Circulating Tumor Cells Identify Patients with Super-High-Risk Non-Muscle-Invasive Bladder Cancer: Updated Outcome Analysis of a Prospective Single-Center Trial.

BACKGROUND: Clinical behavior of non-muscle-invasive bladder cancer (NMIBC) is largely unpredictable, and even patients treated according to European Association of Urology recommendations have a heterogeneous prognosis. High-grade T1 (HGT1) bladder cancer is the highest-risk subtype of NMIBC, with an almost 40% rate of recurrence and 20% of progression at 5 years. Nomograms predicting risk of recurrence, progression, and cancer-specific survival (CSS) are not available specifically within HGT1 bladder cancer, and the identification of robust prognostic biomarkers to better guide therapeutic strategies in this subgroup of patients is of paramount importance. Strategies to identify putative biomarkers in liquid biopsies from blood and urine collected from patients with bladder cancer have been intensively studied in the last few years. SUBJECTS, MATERIALS, AND METHODS: We here report the final analysis of a single-center prospective study aimed to investigate the impact of circulating tumor cells (CTCs) on CSS and overall survival (OS) in 102 patients with HGT1 bladder cancer, in a median follow-up of 63 months. RESULTS: We here demonstrate that the presence of even a single CTC is predictive of shorter CSS and OS, as compared with the standard predictive variables. Points of attention in this multivariable analysis are the long-term follow-up and the adequate number of outcome events. CONCLUSION: The accurate risk stratification provided by CTCs might be essential for determining the best surveillance strategy for patients after diagnosis. A closer follow-up, an early radical surgery, or even a systemic treatment might be recommended in patients with super-high-risk non-muscle-invasive bladder cancer. IMPLICATIONS FOR PRACTICE: Circulating tumor cells identify patients with super-high-risk non-muscle-invasive bladder cancer who require closer monitoring for local recurrence and/or progression of disease. This super-high-risk subgroup of patients might also require more aggressive treatment interventions, which should be evaluated in large prospective cohorts.

Letter to the Editor: "Circulating Cell-Free DNA and Circulating Tumor Cells as Prognostic and Predictive Biomarkers in Advanced Non-Small Cell Lung Cancer Patients Treated with First-Line Chemotherapy".

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Circulating tumor cells isolation: the "post-EpCAM era".

Circulating tumor cells (CTCs) represent a submicroscopic fraction detached from a primary tumor and in transit to a secondary site. The prognostic significance of CTCs in metastatic cancer patients was demonstrated for the first time more than ten years ago. To date, it seems clear enough that CTCs are highly heterogeneous and dynamically change their shape. Thus, the inadequacy of epithelial cell adhesion molecule (EpCAM) as universal marker for CTCs detection seems unquestionable and alternative methods able to recognize a broader spectrum of phenotypes are definitely needed. In this review the pleiotropic functions of EpCAM are discussed in detail and the role of the molecule in the biology of CTCs is critically dissected.

Impact of chronic exposure to bevacizumab on EpCAM-based detection of circulating tumor cells.

BACKGROUND: Circulating tumor cells (CTCs) are often undetected through the immunomagnetic epithelial cell adhesion molecule (EpCAM)-based CellSearch(®) System in breast and colorectal cancer (CRC) patients treated with bevacizumab (BEV), where low CTC numbers have been reported even in patients with evidence of progression of disease. To date, the reasons for this discrepancy have not been clarified. This study was carried out to investigate the molecular and phenotypic changes in CRC cells after chronic exposure to BEV in vitro. METHODS: The human CRC cell line WiDr was exposed to a clinically relevant dose of BEV for 3 months in vitro. The expression of epithelial and mesenchymal markers and EpCAM isoforms was determined by western blotting and immunofluorescence. To evaluate the impact of EpCAM variant isoforms expression on CTC enumeration by CellSearch(®), untreated and treated colon cancer cells were spiked into 7.5 mL of blood from a healthy donor and enumerated by CellSearch(®). RESULTS: Chronic exposure of CRC cell line to BEV induced decreased expression of EpCAM 40 kDa isoform and increased expression EpCAM 42 kDa isoform, together with a decreased expression of cytokeratins (CK), while no evidence of epithelial to mesenchymal transition (EMT) in treated cells was observed. The recovery rate of cells through CellSearch(®) was gradually reduced in course of treatment with BEV, being 84%, 70% and 40% at 1, 2 and 3 months, respectively. CONCLUSIONS: We hypothesize that BEV may prevent CellSearch(®) from capturing CTCs through altering EpCAM isoforms.

Circulating tumor cells detection has independent prognostic impact in high-risk non-muscle invasive bladder cancer.

High-risk non-muscle invasive bladder cancer (NMIBC) progresses to metastatic disease in 10-15% of cases, suggesting that micrometastases may be present at first diagnosis. The prediction of risks of progression relies upon EORTC scoring systems, based on clinical and pathological parameters, which do not accurately identify which patients will progress. Aim of the study was to investigate whether the presence of CTC may improve prognostication in a large population of patients with Stage I bladder cancer who were all candidate to conservative surgery. A prospective single center trial was designed to correlate the presence of CTC to local recurrence and progression of disease in high-risk T1G3 bladder cancer. One hundred two patients were found eligible, all candidate to transurethral resection of the tumor followed by endovesical adjuvant immunotherapy with BCG. Median follow-up was 24.3 months (minimum-maximum: 4-36). The FDA-approved CellSearch System was used to enumerate CTC. Kaplan-Meier methods, log-rank test and multivariable Cox proportional hazard analysis was applied to establish the association of circulating tumor cells with time to first recurrence (TFR) and progression-free survival. CTC were detected in 20% of patients and predicted both decreased TFR (log-rank p < 0.001; multivariable adjusted hazard ratio [HR] 2.92 [95% confidence interval: 1.38-6.18], p = 0.005), and time to progression (log-rank p < 0.001; HR 7.17 [1.89-27.21], p = 0.004). The present findings provide evidence that CTC analyses can identify patients with Stage I bladder cancer who have already a systemic disease at diagnosis and might, therefore, potentially benefit from systemic treatment.

Circulating tumor cells in high-risk nonmetastatic colorectal cancer.

The identification of patients at higher risk of recurrence after primary colorectal cancer resection is currently one of the challenges facing medical oncologists. Circulating tumor cell (CTC) may represent a surrogate marker of an early spread of disease in patients without overt metastases. Thirty-seven high-risk stages II-III colorectal cancer patients were evaluated for the presence of CTC. Enumeration of CTCs in 7.5 ml of blood was carried out with the FDA-cleared CellSearch system. CTC count was performed after primary tumor resection and before the start of adjuvant therapy. CTC was detected in 22 % of patients with a significant correlation with regional lymph nodes involvement and stage of disease. No significant correlation was found among the presence of CTC and other clinicopathological parameters. These data suggest that CTCs detection might help in the selection of high-risk stage II colorectal cancer patient candidates for adjuvant chemotherapy.

Prognostic Role of Circulating Tumor Cell Trajectories in Metastatic Colorectal Cancer.

BACKGROUND: A large amount of evidence from clinical studies has demonstrated that circulating tumor cells are strong predictors of outcomes in many cancers. However, the clinical significance of CTC enumeration in metastatic colorectal cancer is still questioned. The aim of this study was to evaluate the clinical value of CTC dynamics in mCRC patients receiving first-line treatments. MATERIALS AND METHODS: Serial CTC data from 218 patients were used to identify CTC trajectory patterns during the course of treatment. CTCs were evaluated at baseline, at a first-time point check and at the radiological progression of the disease. CTC dynamics were correlated with clinical endpoints. RESULTS: Using a cut-off of ≥1 CTC/7.5 mL, four prognostic trajectories were outlined. The best prognosis was obtained for patients with no evidence of CTCs at any timepoints, with a significant difference compared to all other groups. Lower PFS and OS were recognized in group 4 (CTCs always positive) at 7 and 16 months, respectively. CONCLUSIONS: We confirmed the clinical value of CTC positivity, even with only one cell detected. CTC trajectories are better prognostic indicators than CTC enumeration at baseline. The reported prognostic groups might help to improve risk stratification, providing potential biomarkers to monitor first-line treatments.

Circulating tumour cells lacking cytokeratin in breast cancer: the importance of being mesenchymal.

Circulating tumour cells (CTCs) are independent predictor of prognosis in metastatic breast cancer. Nevertheless, in one third of patients, circulating tumour cells are undetected by conventional methods. Aim of the study was to assess the prognostic value of circulating tumour cells expressing mesenchymal markers in metastatic breast cancer patients. We isolated CTC from blood of 55 metastatic breast cancer patients. CTC were characterized for cytokeratins and markers of epithelial mesenchymal transition. The gain of mesenchymal markers in CTC was correlated to prognosis of patients in a follow-up of 24 months. The presence of mesenchymal markers on CTC more accurately predicted worse prognosis than the expression of cytokeratins alone. Because of the frequent loss of epithelial antigens by CTC, assays targeting epithelial antigens may miss the most invasive cell population. Thus, there is an urgent need to improve detection methods to identify CTC which undergone epithelial mesenchymal transition program.

Epithelial-mesenchymal transition and stemness features in circulating tumor cells from breast cancer patients.

Currently used methods to detect and enumerate circulating tumor cells (CTCs) rely on the expression of the epithelial cell adhesion molecule (EpCAM) and cytokeratins. This selection may exclude cells that have undergone intrinsic modifications of their phenotype, as epithelial-mesenchymal transition (EMT). Aim of the study was to investigate the expression of EMT and stemness markers in CTCs from breast cancer patients in all stages of disease. 92 female breast cancer patients were enrolled. CTCs were isolated by CELLection Dynabeads coated with the monoclonal antibody toward EpCam. Samples found positive for CTCs presence (CD45-/CK+) were evaluated for the expression of ER alpha, HER2, ALDH1, vimentin, and fibronectin. Samples negative for CTCs presence (CD45-/CK-) were also evaluated for the expression of vimentin and fibronectin, used as markers of EMT. CTCs were found in 66% of patients. The distribution of CTCs presence according to stage and grade of disease was found statistically significant. The expression of ALDH1 on CTCs was found to correlate to stage of disease and to the expression of vimentin and fibronectin. In 34% of patients, we detected cells with negative CK/CD45 expression but positive expression of vimentin and fibronectin. There is an urgent need for optimizing CTCs detection methods through the inclusion of EMT markers. The detection of cells in mesenchymal transition, retaining EMT and stemness features, may contribute to discover additional therapeutic targets useful to eradicate micrometastatic disease in breast cancer.

ABCB5 in peripheral blood of a patient affected by multiple primary malignancies.

BACKGROUND: Multiple primary neoplasm malignancies syndrome (MPMN), is the presence of two or more abnormal growths of tissue, occurring simultaneously. Although the number of second malignancies is increasing, due to several factors, the presence of triple or quadruple malignancies is still very rare. PATIENT AND METHODS: We report a case of a 78-year-old man, with six primaries: a prostatic adenocarcinoma, breast cancer, two melanoma, a basal cell carcinoma, and a lymphoma in a four years period. RESULTS: The onset of MPMN is probably caused by a mutation of DNA repair genes, probably the TP53 gene. Common features of this syndrome are early rise and low tendency to metastatize. We reviewed the markers of staminality for various tumors: RNA expression of ALDH1, CD 133, and ABCB 5, extracted from the sentinel lymph node (SLN) and from the peripheral blood of the patient, was verified. CONCLUSION: People with multiple tumors represent a segment of the cancer-survivor population, which is continuously increasing (10%). Several genetic mutation can be involved in this kind of population. Our patient was positive for the expression of ABCB5, a marker for staminality of melanoma, in periphal blood.

A multidisciplinary approach for the differential diagnosis between multiple primary lung adenocarcinomas and intrapulmonary metastases.

PURPOSE: The distinction between multiple primary lung cancers (MPLCs) and intrapulmonary metastases has a significant impact on tumor staging and therapeutic choices. Several criteria have been proposed to solve this diagnostic issue, but a definitive consensus is still missing. We tested the efficacy of a combined clinical, histopathological and molecular ("real world") approach for the correct classification of multiple lung tumors in a selected cohort of patients. METHODS: 24 multiple lung tumors with a diagnosis of adenocarcinoma from 10 patients were retrospectively reviewed. Radiological, pathological and clinical information, including follow-up, were integrated with molecular profiling via a routine multigene panel sequencing. RESULTS: Comprehensive histologic assessment revealed readily distinguishable histologic patterns between multiple tumors suggesting unrelated lesions in 7 cases, in agreement with clinical, radiological and molecular data, thus leading to final diagnosis of MPLCs. In the remaining 3 cases, the differential diagnosis between MPLCs and intrapulmonary metastases was challenging, since the histologic features of the lesions were similar or identical. The final interpretation (2 MPLCs and 1 most likely intrapulmonary metastases) was reached thanks to the integration of all available data, and was confirmed by follow-up. CONCLUSIONS: A multidisciplinary approach including a routinely affordable multigene panel sequencing is a useful tool to discriminate MPLCs from intrapulmonary metastases in multiple lung nodules sharing the adenocarcinoma histotype.

Molecular markers in circulating tumour cells from metastatic colorectal cancer patients.

The prognosis of metastatic cancer patients is still largely affected by treatment failure, mainly due to drug resistance. The hypothesis that chemotherapy might miss circulating tumour cells (CTCs) and particularly a subpopulation of more aggressive, stem-like CTCs, characterized by multidrug resistance, has been recently raised. We investigated the prognostic value of drug resistance and stemness markers in CTCs from metastatic colorectal cancer patients treated with oxaliplatin (L-OHP) and 5-fluoruracil (5-FU) based regimens. Forty patients with metastatic colorectal cancer were enrolled. CTCs were isolated from peripheral blood and analysed for the expression of aldheyde dehydrogenase 1 (ALDH1), CD44, CD133 (used as markers of stemness), multidrug resistance related protein 5 (MRP5 used as marker of resistance to 5-FU and L-OHP) and survivin (used as a marker of apoptosis resistance). CTCs were found in 27/40 (67%) patients. No correlation was found between the expression of either CD44 and CD133 in CTCs and the outcome of patients, while a statistically significant shorter progression-free survival was found in patients with CTCs positive for the expression of ALDH1, survivin and MRP5. These results support the idea that isolating survivin and MRP5+ CTCs may help in the selection of metastatic colorectal cancer patients resistant to standard 5-FU and L-OHP based chemotherapy, for which alternative regimens may be appropriate.

Chemosensitivity profile assay of circulating cancer cells: prognostic and predictive value in epithelial tumors.

The prognostic value associated with the detection of circulating tumor cells (CTCs) in metastatic breast cancer by the CellSearch technology raise additional issues regarding the biological value of this information. We postulated that a drug-resistance profile of CTCs may predict response to chemotherapy in cancer patients and therefore could be used for patient selection. One hundred 5 patients with diagnosis of carcinoma were enrolled in a prospective trial. CTCs were isolated from peripheral blood, and positive samples were evaluated for the expression of a panel of genes involved in anticancer drugs resistance. The drug-resistance profile was correlated with disease-free survival (DFS; patients in adjuvant setting) and time to progression (TTP; metastatic patients) in a 24-months follow-up. Objective response correlation was a secondary end point. Fifty-one percent of patients were found positive for CTCs while all blood samples from healthy donors were negative. The drug-resistance profile correlates with DFS and TTP (p < 0.001 in both). Sensitivity of the test: able to predict treatment response in 98% of patients. Specificity of the test: 100%; no sample from healthy subject was positive for the presence of CTCs. Positive and negative predictive values were found to be 96.5 and 100%, respectively. We identified a drug-resistance profile of CTCs, which is predictive of response to chemotherapy, independent of tumor type and stage of disease. This approach may represent a first step toward the individualization of chemotherapy in cancer patients.

Prognostic significance of survivin-expressing circulating tumour cells in T1G3 bladder cancer.

OBJECTIVE: To evaluate the prognostic significance of survivin in tumour tissues and that of survivin-expressing circulating tumour cells (CTCs) in T1G3 bladder tumours, as the prognosis of T1G3 bladder cancer is highly variable and unpredictable from clinical and pathological prognostic factors. PATIENTS AND METHODS: The study included 54 patients with T1G3 non-muscle-invasive bladder cancer. Additional inclusion criteria were: tumour size <3 cm, absence of carcinoma in situ and multifocality. The planned follow-up was 24 months. Survivin was evaluated by reverse transcription-polymerase chain reaction in tumour tissues. CTCs were isolated from blood by CELLection Dynabeads (Invitrogen, Carlsbad, CA, USA) coated with the monoclonal antibody towards the human epithelial cell adhesion molecule. Cells were lysed and Dynabeads Oligo(dT) was used to capture poly A + mRNA. cDNA was synthesized and analysed for the expression of CD45, CK8 and survivin. The primary endpoint was disease-free survival (DFS); the favourable group at 24 months was defined as that with no clinical evidence of disease; the unfavourable group was that with evidence of recurrent disease or progressive disease. Tumour survivin expression and presence of CTC were correlated with DFS. Multivariate analysis was used to investigate whether the presence of CTC was an independent indicator of DFS. RESULTS: Survivin was found in half of the tumours; patients with survivin-negative tumours had a longer DFS than those with survivin-positive tumours (chi-square, P = 0.029). CTCs were found in 24/54 patients (44%); 92% of CTC expressed survivin. The difference in DFS between CTC-ve and CTC+ve patients was statistically significant (chi-square, P < 0.001). The presence of CTC was an independent prognostic factor for DFS (P < 0.001). CONCLUSION: The presence of CTC is an independent prognostic factor in patients with T1G3 bladder cancer.

Detection of circulating tumor cells in patients with laryngeal cancer using ScreenCell: Comparative pre- and post-operative analysis and association with prognosis.

The presence of circulating tumor cells (CTCs) in the blood of patients with metastatic breast, colorectal and prostate cancer have been widely investigated; however, few studies have examined CTCs in patients with laryngeal cancer. The present pilot study aimed to detect pre- and postoperative CTCs in the blood of patients with laryngeal cancer and evaluate the association with prognosis. Eight patients with laryngeal squamous cell carcinoma (LSCC) at stage III were included in the present study and underwent total or subtotal laryngectomy and radical bilateral neck lymph node dissection. Blood samples were collected from all patients before and after surgery at different time-points. The following processing steps were followed; preoperative blood sampling, surgery, postoperative blood sampling at 3, 6 and 12 month follow-ups, and prognostic association analysis. CTCs were retained on ScreenCell filters for cytological characterization. The presence of CTCs was associated with a less favorable prognosis, whereas a decrease of CTCs in the postoperative sampling was observed in patients who exhibited an improved therapeutic response. The results of the present pilot study revealed a possible association between the presence of CTCs and a less favorable prognosis in patients with LSCC; therefore, these preliminary findings may encourage further research into the incorporation of a liquid biopsy in the management of LSCC, as this may help identify patients with occult metastatic disease earlier and in a non-invasive manner. In addition, this approach may represent novel independent prognostic factor for use in the clinical evaluation of patients with LSCC.

Circulating Methylated DNA to Monitor the Dynamics of RAS Mutation Clearance in Plasma from Metastatic Colorectal Cancer Patients.

The clearance of RAS mutations in plasma circulating tumor DNA (ctDNA) from originally RAS-mutant metastatic colorectal cancer (mCRC) has been recently demonstrated. Clinical trials investigating whether RAS mutant mCRC who "convert" to wild-type in plasma might benefit from EGFR blockade are ongoing. Detection of tumor-specific DNA methylation alterations in ctDNA has been suggested as a specific tool to confirm the tumoral origin of cell-free DNA. We monitored RAS clearance in plasma from patients with RAS-mutant mCRC at baseline (pre-treatment) (T0); after 4 months of first-line therapy (T1); at the time of first (T2) and second (T3) progression. A five-gene methylation panel was used to confirm the presence of ctDNA in samples in which RAS mutation clearance was detected. At T1, ctDNA analysis revealed wild-type RAS status in 83% of samples, all not methylated, suggesting at this time point the lack of ctDNA shedding. At T2, ctDNA analysis revealed wild-type RAS status in 83% of samples, of which 62.5% were found methylated. At T3, 50% of wild-type RAS samples were found methylated. Non-methylated samples were found in patients with lung or brain metastases. This five-gene methylation test might be useful to confirm the presence of ctDNA in RAS wild-type plasma samples.

Baseline CD44v6-positive circulating tumor cells to predict first-line treatment failure in patients with metastatic colorectal cancer.

CD44v6, the CD44 isoform mostly involved in cancer cell migration and invasion, has been identified as a functional biomarker and therapeutic target in colon cancer stem cells. We here provide evidence that baseline CD44v6-positive CTC predict treatment failure in patients with metastatic colorectal cancer undergoing first-line chemotherapy. We suggest that CD44v6-positive CTC can be used to early detect intrinsic drug resistance in this cancer type.

Clinical Multigene Panel Sequencing Identifies Distinct Mutational Association Patterns in Metastatic Colorectal Cancer.

Extensive molecular characterization of human colorectal cancer (CRC) via Next Generation Sequencing (NGS) indicated that genetic or epigenetic dysregulation of a relevant, but limited, number of molecular pathways typically occurs in this tumor. The molecular picture of the disease is significantly complicated by the frequent occurrence of individually rare genetic aberrations, which expand tumor heterogeneity. Inter- and intratumor molecular heterogeneity is very likely responsible for the remarkable individual variability in the response to conventional and target-driven first-line therapies, in metastatic CRC (mCRC) patients, whose median overall survival remains unsatisfactory. Implementation of an extensive molecular characterization of mCRC in the clinical routine does not yet appear feasible on a large scale, while multigene panel sequencing of most commonly mutated oncogene/oncosuppressor hotspots is more easily achievable. Here, we report that clinical multigene panel sequencing performed for anti-EGFR therapy predictive purposes in 639 formalin-fixed paraffin-embedded (FFPE) mCRC specimens revealed previously unknown pairwise mutation associations and a high proportion of cases carrying actionable gene mutations. Most importantly, a simple principal component analysis directed the delineation of a new molecular stratification of mCRC patients in eight groups characterized by non-random, specific mutational association patterns (MAPs), aggregating samples with similar biology. These data were validated on a The Cancer Genome Atlas (TCGA) CRC dataset. The proposed stratification may provide great opportunities to direct more informed therapeutic decisions in the majority of mCRC cases.

A chemosensitivity test to individualize intravesical treatment for non-muscle-invasive bladder cancer.

OBJECTIVE: To describe the design of a new chemosensitivity assay based on the expression of genes involved in the resistance to standard intravesical regimens, to allow individualization of therapy for high-risk non-muscle-invasive bladder cancer. PATIENTS AND METHODS: To date, 35 patients with high-risk non-muscle-invasive bladder cancer have been enrolled, all candidates for transurethral resection of the bladder (TURB) followed by intravesical treatment. The intravesical regimen was chosen according to the risk profile of each patient. All patients were evaluated by cystoscopy 3 and 6 months after TURB. According to the molecular characterization of each tumour, our team of molecular oncologists determined for each patient a molecular profile of chemosensitivity to BCG, mitomycin c, anthracyclines and gemcitabine. This profile was then correlated to the response to intravesical therapy 6 months after TURB. RESULTS: This chemosensitivity test was able to predict response to treatment in 96% of patients. The assay is easy to perform, inexpensive and quick. CONCLUSION: Our results, although preliminary, are encouraging for the future of an individualized therapeutic approach, with the aim to provide a higher treatment success rate while sparing patients unnecessary toxicity from drugs that are not suited for their tumours.

Molecular Characterization of Circulating Tumor Cells to Study Cancer Immunoevasion.

Cancer cells leaving the primary tumor immunosuppressive microenvironment become vulnerable to active immune surveillance and require mechanisms of immunoevasion to survive in the circulation. Studies have identified several pathways by which circulating tumor cells (CTCs) might escape the immune system/immunotherapy attack. The PD-1/PD-L1 axis is an immune checkpoint regulator, playing a major role in maintaining self-tolerance. It is now well recognized that tumor cells co-opt the PD-1/PD-L1 axis of immune regulation to interfere with cytotoxic T lymphocyte function. Transcriptional changes in CTCs, leading to the upregulation of PD-L1, might enable them to survive in circulation. Very recent data revealed a previously unappreciated role of epithelial-mesenchymal transition (EMT) in reprogramming the immune response in the local tumor microenvironment and a mutual regulation between EMT and immunoevasion is becoming apparent. In this chapter, we will describe in detail both EpCAM-dependent and -independent approaches that allow the identification of PD-L1 expression and EMT-like features in circulating tumor cells.