable (+/-, -/-, -/+) and unfavorable groups (+/+). Cox regression analyses evaluated associations with clinical factors. Results: In this pilot study to assess a new CTC detection method, among 31 evaluable patients, 17 (54.8%) were CTC-positive at T₀. No association was found between CTC and objective response to MVAC. CTC dynamic changes better predicted 3-year progression-free (PFS) and overall survival (OS) compared to CTC status assessed at single time points. Unfavorable trend was univariably detrimental on 3-year PFS (10% vs. 49.2%, p = 0.006) and OS (20% vs. 63.5%, p = 0.017). Significance was maintained after controlling for liver metastases (p = 0.031 and p = 0.025 for PFS and OS) and MSKCC score (p = 0.014 and 0.025). Conclusions: Newly described early CTC changes during chemotherapy might be useful to improve our prognostic ability. Pending validation, these results could fulfill the promise to help accelerating therapeutic sequences.

Do circulating tumor cells have a role in deciding on adjuvant chemotherapy after radical cystectomy?

Radical cystectomy (RC) with bilateral pelvic lymphadenectomy with or without perioperative chemotherapy is the golden standard treatment in muscle invasive and recurrent high-grade non-muscle invasive urothelial carcinoma of the bladder (UCB). Despite treatment with curative intent, up to 50% of patients develop metastasis and die from UCB due to micro-metastatic disease undetectable for current staging techniques prior to definitive therapy. Tumor cell dissemination is a crucial step in the natural history of the metastatic cascade. Circulating tumor cells (CTC) are malignant epithelial cells detectable in the peripheral blood of patients with various malignancies. In UCB, CTC are detectable in a significant number of patients prior to RC and associated with inferior outcomes. In this review, we summarize the current literature regarding CTC in UCB, discussing their potential on clinical decision-making regarding multimodal treatment and implications on the application of novel targeted therapies in the future. There is reliable evidence that presence of CTC in clinically non-metastatic UCB patients treated with RC are a powerful predictor for unfavorable outcomes and may be useful for adjuvant chemotherapy decision-making and monitoring. However, currently, the evidence is limited, and thus, integration of CTC in future UCB clinical trials is strongly recommended to shed more light on the potential of this promising biomarker.

Challenges in circulating tumor cell detection by the CellSearch system

Enumeration and characterization of circulating tumor cells (CTC) hold the promise of a real time liquid biopsy. They are however present in a large background of hematopoietic cells making their isolation technically challenging. In 2004, the CellSearch system was introduced as the first and only FDA cleared method designed for the enumeration of circulating tumor cells in 7.5 mL of blood. Presence of CTC detected by CellSearch is associated with poor prognosis in metastatic carcinomas. CTC remaining in patients after the first cycles of therapy indicates a futile therapy. Here we review challenges faced during the development of the CellSearch system and the difficulties in assigning objects as CTC. The large heterogeneity of CTC and the different approaches introduced in recent years to isolate, enumerate and characterize CTC results in a large variation of the number of CTC reported urging the need for uniform definitions and at least a clear definition of what the criteria are for assigning an object as a CTC.

[Tumor cells in the peripheral blood of patients with urothelial carcinoma of the bladder: detection and impact of circulating]

Circulating tumor cells (CTC) play a crucial role in the natural history of several malignancies and, thus, are the subject of intense research efforts. This review summarizes the most contemporary literature data regarding detection of CTC and their impact on the oncological prognosis of patients with urothelial carcinoma of the bladder (UCB). Despite the availability of different methods for CTC detection and isolation in the peripheral blood, the standardized and Food and Drug Administration-approved CellSearch® assay is currently the most commonly used system for CTC detection. The majority of studies did not find any association between presence of CTC and clinicopathologic features. However, CTC have been demonstrated to represent a strong, independent predictor for unfavorable oncological outcomes in UCB. Since the peripheral blood is an easily accessible source, CTC represent a promising biomarker to effectively monitor early disease progression and therapy response in the near future. CTC hold the potential to individualize patient counseling regarding the optimal timing of radical surgery or bladder-sparing treatment as well as multimodal therapies.

Selective organ preservation for the treatment of muscle-invasive transitional cell carcinoma of the bladder: a review of current and future perspectives

Radical treatment remains underutilized for those with muscle-invasive bladder cancer. Radical radiotherapy, in particular, continues to be perceived by many as reserved only for patients unfit for cystectomy. However, with concurrent use of radiosensitizers, radiotherapy can achieve excellent local control and survival comparable to modern surgical series, thus presenting a real alternative to surgery. The possibility of further enhancing patient outcome is likely to come from both advances in radiotherapy treatment delivery and appropriate candidate selection. Growing evidence from selective bladder preservation trials demonstrate long term survival with functional organ preservation. In the era of personalized medicine, we review the evidence supporting an individualized treatment approach, in particular case selection for radical radiotherapy.

In vitro culturing of viable circulating tumor cells of urinary bladder cancer

OBJECTIVE

Approximately one third of patients diagnosed with muscle-invasive urinary bladder cancer (UBC) have undetected metastases at the time of treatment of the primary tumor. Currently there are no reliable specific serum markers for monitoring and evaluating risk profiles of urothelial cancers. Several studies suggest that detection of circulating tumor cells (CTCs) may correlate with the disease status and prognosis at baseline and early in the treatment of cancers. In this study a new way of isolation and in vitro cultivation of CTCs of urinary bladder cancer was introduced.

MATERIALS AND METHODS

Peripheral blood (PB) samples from 53 patients who had undergone urological procedure were evaluated using the MetaCell device (MetaCell s.r.o., Ostrava, Czech Republic). The patients enrolled in the study were both oncological patients with UBC and non-oncological patients with inflammation (14 patients). The sensitivity and quantification of CTCs were evaluated. The separated CTCs were cultured in vitro.

RESULTS

39 patients with confirmed UBC were enrolled in the study. CTCs were detected in 25 (64%) patients, and most of these patients had between 6 and 10 cells. The separated CTCs were successfully cultured in vitro.

CONCLUSION

CTCs were detected in a higher percentage of patients than in other studies. This paper describes the first successful culturing of human UBC cells. The MetaCell approach used in this study enabled the capture of viable intact virgin CTCs (virgin CTC) suitable for next in vitro culturing, single cell analysis or drug testing.

Leukocyte-adjusted epigenome-wide association studies of blood from solid tumor patients

Epigenome-wide studies of DNA methylation using blood-derived DNA from cancer patients are complicated by the heterogeneity of cell types within blood and the associated cell lineage specification of DNA methylation signatures. Here, we applied a novel set of analytic approaches to assess the association between cancer case-status and DNA methylation adjusted for leukocyte variation using blood specimens from three case-control cancer studies (bladder: 223 cases, 205 controls; head and neck: 92 cases, 92 controls; and ovarian: 131 cases, 274 controls). Using previously published data on leukocyte-specific CpG loci and a recently described approach to deconvolute subject-specific blood composition, we performed an epigenome-wide analysis to examine the association between blood-based DNA methylation patterns and each of the three aforementioned solid tumor types adjusted for cellular heterogeneity in blood. After adjusting for leukocyte profile in our epigenome-wide analysis, the omnibus association between case-status and methylation was significant for all three studies (bladder cancer: P = 0.047; HNSCC: P = 0.013; ovarian cancer: P = 0.0002). Subsequent analyses revealed that CpG sites associated with cancer were enriched for transcription factor binding motifs involved with cancer-associated pathways. These results support the existence of cancer-associated DNA methylation profiles in the blood of solid tumor patients that are independent of alterations in normal leukocyte distributions. Adoption of the methods developed here will make it feasible to rigorously assess the influence of variability of normal leukocyte profiles when investigating cancer related changes in blood-based epigenome-wide association studies.

Application of a telomerase-based circulating tumor cell (CTC) assay in bladder cancer patients receiving postoperative radiation therapy: a case study

BACKGROUND

Muscle invasive bladder carcinoma is an often lethal disease that requires aggressive treatment. Improved assays would contribute to better risk prediction and clinical management of this disease. A telomerase-based assay to detect circulating tumor cells (CTCs) may usefully fulfill this role.

METHODS

Two patients (C1 and C2) were enrolled onto an IRB-approved bladder biomarker study before initiating post-operative radiation therapy (RT) for muscle invasive bladder carcinoma. Blood samples were taken at predefined intervals: before, during, and after RT and then retrospectively correlated with imaging studies and disease course.

RESULTS

C1 began RT for positive resection margins on surgical pathology, at which time CTCs were undetectable and pelvic imaging demonstrated no evidence of disease. However, following the completion of treatment, the patient's CTC count was found to have increased to 202 CTCs/mL, and MRI demonstrated new abdominal and pelvic masses consistent with progressive disease. C1 ultimately died of disease with distant and local failure. Conversely, C2 was found to have 632 CTCs/mL before the initiation of RT for positive surgical margins, although imaging demonstrated no visible masses. At the conclusion of RT, repeat imaging showed changes that were indeterminate for either tumor recurrence or post-radiation effects. However, the patient's CTC count had dropped to 184 CTCs/mL. Furthermore, a second follow-up assay performed 6 months later revealed no detectable CTCs and repeat imaging showed complete resolution of worrisome imaging changes, thus excluding tumor progression.

CONCLUSIONS

To our knowledge this is the first report of a telomerase-based assay to identify CTCs in bladder cancer patients. Further studies are required to fully determine the ultimate clinical utility of this assay. However, the two patient vignettes described here illustrate how serial CTC assays may track the disease course and inform the management of bladder cancer patients undergoing adjuvant RT and potentially chemotherapy.

Preventing postoperative metastatic disease by inhibiting surgery-induced dysfunction in natural killer cells

Natural killer (NK) cell clearance of tumor cell emboli following surgery is thought to be vital in preventing postoperative metastases. Using a mouse model of surgical stress, we transferred surgically stressed NK cells into NK-deficient mice and observed enhanced lung metastases in tumor-bearing mice as compared with mice that received untreated NK cells. These results establish that NK cells play a crucial role in mediating tumor clearance following surgery. Surgery markedly reduced NK cell total numbers in the spleen and affected NK cell migration. Ex vivo and in vivo tumor cell killing by NK cells were significantly reduced in surgically stressed mice. Furthermore, secreted tissue signals and myeloid-derived suppressor cell populations were altered in surgically stressed mice. Significantly, perioperative administration of oncolytic parapoxvirus ovis (ORFV) and vaccinia virus can reverse NK cell suppression, which correlates with a reduction in the postoperative formation of metastases. In human studies, postoperative cancer surgery patients had reduced NK cell cytotoxicity, and we show for the first time that oncolytic vaccinia virus markedly increases NK cell activity in patients with cancer. These data provide direct in vivo evidence that surgical stress impairs global NK cell function. Perioperative therapies aimed at enhancing NK cell function will reduce metastatic recurrence and improve survival in surgical cancer patients.

Diagnostic value of circulating tumor cell detection in bladder and urothelial cancer: systematic review and meta-analysis

Background

The diagnostic value and prognostic significance of circulating tumor cell (CTC) detection in patients with bladder cancer is controversial. We performed a meta-analysis to consolidate current evidence regarding the use of CTC detection assays to diagnose bladder and other urothelial cancers and the association of CTC positivity with advanced, remote disease.

Methods

Studies that investigated the presence of CTCs in the peripheral blood of patients with bladder cancer and/or urothelial cancer were identified and reviewed. Sensitivities, specificities, and positive (LR+) and negative likelihood ratios (LR-) of CTC detection in individual studies were calculated and meta-analyzed by random effects model. Overall odds ratio of CTC positivity in patients with advanced disease versus those with organ-confined cancer was also calculated.

Results

Overall sensitivity of CTC detection assays was 35.1% (95%CI, 32.4-38%); specificity, LR+, and LR- was 89.4% (95%CI, 87.2-91.3%), 3.77 (95%CI, 1.95-7.30) and 0.72 (95%CI, 0.64-0.81). CTC-positive patients were significantly more likely to have advanced (stage III-IV) disease compared with CTC-negative patients (OR, 5.05; 95%CI, 2.49-10.26).

Conclusions

CTC evaluation can confirm tumor diagnosis and identify patients with advanced bladder cancer. However, due to the low overall sensitivity, CTC detection assays should not be used as initial screening tests.

Detection of circulating tumor cells in metastatic and clinically localized urothelial carcinoma

OBJECTIVE

To examine the incidence and prognostic value of circulating tumor cells (CTCs) in urothelial cancer (UC). The detection of CTCs is prognostic in several cancer types.

METHODS

A total of 44 subjects with UC were assessed for CTCs using CellSearch Technology and 7.5 mL of peripheral blood, sorted by magnetic separation (epithelial cell adhesion molecule positive) and immunofluorescent staining (positive for cytokeratin 8, 18, or 19, negative for CD45, positive for 4',6-diamidino-2-phenylindole) to identify the CTCs.

RESULTS

Five (17%) of 30 subjects with clinically localized and 7 (50%) of 14 subjects with metastatic UC had ≥1 detectable CTC (range 1-177). Six subjects had ≥5 CTCs. Fluorescence in situ hybridization analysis was performed in 20 samples from 18 unique subjects using the UroVysion probe set. Copy number gains consistent with neoplasm were observed in those with measurable CTCs but not in any of the CTC-negative samples tested. With a median follow-up of 337 days, all 7 patients with metastasis and detectable CTCs had died compared with 3 (43%) of the 7 with metastasis but without detectable CTCs.

CONCLUSION

CTCs are commonly observed in metastatic UC. CTCs were observed in 50% of the patients with metastatic UC tested. Fluorescence in situ hybridization analysis confirmed the aneusomic chromosomal content in the CTCs. These findings suggest that measurable CTCs might be prognostic for shortened survival in patients with metastatic UC, although the optimal threshold for a "positive" finding is unknown. CTCs were also detected in a subset of patients with clinically localized disease, identifying a potential high-risk, preoperative group for future study.

Detection of circulating tumour cells in peripheral blood of patients with advanced non-metastatic bladder cancer

OBJECTIVE

• To prospectively detect and evaluate the biological significance of circulating tumour cells (CTC) in patients with bladder cancer, especially in those patients with non-metastatic, advanced bladder cancer (NMABC).

PATIENTS AND METHODS

• Between July 2007 and January 2009, blood samples of 50 consecutive patients with localized bladder cancer and five patients with metastatic disease scheduled for cystectomy were prospectively investigated for CTC. Peripheral blood (7.5 ml) was drawn before cystectomy. • Detection of CTC was performed using the USA Food and Drug Administration-approved CellSearch(TM) system. Data were compared with the clinical and histopathological findings.

RESULTS

• CTC were detected in 15 of 50 patients (30%) with non-metastatic disease and five of five patients with metastatic disease. The overall mean number of CTC was 33.7 (range: 1-372; median: 2). In non-metastatic patients, the mean number of CTC was 3.1 (range: 1-11; median: 1). Except for a univariate association between CTC with vessel infiltration (P= 0.047), all other common clinical and histopathological parameters did not reveal a significant correlation with CTC detection. • A median 1-year follow up was available for 53 patients (96.4%). Ten out of 19 preoperatively CTC-positive patients died as a result of cancer progression. • CTC-positive patients showed significantly worse overall (P = 0.001), progression-free (P < 0.001) and cancer specific survival (P < 0.001) compared to preoperatively CTC-negative patients.

CONCLUSION

• This is the largest study demonstrating that detection of CTC in NMABC patients is feasible using the CellSearch(TM) system. Our findings suggest that the presence of CTC may be predictive for early systemic disease.