Relationship among circulating tumor cells, CEA and overall survival in patients with metastatic colorectal cancer

Presence of CD44v9-Expressing Cancer Stem Cells in Circulating Tumor Cells and Effects of Carcinoembryonic Antigen Levels on the Prognosis of Colorectal Cancer

Circulating tumor cells (CTCs) are cancer cells released from the primary tumor into the bloodstream, and contain cancer stem cells that influence tumor survival, recurrence, and metastasis. Here, we investigated CD44v9 expression in CTCs and impact of preoperative carcinoembryonic antigen (CEA) levels on colorectal cancer (CRC) prognosis. We analyzed the expression of CD44v9 mRNA in CTCs using reverse transcription-polymerase chain reaction and preoperative CEA levels in blood samples obtained from 300 patients with CRC. Subsequently, we evaluated the association of CD44v9 expression and CEA levels with clinicopathological factors. CD44v9 mRNA was expressed in 31.3% of the patients, and was significantly associated with liver metastasis. Patients with positive CD44v9 expression had a lower 5-year survival rate (62.3%) than those with negative CD44v9 expression (82.8%, p < 0.001). Cox regression analysis identified CD44v9 expression and high CEA levels (≥5 ng/mL) as poor prognostic factors, while negative CD44v9 expression and low CEA levels (<5 ng/mL) were associated with favorable prognosis (hazard ratio = 0.285, p = 0.006). These results suggest that a combination of CD44v9 mRNA expression in CTCs and serum CEA levels could serve as a valuable prognostic marker for CRC, potentially enhancing the accuracy of prognosis predictions.

Prognostic value of circulating tumor cells combined with neutrophil-lymphocyte ratio in patients with hepatocellular carcinoma

BACKGROUND

Circulating tumor cell (CTC) count and neutrophil-to-lymphocyte ratio (NLR) are both closely associated with the prognosis of hepatocellular carcinoma (HCC).

AIM

To investigate the prognostic value of combining these two indicators in HCC.

METHODS

Clinical data were collected from patients with advanced HCC who received immune therapy combined with targeted therapy at the Department of Oncology, the Affiliated Hospital of Southwest Medical University, Sichuan, China, from 2021 to 2023. The optimal cutoff values for CTC programmed death-ligand 1 (PD-L1) (+) > 1 or CTC PD-L1 (+) ≤ 1 and NLR > 3.89 or NLR ≤ 3.89 were evaluated using X-Tile software. Patients were categorized into three groups based on CTC PD-L1 (+) counts and NLR: CTC-NLR (0), CTC-NLR (1), and CTC-NLR (2). The relationship between CTC-NLR and clinical variables as well as survival rates was assessed.

RESULTS

Patients with high CTC PD-L1 (+) expression or NLR at baseline had shorter median progression-free survival (mPFS) and median overall survival (mOS) than those with low levels of CTC PD-L1 (+) or NLR (P < 0.001). Meanwhile, patients in the CTC-NLR (2) group showed a significant decrease in mPFS and mOS. Cox regression analysis revealed that alpha-fetoprotein (AFP), CTC PD-L1 (+), and CTC-NLR were independent predictors of OS. The time-dependent receiver operating characteristic curve showed that the area under the curve of CTC-NLR at 12 months (0.821) and 18 months (0.821) was superior to that of AFP and CTC PD-L1 (+).

CONCLUSION

HCC patients with high CTC PD-L1 (+) or NLR expression tend to exhibit poor prognosis, and a high baseline CTC-NLR score may indicate low survival. CTC-NLR may serve as an effective prognostic indicator for patients with advanced HCC receiving immunotherapy combined with targeted therapy.

Dynamic monitoring of serum CEA and CA19-9 predicts the prognosis of postoperative stage II colon cancer

BACKGROUND

We sought to investigate the prognostic significance of carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) dynamics for stage II colon cancer patients undergoing radical resection.

METHODS

This study retrospectively analyzed 1517 stage II colon cancer patients admitted to the Harbin Medical University Cancer Hospital from January 2011 to December 2016. To observe the relationship between tumor markers dynamic monitoring and survival, we calculated cut-off values for ΔCEA and ΔCA19-9. Group according to the cut-off values and compare the differences in survival between subgroups.

RESULTS

Preoperative CA199 (HR = 3.122), postoperative CEA (HR = 2.941) and histological type (HR = 2.855) were independent prognostic factors in multivariate Cox proportional hazards models. The 5-year overall survival (OS) in the patients with normal preoperative CEA and CA19-9 was significantly better than the patients with elevated preoperative CEA or CA19-9 and the patients with elevated preoperative CEA and CA19-9 (92.6 % vs. 87.6 % vs. 81.0 %, P < 0.05). 469 patients with normal pre- and post-operative CEA had the highest 5-year OS (93.5 %, P < 0.05). Among the 177 patients with elevated pre- and post-operative CEA, the 5-year OS rate was only 81.8 % (P < 0.05). The cut-off values for Δ CEA and Δ CA19-9 in stage II colon cancer patients with elevated preoperative tumor markers were 2.625 ng/ml and 7.835 U/ml, respectively. The Kaplan-Meier curves showed that Δ CEA≥2.625 ng/ml and Δ CA19-9≥7.835 U/mL were associated with better outcome (87.8 % vs. 79.6 %, P < 0.05; 85.8 % vs. 79.1 %, P > 0.05). At the same time, we found that adjuvant chemotherapy significantly improved 5-year OS in patients with elevated preoperative CEA or CA19-9 (91.0 % vs. 80.9 % and 89.6 % vs. 80.2 %, P < 0.05).

CONCLUSIONS

Persistent postoperative elevation of CEA/CA19-9 is associated with a poor prognosis. CEA and CA19-9 may be high-risk factors for postoperative adjuvant therapy in stage II colon cancer patients. For stage II colon cancer patients with elevated preoperative CEA, patients with Δ CEA<2.625 ng/ml have poor survival and can improve prognosis by receiving adjuvant therapy.

Mitochondrially targeted tamoxifen as anticancer therapy: case series of patients with renal cell carcinoma treated in a phase I/Ib clinical trial

Mitochondrially targeted anticancer drugs (mitocans) that disrupt the energy-producing systems of cancer are emerging as new potential therapeutics. Mitochondrially targeted tamoxifen (MitoTam), an inhibitor of mitochondrial respiration respiratory complex I, is a first-in-class mitocan that was tested in the phase I/Ib MitoTam-01 trial of patients with metastatic cancer. MitoTam exhibited a manageable safety profile and efficacy; among 37% (14/38) of responders, the efficacy was greatest in patients with metastatic renal cell carcinoma (RCC) with a clinical benefit rate of 83% (5/6) of patients. This can be explained by the preferential accumulation of MitoTam in the kidney tissue in preclinical studies. Here we report the mechanism of action and safety profile of MitoTam in a case series of RCC patients. All six patients were males with a median age of 69 years, who had previously received at least three lines of palliative systemic therapy and suffered progressive disease before starting MitoTam. We recorded stable disease in four, partial response in one, and progressive disease (PD) in one patient. The histological subtype matched clear cell RCC (ccRCC) in the five responders and claro-cellular carcinoma with sarcomatoid features in the non-responder. The number of circulating tumor cells (CTCs) was evaluated longitudinally to monitor disease dynamics. Beside the decreased number of CTCs after MitoTam administration, we observed a significant decrease of the mitochondrial network mass in enriched CTCs. Two patients had long-term clinical responses to MitoTam, of 50 and 36 weeks. Both patients discontinued treatment due to adverse events, not PD. Two patients who completed the trial in November 2019 and May 2020 are still alive without subsequent anticancer therapy. The toxicity of MitoTam increased with the dosage but was manageable. The efficacy of MitoTam in pretreated ccRCC patients is linked to the novel mechanism of action of this first-in-class mitochondrially targeted drug.

Circulating tumour cells for early detection of clinically relevant cancer

Given that cancer mortality is usually a result of late diagnosis, efforts in the field of early detection are paramount to reducing cancer-related deaths and improving patient outcomes. Increasing evidence indicates that metastasis is an early event in patients with aggressive cancers, often occurring even before primary lesions are clinically detectable. Metastases are usually formed from cancer cells that spread to distant non-malignant tissues via the blood circulation, termed circulating tumour cells (CTCs). CTCs have been detected in patients with early stage cancers and, owing to their association with metastasis, might indicate the presence of aggressive disease, thus providing a possible means to expedite diagnosis and treatment initiation for such patients while avoiding overdiagnosis and overtreatment of those with slow-growing, indolent tumours. The utility of CTCs as an early diagnostic tool has been investigated, although further improvements in the efficiency of CTC detection are required. In this Perspective, we discuss the clinical significance of early haematogenous dissemination of cancer cells, the potential of CTCs to facilitate early detection of clinically relevant cancers, and the technological advances that might improve CTC capture and, thus, diagnostic performance in this setting.

A Multiple-Array SPRi Biosensor as a Tool for Detection of Gynecological-Oncological Diseases

Diagnostics based on the determination of biomarkers in body fluids will be more successful when several biomarkers are determined. A multiple-array SPRi biosensor for the simultaneous determination of CA125, HE4, CEA, IL-6 and aromatase has been developed. Five individual biosensors were placed on the same chip. Each of them consisted of a suitable antibody covalently immobilized onto a gold chip surface via a cysteamine linker by means of the NHS/EDC protocol. The biosensor for IL-6 works in the pg mL^-1 range, that for CA125 in the µg mL^-1 range, and the other three within the ng mL^-1 range; these are ranges suitable for the determination of biomarkers in real samples. The results obtained with the multiple-array biosensor are very similar to those obtained with a single biosensor. The applicability of the multiple biosensor was demonstrated using several examples of plasma from patients suffering from ovarian cancer and endometrial cyst. The average precision was 3.4% for the determination of CA125, 3.5% for HE4, 5.0% for CEA and IL-6, and 7.6% for aromatase. The simultaneous determination of several biomarkers may be an excellent tool for the screening of the population for earlier detection of diseases.

Biology, vulnerabilities and clinical applications of circulating tumour cells

In recent years, exceptional technological advances have enabled the identification and interrogation of rare circulating tumour cells (CTCs) from blood samples of patients, leading to new fields of research and fostering the promise for paradigm-changing, liquid biopsy-based clinical applications. Analysis of CTCs has revealed distinct biological phenotypes, including the presence of CTC clusters and the interaction between CTCs and immune or stromal cells, impacting metastasis formation and providing new insights into cancer vulnerabilities. Here we review the progress made in understanding biological features of CTCs and provide insight into exploiting these developments to design future clinical tools for improving the diagnosis and treatment of cancer.

Synergistic diagnostic value of circulating tumor cells and tumor markers CEA/CA19-9 in colorectal cancer

BACKGROUND

Circulation tumor cells (CTCs) play a crucial role in cancer spread and have a strong correlation with cancer progression. Previous works of research have shown that the number of CTCs can be used to predict the recurrence of colorectal cancer (CRC).

METHODS

In this study, we used the Cyttel method to isolate and detect CTCs, and analyzed their correlation with carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) levels.

RESULTS

We found that the amount and positive (CTC number ≥2 in 3.2 mL peripheral blood) rate of CTCs were higher in peripheral blood (PB) of patients in stage III/IV than that of patients in stage I/II, suggesting the number of CTCs in CRC patients may have a higher correlation with metastasis. Furthermore, the number of CTCs was correlated to CEA and CA19-9 levels in individuals with all stages of CRC, and all of them predicted a worse prognosis and higher recurrence rate. Notably, triple positive (CTCs ≥ 2, CEA ≥ 5 ng/mL, CA19-9 ≥ 37 U/mL in PB) leads to the worst outcome indicated by overall survival and recurrence rate.

CONCLUSION

Taken together, this study first revealed that a triple combination of CTCs, which were detected by the Cyttel method but not other approaches, CEA and CA19-9 is a promising prognostic marker on the recurrence of colorectal cancer and overall survival in clinic practice.

Detection of Circulating Tumor Cells Using the Attune NxT

Circulating tumor cells (CTCs) have been detected in many patients with different solid malignancies. It has been reported that presence of CTCs correlates with worse survival in patients with multiple types of cancer. Several techniques have been developed to detect CTCs in liquid biopsies. Currently, the only method for CTC detection that is approved by the Food and Drug Administration is CellSearch. Due to low abundance of CTCs in certain cancer types and in early stages of disease, its clinical application is currently limited to metastatic colorectal cancer, breast cancer and prostate cancer. Therefore, we aimed to develop a new method for the detection of CTCs using the Attune NxT-a flow cytometry-based application that was specifically developed to detect rare events in biological samples without the need for enrichment. When healthy donor blood samples were spiked with variable amounts of different EpCAM+EGFR+ tumor cell lines, recovery yield was on average 75%. The detection range was between 1000 and 10 cells per sample. Cell morphology was confirmed with the Attune CytPix. Analysis of blood samples from metastatic colorectal cancer patients, as well as lung cancer patients, demonstrated that increased EpCAM+EGFR+ events were detected in more than half of the patient samples. However, most of these cells showed no (tumor) cell-like morphology. Notably, CellSearch analysis of blood samples from a subset of colorectal cancer patients did not detect CTCs either, suggesting that these blood samples were negative for CTCs. Therefore, we anticipate that the Attune NxT is not superior to CellSearch in detection of low amounts of CTCs, although handling and analysis of samples is easier. Moreover, morphological confirmation is essential to distinguish between CTCs and false positive events.

Early circulating tumor DNA dynamics as a pan-tumor biomarker for long-term clinical outcome in patients treated with durvalumab and tremelimumab

There is an urgent need to identify biomarkers of early response that can accurately predict the benefit of immune checkpoint inhibitors (ICI). Patients receiving durvalumab/tremelimumab had tumor samples sequenced before treatment (baseline) to identify variants for the design of a personalized circulating tumor (ctDNA) assay. ctDNA was assessed at baseline and at 4 and/or 8 weeks into treatment. Correlations between ctDNA changes to radiographic response and overall survival (OS) were made to assess potential clinical benefit. 35/40 patients (87.5%) had personalized ctDNA assays designed, and 29/35 (82.9%) had plasma available for baseline analysis, representing 16 unique solid tumor histologies. As early as 4 weeks after treatment, decline in ctDNA from baseline predicted improved OS (P = 0.0144; HR = 9.98) and ctDNA changes on treatment-supported and refined radiographic response calls. ctDNA clearance at any time through week 8 identified complete responders by a median lead time of 11.5 months ahead of radiographic imaging. ctDNA response monitoring is emerging as a dynamic, personalized biomarker method that may predict survival outcomes in patients with diverse solid tumor histologies, complementing and sometimes preceding standard-of-care imaging assessments.

Meta-analysis of the prognostic value of circulating tumor cells in gastrointestinal cancer

BACKGROUND

Detecting circulating tumor cells (CTCs) has become a new strategy for predicting the prognosis of cancer patients. However, limited systematic research evidence is available for the detection of CTCs in various gastrointestinal tumors such as esophageal cancer (EC), colorectal cancer (CRC) and gastric cancer (GC). This topic was addressed to assess the prognostic significance of CTCs in gastrointestinal tumors.

METHODS

We conducted a literature search according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist (from November 20, 2021). We performed a meta-analysis using the random effects model and Review Manager 5.3 software (The Cochrane Collaboration, Copenhagen, Denmark) according to the inclusion and exclusion criteria, data extraction and evaluation methods.

RESULTS

Twenty-four articles met the inclusion criteria for this study, and they included 3803 EC, CRC and GC patients, including 1189 CTC-positive and 2462 CTC-negative cases. The meta-analysis showed that the presence of CTCs was associated with worse OS (HR = 2.05, 95% CI = 1.75-2.40, P = .060) and PFS (HR = 2.27, 95% CI = 1.79-2.89, P < .001). Further meta-regression and subgroup analyses showed that CTC-positive patients also showed worse OS and PFS in different subgroups.

CONCLUSION

Our meta-analysis suggests that detecting CTCs in peripheral blood may be an important tool for improving the prognosis of patients with gastrointestinal tumors. Moreover, CTCs detection results could be used to develop personalized treatment plans in the future.

Defining A Liquid Biopsy Profile of Circulating Tumor Cells and Oncosomes in Metastatic Colorectal Cancer for Clinical Utility

Simple Summary

Metastatic colorectal cancer (mCRC) is typified by its tumor heterogeneity and changing disease states, suggesting that personalized medicine approaches could be vital to improving clinical practice. As a minimally invasive approach, the liquid biopsy has the potential to be a powerful longitudinal prognostic tool. We investigated mCRC patients’ peripheral blood samples using an enrichment-free single-cell approach to capture the broader rare-event population beyond the conventionally detected epithelial-derived circulating tumor cell (CTC). Our analysis reveals a heterogenous profile of CTCs and oncosomes not commonly found in normal donor samples. We identified select rare cell types based on their distinct immunofluorescence expression and morphology across multiple assays. Lastly, we highlight correlations between enumerations of the blood-based analytes and progression-free survival. This study clinically validates an unbiased rare-event approach in the liquid biopsy, motivating future studies to further investigate these analytes for their prognostic potential.

Abstract

Metastatic colorectal cancer (mCRC) is characterized by its extensive disease heterogeneity, suggesting that individualized analysis could be vital to improving patient outcomes. As a minimally invasive approach, the liquid biopsy has the potential to longitudinally monitor heterogeneous analytes. Current platforms primarily utilize enrichment-based approaches for epithelial-derived circulating tumor cells (CTC), but this subtype is infrequent in the peripheral blood (PB) of mCRC patients, leading to the liquid biopsy’s relative disuse in this cancer type. In this study, we evaluated 18 PB samples from 10 mCRC patients using the unbiased high-definition single-cell assay (HDSCA). We first employed a rare-event (Landscape) immunofluorescence (IF) protocol, which captured a heterogenous CTC and oncosome population, the likes of which was not observed across 50 normal donor (ND) samples. Subsequent analysis was conducted using a colorectal-targeted IF protocol to assess the frequency of CDX2-expressing CTCs and oncosomes. A multi-assay clustering analysis isolated morphologically distinct subtypes across the two IF stains, demonstrating the value of applying an unbiased single-cell approach to multiple assays in tandem. Rare-event enumerations at a single timepoint and the variation of these events over time correlated with progression-free survival. This study supports the clinical utility of an unbiased approach to interrogating the liquid biopsy in mCRC, representing the heterogeneity within the CTC classification and warranting the further molecular characterization of the rare-event analytes with clinical promise.

PPy@Fe3O4 nanoparticles inhibit the proliferation and metastasis of CRC via suppressing the NF-κB signaling pathway and promoting ferroptosis

Colorectal cancer (CRC) is one of the most common cancers of the digestive tract, and patients with advanced-stage cancer have poor survival despite the use of multidrug conventional chemotherapy regimens. Intra-tumor heterogeneity of cancerous cells is the main obstacle in the way to effective cancer treatments. Therefore, we are looking for novel approaches to eliminate just cancer cells including nanoparticles (NPs). PPy@Fe3O4 NPs were successfully synthesized through a portable method. The characterization of transmission electron microscopy (TEM), Fourier-Transformed infrared spectrometer, and X-ray powder diffraction have further proved successful preparation of PPy@Fe3O4 NPs. NIR irradiation was used to test the photothermal properties of NPs and an infrared camera was used to record their temperature. The direct effects of PPy@Fe3O4 NPs on colorectal cancer cell DLD1 were assessed using CCK8, plate clone, transwell, flow cytometry, and western blotting in CRC cell. The effect of PPy@Fe3O4 NPs on neoplasm growth in nude mice was evaluated in vivo. This study demonstrated that PPy@ Fe3O4 NPs significantly inhibit the growth, migration, and invasion and promote ferroptosis to the untreated controls in colorectal cancer cells. Mechanical exploration revealed that PPy@Fe3O4 NPs inhibit the multiplication, migration, and invasion of CRC cells in vitro by modulating the NF-κB signaling pathway. Importantly, Ferroptosis inhibitors Fer-1 can reverse the changes in metastasis-associated proteins caused by NPs treatment. Collectively, our observations revealed that PPy@Fe3O4 NPs were blockers of tumor progression and metastasis in CRC. This study brought new insights into bioactive NPs, with application potential in curing CRC or other human disorders.

AST·MLR index and operation injury condition are novel prognostic predictor for the prediction of survival in patients with colorectal cancer liver metastases undergoing surgical resection

Background

The prognostic values of preoperative aspartate aminotransferase (AST), monocyte-to-lymphocyte ratio (MLR), AST·MLR index (AMLRI) and operation injury condition in patients with colorectal cancer liver metastases (CRLM) remains unclear. This retrospective study assessed the relationship between these markers, progression-free survival (PFS), and overall survival (OS) in CRLM patients undergoing resection.

Methods

AMLRI was defined as AST × MLR. Operation injury condition was defined according to operation time and blood loss. Cox regression analyses were used to identify risk factors and to develop nomograms. C-indexes, time-dependent receiver operating characteristic (time-ROC) curves and calibration curves were used to assess the models.

Results

A total of 379 patients were enrolled. The optimal cut-off value of the AMLRI was 3.33. In the multivariable analysis, AMLRI > 3.33 (hazard ratio [HR] = 2.162, p = 0.002) and serious operation injury condition (HR = 1.539, p = 0.012) were predictive for unfavourable OS, and AMLRI > 3.33 (HR = 1.462, p = 0.021) was predictive for unfavourable PFS. The nomograms were superior to Fong’s Clinical Risk Score (CRS) according to the C-indexes (PFS: 0.682 vs. 0.600; OS: 0.730 vs. 0.586) and time-ROCs.

Conclusions

Preoperative AMLRI and operation injury condition are easily accessible predictors for prognosis. The nomograms performed better than CRS for the prediction of recurrence and survival.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-10009-4.

Gold nanoparticles-oxidized multi-walled carbon nanotubes as electrochemiluminescence immunosensors

Oxidized multi-walled carbon nanotube/nano-gold (AuNP-ox-MWCNT) composites with strong electrochemiluminescence (ECL) activity were applied to construct a new ECL immunosensor for the detection of carcinoembryonic antigen (CEA). The immunosensor showed a linear response range of 10-100 ng mL^-1 and detection limit of 0.76 ng mL^-1 (at a signal-to-noise ratio of 3). The as-developed immunosensor exhibited several advantages, including being simple to fabricate and being label free. The results indicated that ox-MWCNTs as a luminescent material have great application potential in analysis.

Potential Values of Circulating microRNA-21 to Predict Early Recurrence in Patients with Colorectal Cancer after Treatments

Insufficient prognosis of local recurrence contributes to the poor progression-free survival rate and death in colorectal cancer (CRC) patients. Various biomarkers have been explored in predicting CRC recurrence. This study investigated the expressions of plasma/exosomal microRNA-21 (miR-21) in 113 CRC patients by qPCR, their values of predicting CRC recurrence, and the possibility to improve the prognostic efficacy in early CRC recurrence in stratified patients by combined biomarkers including circulating miR-21s, circulating tumour cells/microemboli (CTCs/CTM), and serum carcinoembryonic antigen (CEA)/carbohydrate antigen 19-9 (CA19-9). Expressions of plasma and exosomal miR-21s were significantly correlated (p < 0.0001) in all and late-stage patients, presenting similar correlations with other biomarkers. However, stage IV patients stratified by a high level of exosomal miR-21 and stage I to III patients stratified by a high level of plasma miR-21 displayed significantly worse survival outcomes in predicting CRC recurrence, suggesting their different values to predict CRC recurrence in stratified patients. Comparable and even better performances in predicting CRC recurrence in late-stage patients were found by CTCs/CTM from our blood samples as sensitive biomarkers. Improved prognosing efficacy in CRC recurrence and better outcomes to significantly differentiate recurrence in stratified patients could be obtained by analysing combined biomarkers.

Circulating Tumor Cell Kinetics and Morphology from the Liquid Biopsy Predict Disease Progression in Patients with Metastatic Colorectal Cancer Following Resection

Simple Summary

As a minimally invasive procedure, the liquid biopsy enables the longitudinal evaluation of a patient’s disease and response to treatment. Current clinical practice stratifies patient status based on a uniform threshold for circulating tumor cell (CTC) positivity, overlooking various cell subtypes and timepoints of sample collection. In a disease known for its tumor heterogeneity, we investigated colorectal cancer patients’ peripheral blood samples to determine whether the prevalence of morphologically distinct CTC subtypes and time-points of sample collection correlate with clinical disease hallmarks and survival data. Our results highlight nuances between the CTC subtypes’ clinical and survival significance. Furthermore, we found that time-point-conscious cell enumeration is critical, both for determining CTC positivity and the change in cell populations over time. To improve its clinical utility moving forward, we suggest that liquid biopsy analysis integrates morphology and time-based analysis alongside standard CTC enumeration at various stages of a patient’s treatment.

Abstract

The liquid biopsy has the potential to improve current clinical practice in oncology by providing real-time personalized information about a patient’s disease status and response to treatment. In this study, we evaluated 161 peripheral blood (PB) samples that were collected around surgical resection from 47 metastatic colorectal cancer (mCRC) patients using the High-Definition Single Cell Assay (HDSCA) workflow. In conjunction with the standard circulating tumor cell (CTC) enumeration, cellular morphology and kinetics between time-points of collection were considered in the survival analysis. CTCs, CTC-Apoptotic, and CTC clusters were found to indicate poor survival with an increase in cell count from pre-resection to post-resection. This study demonstrates that CTC subcategorization based on morphological differences leads to nuanced results between the subtypes, emphasizing the heterogeneity within the CTC classification. Furthermore, we show that factoring in the time-point of each blood collection is critical, both for its static enumeration and for the change in cell populations between draws. By integrating morphology and time-based analysis alongside standard CTC enumeration, liquid biopsy platforms can provide greater insight into the pathophysiology of mCRC by highlighting the complexity of the disease across a patient’s treatment.

Discriminating Epithelial to Mesenchymal Transition Phenotypes in Circulating Tumor Cells Isolated from Advanced Gastrointestinal Cancer Patients

Gastrointestinal (GI) cancers constitute a group of highest morbidity worldwide, with colorectal cancer (CRC) and gastric cancer being among the most frequently diagnosed. The majority of gastrointestinal cancer patients already present metastasis by the time of diagnosis, which is widely associated with cancer-related death. Accumulating evidence suggests that epithelial-to-mesenchymal transition (EMT) in cancer promotes circulating tumor cell (CTCs) formation, which ultimately drives metastasis development. These cells have emerged as a fundamental tool for cancer diagnosis and monitoring, as they reflect tumor heterogeneity and the clonal evolution of cancer in real-time. In particular, EMT phenotypes are commonly associated with therapy resistance. Thus, capturing these CTCs is expected to reveal important clinical information. However, currently available CTC isolation approaches are suboptimal and are often targeted to capture epithelial CTCs, leading to the loss of EMT or mesenchymal CTCs. Here, we describe size-based CTCs isolation using the RUBYchip™, a label-free microfluidic device, aiming to detect EMT biomarkers in CTCs from whole blood samples of GI cancer patients. We found that, for most cases, the mesenchymal phenotype was predominant, and in fact a considerable fraction of isolated CTCs did not express epithelial markers. The RUBYchip™ can overcome the limitations of label-dependent technologies and improve the identification of CTC subpopulations that may be related to different clinical outcomes.

Clinical significance of circulating tumor cells in predicating the outcomes of patients with colorectal cancer

BACKGROUND

Relapse and metastasis of patients with Colorectal Cancer (CRC) is the major obstacle to the long-term life of patients. Its mechanisms remain defined.

METHODS

A total of 48 CRC patients were enrolled and 68 samples were obtained from the peripheral blood of patients before or after treatments in this study. Twenty non-cancer patients were also detected as a negative control. Circulating Tumor Cells (CTCs), including Epithelial CTCs (eCTCs), Mesenchymal (MCTCs), and epithelial/mesenchymal mixed phenotypes (mixed CTCs), were identified by CanPatrol^TM CTC enrichment and RNA in situ hybridization. The relationship between CTCs number and Progression-Free Survival (PFS) or Overall Survival (OS) was evaluated.

RESULTS

Thirty-four of 48 patients (70.8%) were found to have positive CTCs. Total CTCs and MCTCs in the post-treatment had a significant correlation PFS and OS. When total CTCs or MCTCs in 5 mL blood of patients were more than 6 CTCs or 5 MCTCs, PFS of the patients was significantly shorter (p < 0.05) than that in patients with less than 6 CTCs or 5 MCTCs. The patients with > 5 CTCs count changes were found to exhibit poor PFS and OS rates (p < 0.05).

CONCLUSION

Total CTCs and MCTCs number detection in patients with colorectal cancer was very useful biomarker for predicting the prognosis of patients. Higher CTCs or MCTCs had poorer PFS and OS rates.

Clinical significance of circulating tumour cells and tumour marker detection in the chemotherapeutic evaluation of advanced colorectal cancer

AIM

Systemic chemotherapy combining biological targeted therapies is the standard therapy for patients with metastatic colorectal cancer (mCRC), but effective markers are needed to identify clinical responders. Circulating tumour cells (CTCs) have been associated with prognosis in patients with mCRC. This study aimed to explore the relationship between CTC number and the clinical response of patients with advanced CRC.

METHOD

Epithelial cell adhesion molecule-independent enrichment and CD45^- fluorescence in situ hybridization immunofluorescence were used to detect peripheral blood CTCs in 79 patients with advanced CRC. Fisher's exact test and Spearman's rank correlation coefficient were used to analyse the correlation between CTC number and efficacy of chemotherapy. Kaplan-Meier and Cox regression analyses were used to evaluate progression-free survival (PFS).

RESULTS

Among the evaluable patients, CTCs were significantly correlated with clinical response (r =4.891, p = 0.031). High CTC numbers were associated with a poor treatment response (r = -0.250, p = 0.027). Dynamic decrease in CTC number was associated with clinical response (p = 0.046). High baseline CTC number and carcinoembryonic antigen levels were prognostic factors for unfavourable PFS in multivariable analysis [hazard ratio (HR) = 3.30, p = 0.011 and HR = 2.04, p = 0.044, respectively]. Compared with the CTC-positive group, the CTC-negative group showed superior PFS (median PFS 15.53 vs. 9.43 months, p = 0.041) among CRC patients receiving first-line treatment.

CONCLUSION

CTC number is a feasible biomarker for predicting outcomes in mCRC patients receiving systemic chemotherapy.

An electrochemical immunosensor for the detection of carcinoembryonic antigen based on Au/g-C3N4 NSs-modified electrode and CuCo/CNC as signal tag

Carcinoembryonic antigen levels in the human body reflect the conditions associated with a variety of tumors and can be used for the identification, development, monitoring, and prognosis of lung cancer, colorectal cancer, and breast cancer. In this study, an amperometric immunosensor with CuCo/carbon nanocubes (CuCo/CNC) as the signal label is constructed. The bimetal-doped carbon skeleton structure has a high specific surface area and exhibits good electrocatalytic activity. In addition, Au/g-C₃N₄ nanosheets (Au/g-C₃N₄ NSs) are used to modify the substrate platform, facilitating the loading of more capture antibodies. The reaction mechanism was explored through electrochemical methods, X-ray powder diffraction, X-ray photoelectron spectroscopy, and other methods. Kinetic studies have shown that CuCo/CNC have good peroxidase-like activity. In addition, the electrocatalytic reduction ability of CuCo/CNC on hydrogen peroxide can be monitored using amperometric i-t curve (- 0.2 V, vs. SCE), and the response current value is positively correlated with the CEA antigen concentration. The prepared electrochemical immunosensor has good selectivity, precision, and stability. The dynamic range of the sensor was 0.0001-80 ng/mL, and the detection limit was 0.031 pg/mL. In addition, the recovery and relative standard deviation in real serum samples were 97.7-103 % and 3.25-4.13 %, respectively. The results show that the sensor has good analytical capabilities and can provide a new method for the clinical monitoring of CEA.

Clinical Significance of Circulating Tumor Cell Induced Epithelial-Mesenchymal Transition in Patients with Metastatic Colorectal Cancer by Single-Cell RNA-Sequencing

BACKGROUND

Circulating tumor cells (CTCs) are a prognostic marker in patients with metastatic colorectal cancer (mCRC). However, little is known about the characterization of CTCs in mCRC at the single-cell level using RNA sequencing. The purpose of this study was to validate the capability to detect and isolate single CTCs for single-cell RNA sequencing (scRNA-seq) and to identify clinical significance at a single CTC level.

METHODS

Single CTCs from 27 mCRC patients were collected by CTC-FIND, which is comprised of filter separation and immunomagnetic depletion to collect ultra-pure CTC samples. To address tumor heterogeneity, CTCs were collected without relying on any traditional CTC markers, such as epithelial and mesenchymal cell antigens, and were undertaken by scRNA-seq using SMART-Seq v4.

RESULTS

We identified 59 single CTCs which were classified into four groups by epithelial, epithelial-mesenchymal transition (EMT) and stem cell-related gene expression. Patients receiving second or later-line treatment who had EMT gene expressing CTCs had a significantly shorter PFS and OS.

CONCLUSIONS

Exploiting CTC-FIND with SMART-Seq v4 showed that scRNA-seq of CTCs may shed new insight into tumor heterogeneity of mCRC and that the presence of CTCs expressing EMT-related genes at the single-cell level could have prognostic value in mCRC patients.

CEA, CA19-9, circulating DNA and circulating tumour cell kinetics in patients treated for metastatic colorectal cancer (mCRC)

BACKGROUND

We previously reported that CEA kinetics are a marker of progressive disease (PD) in metastatic colorectal cancer (mCRC). This study was specifically designed to confirm CEA kinetics for predicting PD and to evaluate CA19-9, cell-free DNA (cfDNA), circulating tumour DNA (ctDNA) and circulating tumour cell (CTC) kinetics.

METHODS

Patients starting a chemotherapy (CT) with pre-treatment CEA > 5 ng/mL and/or CA19.9 > 30 UI/mL were prospectively included. Samples were collected from baseline to cycle 4 for CEA and CA19-9 and at baseline and the sixth week for other markers. CEA kinetics were calculated from the first to the third or fourth CT cycle.

RESULTS

A total of 192 mCRC patients were included. CEA kinetics based on the previously identified >0.05 threshold was significantly associated with PD (p < 0.0001). By dichotomising by the median value, cfDNA, ctDNA and CA19-9 were associated with PD, PFS and OS in multivariate analysis. A circulating scoring system (CSS) combining CEA kinetics and baseline CA19-9 and cfDNA values classified patients based on high (n = 58) and low risk (n = 113) of PD and was independently associated with PD (ORa = 4.6, p < 0.0001), PFS (HRa = 2.07, p < 0.0001) and OS (HRa = 2.55, p < 0.0001).

CONCLUSIONS

CEA kinetics alone or combined with baseline CA19-9 and cfDNA are clinically relevant for predicting outcomes in mCRC.

TRIAL REGISTRATION NUMBER

NCT01212510.

Enhancing Prediction Performance by Add-On Combining Circulating Tumor Cell Count, CD45neg EpCAMneg Cell Count on Colorectal Cancer, Advance, and Metastasis

Simple Summary

Information describing circulating tumor cells (CTCs) holds promise for clinical applications. However, conventional CTCs enumeration could ignore the CTCs more relevant to cancer metastasis. Thus, negative selection CTC enumeration was proposed, by which information on the numbers of CTCs and CD45^neg EpCAM^neg cells can be obtained. By combining this approach with the conventional biomarker carcinoembryonic antigen (CEA), this study aimed to explore whether any combination of these biomarkers could improve the predictive performance for colorectal cancer (CRC) or its status. Results revealed that a combination of the two cell populations showed improved performance (AUROC: 0.893) for CRC prediction over the use of only one population. Compared with CEA alone, the combination of the three biomarkers increased the performance (AUROC) for advanced CRC prediction from 0.643 to 0.727. Compared with that of CEA alone for metastatic CRC prediction, the AUROC was increased from 0.780 to 0.837 when the CTC count was included.

Abstract

Conventional circulating tumor cell (CTC) enumeration could ignore the CTCs more relevant to cancer metastasis. Thus, negative selection CTC enumeration was proposed, by which information on two cellular biomarkers (numbers of CTCs and CD45^neg EpCAM^neg cells) can be obtained. By combining this approach with the conventional biomarker carcinoembryonic antigen (CEA), this study aimed to explore whether any combination of these biomarkers could improve the predictive performance for colorectal cancer (CRC) or its status. In this work, these two cell populations in healthy donors and CRC patients were quantified. Results revealed that enumeration of these two cell populations was able to discriminate healthy donors from CRC patients, even patients with non-advanced CRC. Moreover, the combination of the two cell populations showed improved performance (AUROC: 0.893) for CRC prediction over the use of only one population. Compared with CEA alone, the combination of the three biomarkers increased the performance (AUROC) for advanced CRC prediction from 0.643 to 0.727. Compared with that of CEA alone for metastatic CRC prediction, the AUROC was increased from 0.780 to 0.837 when the CTC count was included. Overall, this study demonstrated that the combination of these two cellular biomarkers with CEA improved the predictive performance for CRC and its status.

Liquid Biopsy for Prognosis and Treatment in Metastatic Colorectal Cancer: Circulating Tumor Cells vs Circulating Tumor DNA

Liquid biopsy recently gained widespread attention as a noninvasive alternative/complementary technique to tissue biopsy in patients with cancer. As technological advances have improved both feasibility and turnaround time, liquid biopsy has expanded tumor molecular analysis with acknowledgement of both spatial and temporal heterogeneity, overcoming many limitations of traditional tissue biopsy. Because of its diagnostic, prognostic, and predictive value, liquid biopsy has been extensively studied also in metastatic colorectal cancer. Indeed, as personalized medicine establishes its role in cancer treatment, genetic biomarkers unveiling the emergence of early resistance are needed. Among the wide variety of tumor analytes amenable to collection, circulating DNA and circulating tumor cells are the most adopted approaches, and both carry clinical relevance in colorectal cancer. However, few studies focused on comparing feasibility between these two approaches. In this review, we discuss the potential implications of liquid biopsy in metastatic colorectal cancer, assessing the advantages and drawbacks of circulating DNA and circulating tumor cells, and highlighting the most relevant trials for clinical practice.

Liquid Biopsy: From Discovery to Clinical Application

Over the past 10 years, circulating tumor cells (CTC) and circulating tumor DNA (ctDNA) have received enormous attention as new biomarkers and subjects of translational research. Although both biomarkers are already used in numerous clinical trials, their clinical utility is still under investigation with promising first results. Clinical applications include early cancer detection, improved cancer staging, early detection of relapse, real-time monitoring of therapeutic efficacy, and detection of therapeutic targets and resistance mechanisms. Here, we propose a conceptual framework of CTC and ctDNA assays and point out current challenges of CTC and ctDNA research, which might structure this dynamic field of translational cancer research. SIGNIFICANCE: The analysis of blood for CTCs or cell-free nucleic acids called "liquid biopsy" has opened new avenues for cancer diagnostics, including early detection of tumors, improved risk assessment and staging, as well as early detection of relapse and monitoring of tumor evolution in the context of cancer therapies.

The Clinical Application of Circulating Tumor Cells and DNAs as Prognostic and Predictive Biomarkers in Gastrointestinal Cancer

Gastrointestinal (GI) cancer is one of the most common cancers globally. Genetic and epigenetic mechanisms are involved in its pathogenesis. The conventional methods for diagnosis and screening for GI cancers are often invasive and have other limitations. In the era of personalized medicine, a novel non-invasive approach called liquid biopsy has been introduced for the detection and management of GI cancers, which focuses on the analysis of circulating tumor cells (CTCs) and circulating cell-free tumor DNA (ctDNA). Several studies have shown that this new approach allows for an improved understanding of GI tumor biology and will lead to an improvement in clinical management. The aim of the current review is to explore the clinical applications of CTCs and ctDNA in patients with GI cancer.

An immunosensor for the determination of carcinoembryonic antigen by Surface Plasmon Resonance imaging

Carcinoembryonic antigen (CEA) is one of the biomarkers most commonly used to determine tumor activity. In this work, a Surface Plasmon Resonance imaging (SPRi) immunosensor was developed. The immunosensor consists of a cysteamine linker attached to a gold chip and mouse monoclonal anti-CEA antibody bonded by the "EDC/NHS protocol". The formation of successive immunosensor layers was confirmed by AFM measurements. The concentration of the antibody was optimized. The linear response range of the developed immunosensor is between 0.40 and 20 ng mL^-1, and it is suitable for CEA measurement in both blood cancer patients and healthy individuals. Only 3 μL of serum or plasma sample is required, and no preconcentration is used. The method has a precision of 2-16%, a recovery of 101-104% depending on CEA concentration, a detection limit of 0.12 ng mL^-1 and a quantification limit of 0.40 ng mL^-1. The method is selective (with respect to albumin, leptin, interleukin 6, metalloproteinase-1, metallopeptidase inhibitor 1 and CA 125/MUC16) and it was validated by comparison with the standard electrochemiluminescence method on a series of colorectal cancer blood samples.

Bimetallic PtCu nanoparticles supported on molybdenum disulfide-functionalized graphitic carbon nitride for the detection of carcinoembryonic antigen

A molybdenum disulfide based graphite phase carbon nitride (MoS₂/g-C₃N₄) which is supported by a platinum-copper nanoparticle (PtCu) Z-type catalyst was created in this study. The catalyst exploits optoelectronic synergistic effect with large surface area, good catalysis, and biocompatibility to amplify the signal. The electrode impedance of the synthesized MoS₂/g-C₃N₄-PtCu was reduced five times in visible light compared with dark conditions, thereby improving the detection of carcinoembryonic antigen (CEA). At a voltage of - 0.4 V, the immunoprobe constructed with this material is used for CEA detection. A linear relationship between 100 fg mL^-1 and 80 ng mL^-1 concentrations was achieved with a minimum detection limit of 33 fg mL^-1 (S/N = 3). The recovery rate was 103-104%, and the relative standard deviation was 2.9-3.8%. This implies that the sandwich immunosensors have good reproducibility, selectivity, and stability and can be used in various applications. Graphical Abstract.

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.

Extracellular Vesicle-Transported Long Non-Coding RNA (LncRNA) X Inactive-Specific Transcript (XIST) in Serum is a Potential Novel Biomarker for Colorectal Cancer Diagnosis

Background

Colorectal cancer (CRC) cell-derived extracellular vesicles (EVs) contribute to tumor progression. Differentially expressed long non-coding (lnc)RNAs may serve as biomarkers for CRC diagnosis. This study aimed to discuss the diagnostic value of serum EV-derived lncRNA X inactive-specific transcript (XIST) in CRC.

Material/Methods

Serum EVs were extracted and identified. Microarray analysis was performed to screen out the differentially expressed lncRNAs in serum EVs. The expression and diagnostic efficacy of the most differentially expressed lncRNA were measured. Kaplan-Meier survival analysis was performed to evaluate the association between survival time and XIST expression in EVs. The expression profile of serum EV-carried XIST in 94 CRC patients with different tumor-node-metastasis stages, lymph node metastasis, and differentiation was assessed. The serum contents of CEA, CA242, CA199, and CA153 were measured.

Results

XIST in serum EVs in CRC patients was upregulated, with greatest diagnostic value. CRC patients with higher expression of XIST in serum EVs had worse 5-year survival rates and shorter life cycles, lower differentiation, higher lymph node metastasis, and tumor-node-metastasis than patients with lower XIST expression. XIST expression in serum EVs was positively correlated with CRC marker contents.

Conclusions

XIST upregulation in serum EVs is related to CRC progression, which may be helpful to the clinical diagnosis and prognosis of CRC.

Comparing Circulating Tumor Cell Counts with Dynamic Tumor Size Changes as Predictor of Overall Survival: A Quantitative Modeling Framework

PURPOSE

Quantitative relationships between treatment-induced changes in tumor size and circulating tumor cell (CTC) counts, and their links to overall survival (OS), are lacking. We present a population modeling framework identifying and quantifying such relationships, based on longitudinal data collected in patients with metastatic colorectal cancer (mCRC) to evaluate the value of tumor size and CTC counts as predictors of OS.

EXPERIMENTAL DESIGN

A pharmacometric approach (i.e., population pharmacodynamic modeling) was used to characterize the changes in tumor size and CTC count and evaluate them as predictors of OS in 451 patients with mCRC treated with chemotherapy and targeted therapy in a prospectively randomized phase III study (CAIRO2).

RESULTS

A tumor size model of tumor quiescence and drug resistance was used to characterize the tumor size time-course, and was, in addition to the total normalized dose (i.e., of all administered drugs) in a given cycle, related to the CTC counts through a negative binomial model (CTC model). Tumor size changes did not contribute additional predictive value when the mean CTC count was a predictor of OS. Treatment reduced the typical mean count from 1.43 to 0.477 (HR = 3.94). The modeling framework was applied to explore whether dose modifications (increased and reduced) would result in a CTC count below 1/7.5 mL after 1 to 2 weeks of treatment.

CONCLUSIONS

Time-varying CTC counts can be useful for early predicting OS in patients with mCRC, and may therefore have potential for model-based treatment individualization. Although tumor size was connected to CTC, its link to OS was weaker.

Evolution of Estrogen Receptor Status from Primary Tumors to Metastasis and Serially Collected Circulating Tumor Cells

Background: The estrogen receptor (ER) can change expression between primary tumor (PT) and distant metastasis (DM) in breast cancer. A tissue biopsy reflects a momentary state at one location, whereas circulating tumor cells (CTCs) reflect real-time tumor progression. We evaluated ER-status during tumor progression from PT to DM and CTCs, and related the ER-status of CTCs to prognosis. Methods: In a study of metastatic breast cancer, blood was collected at different timepoints. After CellSearch^® enrichment, CTCs were captured on DropMount slides and evaluated for ER expression at baseline (BL) and after 1 and 3 months of therapy. Comparison of the ER-status of PT, DM, and CTCs at different timepoints was performed using the McNemar test. The primary endpoint was progression-free survival (PFS). Results: Evidence of a shift from ER positivity to negativity between PT and DM was demonstrated (p = 0.019). We found strong evidence of similar shifts from PT to CTCs at different timepoints (p < 0.0001). ER-positive CTCs at 1 and 3 months were related to better prognosis. Conclusions: A shift in ER-status from PT to DM/CTCs was demonstrated. ER-positive CTCs during systemic therapy might reflect the retention of a favorable phenotype that still responds to therapy.

Three-year Survival Rate after Radiofrequency Ablation for Surgically Resectable Colorectal Lung Metastases: A Prospective Multicenter Study

Background Although radiofrequency ablation (RFA) is widely performed for the treatment of colorectal cancer (CRC) lung metastases, its efficacy for candidates with surgically resectable disease is unclear. Purpose To evaluate the prognosis after RFA in participants with resectable CRC lung metastases. Materials and Methods For this prospective multicenter study (ClinicalTrials.gov identifier: NCT00776399), participants with five or fewer surgically resectable lung metastases measuring 3 cm or less were included. Participants with CRC and a total of 100 lung metastases measuring 0.4-2.8 cm (mean, 1.0 cm ± 0.5) were chosen and treated with 88 sessions of RFA from January 2008 to April 2014. The primary end point was the 3-year overall survival (OS) rate, with an expected rate of 55%. The local tumor progression rate and safety were evaluated as secondary end points. The OS rates were generated by using the Kaplan-Meier method. Log-rank tests and Cox proportional regression models were used to identify the prognostic factors by means of univariable and multivariable analyses. Adverse events were evaluated according to the Common Terminology Criteria for Adverse Events, version 3.0. Results Seventy participants with CRC (mean age, 66 years ± 10; 49 men) were evaluated. The 3-year OS rate was 84% (59 of 70 participants; 95% confidence interval [CI]: 76%, 93%). In multivariable analysis, factors associated with worse OS included rectal rather than colon location (hazard ratio [HR] = 7.7; 95% CI: 2.6, 22.6; P < .001), positive carcinoembryonic antigen (HR = 5.8; 95% CI: 2.0, 16.9; P = .001), and absence of previous chemotherapy (HR = 9.8; 95% CI: 2.5, 38.0; P < .001). Local tumor progression was found in six of the 70 participants (9%). A grade 5 adverse event was seen in one of the 88 RFA sessions (1%), and grade 2 adverse events were seen in 18 (20%). Conclusion Lung radiofrequency ablation provided a favorable 3-year overall survival rate of 84% for resectable colorectal lung metastases measuring 3 cm or smaller. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Gemmete in this issue.

A new Bi2MoO6 nano-tremella-based electrochemical immunosensor for the sensitive detection of a carcinoembryonic antigen

Novel Bi₂MoO₆ nanohybrids with a tremella-like structure modified with gold nanoparticles were used to fabricate an electrochemical immunosensing platform of CEA.

Prognostic significance of serum p53 antibody according to KRAS status in metastatic colorectal cancer patients

BACKGROUND

Serum anti-p53 antibody is used clinically as a tumor marker of colorectal cancer. However, its prognostic significance in patients with metastatic colorectal cancer (mCRC) remains unclear. KRAS status may influence the host immune response against tumor progression. In the present study, we investigated the prognostic significance of serum anti-p53 in mCRC patients with wild-type KRAS and mutant KRAS treated with systemic chemotherapy.

METHODS

A retrospective study of 150 mCRC patients in whom serum anti-p53 antibody was measured before first-line chemotherapy was conducted. The patients were divided into two groups, high p53 and low p53, based on their serum anti-p53 antibody levels. Associations between serum anti-p53 level and clinical outcomes were evaluated in conjunction with KRAS status.

RESULTS

There were 97 (64.7%) patients with wild-type KRAS and 53 (35.3%) with mutant KRAS. In an analysis of all patients, there was no significant difference in overall survival (OS) between the high p53 and low p53 groups. In patients with mutant KRAS, those in the high p53 group exhibited significantly longer OS than those in the low p53 group (p = 0.017, log-rank test). In the multivariate analysis, serum p53 antibody level was an independent predictor of OS in mCRC patients (high vs. normal; hazard ratio 0.438, 95% confidence interval 0.178-0.974, p < 0.05).

CONCLUSIONS

Serum anti-p53 antibody level may be an independent predictor of OS in mCRC patients with KRAS mutant tumors.

The prognostic role of circulating tumor cells in colorectal cancer

Introduction: Metastasis is the main cause of cancer-associated death in colorectal cancer (CRC). The presence of circulating tumor cells (CTC) in the blood is associated with an increased risk of recurrence and poor prognosis. The clinical significance of CTCs as a novel biomarker has been extensively studied in the last decade. It has been shown that CTC detection applies to early cancer detection. The presence of CTCs is associated with metastatic spread and poor survival and is also useful as a marker for therapy response.Areas covered: We summarize the role of CTC in CRC, their clinical significance, current methods for CTC detection and challenges as well as future perspectives of CTC research.Expert commentary: The clinical significance of CTC in CRC patients is well established. Although insightful, the available marker-based approaches hampered our understanding of the CTCs and their biology, as such approaches do not take into account the heterogeneity of these cell populations. New technologies should expand the marker-based detection to multi biomarker-based approaches together with recent technological advances in microfluidics for single cell enrichment and analysis.

Circulating Tumour Cells, Circulating Tumour DNA and Circulating Tumour miRNA in Blood Assays in the Different Steps of Colorectal Cancer Management, a Review of the Evidence in 2019

Despite many advances in the diagnosis and treatment of colorectal cancer (CRC), its incidence and mortality rates continue to make an impact worldwide and in some countries rates are mounting. Over the past decade, liquid biopsies have been the object of fundamental and clinical research with regard to the different steps of CRC patient care such as screening, diagnosis, prognosis, follow-up, and therapeutic response. They are attractive because they are considered to encompass both the cellular and molecular heterogeneity of tumours. They are easily accessible and can be applied to large-scale settings despite the cost. However, liquid biopsies face drawbacks in detection regardless of whether we are testing for circulating tumour cells (CTCs), circulating tumour DNA (ctDNA), or miRNA. This review highlights the different advantages and disadvantages of each type of blood-based biopsy and underlines which specific one may be the most useful and informative for each step of CRC patient care.

Nanotechnology in Radiation Oncology

Nanotechnology has made remarkable contributions to clinical oncology. Nanotherapeutics and diagnostic tools have distinctive characteristics which allow them superior abilities to deliver therapeutics and imaging agents for radiation oncology. Compared to solid biopsies and imaging, the analysis of circulating tumor cells (CTCs) offers a more rapid, real-time, and less invasive method to monitor the dynamic molecular profiles of tumors. The potential of CTCs to be translated as a novel cancer biomarker has been demonstrated in numerous clinical studies. This review will discuss clinical applications of nanomaterials in radiation oncology and the implication of CTCs in cancer detection and monitoring.

Microslit on a chip: A simplified filter to capture circulating tumor cells enlarged with microbeads

Microchips are widely used to separate circulating tumor cells (CTCs) from whole blood by virtues of sophisticated manipulation for microparticles. Here, we present a chip with an 8 μm high and 27.9 mm wide slit to capture cancer cells bound to 3 μm beads. Apart from a higher purity and recovery rate, the slit design allows for simplified fabrication, easy cell imaging, less clogging, lower chamber pressure and, therefore, higher throughput. The beads were conjugated with anti-epithelial cell adhesion molecules (anti-EpCAM) to selectively bind to breast cancer cells (MCF-7) used to spike the whole blood. The diameter of the cell-bead construct was in average 23.1 μm, making them separable from other cells in the blood. As a result, the cancer cells were separated from 5 mL of whole blood with a purity of 52.0% and a recovery rate of 91.1%, and also we confirmed that the device can be applicable to clinical samples of human breast cancer patients. The simple design with microslit, by eliminating any high-aspect ratio features, is expected to reduce possible defects on the chip and, therefore, more suitable for mass production without false separation outputs.

The significance of CO2 combining power in predicting prognosis of patients with stage II and III colorectal cancer

Aim: This study was to evaluate whether CO₂CP level in venous blood could predict prognosis of patients with colorectal cancer (CRC). Materials & methods: A retrospective cohort of 238 patients with CRC who received surgical resection and 176 CRC Stage IV patients were included. A total of 114 healthy people were recruited as control. CO₂CP levels were obtained from medical records. Survival analysis was performed to evaluate CO₂CP predictive potential. The patients were divided into CO₂CP high or low group based on CO₂CP optimal cut-off values. Conclusion: The decreased CO₂CP in CRC patients was associated with advanced clinical stage, and suggested that decreased CO₂CP may predict the worse outcomes of disease-free survival in II/III stage CRC patients.

Fibrinogen-Albumin Ratio Index (FARI): A More Promising Inflammation-Based Prognostic Marker for Patients Undergoing Hepatectomy for Colorectal Liver Metastases

BACKGROUND

Systemic inflammation response is involved in the development and progression of cancers. This study aimed to evaluate the prognostic value of a preoperative Fibrinogen-Albumin Ratio Index (FARI) in patients undergoing hepatectomy for colorectal liver metastases (CRLM) and compare it with established systemic inflammation markers, including the neutrophil-lymphocyte ratio, lymphocyte-monocyte ratio, platelet-lymphocyte ratio, and systemic immune-inflammation index.

METHODS

Patients who underwent hepatectomy for CRLM between November 2002 and December 2016 were considered for inclusion. Time-dependent receiver operating characteristic (ROC) curve analysis was conducted to evaluate the ability of markers in predicting survival. Multivariable Cox regression analysis was used to identify independent predictors for overall survival (OS) or disease-free survival (DFS).

RESULTS

A total of 452 consecutive patients were enrolled. The areas under the ROC curve of the FARI in predicting OS and DFS were superior to other inflammatory markers and carcinoembryonic antigen (CEA). The optimal cut-off value of the FARI was 7.6%. Patients with a high FARI (> 7.6%) showed significantly decreased OS and DFS (all p < 0.001). In multivariable analysis, the FARI was the only inflammatory marker that independently predicted OS and DFS. Additionally, regardless of patients having a high or low CEA, the FARI further stratified these patients into subgroups with significantly distinct OS and DFS (all p < 0.05). The FARI also showed good clinical utility in patients with different clinical characteristics.

CONCLUSIONS

A preoperative FARI is an independent predictor of OS and DFS for patients undergoing hepatectomy for CRLM, superior to the established systemic inflammation markers and CEA.

Circulating biomarkers for early detection and clinical management of colorectal cancer

New non-invasive approaches that can complement and improve on current strategies for colorectal cancer (CRC) screening and management are urgently needed. A growing number of publications have documented that components of tumors, which are shed into the circulation, can be detected in the form of liquid biopsies and can be used to detect CRC at early stages, to predict response to certain therapies and to detect CRC recurrence in a minimally invasive way. The analysis of circulating tumor DNA (ctDNA), tumor-derived cells (CTC, circulating tumor cells) or circulating microRNA (miRNA) in blood and other body fluids, have a great potential to improve different aspects of CRC management. The challenge now is to find which types of components, biofluids and detection methods would be the most suitable to be applied in the different steps of CRC detection and treatment. This chapter will provide an up to date review on ctDNA, CTCs and circulating miRNAs as new biomarkers for CRC, either for clinical management or early detection, highlighting their advantages and limitations.

The difference in prognosis of stage II and III colorectal cancer based on preoperative serum tumor markers

Background: Preoperative serum tumor markers have been widely used to predict prognosis in stage II and III colorectal cancer (CRC). However, few previous studies addressed the effect of increased preoperative numbers of tumor markers.

Methods: Patients with stage II and III CRC who underwent curative resection were included from January 2009 to October 2015. The relationship between serum tumor markers and clinicopathological parameters was analyzed. DFS and OS were compared in stage II and III CRC.

Results: The median follow-up was 45 months. In this study, 735 enrolled patients were assessed based on the numbers of increased tumor markers. We found that these increased tumor markers were closely associated with clinical stage, T stage, N stage, tumor location, pathology type, differentiation, lymphatic invasion and vascular invasion (all p values < 0.05). Furthermore, the number of increased tumor markers directly affected the survival of patients with CRC after curative surgery. The 3-year DFS and OS of patients with a score of 0 were 84.0% and 91.0%, respectively, which are much higher than those of patients with a score of 4 (42.9% and 37.8%, respectively) (p < 0.05). The 5-year DFS and OS of patients with a score of 0 were 75.9% and 77.9%, respectively, which are much higher than those of patients with a score of 4 (31.7% and 23.6%, respectively). Interestingly, our results suggested that stage III CRC patients with a score of 0 had longer DFS and OS times than stage II patients with scores of 3 and 4. Further analysis revealed statistically significant differences in OS (p < 0.05) but not in DFS.

Conclusions: The number of increased tumor markers could significantly predict prognosis in stage II and III CRC. In addition, these increased tumor markers had direct impacts on metastasis as well as the recurrence status and survival time of stage II and III CRC patients.

Liquid biopsy in central nervous system metastases: a RANO review and proposals for clinical applications

Liquid biopsies collect and analyze tumor components in body fluids, and there is an increasing interest in the investigation of liquid biopsies as a surrogate for tumor tissue in the management of both primary and secondary brain tumors. Herein we critically review available literature on spinal fluid and plasma circulating tumor cells (CTCs) and cell-free tumor (ctDNA) for diagnosis and monitoring of leptomeningeal and parenchymal brain metastases. We discuss technical issues and propose several potential applications of liquid biopsies in different clinical settings (ie, for initial diagnosis, for assessment during treatment, and for guidance of treatment decisions). Last, ongoing clinical studies on CNS metastases that include liquid biopsies are summarized, and recommendations for future clinical studies are provided.

Heterogeneity in Circulating Tumor Cells: The Relevance of the Stem-Cell Subset

The release of circulating tumor cells (CTCs) into vasculature is an early event in the metastatic process. The analysis of CTCs in patients has recently received widespread attention because of its clinical implications, particularly for precision medicine. Accumulated evidence documents a large heterogeneity in CTCs across patients. Currently, the most accepted view is that tumor cells with an intermediate phenotype between epithelial and mesenchymal have the highest plasticity. Indeed, the existence of a meta-stable or partial epithelial–mesenchymal transition (EMT) cell state, with both epithelial and mesenchymal features, can be easily reconciled with the concept of a highly plastic stem-like state. A close connection between EMT and cancer stem cells (CSC) traits, with enhanced metastatic competence and drug resistance, has also been described. Accordingly, a subset of CTCs consisting of CSC, present a stemness profile, are able to survive chemotherapy, and generate metastases after xenotransplantation in immunodeficient mice. In the present review, we discuss the current evidence connecting CTCs, EMT, and stemness. An improved understanding of the CTC/EMT/CSC connections may uncover novel therapeutic targets, irrespective of the tumor type, since most cancers seem to harbor a pool of CSCs, and disclose important mechanisms underlying tumorigenicity.

CTCs as a prognostic and predictive biomarker for stage II/III Colon Cancer: a companion study to the PePiTA trial

BACKGROUND

Adjuvant therapy improves the prognosis of stage II & III colon cancer patients. Unfortunately, most patients do not benefit from this treatment. PePITA (NCT00994864) is a prospective, multicenter, non-randomized study whose primary objective is to predict the outcome of adjuvant therapy in colon cancer.

METHODS

The primary objective was to determine the prognostic and predictive value of circulating tumor cell (CTC) detection before therapy and after one course of preoperative FOLFOX.

RESULTS

Out of the 58 first patients accrued in PePiTA trial, 36 patients participated in the CTC companion study, of whom 32 had at least one evaluable sample. Only 5 patients (14, 95% CI = 5-30%) had ≥1 CTC/22.5 ml blood in at least one of the two timepoints with 2 patients having ≥1 CTC/22.5 ml at baseline (6, 95% CI: 1-19%). The detection rate of patients with CTCs at baseline being lower than expected, the inclusion of patients in the PePiTA CTC substudy was stopped. The limited sample size did not allow us to investigate the prognostic and predictive value of CTCs in locally advanced colon cancer.

CONCLUSIONS

Our data illustrate the need for further standardized studies in order to find the most reliable prognostic/predictive biomarker in early-stage colon cancer.

TRIAL REGISTRATION

This trial was prospectively registered at Jules Bordet institute ( NCT00994864 ) on the October 14, 2009.

The Significance of Circulating Tumour Cells in the Clinic

BACKGROUND

Despite the hype about circulating tumour cells (CTCs) in the early 2000s and their potential in the diagnosis of metastasis, in recent years, the hope for personalised cancer management relies more on circulating tumour (ct)DNA that has entered the clinic in a much more efficient way. So far, approved methods for CTCs in the clinic only provide the counting of CTCs, which enables monitoring of the progression of metastatic breast, prostate, and colorectal cancer patients with therapy. Approved methods for ctDNA facilitate the analysis of specific mutations in lung cancer, thereby providing indications for potentially successful treatments. This situation inclined the balance towards molecular analysis in liquid biopsy, leveraged by new technologies and companies providing broader mutation and gene expression analysis towards the early diagnosis of cancer.

STUDY DESIGN

We conducted a search for the studies published to date that provide details about the significance of CTCs in the clinic.

RESULTS

Many studies and clinical trials have demonstrated the potential of CTCs in patient screening, early diagnosis, therapy resistance, and patient prognosis.

CONCLUSIONS

Large multi-centre studies are still needed to formally validate the clinical relevance of CTCs. Meticulous design of the clinical trials is a crucial point to achieve this long-sought objective.