Meta-analysis shows that detection of circulating tumor cells indicates poor prognosis in patients with colorectal cancer

Investigating the role of circulating tumor cells in gastric cancer: a comprehensive systematic review and meta-analysis

Investigating the role of circulating tumor cells (CTCs) and their characteristics is still controversial in patients with gastric cancer (GC). Therefore, in this study, to provide a comprehensive review and meta-analyses of the literature on association of CTCs with gastric cancer, Scopus, Web of Science, Embase, and Medline were searched for systematic reviews and meta-analyses conducted during February 2022 using the keywords. Risk of bias, hazard ratios (HRs), and risk differences (RD) were assessed. Forty-five studies containing 3,342 GC patients from nine countries were assessed. The overall prevalence of CTC in GC was 69.37% (60.27, 77.78). The pooled result showed that increased mortality in GC patients was significantly associated with positive CTCs, poor overall survival (HR = 2.73, 95%CI 2.34-3.24, p < 0.001), and progression-free survival rate (HR = 2.78, 95%CI 2.01-3.85, p < 0.001). Subgroup analyses regarding markers, detection methods, treatment type, presence of distance metastasis, presence of lymph node metastasis, and overall risk of bias showed significant associations between the groups in terms of the incidence rates of CTCs, OS, and PFS. In addition, the results of risk differences based on sampling time showed that the use of the cell search method (RD: - 0.19, 95%CI (- 0.28, - 0.10), p < 0.001), epithelial marker (RD: - 0.12, 95%CI (- 0.25, 0.00), p 0.05) and mesenchymal markers (RD: - 0.35, 95%CI (- 0.57, - 0.13), p 0.002) before the treatment might have a higher diagnostic power to identify CTCs and also chemotherapy treatment (RD: - 0.17, 95%CI (- 0.31, - 0.03), p 0.016) could significantly reduce the number of CTCs after the treatment. We also found that the risk differences between the clinical early and advanced stages were not statistically significant (RD: - 0.10, 95%CI (- 0.23, 0.02), P 0.105). Also, in the Lauren classification, the incidence of CTC in the diffuse type (RD: - 0.19, 95%CI (- 0.37, - 0.01), P0.045) was higher than that in the intestinal type. Meta-regression analysis showed that baseline characteristics were not associated with the detection of CTCs in GC patients. According to our systematic review and meta-analysis, CTCs identification may be suggested as a diagnostic technique for gastric cancer screening, and the outcomes of CTC detection may also be utilized in the future to create personalized medicine programs.

Anaesthesia in Veterinary Oncology: The Effects of Surgery, Volatile and Intravenous Anaesthetics on the Immune System and Tumour Spread

Throughout the course of oncological disease, the majority of patients require surgical, anaesthetic and analgesic intervention. However, during the perioperative period, anaesthetic agents and techniques, surgical tissue trauma, adjuvant drugs for local pain and inflammation and other non-pharmacological factors, such as blood transfusions, hydration, temperature and nutrition, may influence the prognosis of the disease. These factors significantly impact the oncologic patient's immune response, which is the primary barrier to tumour progress, promoting a window of vulnerability for its dissemination and recurrence. More research is required to ascertain which anaesthetics and techniques have immunoprotective and anti-tumour effects, which will contribute to developing novel anaesthetic strategies in veterinary medicine.

Molecular Biomarkers of Bladder Cancer: A Mini-Review

Cancers are quite common, but mostly very serious diseases and therefore belong to the most important areas of scientific research activity. Bladder cancer is one of the most common malignancies, it is a heterogeneous disease with significant diagnostic, therapeutic, and prognostic problems. It represents a disease with a variable course and a different response to therapy. The "conventional" prognostic markers used so far cannot reliably predict the natural course of the disease or estimate the tumor response to the chosen type of treatment. Molecular markers can provide us with the opportunity to diagnose a bladder tumor early, identify patients who are at risk of recurrence, or predict how tumors will respond to therapeutic approaches. As a result, diagnostics are found to help clinicians find the best therapeutic options for patients with bladder cancer. In this study, we focused on a brief description of potential molecular markers in bladder tumors in the context of precise diagnostics. Last but not least, we also focused on a new approach to the treatment of cancer using nanomaterials.

Long Term Outcomes of No-Touch Isolation Principles Applied in Pancreaticoduodenectomy for Treatment of Pancreatic Adenocarcinoma: A Multicenter Retrospective Study with Propensity Score Matching

Background: The recurrence and liver metastasis rates are still high in pancreatic head cancer with curative surgical resection. A no-touch isolation principle in pancreaticoduodenectomy (PD) may improve this situation, however, the exact advantages and efficacy of these principles have not been confirmed. Materials and methods: Among 370 patients who underwent PD, three centers were selected and classified into two groups: the no-touch PD group (n = 70) and the conventional PD group (n = 300). Propensity score matching was used to control for selection bias at a ratio of 1:1. The confounding variables were age, sex, body mass index, adjuvant chemotherapy, carbohydrate antigen 19-9, tumor size and tumor differentiation. Results: Patients in the no-touch PD group had better overall survival (OS) and disease-free survival (DFS) than those in the conventional PD group (OS: 17 vs. 13 months, p = 0.0035, DFS: 15 vs. 12 months, p = 0.087), with lower 1- and 2-year disease-related mortality rates (1-year: 32.9% vs. 47%, p = 0.032; 2-year: 42.5% vs. 82% p = 0.000) and recurrence and liver metastasis rates (1-year: 30.0% vs. 43.3%, p = 0.041; 2-year: 34.3% vs. 48.7%, p = 0.030). Compared with the matched conventional PD group, the no-touch PD group also had a better OS (17 vs. 12 months, p = 0.032). Conclusions: Our study showed the no-touch isolation principle may be a better choice to improve long-term survival for pancreatic cancer patients.

Influence of Perioperative Anesthesia on Cancer Recurrence: from Basic Science to Clinical Practice

PURPOSEOF REVIEW

In this review, we will summarize the effects of these perioperative anesthetics and anesthetic interventions on the immune system and tumorigenesis as well as address the related clinical evidence on cancer-related mortality and recurrence.

RECENT FINDINGS

Cancer remains a leading cause of morbidity and mortality worldwide. For many solid tumors, surgery is one of the major therapies. Unfortunately, surgery promotes angiogenesis, shedding of circulating cancer cells, and suppresses immunity. Hence, the perioperative period has a close relationship with cancer metastases or recurrence. In the perioperative period, patients require multiple anesthetic management including anesthetics, anesthetic techniques, and body temperature control. Preclinical and retrospective studies have found that these anesthetic agents and interventions have complex effects on cancer outcomes. Therefore, well-planned, prospective, randomized controlled trials are required to explore the effects of different anesthetics and techniques on long-term outcomes after cancer surgery. Due to the conflicting effects of anesthetic management on cancer recurrence, further preclinical and clinical trials are required and beneficial to the development of systemic cancer therapies.

Prognostic value of epithelial–mesenchymal transition circulating tumor cells in female breast cancer: A meta-analysis

Background

Epithelial–mesenchymal transition (EMT) conferred metastatic properties on circulating tumor cells (CTCs) and was considered to be correlated with bad survival outcomes in patients with breast cancer. However, different studies have reported controversial results regarding the relationship between CTCs that have undergone EMT (EMT-CTCs) and prognosis of breast cancer. Therefore, this meta-analysis aimed to investigate the prognostic role of EMT-CTCs in patients with breast cancer.

Methods

In total, 842 patients from nine studies that were screened from Web of Science, Embase, and PubMed were included. The hazard ratio (HR) and 95% confidence interval (CI) for progression-free survival (PFS) and overall survival (OS) were extracted or estimated by the Kaplan–Meier survival curve for the meta-analysis. Sensitivity analysis was performed to characterize heterogeneity among the trials. Meanwhile, subgroup analysis was performed to present the effects of cancer stage, identification method, sampling volume, and region on the prognostic value of EMT-CTCs.

Results

The pooled HRs for PFS were 1.97 (univariate: 95% CI, 1.19–3.24; p = 0.008) and 2.23 (multivariate: 95% CI, 1.29–3.86; p = 0.004). The pooled HRs for OS were 2.03 (univariate: 95% CI, 1.07–3.84; p = 0.029) and 1.70 (multivariate: 95% CI, 1.14–2.52; p = 0.009). Subgroup analysis showed that EMT-CTCs were associated with PFS in the primary breast cancer group (pooled HR = 2.58, 95% CI, 1.66–4.00, p &lt; 0.001), the polymerase chain reaction (PCR) group (pooled HR = 2.69, 95% CI, 1.66–4.35, p &lt; 0.001), the sampling volume of the &gt;7.5-ml group (pooled HR = 1.93, 95% CI, 1.36–2.73, p &lt; 0.001), and the Asia group (pooled HR = 1.92, 95% CI, 1.13–3.29, p = 0.017) and with OS in the primary breast cancer group (pooled HR = 3.59, 95% CI, 1.62–7.95; p = 0.002).

Conclusion

The meta-analysis showed that EMT-CTCs were associated with poorer survival outcomes in patients with breast cancer. More accurate methods and designed clinical trials with unified standards are essential to establish the real role of EMT-CTCs in disease progression in women with breast cancer.

Where Are We Now and Where Might We Be Headed in Understanding and Managing Brain Metastases in Colorectal Cancer Patients?

OPINION STATEMENT

Compared to liver and lung metastases, brain metastases (BMs) from colorectal cancer (CRC) are rare and remain poorly investigated despite the anticipated rise in their incidence. CRC patients bearing BM have a dismal prognosis with a median survival of 3-6 months, significantly lower than that of patients with BM from other primary tumors, and of those with metastatic CRC manifesting extracranially. While liver and lung metastases from CRC have more codified treatment strategies, there is no consensus regarding the treatment of BM in CRC, and their management follows the approaches of BM from other solid tumors. Therapeutic strategies are driven by the number and localisation of the lesion, consisting in local treatments such as surgery, stereotactic radiosurgery, or whole-brain radiotherapy. Novel treatment modalities are slowly finding their way into this shy unconsented armatorium including immunotherapy, monoclonal antibodies, tyrosine kinase inhibitors, or a combination of those, among others.This article reviews the pioneering strategies aiming at understanding, diagnosing, and managing this disease, and discusses future directions, challenges, and potential innovations in each of these domains.

HIGHLIGHTS

• With the increasing survival in CRC, brain and other rare/late-onset metastases are rising. • Distal colon/rectal primary location, long-standing progressive lung metastases, and longer survival are risk factors for BM development in CRC. • Late diagnosis and lack of consensus treatment strategies make BM-CRC diagnosis very dismal. • Liquid biopsies using circulating tumor cells might offer excellent opportunities in the early diagnosis of BM-CRC and the search for therapeutic options. • Multi-modality treatment including surgical metastatic resection, postoperative SRS with/without WBRT, and chemotherapy is the best current treatment option. • Recent mid-sized clinical trials, case reports, and preclinical models show the potential of unconventional therapeutic approaches as monoclonal antibodies, targeted therapies, and immunotherapy. Graphical abstract.

Association of Clinical Features of Colorectal Cancer with Circulating Tumor Cells and Systemic Inflammatory Markers

Background. Circulating tumor cells (CTCs) in peripheral blood have been shown to reflect the prognosis of patients with colorectal cancer, and epithelial and mesenchymal markers further predict the likelihood of cancer dissemination. This study was conducted to identify possible association of clinical features of colorectal cancer with CTC counts, their subtypes, and systemic inflammatory markers. Methods. Blood samples of 316 colorectal cancer patients were used for CTC detection and subtyping with EpCAM, CK8/18/19, vimentin, and twist as biomarkers. The neutrophil/lymphocyte ratio, platelet/lymphocyte ratio, C-reactive protein/albumin ratio, lymphocyte/monocyte ratio, and systemic immune-inflammation index (SII) were also measured. The relationship between clinical data and these markers or parameters was analyzed. Results. Total CTC counts were correlated with whether there was lymph node involvement but was not correlated with TNM staging. There was a difference in mesenchymal CTCs between patients with and without lymph node involvement ( $P<0.05$ ). Also, more patients with metastasis tested positive for mesenchymal CTCs ( $P<0.05$ ). Of the systemic inflammatory markers, platelet/lymphocyte ratio was positively correlated with CTC counts ( $P<0.01$ ), and lymphocyte/monocyte ratio was negatively correlated with CTC counts ( $P<0.05$ ). Conclusions. Colorectal cancer patients with the mesenchymal markers on their CTCs are more likely to have lymph node involvement or distant metastasis than those without these markers.

Circulating Tumor Cells and the Non-Touch Isolation Technique in Surgery for Non-Small-Cell Lung Cancer

Circulating tumor cells (CTCs) are dislodged from the primary tumor into the bloodstream, travel within the bloodstream to distant organs, and finally extravasate and proliferate as epithelial metastatic deposits. The relationship between the existence of CTCs and tumor prognosis has been demonstrated by many researchers. In surgery for malignancies, the surgical manipulation of tumors and tissues around the tumor may lead to the release of CTCs into the bloodstream. The non-touch isolation technique (NTIT) has been advocated to prevent the release of CTCs during surgery. The concept of NTIT is the prevention of intraoperative increment of CTCs from the primary tumor by the early blockade of outflow vessels, and ‘pulmonary vein (PV)-first lobectomy’ during surgery for non-small-cell lung cancer (NSCLC) corresponds to this technique. The concept of PV-first lobectomy is well known among thoracic surgeons, but evidence of its efficacy for preventing the increase of intra- and postoperative CTCs and for improving postoperative prognosis is still uncertain. Our study summarizes evidence regarding the relationship between NTIT and CTCs in NSCLC and suggests the need for further research on CTCs and CTC-detecting modalities.

Bacterial Involvement in Progression and Metastasis of Colorectal Neoplasia

While the gut microbiome is composed of numerous bacteria, specific bacteria within the gut may play a significant role in carcinogenesis, progression, and metastasis of colorectal carcinoma (CRC). Certain microbial species are known to be associated with specific cancers; however, the interrelationship between bacteria and metastasis is still enigmatic. Mounting evidence suggests that bacteria participate in cancer organotropism during solid tumor metastasis. A critical review of the literature was conducted to better characterize what is known about bacteria populating a distant site and whether a tumor depends upon the same microenvironment during or after metastasis. The processes of carcinogenesis, tumor growth and metastatic spread in the setting of bacterial infection were examined in detail. The literature was scrutinized to discover the role of the lymphatic and venous systems in tumor metastasis and how microbes affect these processes. Some bacteria have a potent ability to enhance epithelial–mesenchymal transition, a critical step in the metastatic cascade. Bacteria also can modify the microenvironment and the local immune profile at a metastatic site. Early targeted antibiotic therapy should be further investigated as a measure to prevent metastatic spread in the setting of bacterial infection.

Liquid Biopsy: A Distinctive Approach to the Diagnosis and Prognosis of Cancer

Cancer is a leading cause of morbidity and mortality worldwide. Over the past decades, the concept of precision cancer medicine has emerged as a novel approach in the field of oncology that aims to tailor the most effective treatment options to each individual cancer patient based on the genetic profile of the tumor of each individual patient. Recently, tissue biopsy has become an essential part of cancer care and is widely used to characterize the tumor. However, tissue biopsy techniques face different challenges due to their invasiveness, cost, time, and adversity in potential sampling due to tissue heterogeneity. To overcome these issues, a non-invasive approach has developed, which is known as liquid biopsy. It is a simple, fast, and worthwhile technique based on the analysis of circulating tumor DNA (which is a fraction of cfDNA), circulating tumor cells (CTCs), and other tumor-derived material in blood plasma. This review provides an overview of the concept of liquid biopsy and briefly discusses the role of ctDNA and CTC analysis as tools for early diagnosis and prognosis of cancer. In this review, we also speculate on the advantages of liquid biopsy as opposed to tissue biopsy and postulate that liquid biopsy may be a comprehensive approach to overcome the current limitations associated with costly, invasive, and time-consuming tissue biopsy.

The Simultaneous Presence of Isolated Tumour Cells and Bone Marrow Micrometastases in Stage I and II Colon Cancer-Challenging the Theory of a Chronological Pathway of Tumour Cell Dissemination

Background

According to the common tenet, tumour progression is a chronological process starting with lymphatic invasion. In this respect, the meaning of bone marrow micrometastases (BMM) in patients with lymph node negative colon cancer (CC) is unclear. This study examines the relationship of isolated tumour cells (ITC) in sentinel lymph nodes (SLN) and BMM in patients in early CC.

Methods

BM aspirates were taken from both pelvic crests and in vivo SLN mapping was done during open oncologic colon resection in patients with stage I and II CC. Stainings were performed with the pancytokeratin markers A45-B/B3 and AE1/AE3 as well as H&E. The correlation between the occurrence of ITC+ and BMM+ and their effects on survival was examined using Cox regression analysis.

Results

In a total of 78 patients with stage I and II CC, 11 patients (14%) were ITC+, 29 patients (37%) BMM+. Of these patients, only two demonstrated simultaneous ITC+ /BMM+. The occurrence of BMM+ was neither associated with ITC+ in standard correlation (kappa = − 0.13 [95% confidence interval [CI] = − 0.4–0.14], p = 0.342) nor univariate (odds ratio [OR] = 0.39, 95%CI:0.07–1.50, p = 0.180) or multivariate (OR = 0.58, 95%CI: 0.09–2.95, p = 0.519) analyses. Combined detection of ITC+ /BMM+ demonstrated the poorest overall (HR = 61.60, 95%CI:17.69–214.52, p = 0.032) and recurrence free survival (HR = 61.60, 95%CI: 17.69–214.5, p = 0.032).

Conclusions

These results indicate that simultaneous and not interdependent presence of very early lymphatic and haematologic tumour spread may be considered as a relevant prognostic risk factor for patients with stage I and II CC, thereby suggesting the possible need to reconsider the common assumptions on tumour spread proposed by the prevalent theory of sequential tumour progression.

The Role of General Anesthetic Drug Selection in Cancer Outcome

Cancer remains to be the leading cause of death globally. Surgery is a mainstay treatment for solid tumors. Thus, it is critical to optimize perioperative care. Anesthesia is a requisite component for surgical tumor resection, and general anesthesia is given in the vast majority of tumor resection cases. Because anesthetics are growingly recognized as immunomodulators, it is critical to optimize anesthetic regimens for cancer surgery if the selection can affect outcomes. Here, we reviewed the role of volatile and intravenous anesthesia used for cancer surgery in cancer recurrence.

Evaluation of circulating tumor cells in colorectal cancer using flow cytometry

Objective

We aimed to evaluate the prognostic value of circulating tumor cells (CTCs) and the impact of intraoperative tumor manipulation on CTCs in colorectal cancer (CRC) patients.

Methods

We performed a prospective study on 40 patients with CRC stages I to IV who received curative surgery using the no-touch technique. Flow cytometry was used to identify CTCs in peripheral blood samples (4 mL/sample) collected at two surgical moments: skin incision (T1) and after surgical resection (T2). A threshold of ≥4 CTCs/4 mL blood was established for considering patients CTC positive.

Results

In the univariate analysis, CTC evaluation at T2 was correlated with female sex, vascular invasion, tumor localization in the colon and metastatic lymph nodes. In the multivariate analysis, only female sex and colon cancer maintained statistical significance. At a medium follow-up of 15 months (1–25 months), the mortality rate was 10% (n = 4), with no significant differences between the overall survival of T1 or T2 CTC-positive and CTC-negative patients.

Conclusions

Flow cytometry is a feasible CTC identification technique in CRC, and although surgical manipulation has no influence on CTC numbers, CTCs may serve as a prognostic and predictive factor.

Colonic Stent as Bridge to Surgery for Malignant Obstruction Induces Gene Expressional Changes Associated with a More Aggressive Tumor Phenotype

BACKGROUND

Colonic stent is recommended as a bridge to elective surgery for malignant obstruction to improve short-term clinical outcomes for patients with colorectal cancer. However, since the oncological outcomes remain controversial, this study aimed to investigate the impact of self-expandable metallic stent (SEMS) on the tumor microenvironment.

METHODS

Patients treated with colonic stent as a bridge to surgery from 2010 to 2015 were identified from hospital records. Tumor biopsies and resected tumor samples of the eligible patients were retrieved retrospectively. Gene expression analysis was performed using the NanoString nCounter PanCancer IO 360 gene expression panel.

RESULTS

Of the 164 patients identified, this study included 21 who underwent colonic stent placement as a bridge to elective surgery. Gene expression analysis revealed 82 differentially expressed genes between pre- and post-intervention specimens, of which 72 were upregulated and 10 downregulated. Among the significantly upregulated genes, 46 are known to have protumor functions, of which 26 are specifically known to induce tumorigenic mechanisms such as proliferation, migration, invasion, angiogenesis, and inflammation. In addition, ten differentially expressed genes were identified that are known to promote antitumor functions.

CONCLUSION

SEMS induces gene expressional changes in the tumor microenvironment that are associated with tumor progression in colorectal cancer and may potentiate a more aggressive phenotype. Future studies are warranted to establish optimal timing of surgery after SEMS insertion in patients with obstructive colorectal cancer.

Monitoring of circulating epithelial tumor cells using the Maintrac® method and its potential benefit for the treatment of patients with colorectal cancer

Circulating tumor cells are an important link between primary tumors and metastases. A longitudinal monitoring of their numbers and properties can provide valuable information on therapy response and disease progression for patients with colorectal cancer. As several techniques for the detection of circulating tumor cells are notorious for yielding low detection rates in patients with non-metastatic colorectal cancer, the present study aimed to perform a proof-of-principle study using the Maintrac^® approach for an assessment of circulating epithelial tumor cells (CETCs) in patients with colorectal cancer receiving neoadjuvant and/or adjuvant radio/chemotherapy (R/CT). CETCs in the peripheral blood of 22 patients with colorectal cancer were quantified by fluorescence image analysis (Maintrac^®) before and after the first cycle of a neoadjuvant and/or adjuvant R/CT, as well as before and after surgical resection of the primary tumor. To determine that blood-borne CETCs originate from tumor tissues, spheres were cultured from CETCs as well as from primary tumor tissue and compared with the expression of tumor-specific antigens. Within the scope of this study, it was demonstrated that the Maintrac^® method allows for the precise detection and characterization of CETCs in the blood of patients with colorectal cancer independent of tumor stage. Furthermore, correlations between CETC parameters and patients' response to neoadjuvant and/or adjuvant R/CT that have been described in previous literature could be reproduced. Whether the observed trends are of a general nature and suitable as an auxiliary criterion for prognosis and treatment decisions remains to be shown. Patients with rectal cancer may benefit from CETC monitoring as a method to select suitable patients for adjuvant therapy.

High CTC-TRPC5 Expression Significantly Associated With Poor Prognosis in Radical Resected Colorectal Cancer Patients

Recurrence is the main reason of treatment failure of redical resected colorectal cancer (CRC). Although some factors including staging and differentiation have been proven to useful for recurrence evaluation, prognosis of certain patients does not conform to this evaluation approach. Circulating tumor cells (CTC) have been found to have prognostic value in CRC, and previous studies on CTC have primarily focused on their numbers. CTC are functionally heterogeneous cell populations, and different CTC subgroups may have different functions and clinical values. In our previous study, we discovered that elevated expression of the transient receptor potential channel TRPC5 was associated with a significantly poor prognosis in CRC. In this study, we collected peripheral blood from CTC-positive CRC patients, identified the TRPC5 protein expression on CTC (CTC-TRPC5), and analyzed the relationship between CTC-TRPC5 expression levels and the prognosis. The results showed that CTC-TRPC5 level is significantly related to the T stage and differentiation of tumors. High level of CTC-TRPC5 is more common in a high T stage as well as poorly differentiated tumors and is significantly associated with shorter disease free survival (DFS). The median DFS of CRC patients with high and low CTC-TRPC5 level was 17.1 and 22.0 months, respectively (p < 0.05). This study revealed a clinically significant CTC subgroup of CRC, providing a new indicator for clinical evaluation of CRC prognosis.

Pathological Features of Brain Metastases

Metastases are the most common intracranial tumors in adults. Lung cancer, melanoma, renal cell carcinoma, and breast cancer are the most common primary tumors that metastasize to the brain. Improved detection of small metastases by MRI, and improved systemic therapy for primary tumors, resulted in increased incidence of brain metastasis. Advances in neuroanesthesia and neurosurgery have significantly improved the safety of surgical resection of brain metastases. Surgical approach and active management have become applicable for many patients. Subsequently, brain metastases diagnosis no longer equals palliative treatment. Moreover, the demand for diagnosing brain masses has increased with its associated challenges.

Prognostic value of circulating tumor cells in patients with bladder cancer: A meta-analysis

Background

Circulating tumor cells (CTCs) have been considered diagnostic and prognostic biomarkers for urothelial cancer. However, the prognostic role of CTCs in bladder cancer (BC) remains controversial. Here, we conducted a meta-analysis to evaluate the prognostic significance of CTCs for patients with BC.

Methods

All studies relevant to this topic were searched in the PubMed, Embase, and Web of Science databases. The hazard ratio (HR) and 95% confidence interval (95% CI) were set as effect measures. The outcomes were overall survival (OS), cancer-free survival (CSS), progression-free survival (PFS)/time to progression (TTP), and disease-free survival (DFS)/recurrence-free survival (RFS)/time to first recurrence (TFR). All analyses were conducted in STATA 15.1.

Results

Eleven eligible studies comprising 1,062 patients with BC were included in this meta-analysis. Overall analyses showed that CTC-positive patients had poorer survival (OS: HR 3.88, 95% CI 2.52–5.96, p < 0.001; CSS: HR 3.89, 95% CI 2.15–7.04, p < 0.001) and more aggressive progression (PFS/TTP: HR 5.92, 95% CI 3.75–9.35, p < 0.001; DFS/RFS/TFR: HR 4.57, 95% CI 3.34–6.25, p < 0.001) than CTC-negative patients. Subgroup analyses according to the number of patients, detection method, positivity rate, and follow-up time revealed that the presence of CTCs predicted a high risk of mortality and disease progression in most subgroups.

Conclusion

The meta-analysis confirmed that CTCs are a promising prognostic biomarker of poor survival and aggressive tumor progression for patients with BC.

Prospero registration number

CRD42021224865.

ViBiBa: Virtual BioBanking for the DETECT multicenter trial program - decentralized storage and processing

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ViBiBa is an open-source sample banking tool.

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ViBiBa was purpose built for liquid biopsy specimen.

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ViBiBa allows for decentralized storage while promoting collaboration.

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ViBiBa's plugin support requires no change in existing data structures.

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ViBiBa empowers translational research projects and cohort formation.

Background

Liquid Biopsy (LB) in the form of e.g., circulating tumor cells (CTCs) is a promising non-invasive approach to support current therapeutic cancer management. However, the proof of clinical utility of CTCs in informing therapeutic decision-making for e.g., breast cancer in clinical trials and associated translational research projects is facing the issues of low CTC positivity rates and low CTC numbers – even in the metastasized situation. To compensate for this dilemma, clinical CTC trials are designed as large multicenter endeavors with decentralized sample collection, processing and storage of products, making data management highly important to enable high-quality translational CTC research.

Aim

In the DETECT clinical CTC trials we aimed at developing a custom-made, browser-based virtual database to harmonize and organize both decentralized processing and storage of LB specimens and to enable the collection of clinically meaningful LB sample.

Methods

ViBiBa processes data from various sources, harmonizes the data and creates an easily searchable multilayered database.

Results

An open-source virtual bio-banking web-application termed ViBiBa was created, which automatically processes data from multiple non-standardized sources. These data are automatically checked and merged into one centralized databank and are providing the opportunity to extract clinically relevant patient cohorts and CTC sample collections.

Summary

ViBiBa, which is a highly flexible tool that allows for decentralized sample storage of liquid biopsy specimens, facilitates a solution which promotes collaboration in a user-friendly, federalist and highly structured way. The source code is available under the MIT license from https://vibiba.com or https://github.com/asperciesl/ViBiBa

Proteomic Analyses of Fibroblast- and Serum-Derived Exosomes Identify QSOX1 as a Marker for Non-invasive Detection of Colorectal Cancer

Simple Summary

Early diagnosis of colorectal cancer (CRC) is crucial to improve patient outcomes. The tumour microenvironment immediately adapts to malignant transformations, including the activation of fibroblasts in the connective tissue nearby. In this study, we investigated fibroblast activity-related protein secretion via extracellular vesicles (EVs). QSOX1, a protein identified to be significantly reduced in activated fibroblasts and derived EVs, was also found to be significantly reduced in circulating blood plasma EVs of CRC patients as compared to control patients. Hence, blood plasma EV-associated QSOX1 represents a promising platform for diagnostic CRC screening.

Abstract

The treatment of colorectal cancer (CRC) has improved during the last decades, but methods for crucial early diagnosis are yet to be developed. The influence of the tumour microenvironment on liquid biopsies for early cancer diagnostics are gaining growing interest, especially with emphasis on exosomes (EXO), a subgroup of extracellular vesicles (EVs). In this study, we established paired cancer-associated (CAFs) and normal fibroblasts (NF) from 13 CRC patients and investigated activation status-related protein abundance in derived EXOs. Immunohistochemical staining of matched patient tissue was performed and an independent test cohort of CRC patient plasma-derived EXOs was assessed by ELISA. A total of 11 differentially abundant EV proteins were identified between NFs and CAFs. In plasma EXOs, the CAF-EXO enriched protein EDIL3 was elevated, while the NF-EXO enriched protein QSOX1 was diminished compared to whole plasma. Both markers were significantly reduced in patient-matched CRC tissue compared to healthy colon tissue. In an independent test cohort, a significantly reduced protein abundance of QSOX1 was observed in plasma EXOs from CRC patients compared to controls and diagnostic ROC curve analysis revealed an AUC of 0.904. In conclusion, EXO-associated QSOX1 is a promising novel marker for early diagnosis and non-invasive risk stratification in CRC.

Proteomic Analyses of Fibroblast- and Serum-Derived Exosomes Identify QSOX1 as a Marker for Non-invasive Detection of Colorectal Cancer

The treatment of colorectal cancer (CRC) has improved during the last decades, but methods for crucial early diagnosis are yet to be developed. The influence of the tumour microenvironment on liquid biopsies for early cancer diagnostics are gaining growing interest, especially with emphasis on exosomes (EXO), a subgroup of extracellular vesicles (EVs). In this study, we established paired cancer-associated (CAFs) and normal fibroblasts (NF) from 13 CRC patients and investigated activation status-related protein abundance in derived EXOs. Immunohistochemical staining of matched patient tissue was performed and an independent test cohort of CRC patient plasma-derived EXOs was assessed by ELISA. A total of 11 differentially abundant EV proteins were identified between NFs and CAFs. In plasma EXOs, the CAF-EXO enriched protein EDIL3 was elevated, while the NF-EXO enriched protein QSOX1 was diminished compared to whole plasma. Both markers were significantly reduced in patient-matched CRC tissue compared to healthy colon tissue. In an independent test cohort, a significantly reduced protein abundance of QSOX1 was observed in plasma EXOs from CRC patients compared to controls and diagnostic ROC curve analysis revealed an AUC of 0.904. In conclusion, EXO-associated QSOX1 is a promising novel marker for early diagnosis and non-invasive risk stratification in CRC.

Assessment of the Circulating Tumor Cells and Microsatellite Instability in Colorectal Cancer Patients: Prognostic and Diagnostic Value

Background

Microsatellite instability (MSI) and circulating tumor cells (CTCs) play important roles in the diagnosis, prognosis and management of colorectal cancer (CRC) patients.

Methods

CTCs and MSI were assessed in the blood and representative tumor tissues of 100 CRC patients by flow cytometry (FCM) and PCR amplification. The data were correlated to relevant clinicopathological features of the patients, progression-free survival (PFS) and overall survival (OS) rates.

Results

MSI-high was detected in 44 (44.0%) patients, MSI-low in 37 (37%), and microsatellite stable (MSS) in 19 (19.0%) patients (P=0.007). The baseline CTCs count (<4 cells/7mL blood) was reported in 39% of the patients, and CTCs ≥4 cells/7mL blood in 61% of the patients (P=0.028). Improved PFS and OS rates were associated significantly with MSI-high (P<0.001), decreased CTC levels during the course of treatment (P<0.001) and post-treatment CTCs (P=0.008). There was no significant association between MSI-high and PFS or OS in early-stage patients (P=0.187 and P=0.187; respectively); however, it was associated significantly with better PFS and OS in late-stage patients (P<0.001). Multivariate analysis showed that only a change in serial CTC levels is considered an independent prognostic factor for OS (P<0.012). Post-treatment CTCs level, serial CTCs level changes during the course of treatment, lymph nodes and distant metastasis were independent prognostic factors for PFS (P<0.001, P= 0.047, P=0.001 and P<0.001; respectively).

Conclusion

MSI and CTCs could be used as accurate, reliable and sensitive diagnostic and prognostic biomarkers for CRC patients’ survival rates and outcomes.

Biomarkers for Precision Urothelial Carcinoma Diagnosis: Current Approaches and the Application of Single-Cell Technologies

Simple Summary

Urothelial carcinoma (UC) is the most frequently diagnosed cancer of the urinary tract and is ranked the sixth most diagnosed cancer in men worldwide. About 70–75% of newly diagnosed UCs are non-invasive or low grade. Different tests such as urine cytology and cystoscopy are used to detect UC. If abnormal tissue is found during cystoscopy, then a biopsy will be performed. Cytology has low sensitivity for low-grade cancer while cystoscopy is invasive and costly. Detecting UC early improves the chances of treatment success. Therefore, many researchers have painstakingly identified urine biological markers for non-invasive UC diagnosis. In this review, we summarize some of the latest and most promising biological markers (including FDA-approved and investigational markers). We also discuss some new technologies that can aid research efforts in biological marker discovery for early UC detection.

Abstract

Urothelial carcinoma (UC) is the most frequent malignancy of the urinary system and is ranked the sixth most diagnosed cancer in men worldwide. Around 70–75% of newly diagnosed UC manifests as the non-muscle invasive bladder cancer (NMIBC) subtype, which can be treated by a transurethral resection of the tumor. However, patients require life-long monitoring due to its high rate of recurrence. The current gold standard for UC diagnosis, prognosis, and disease surveillance relies on a combination of cytology and cystoscopy, which is invasive, costly, and associated with comorbidities. Hence, there is considerable interest in the development of highly specific and sensitive urinary biomarkers for the non-invasive early detection of UC. In this review, we assess the performance of current diagnostic assays for UC and highlight some of the most promising biomarkers investigated to date. We also highlight some of the recent advances in single-cell technologies that may offer a paradigm shift in the field of UC biomarker discovery and precision diagnostics.

Anterior Approach vs Conventional Hepatectomy for Resection of Colorectal Liver Metastasis: A Randomized Clinical Trial

Importance

Tumor relapse after partial hepatectomy for colorectal liver metastasis (CRLM) remains an unsolved issue. Intraoperative manipulation of the liver during conventional hepatectomy might enhance hematogenous tumor cell spread. The anterior approach is an alternative approach that may reduce intraoperative tumor cell dissemination.

Objective

To determine the efficacy and safety of the anterior approach compared with conventional hepatectomy in patients undergoing resection for CRLM.

Design, Setting, and Participants

This randomized clinical study evaluated the efficacy and safety of the anterior approach compared with conventional hepatectomy in adult patients with CRLM who were scheduled for hepatectomy from February 1, 2003, to March 31, 2012, at a tertiary-care hospital. A total of 80 patients with CRLM were randomized to the anterior approach and conventional hepatectomy groups in a 1:1 ratio. Bone marrow and blood samples were analyzed for disseminated tumor cells and circulating tumor cells (CTC) using cytokeratin 20 reverse transcriptase-polymerase chain reaction analysis. Data were analyzed from April 1 to December 1, 2018, using intention to treat.

Interventions

Anterior approach vs conventional hepatectomy.

Main Outcomes and Measures

The primary end point was intraoperative CTC detection in central blood samples after liver resection. Secondary end points included postoperative morbidity, mortality, and long-term survival.

Results

Among the 80 patients included in the analysis (48 men [60%]; mean [SD] age, 61 [10] years), baseline characteristics, including preoperative CTC detection, were comparable between both groups. There was no statistically significant difference in intraoperative CTC detection between patients in the conventional hepatectomy (5 of 21 [24%]) and anterior approach (6 of 22 [27%]) groups (P = .54). Except for a longer operating time in the anterior approach group (mean [SD], 171 [53] vs 221 [53] minutes; P < .001), there were no significant differences in intraoperative and postoperative outcomes between both study groups. Although detection of CTC was associated with poor overall (median, 46 [95% CI, 40-52] vs 81 [95% CI, 54-107] months; P = .03) and disease-free (median, 40 [95% CI, 34-46] vs 60 [95% CI, 46-74] months; P = .04) survival, there was no significant difference in overall (median, 73 [95% CI, 42-104] vs 55 [95% CI, 35-75] months; P = .43) and disease-free (median, 48 [95% CI, 40-56] vs 40 [95% CI, 28-52] months; P = .88) survival between the conventional hepatectomy and anterior approach groups. Also, there was no significant difference in patterns of recurrence between both groups.

Conclusions and Relevance

This randomized clinical trial found that the anterior approach was not superior to conventional hepatectomy in reducing intraoperative tumor cell dissemination in patients undergoing resection of CRLM.

Trial Registration

isrctn.org Identifier: ISRCTN45066244.

Subtypes of minimal residual disease and outcome for stage II colon cancer treated by surgery alone

Introduction

Twenty-five percent of stage II colon cancer (CC) patients relapse within 5 years due to minimal residual disease (MRD) not eliminated by surgery. We hypothesise that subtypes of MRD, defined by circulating tumour cells (CTCs) and bone marrow micrometastasis (mM), have different types and kinetics of relapse.

Methods and patients

One month after surgery, blood and bone marrow samples were taken to detect CTCs and mM using immunocytochemistry with anti-carcinoembryonic antigen (CEA). Follow-up was for up to 5 years or relapse. Disease-free survival curves using Kaplan-Meier (DFS) and restricted mean disease-free survival times (RMST) were calculated for three prognostic groups: A: MRD (-), B: mM (+) CTC (-) MRD and C: CTC (+) MRD.

Results

One hundred and eighty-one patients (82 men) have participated, mean age was 68 years and median follow-up was 4.04 years (A (N = 105), B (N = 36) and C (N = 40)). For the whole cohort of 5 years, DFS was 70%, median DFS has not reached (Groups A: 98%, B: 63% and C: 7%) and median DFS for Groups A and B have not reached. RMST for the whole cohort of 4.1 years, Group A was 4.9 years, B was 4.1 years and C was 1.7 years. Serum CEA was significantly higher in Group C. No significant differences for sex, age or high-risk adverse prognostic factors between groups were detected.

Conclusions

MRD subtypes define relapse patterns and may be useful to define the risk of relapse in stage II CC patients, in which patients may benefit or not from additional therapy and warrants further studies with a larger number of patients.

Assessment of circulating tumor cells in peripheral blood using flow cytometry in patients with surgery for colorectal cancer – review

Introduction: Colorectal cancer (CRC) is the third most common neoplasia in the world. Circulating tumor cells (CTC) have a prognostic value and can be useful in monitoring solid neoplasia. Only one method for CTC identification has received the approval and this is the CellSearch® system based on the immunomagnetic separation. Multiple markers are used in CTC identification, as epithelial markers and cytokeratines. CTC identification in peripheral blood is associated with a worse prognostic and reduced free survival in CRC.

Material and methods: We performed a systematic search in PubMed database for articles that reports the circulating tumor cells in CRC until July 2019. We selected studies in English and French and the main words used for search were ‘circulating tumor cells’, ‘colorectal cancer’, ‘colon cancer’, ‘rectal cancer’, ‘flow cytometry’, ‘peripheral blood’. We included studies with more than 10 patients, where samples were collected from the blood in relation with surgery and flow cytometry was used as analyzing technique.

Results: We included 7 studies in final analysis, that showed in flow cytometry analysis a cut-off value of CTC that can vary from 2-4 CTC/ 7.5 ml peripheral blood with a sensitivity of 50.8% and specificity of 95%. Patients with positive CTC were associated with higher T stage and positive lymph nodes, with a worse overall survival (OS) and disease free survival (DFS) comparing with negative patients.

Conclusion: CTC are considered to be a prognostic factor who needs more validation studies in order to be included in the clinical practice.

Association of postoperative influenza vaccine on overall mortality in patients undergoing curative surgery for solid tumors

Recent findings have found that the influenza vaccine induces changes in the immune system in favor of antitumor cytotoxicity. The aim of our study was to investigate if an influenza vaccine given in the postoperative period decreased overall and cancer-specific mortality in patients undergoing curative surgery for solid cancers. We conducted a registry-based national observational study in Denmark in the period January 1, 2010 to December 31, 2015 with a follow-up period of 3 years starting from 180 days after surgery. Patients with solid cancers undergoing curative surgery were included. The primary outcome was overall mortality. The secondary outcome was cancer-specific mortality. A total of 21 462 patients were included in the study with 2557 patients receiving an influenza vaccine within 6 months after surgery. In a Cox regression model, a decrease in overall mortality (hazard ratio [HR] = 0.89, 95% confidence interval [CI] = 0.81-0.99, P = .03) and cancer-related mortality (HR = 0.82, 95% CI = 0.71-0.93, P = .003) was found among patients given a vaccine vs patients never receiving a vaccine. In a predefined subgroup of patients receiving a vaccine within 30 days after surgery, a decrease in overall mortality (HR = 0.82, 95% CI = 0.72-0.94, P = .007) and cancer-specific mortality (HR = 0.70, 95% CI = 0.53-0.91, P = .009) was found. No association was evident in patients receiving the vaccine after 30 days to 6 months after surgery (overall mortality: HR = 0.96, 95% CI = 0.86-1.07, P = .46); cancer-specific mortality: HR = 0.88, 95% CI = 0.76-1.03, P = .12). These findings must be investigated in larger clinical trials where both immunological biomarkers and survival outcomes are included.

Clinical Potential of Circulating Tumor Cells in Colorectal Cancer: A Prospective Study

Circulating tumor cells (CTCs) in the blood have been used as diagnostic markers in patients with colorectal cancer (CRC). In this study, we evaluated a CTC detection system based on cell size to assess CTCs and their potential as early diagnostic and prognostic biomarkers for CRC.

Platelet adherence to cancer cells promotes escape from innate immune surveillance in cancer metastasis

The impacts of post‑operative abdominal infectious complications increase hematogenous distant metastasis and result in poor long‑term survival after curative resection. Even if curative resection can be performed, the presence of circulating tumor cells is affected. The liver, the most common site of metastases, is an important organ in innate immune surveillance. However, the molecular mechanisms of distant hematogenous metastasis are not yet fully known. Platelets are crucial components in the tumor microenvironment that function to promote tumor progression and metastasis. The purpose of this study was to identify the effect of platelets on escape from innate immune surveillance in post‑operative abdominal infectious complications. Platelet adherence was assessed by co‑culturing human pancreatic cancer cells including transforming growth factor (TGF‑β)‑treated BxPC‑3. CD44 isoform, transcription factors and epithelial‑mesenchymal transition markers were examined using western blotting. We also assessed whether cancer cells surrounded by activated platelets could escape from innate immune surveillance, using infectious and non‑infectious mouse models injected intraperitoneally with LPS. Platelets were found to preferentially adhere to mesenchymal cells rather than epithelial cells. BxPC‑3 epithelial cells showed upregulation of CD44‑variant and epithelial splicing regulatory protein 1 (ESRP‑1) expression. However, Panc‑1 mesenchymal cells and TGF‑β‑treated BxPC‑3 cells showed upregulation of CD44‑standard and zinc finger E‑box‑binding homeobox 1 (ZEB‑1) expression and a reduction in ESRP‑1. In the non‑infectious model, cancer cells were not found in the liver. In the infectious model, although epithelial cells without platelet adhesion were in an apoptotic state, mesenchymal cells showed many viable cancer cells surrounded by activated platelets. Cancer cells were suggested to have phenotypic plasticity through the switching of CD44 isoforms. Mesenchymal cells, which express CD44‑standard, could escape from immune surveillance by becoming surrounded by adhered activated platelets. Therefore, it may be necessary to administer antiplatelet agents to prevent distant hematogenous metastasis when post‑operative abdominal infectious complications occur.

Liquid Biopsy in Colorectal Carcinoma: Clinical Applications and Challenges

Colorectal carcinoma (CRC) is characterized by wide intratumor heterogeneity with general genomic instability and there is a need for improved diagnostic, prognostic, and therapeutic tools. The liquid biopsy provides a noninvasive route of sample collection for analysis of circulating tumor cells (CTCs) and genomic material, including cell-free DNA (cfDNA), as a complementary biopsy to the solid tumor tissue. The solid biopsy is critical for molecular characterization and diagnosis at the time of collection. The liquid biopsy has the advantage of longitudinal molecular characterization of the disease, which is crucial for precision medicine and patient-oriented treatment. In this review, we provide an overview of CRC and the different methodologies for the detection of CTCs and cfDNA, followed by a discussion on the potential clinical utility of the liquid biopsy in CRC patient care, and lastly, current challenges in the field.

Characterization of Stem-like Circulating Tumor Cells in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is the fourth most frequent cause of death from cancer. Circulating tumor cells (CTCs) with stem-like characteristics lead to distant metastases and thus contribute to the dismal prognosis of PDAC. Our purpose is to investigate the role of stemness in CTCs derived from a genetically engineered mouse model of PDAC and to further explore the potential molecular mechanisms. The publically available RNA sequencing dataset GSE51372 was analyzed, and CTCs with (CTC-S) or without (CTC-N) stem-like features were discriminated based on a principal component analysis (PCA). Differentially expressed genes, weighted gene co-expression network analysis (WGCNA), and further functional enrichment analyses were performed. The prognostic role of the candidate gene (CTNNB1) was assessed in a clinical PDAC patient cohort. Overexpression of the pluripotency marker Klf4 (Krüppel-like factor 4) in CTC-S cells positively correlates with Ctnnb1 (β-Catenin) expression, and their interaction presumably happens via protein-protein binding in the nucleus. As a result, the adherens junction pathway is significantly enriched in CTC-S. Furthermore, the overexpression of Ctnnb1 is a negative prognostic factor for progression-free survival (PFS) and relapse-free survival (RFS) in human PDAC cohort. Overexpression of Ctnnb1 may thus promote the metastatic capabilities of CTCs with stem-like properties via adherens junctions in murine PDAC.

Clinical significance of epithelial-mesenchymal transition typing of circulating tumour cells in colorectal cancer

AIM

The aim was to determine the diagnostic value of epithelial-mesenchymal transition typing of circulating tumour cells (CTCs) in colorectal cancer (CRC).

METHOD

Peripheral blood samples were collected from 51 CRC patients before anti-tumour treatment from April 2016 to June 2018 at the Peking University Shenzhen Hospital. The blood samples were analysed using the CanPatrol CTC typing technique (SurExam, Guangzhou, China), which combines nanomembrane enrichment with mRNA in situ hybridization. Based on the marker expression, the CTCs were classified into epithelial, epithelial mesenchymal and mesenchymal (M-CTC) types. The correlation between the CTC counts and clinicopathological characteristics such as gender, age, TNM stage, lymph node metastasis and distant metastasis were analysed by univariate and multivariate Cox regression models. The overall survival and progression-free survival (PFS) of patients demarcated by CTC typing were analysed using the Kaplan-Meier method and log-rank tests.

RESULT

M-CTCs were detected more frequently in patients with lymph node metastasis (N2 81.8%; N1 72.7%; N0 38.9%) as well as distant metastasis (M0 50%; M1a 81.25%; M1b 85.7%) compared to those without metastasis. In addition, the presence of M-CTCs was significantly correlated with distant metastasis (P < 0.01). Univariate analysis showed that lymph node metastasis (P = 0.035), distant metastasis (P < 0.001) and total CTC count ≥ 4 (P = 0.007) and M-CTC count ≥ 1 (P < 0.001) were significantly associated with unfavourable PFS, and lymph node metastasis (P = 0.04), distant metastasis (P = 0.01) and M-CTC count ≥ 1 (P < 0.001) were significantly associated with unfavourable overall survival. Multivariate analysis showed that the presence of M-CTCs was the only independent prognostic factor for poor PFS, and patients with M-CTCs had significantly shorter PFS than those without (P = 0.011).

CONCLUSION

M-CTCs are significantly associated with CRC severity and metastasis, and M-CTC count is an independent predictor of prognosis.

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.

Gauging the Impact of Cancer Treatment Modalities on Circulating Tumor Cells (CTCs)

The metastatic cascade consists of multiple complex steps, but the belief that it is a linear process is diminishing. In order to metastasize, cells must enter the blood vessels or body cavities (depending on the cancer type) via active or passive mechanisms. Once in the bloodstream and/or lymphatics, these cancer cells are now termed circulating tumor cells (CTCs). CTC numbers as well as CTC clusters have been used as a prognostic marker with higher numbers of CTCs and/or CTC clusters correlating with an unfavorable prognosis. However, we have very limited knowledge about CTC biology, including which of these cells are ultimately responsible for overt metastatic growth, but due to the fact that higher numbers of CTCs correlate with a worse prognosis; it would seem appropriate to either limit CTCs and/or their dissemination. Here, we will discuss the different cancer treatments which may inadvertently promote the mobilization of CTCs and potential CTC therapies to decrease metastasis.

Perspectives of the Application of Liquid Biopsy in Colorectal Cancer

Colorectal cancer (CRC) is one of the most common gastrointestinal tumors and the second leading cause of cancer death worldwide. Since traditional biopsies are invasive and do not reflect tumor heterogeneity or monitor the dynamic progression of tumors, there is an urgent need for new noninvasive methods that can supplement and improve the current management strategies of CRC. Blood-based liquid biopsies are a promising noninvasive biomarker that can detect disease early, assist in staging, monitor treatment responses, and predict relapse and metastasis. Over time, an increasing number of experiments have indicated the clinical utility of liquid biopsies in CRC. In this review, we mainly focus on the development of circulating tumor cells and circulating tumor DNA as key components of liquid biopsies in CRC and introduce the potential of exosomal microRNAs as emerging liquid biopsy markers in clinical application for CRC.

Circulating guanylyl cyclase C (GCC) mRNA is a reliable metastatic predictor and prognostic index of colorectal cancer

Background

Currently, few specific biomarkers or standard cutoff values are available for circulating tumor cells (CTCs) detection and survival prediction in patients with early stage colorectal cancer (CRC). Guanylyl cyclase C (GCC) presents as a specific expression in intestinal tumor cells and during their metastases, indicating its potential application as a metastatic predictor of CRC.

Methods

The circulating GCC mRNA of 160 colorectal cancer patients at stage I–III was detected via quantitative real-time (qRT)-PCR in our study, and the correlation of GCC mRNA level with tumor metastasis and long-term survival was explored.

Results

GCC mRNA was found to be positive in 43 out of 160 CRC patients and negative in ten healthy controls. It was found that GCC mRNA over the baseline (>100 copies/µL and 200 copies/µL) showed a significant correlation with disease-free survival (DFS) and overall survival (OS) in the stage II subgroup. It was further revealed that GCC mRNA over 300 copies/µL or higher than the median value of copy numbers was significantly correlated with reduced OS and DFS in CRC patients. A nomogram model based on variables including GCC mRNA copy number was established for predicting the OS of CRC patients (AUC =0.98).

Conclusions

Circulating GCC mRNA over baseline is a reliable predictor for tumor metastasis and can be a prognostic index in CRC patients.

Exosomal Non Coding RNA in LIQUID Biopsies as a Promising Biomarker for Colorectal Cancer

Colorectal cancer (CRC) is one of the most common cancers worldwide, with a high mortality rate, especially in those that are diagnosed in late stages of the disease. The current screening blood-based markers, such as carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9), have low sensitivity and specificity. Meanwhile, other modalities are either expensive or invasive. Therefore, recent research has shifted towards a minimally invasive test, namely, liquid biopsy. Exosomes are favorable molecules sought in blood samples, since they are abundant, stable in circulation, and harbor genetic information and other biomolecules that could serve as biomarkers or even therapeutic targets. Furthermore, exosomal noncoding RNAs, such as miRNAs, lncRNAs, and circRNAs, have demonstrated the diagnostic potential to detect CRC at an early stage with a higher sensitivity and specificity than CEA and CA19-9 alone. Moreover, they have prognostic potential that is TNM stage specific and could serve as predictive biomarkers for the most common chemotherapeutic drug and combination regimen in CRC, which are 5-FU and FOLFOX, respectively. Therefore, in this review, we focus on the role of these exosomal noncoding RNAs as diagnostic, prognostic, and predictive biomarkers. In addition, we discuss the advantages and challenges of exosomes as a liquid biopsy target.

Association Between Microsatellite Instability Status and Peri-Operative Release of Circulating Tumour Cells in Colorectal Cancer

Microsatellite instability (MSI) in colorectal cancer (CRC) is a marker of immunogenicity and is associated with an increased abundance of tumour infiltrating lymphocytes (TILs). In this subgroup of colorectal cancer, it is unknown if these characteristics translate into a measurable difference in circulating tumour cell (CTC) release into peripheral circulation. This is the first study to compare MSI status with the prevalence of circulating CTCs in the peri-operative colorectal surgery setting. For this purpose, 20 patients who underwent CRC surgery with curative intent were enrolled in the study, and peripheral venous blood was collected at pre- (t1), intra- (t2), immediately post-operative (t3), and 14–16 h post-operative (t4) time points. Of these, one patient was excluded due to insufficient blood sample. CTCs were isolated from 19 patients using the Isoflux^TM system, and the data were analysed using the STATA statistical package. CTC number was presented as the mean values, and comparisons were made using the Student t-test. There was a trend toward increased CTC presence in the MSI-high (H) CRC group, but this was not statistically significant. In addition, a Poisson regression was performed adjusting for stage (I-IV). This demonstrated no significant difference between the two MSI groups for pre-operative time point t1. However, time points t2, t3, and t4 were associated with increased CTC presence for MSI-H CRCs. In conclusion, there was a trend toward increased CTC release pre-, intra-, and post-operatively in MSI-H CRCs, but this was only statistically significant intra-operatively. When adjusting for stage, MSI-H was associated with an increase in CTC numbers intra-operatively and post-operatively, but not pre-operatively.

Retrograde en bloc resection for non-muscle invasive bladder tumor can reduce the risk of seeding cancer cells into the peripheral circulation

Objective

To ascertain whether en bloc resection could reduce the risk of seeding cancer cells into the circulation during the resection of non-muscle invasive bladder cancer (NMIBC).

Methods

Patients with primary NMIBC were enrolled in this prospective study from October 2017 to May 2018. Patients were allocated to receive conventional transurethral resection of the bladder (TURB) or retrograde en bloc resection technique of the bladder tumor (RERBT). Blood samples (1 ml) for circulating tumor cell (CTC) enumeration were drawn from the peripheral vein prior to resection (PV1), immediately after resection of the tumor base (PV2), and at 12 h after resection (PV3). Intra-group comparisons of the changes in the number of CTCs identified among the PV1, PV2, and PV3 blood samples were performed in each group.

Results

A total of 21 patients (12 in the RERBT group and 9 in the TURB group) were recruited. For patients receiving TURB, the level of CTCs identified in PV3 was significantly higher than that in PV1 (p = 0.047). However, there was no significant difference in CTC counts before and after resection in the RERBT group.

Conclusion

RERBT did not increase the number of tumor cells in the bloodstream.

EUS-Guided Portal Venous Sampling of Circulating Tumor Cells

PURPOSE OF REVIEW

Although liquid biopsies hold significant promise in the management of patients with cancer, peripheral blood analyses remain dependent on the degree of tumor burden with prohibitively low yields until the cancer is widely metastatic. Multiple lines of evidence support a dynamic, spatiotemporal localization of circulating tumor cells (CTCs) supporting specific targeting of vascular compartments, such as the portal vein. This review discusses the literature evaluating the possibility of portal venous blood as a new, potentially higher yield liquid biopsy and the current devices and techniques for endoscopic ultrasound (EUS)-guided portal venous sampling for CTC detection.

RECENT FINDINGS

Two recent studies in pancreatic cancer have demonstrated that portal venous blood can be safely sampled via EUS and consistently yields significantly higher CTC counts compared with matched peripheral blood. EUS-acquired samples can be used for molecular testing, clinical prognostication, and drug sensitivity analyses. Portal venous CTCs are identified in higher quantity relative to peripheral blood and can be safely obtained via EUS. Further studies are required to demonstrate the clinical utility of EUS-guided portal venous tumor material enrichment and analysis; however, obtaining EUS-guided "liquid biopsies" appears to merit significant consideration for procedural adoption.

Association Between Liquid Biopsy and Prognosis of Gastric Cancer Patients: A Systematic Review and Meta-Analysis

Background: Reports regarding liquid biopsy and gastric cancer (GC) have emerged rapidly in recent decades, yet their prognostic value still remains controversial. This study was aimed to assess the impact of liquid biopsy, including circulating tumor cells (CTCs) and cell-free nucleic acids, on GC patients' prognosis.

Methods: PubMed, Medline, EMBASE, and ClinicalTrial.gov databases were searched for studies that report GC patient survival data stratified by CTC/circulating tumor DNA (ctDNA)/circulating miRNAs' status. The hazard ratios (HRs) and their 95% confidence intervals (CIs) for patients' overall survival (OS) and disease-free survival (DFS)/progression-free survival (PFS) were recorded or calculated depending on circulating target status.

Results: We initially identified 4,221 studies, from which 43 were eligible for further analysis, comprising 3,814 GC patients. Pooled analyses showed that detection of certain CTCs, ctDNA, and circulating miRNA was associated with poorer OS (CTCs: HR = 1.84, 95%CI 1.50–2.26, p < 0.001; ctDNA: HR = 1.78, 95%CI 1.36–2.34, p < 0.001; circulating miRNA: HR = 1.74, 95%CI 1.13–2.69, p < 0.001) and DFS/PFS (CTCs: HR = 3.39, 95%CI 2.21–5.20, p < 0.001; ctDNA: HR = 2.38, 95%CI 1.31–4.32, p = 0.004; circulating miRNA: HR = 3.30, 95%CI 2.39–4.55, p < 0.001) of GC patients, regardless of disease stage and time point at which sample is taken (at baseline or post-treatment).

Conclusions: The presence of CTCs and/or cellular components identifies a group of GC with poorer prognosis. Among circulating markers, CTCs demonstrated a stronger and more stable predictive value for late-stage disease and among Mongolian populations with GC. Less data are available for ctDNA and miRNA; however, their presence may also reflect aggressive biology and warrants further prospective study.

Circulating tumor cells are associated with poor outcomes in early-stage hepatocellular carcinoma: a prospective study

BACKGROUND

Previous studies evaluating association between circulating tumor cells (CTCs) and clinical outcomes in hepatocellular carcinoma (HCC) have shown inconsistent results due to suboptimal detection methods and patient heterogeneity.

METHODS

Patients undergoing surgery for early-stage HCC were prospectively enrolled. The CTC numbers were determined using a tapered slit platform, which detects CTCs based on the cell size and morphology. Survival and recurrence were evaluated, and Cox proportional hazards models were used to demonstrate the prognostic significance of CTC.

RESULTS

Of 105 patients, 25 had increased CTC numbers after surgery (ΔCTC > 0, defined as positive) and a significantly higher level of recurrence (p = 0.042). A positive ΔCTC was seen to be an independent predictor of recurrence (hazard ratio 2.28), along with hepatitis B virus infection, alanine aminotransferase level, and the presence of satellite nodules (all p < 0.05). Subgroup analyses showed that a positive ΔCTC was associated with lower survival and higher recurrence among patients with low alpha-fetoprotein levels and cirrhosis (all p < 0.05).

CONCLUSION

Calculation of ΔCTC based on the physical properties of the cells is predictive of recurrence in patients with early HCC undergoing surgery.

A prospective feasibility study evaluating the role of multimodality imaging and liquid biopsy for response assessment in locally advanced rectal carcinoma

PURPOSE

Colorectal cancer is a commonly encountered disease that poses several diagnostic and therapeutic challenges. The inherent heterogeneity of tumor biology and propensity to relapse despite "curative" resection pose significant challenges with regard to response assessment. Although MR imaging already plays a key role in primary staging of patients with rectal carcinoma, its reliability in restaging after neoadjuvant therapy is debatable (Van der broek et al. in Dis Colon Rectum 60(3):274-283, 2017). Therefore, there is significant interest in developing additional methods which may improve diagnostic accuracy. This study aims to evaluate the role of multimodality imaging and liquid biopsy in therapeutic response assessment.

METHODS

Seventeen patients were enrolled into the study over a span of 24 months. All underwent hybrid PET-MRI and CT-perfusion (CT-P), prior to and following neoadjuvant therapy for locally advanced rectal carcinoma. Twelve of the 17 patients also underwent liquid biopsy, which consisted of blood sampling and analysis of circulating tumor cells (CTCs) and extracellular vesicles (EVs), including cell fragments and microparticles (MPs), using the Cell Search System (Menarini Silicon Biosystems). SUV, DWI, and ADC were calculated during PET-MRI, and several parameters were evaluated during CT-perfusion, including average perfusion, blood flow (BF), blood volume (BV), mean transit time (MTT), permeability-surface area product (PS), contrast extraction efficiency (E), and K-trans (K). Changes observed pre- and post-neoadjuvant therapy in each modality were compared to tumor response at histopathology using a modified Ryan tumor regression grading system.

RESULTS

Of the 17 patients included in the study, 14 were classified as non-responders, and 3 were classified as responders as determined by the modified Ryan Tumor Regression Grade (TRG) scoring system (Van der broek et al. in Dis Colon Rectum 60(3):274-283, 2017). When combined, blood markers and CT-P parameters (mean transit time (MTT), K-trans, and permeability-surface area product (PS)) produced the strongest models (p < 0.01). PET (SUV measurement) combined with CT-P-derived K-trans produced a marginally significant (p = 0.057) model for predicting response. MRI-derived ADC value did not provide a significant model for response prediction.

CONCLUSION

A model of CT-P parameters plus liquid biopsy more accurately predicts tumor response than PET-MRI, CT-P alone, or liquid biopsy alone. These results suggest that in the evaluation of treatment response, liquid biopsy could provide additional information to functional imaging modalities such as CT-P and should therefore be explored further in a trial with larger sample size.

Ropivacaine via nuclear factor kappa B signalling modulates CD62E expression and diminishes tumour cell arrest

BACKGROUND

The issue whether anaesthesia has an impact on the prognosis of carcinoma has been widely discussed and remains debated. Ropivacaine has been widely used in perioperative period as a long acting local anesthetic. An early event during recurrence or metastasis of carcinoma is the adhesion of circulating tumour cells (CTCs) to endothelial cells (ECs) through binding adhesion molecules that are up-regulated on inflamed endothelium during the perioperative period or other periods. This study was to explore the impact of ropivacaine on the adhesion of tumour cells, providing evidences of its influence on the prognosis of carcinoma.

MATERIALS AND METHODS

Human umbilical vein endothelial cells (HUVECs) were pre-treated with ropivacaine (10^-7-10^-5 M; 30 min) prior to treatment with tumour necrosis factor alpha (TNFα) (10 ng ml^-1; 1, 4 and 8 h). Intercellular adhesion molecule-1 (ICAM-1), endothelial-selectin (CD62E) and vascular cell adhesion molecule-1 (VCAM-1) mRNA levels were detected via quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR). To clarify the underlying action mechanism, p65, p-p65, IκBα, p-IκBα, IKKα/β and p-IKKα/β protein levels were evaluated via western blotting. Cell viability and tumour cell adhesion assays were also assessed.

RESULTS

The clinically usage concentration of ropivacaine (10^-6 M) produced a significant decrease in CD62E expression compared with that produced by TNFα only (p < 0.001). Moreover, adhesion assays showed that ropivacaine effectively inhibited the adhesion of hepatoma cells (p < 0.01), human colon cancer cells (p < 0.01) and human leukemic monocyte (p < 0.01). Western blot results showed that pre-treatment with ropivacaine inhibited the phosphorylation of p65 (p < 0.05), IκBα (p < 0.001) and IKKα/β (p < 0.01).

CONCLUSIONS

Ropivacaine decreased the adhesion of tumour cells. Ropivacaine modulated CD62E expression by inhibiting the activation of NF-κB. These results might provide new insight into the issue whether anaesthesia has an impact on the prognosis of carcinoma.

Circulating Tumor Cells and Cell-Free DNA in Pancreatic Ductal Adenocarcinoma

Pancreatic cancer is detected late in the disease process and has an extremely poor prognosis. A blood-based biomarker that can enable early detection of disease, monitor response to treatment, and potentially allow for personalized treatment would be of great benefit. This review analyzes the literature regarding two potential biomarkers, circulating tumor cells (CTCs) and cell-free DNA (cfDNA), with regard to pancreatic ductal adenocarcinoma. The origin of CTCs and the methods of detection are discussed and a decade of research examining CTCs in pancreatic cancer is summarized, including both levels of CTCs and analyzing their molecular characteristics and how they may affect survival in both advanced and early disease and allow for treatment monitoring. The origin of cfDNA is discussed, and the literature over the past 15 years is summarized. This includes analyzing cfDNA for genetic mutations and methylation abnormalities, which have the potential to be used for the detection and prognosis of pancreatic ductal adenocarcinoma. However, the research certainly remains in the experimental stage, warranting future large trials in these areas.