Plasma Carcinoembryonic Antigen Research Articles

Abstract 3637: Ultrasensitive assays for combined detection of CEA+ extracellular vesicles and soluble CEA

Abstract Colorectal cancer (CRC) is the third most common cancer worldwide and is the second leading cause of cancer death in the United States. Carcinoembryonic antigen (CEA) is a biomarker commonly used in the management of CRC. It is typically present at low levels in the blood of healthy adults but is elevated in CRC samples and some other cancers. CEA is most commonly used to monitor treatment efficacy and as a critical part of post-treatment surveillance for residual disease, recurrence, and/or progression/metastasis. The CRC recurrence rate averages >25%, and liver metastasis occurs in 25-30% of cases. Improved CEA assays could enable earlier determination of treatment failure, detection of lower levels of minimal residual disease (MRD) after treatment, or earlier detection of recurrence. CEA is a GPI-linked membrane protein secreted from CRC cells mainly by enzymatic cleavage of its GPI anchor. However, we have identified alternative secretion of CEA in association with extracellular vesicles (EVs). We hypothesized that the soluble CEA produced by canonical shedding and the alternatively secreted CEA may provide distinct information about the tumor or its microenvironment and serve as independent but complementary biomarkers of CRC. We developed ultrasensitive, multi-marker electrochemiluminescence (ECL) immunoassays for measuring intact EVs presenting CEA, CD73, or both in human plasma. We observed that plasma levels of CEA+EVs and CD73+EVs were elevated in some late-stage CRC samples compared to controls. CEA and CD73 double-positive EV (CEA+CD73+EVs) levels were also elevated in the same samples, exhibiting a 3-fold improved separation of these samples with CRC from controls, compared to detection of CEA+EVs. Additionally, approximately 25% of stage IV CRC samples had elevated CEA+EV and CEA+CD73+EV levels while exhibiting low soluble CEA. We confirmed this result in an independent sample set that included samples across all CRC stages, and also identified a few earlier-stage samples that exhibited high CEA+EVs and CEA+CD73+EVs without elevated soluble CEA. Since CEA+CD73+EVs and soluble CEA assays identified different subsets of samples, we combined the two assays into a single classifier for late stage CRC and controls, yielding improved receiver operator characteristic (ROC) with area under the curve (AUC) of 0.975 versus 0.927 for the standard soluble CEA assay or 0.788 for CEA+CD73+EVs alone. These results suggest that assaying EVs presenting multiple surface markers can increase specificity for the detection of tumor-derived EVs relative to a single marker and that assaying both soluble and EV-associated forms of CEA in plasma may improve the value of CEA measurement in CRC. Citation Format: Lucie Hebert, Misk Al-Ameen, Talis Spriggs, Collin Nelson, Evan A. Gizzie, Jeffrey L. Franklin, Robert J. Coffey, David A. Routenberg, Jacob N. Wohlstadter. Ultrasensitive assays for combined detection of CEA+ extracellular vesicles and soluble CEA [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3637.

Abstract 1038: Identification of diagnostic biomarkers for colon adenocarcinoma by analyzing proteins in human-derived extracellular vesicles and particles

Abstract There is an unmet medical need for circulating biomarkers to improve early cancer detection in colon adenocarcinoma (COAD). We investigated the proteomic profile of extracellular vesicles and particles (EVPs) from the colon tissue explants and plasmas in COAD. The research aims to overcome the limitations of traditional serum Carcinoembryonic Antigen (CEA) testing and invasive procedures like colonoscopy. We analyzed EVPs sourced from tumor and adjacent non-tumor tissues and preoperative and postoperative plasma in COAD patients to identify potential EVP-based tumor diagnostic markers. In the Discovery phase with 50 COAD patients, we conducted a proteomic analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS), identifying approximately 50 markers each from tissue explants and plasma. These markers were validated in an independent cohort of 104 participants, including 84 COAD patients and 20 healthy controls. We utilized ELISA to quantify 11 selected EVP proteins. Notably, seven of these proteins exhibited significant differential expression in preoperative and postoperative plasma, highlighting their diagnostic relevance. These seven proteins also showed marked elevation in preoperative plasma compared to healthy controls, reinforcing their potential as diagnostic markers. The study extended to evaluate the diagnostic accuracy of these seven proteins, referred to as "EV-7 levels", across various stages of COAD. Their performance was compared with serum CEA levels and plasma cfDNA mutation rates, as detected by an FDA-approved liquid biopsy assay. The EV-7 levels demonstrated superior detection rates in the early stages of COAD, particularly in Stages I and II, in contrast to the serum CEA method. Among the 84 patients, 73 (86.9%) exhibited EV-7 levels exceeding the established cut-off. In the validation cohort, EV-7 levels were more accurate across different COAD stages than serum CEA levels and cfDNA mutation rates. CEA levels above 5 ng/ml were 27%, 45%, 42%, and 64% for Stages I through IV. cfDNA somatic mutation rates were 60%, 80%, 75%, and 75%. EV-7 levels exceeding the cut-off were 73%, 100%, 88%, and 84%, respectively, with Stages I and II having the highest detection rate among the three methods. ROC curve analysis for EV-7 levels in Stages I to IV showed statistically significant, with AUC values of 0.913, 1.000, 0.985, and 0.984, respectively. Our findings indicate that the seven EVP proteins are significantly present in the plasma of early-stage COAD patients. Integrating these markers with current diagnostic approaches could improve early cancer detection, showing promise for practical application in clinical settings. Citation Format: Yura Seo, Yoon Dae Han, Linda Bojmar, Kyung-A Kim, Yurin Seo, David Lyden, Han Sang Kim. Identification of diagnostic biomarkers for colon adenocarcinoma by analyzing proteins in human-derived extracellular vesicles and particles [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1038.

Chemical Proteomic Approach for In-Depth Glycosylation Profiling of Plasma Carcinoembryonic Antigen in Cancer Patients

Carcinoembryonic antigen (CEA) of human plasma is a biomarker of many cancer diseases, and its N-glycosylation accounts for 60% of molecular mass. It is highly desirable to characterize its glycoforms for providing additional dimension of features to increase its performance in prognosis and diagnosis of cancers. However, to systematically characterize its site-specific glycosylation is challenging because of its low abundance. Here, we developed a highly sensitive strategy for in-depth glycosylation profiling of plasma CEA through chemical proteomics combined with multienzymatic digestion. A trifunctional probe was utilized to generate covalent bond of plasma CEA and its antibody upon UV irradiation. As low as 1 ng/ml CEA in plasma could be captured and digested with trypsin and chymotrypsin for intact glycopeptide characterization. Twenty six of 28 potential N-glycosylation sites were well identified, which were the most comprehensive N-glycosylation site characterization of CEA on intact glycopeptide level as far as we known. Importantly, this strategy was applied to the glycosylation analysis of plasma CEA in cancer patients. Differential site-specific glycoforms of plasma CEA were observed in patients with colorectal cancers (CRCs) and lung cancer. The distributions of site-specific glycoforms were different as the progression of CRC, and most site-specific glycoforms were overexpressed in stage II of CRC. Overall, we established a highly sensitive chemical proteomic method to profile site-specific glycosylation of plasma CEA, which should generally applicable to other well-established cancer glycoprotein biomarkers for improving their cancer diagnosis and monitoring performance.

Homogeneous immunoassay utilizing fluorescence resonance energy transfer from quantum dots to tyramide dyes deposited on full immunocomplexes.

There is an urgent need for homogeneous immunoassays that offer sufficient sensitivity for routine clinical practice. In this study, we have developed a highly sensitive, fluorescence resonance energy transfer (FRET)-based homogeneous immunoassay. Unlike previous FRET-based homogeneous immunoassays, where acceptors were attached to antibody molecules located far from the donor, we employed acceptors to label the entire sandwich-structured immunocomplex, including two antibodies and one antigen. As a result, the FRET signal was amplified by a factor of 10, owing to the reduced distance between the donor and acceptors. We validated our method by quantifying carcinoembryonic antigen (CEA) and α-fetoprotein (AFP) in PBS buffer and blank plasma. The limits of detection (LOD) for CEA and AFP in both PBS buffer and blank plasma were comparable, reaching sub-femtomolar levels. Furthermore, we successfully quantified CEA and AFP in three human plasma samples, thereby confirming the reliability of our method for clinical applications.

Plasma CXCL3 Levels Are Associated with Tumor Progression and an Unfavorable Colorectal Cancer Prognosis.

Background The CXC chemokines belong to a unique family of chemotactic cytokines that influence the initiation, progression, and clinical outcome of many tumor types. Herein, we investigated the association of the CXC-chemokine ligand 3 (CXCL3) with tumor progression and an unfavorable prognosis for colorectal cancer (CRC). Methods The quantitative real-time polymerase chain reaction was used to explore the expression of CXCL3 in CRC tissue, adjacent tissue, and plasma. The usefulness of plasma levels of CXCL3 for the diagnosis of CRC was evaluated by receiver operating characteristic curve analysis. Pearson's correlation analysis assessed relationships among plasma CXCL3, cancer tissue CXCL3, and plasma carcinoembryonic antigen (CEA). Kaplan–Meier analysis was used to assess the survival of CRC patients with high and low expression levels of CXCL3. Survival differences were compared by log-rank test. Results Initial analysis of the GSE156720 dataset identified CXCL3 as the most enriched CXCL gene in CRC patients. Higher CXCL3 levels were detected in CRC tissue than in adjacent tissue (P < 0.001). Compared to healthy controls, CRC patient plasma CXCL3 levels were higher (P < 0.001). The area under the curve was 0.81 with a sensitivity of 0.71 and specificity of 0.82, distinguishing CRC from other tumor types. Plasma CXCL3 was positively related to CXCL3 in cancer tissue (r = 0.78, P < 0.01), and also to plasma CEA (r = 0.50, P < 0.01). Plasma CXCL3 was also related to tumor size (P = 0.034), staging (P < 0.001), tumor stage (P = 0.003), differentiation (P = 0.001), and lymph node metastasis (P = 0.007), but not to sex (P = 0.853), age (P = 0.691), tumor site (P = 1.347), or distant metastasis (P = 1.218). Conclusions CXCL3 levels were increased in CRC patients, with plasma CXCL3 levels associated with tumor progression and an unfavorable CRC prognosis. The results of this study suggest that plasma CXCL3 may be a novel diagnostic and prognostic biomarker for CRC.

The Index of Esophageal Cancer Related Ischemic Stroke: A Retrospective Patient Control Study.

PurposeTo investigate independent risk factors for esophageal cancer-related ischemic stroke (ECIS) and to use them to develop an index of ECIS to help clinicians identify patients at high risk for ECIS or to identify ECIS from other types of ischemic stroke.MethodsWe retrospectively enrolled active esophageal cancer (EC) patients with acute ischemic stroke (ECIS group) and patients with active EC without ischemic stroke (EC group), age- and sex-matched with ECIS patients, at seven centers from January 2011 to December 2020. Clinical data and laboratory and imaging findings were collected. Univariate and multivariate analyses were performed to analyze the independent risk factors for ECIS. Optimal cutoffs for sensitivities and specificities were obtained by Youden’s J statistic following a receiver operator characteristic (ROC) analysis of each risk factor and the product of the risk factors.ResultsA total of 91 ECIS patients and 91 EC patients were included. Elevated levels of carcinoembryonic antigen (CEA) [odds ratio (OR) = 0.105, 95% confidence interval (CI): 1.051–1.174, P < 0.001], D-dimer (DD) (OR = 0.003, 95% CI: 1.002–1.004, P < 0.001), and neutrophil count (OR = 0.857, 95% CI: 1.628–3.407, P < 0.001) were independent risk factors for ECIS. The area under the curve (AUC) of each independent risk factor and the product of the three independent risk factors were calculated by a receiver operator characteristic (ROC) curve, and the cutoff value from the largest AUC was called the ECIS index.ConclusionIt was suggested that elevated plasma DD and CEA levels and increased neutrophils in EC patients may altogether contribute to the development of ECIS. The index of ECIS may facilitate clinicians to identify patients at high risk for ECIS or to identify ECIS from other etiologic types of ischemic stroke.

Circadian and chemotherapy-related changes in urinary modified nucleosides excretion in patients with metastatic colorectal cancer

Urinary levels of modified nucleosides reflect nucleic acids turnover and can serve as non-invasive biomarkers for monitoring tumour circadian dynamics, and treatment responses in patients with metastatic colorectal cancer. In 39 patients, median overnight urinary excretion of LC-HRMS determinations of pseudouridine, was ~ tenfold as large as those of 1-methylguanosine, 1-methyladenosine, or 4-acetylcytidine, and ~ 100-fold as large as those of adenosine and cytidine. An increase in any nucleoside excretion after chemotherapy anticipated plasma carcinoembryonic antigen progression 1–2 months later and was associated with poor survival. Ten fractionated urines were collected over 2-days in 29 patients. The median value of the rhythm-adjusted mean of urinary nucleoside excretion varied from 64.3 for pseudouridine down to 0.61 for cytidine. The rhythm amplitudes relative to the 24-h mean of 6 nucleoside excretions were associated with rest duration, supporting a tight link between nucleosides turnover and the rest-activity rhythm. Moreover, the amplitude of the 1-methylguanosine rhythm was correlated with the rest-activity dichotomy index, a significant predictor of survival outcome in prior studies. In conclusion, urinary excretion dynamics of modified nucleosides appeared useful for the characterization of the circadian control of cellular proliferation and for tracking early responses to treatments in colorectal cancer patients.

Correlation between circulating tumor DNA and carcinoembryonic antigen levels in patients with metastatic colorectal cancer.

BackgroundCirculating tumor DNA (ctDNA) is a biomarker with potential to reflect comprehensive genomic information and overcome intratumor heterogeneity. In contrast, carcinoembryonic antigen (CEA) is a conventional tumor marker for predicting recurrence, survival, and chemotherapeutic efficacy in patients with metastatic colorectal cancer (mCRC). However, the relationship between them remains unclear. Here, the relationship between plasma ctDNA and CEA levels was evaluated to clarify the advantages and disadvantages of their clinical use.MethodsA total of 110 patients with mCRC underwent chemotherapy were enrolled. Amplicon‐based plasma genomic profiling of 14 genes that are commonly mutated in CRC by next‐generation sequencing was compared to the CEA level and tumor diameter using Spearman’s correlation coefficient.ResultsThe overall concordance rate between the ctDNA and CEA levels was 75.5% (83/110). The correlation coefficient between the ctDNA and CEA levels was lower in the group of patients without liver and lymph node metastases (r = 0.18, p = 0.44) than in the group of patients with liver metastasis (r = 0.48, p < 0.0001). Although the correlation coefficients between tumor diameter and both ctDNA and CEA levels were high in the group of patients with liver metastasis, only the CEA correlation coefficient was maintained in the group of patients without liver and lymph node metastases (r = 0.53, p = 0.01). The characteristics that influenced discordance were liver metastasis and the sum of tumor diameter.ConclusionsThe status of ctDNA and CEA may not be consistent in patients with mCRC without liver metastasis or with a low tumor volume; both results should be considered when deciding a treatment strategy.

Elevated carcinoembryonic antigen in patients with COVID-19 pneumonia

PurposeCoronavirus disease 2019 (COVID-19) tends to affect multiple organs and induce abnormal laboratory parameters. We designed this study to investigate the association between carcinoembryonic antigen (CEA) elevation and SARS-CoV-2 infection.MethodsWe retrospectively analyzed 177 patients with confirmed SARS-CoV-2 infection who received plasma CEA assays during hospitalization. Patients with other causes of CEA elevation were excluded. Data regarding epidemiological and demographical characteristics, clinical symptoms, laboratory tests, and outcomes were analyzed. Linear regression analysis was used to evaluate the correlation between CEA levels and inflammation severity.Results171 patients were included in the final study and 32 patients (18.7%) had raised serum of CEA (> 5 ng/ml), with a median (range) age of 66 (53–86). The median [interquartile range (IQR)] CEA level was 11.4 ng/ml (8.1–21.6), which was significantly higher than the upper limit of reference range. CEA level between 5–10 ng/ml was in 11 patients, 10–15 ng/ml in 10 patients, and > 15 ng/ml in 11 patients. No correlation was found between CEA levels and lymphocyte (R2 = 0.055; P = 0.10) nor CRP (R2 = 0.026; P = 0.38). The median levels of CEA were 20.0 ng/ml (IQR, 14.7–23.0) in non-survivors and 10.9 ng/ml (IQR 7.5–16.1) in survivors, and the difference between two groups was statistically significant (P = 0.048).ConclusionSARS-CoV-2 infection might be another cause of CEA elevation, with nearly 20% of patients experienced transient and marked CEA increment during COVID-19 pneumonia. The false-positive results of CEA elevation might have clinical significance for patients with colorectal cancer.

The Level of Preoperative Plasma KRAS Mutations and CEA Predict Survival of Patients Undergoing Surgery for Colorectal Cancer Liver Metastases.

Colorectal cancer (CRC) belongs to the most common cancers. The liver is a predominant site of CRC dissemination. Novel biomarkers for predicting the survival of CRC patients with liver metastases (CLM) undergoing metastasectomy are needed. We examined KRAS mutated circulating cell-free tumor DNA (ctDNA) in CLM patients as a prognostic biomarker, independently or in combination with carcinoembryonic antigen (CEA). Thereby, a total of 71 CLM were retrospectively analyzed. Seven KRAS G12/G13 mutations was analyzed by a ddPCR™ KRAS G12/G13 Screening Kit on QX200 Droplet Digital PCR System (Bio-Rad Laboratories, Hercules, CA, USA) in liver metastasis tissue and preoperative and postoperative plasma samples. CEA were determined by an ACCESS CEA assay with the UniCel DxI 800 Instrument (Beckman Coulter, Brea, CA, USA). Tissue KRAS positive liver metastases was detected in 33 of 69 patients (47.8%). Preoperative plasma samples were available in 30 patients and 11 (36.7%) were KRAS positive. The agreement between plasma- and tissue-based KRAS mutation status was 75.9% (22 in 29; kappa 0.529). Patients with high compared to low levels of preoperative plasma KRAS fractional abundance (cut-off 3.33%) experienced shorter overall survival (OS 647 vs. 1392 days, p = 0.003). The combination of high preoperative KRAS fractional abundance and high CEA (cut-off 3.33% and 4.9 µg/L, resp.) best predicted shorter OS (HR 13.638, 95%CI 1.567–118.725) in multivariate analysis also (OS HR 44.877, 95%CI 1.59–1266.479; covariates: extend of liver resection, biological treatment). KRAS mutations are detectable and quantifiable in preoperative plasma cell-free DNA, incompletely overlapping with tissue biopsy. KRAS mutated ctDNA is a prognostic factor for CLM patients undergoing liver metastasectomy. The best prognostic value can be reached by a combination of ctDNA and tumor marker CEA.

Risk factors for lymph node metastasis and surgical methods in patients with early-stage peripheral lung adenocarcinoma presenting as ground glass opacity

BackgroundIt is difficult to predict lymph node metastasis in patients with early lung cancer. Pure ground glass opacity (GGO) on computed tomography indicates an early-stage adenocarcinoma that can be removed by limited resection or lobectomy without the need for mediastinal lymph node dissection or sampling, and lung adenocarcinoma with GGO therefore has a good prognosis. We examined the incidence and risk factors of lymph node metastasis in patients with clinical stage IA lung adenocarcinoma.MethodsWe retrospectively analyzed clinical data for 327 patients with stage IA peripheral lung cancer treated in our hospital from March 2014 to December 2018. The patients were divided into four groups according to computed tomography signs. Lobectomy and systematic lymph node dissection were performed in all patients. Correlations between lymph node metastasis and clinical pathological factors were analyzed by logistic regression.ResultsAmong the 327 patients, 26 (7.95%) had lymph node metastasis. No patients with pure GGO or GGO-dominant types had lymph node metastasis. Logistic regression identified tumor diameter, solid content, plasma carcinoembryonic antigen (CEA) level, pathological type, lymphovascular invasion, and pleural invasion as factors related to the presence of lymph node metastasis.ConclusionsTumor diameter, solid component ratio, plasma CEA level, pathological type, vascular tumor thrombus, and pleural invasion are possible independent risk factors for lymph node metastasis in patients with stage IA lung adenocarcinoma. In contrast, lymph node metastasis is rare in patients with pure GGO or GGO-dominant lung adenocarcinoma.

An immunosensor detects carcinoembryonic antigen by a double reduction strategy based on polyphenylamine as a sacrifice reducing agent

In this paper, a novel Ag NPs-PANI/MnO2 tag was synthesized for the first time, and the electrochemical immunoassay for carcinoembryonic antigen (CEA) was achieved. In this experiment, gold nanoparticles (Au NPs) were used as an electrochemical sensing platform to increase conductivity and improve electrode surface capture antibody (Ab1). We use PANI as a green sacrificial agent reduces Ag NPs and MnO2, while improving the conductivity and electrochemical stability of the immunosensor. MnO2 and Ag NPs effectively raise the sensitivity of the sensor by catalytically reducing hydrogen peroxide (H2O2) into water and oxygen to achieve a double amplified sensing signal. It is found that the surface plasmon resonance of Ag NPs has an interesting SERS characteristic structure, and the equivalent circuit simulation of the electrode assembly process results in an error of less than 10%, indicating that the electrochemical immunosensor is successfully prepared. Under optimal conditions, the electrochemical immunosensor has a linear range of 0.0005–80 ng/mL and a detection limit of 0.17 pg/mL (S/N = 3). The immunosensor is expected to be used in clinical laboratories to detect CEA and other tumor markers in human plasma for precancerous screening or surveillance.

YAP Levels Combined with Plasma CEA Levels Are Prognostic Biomarkers for Early-Clinical-Stage Patients of Colorectal Cancer.

Background Colorectal cancer (CRC) is one of the most common cancers worldwide. Surgical operation is routinely applied to patients with CRC. An important part of postoperative care for patients is to assess the prognosis of patients, especially those with early-stage cancers. However, effective biomarkers for CRC prognosis remain inadequate. The purpose of this study was to assess the prognostic potential of Yes-associated protein (YAP) and carcinoembryonic antigen (CEA) in early-stage CRC. Methods A total of 116 matched pairs of CRC tissues and adjacent normal mucosae as well as 73 cases of metastatic lymph nodes were analyzed. Results The results show that CRC tissues exhibited higher YAP expression compared with the adjacent normal mucosae. Immunohistochemical analysis shows that YAP expression in the CRC or lymphatic metastatic tissues was clearly higher than that in normal mucosae (P < 0.01), whereas that in CRC tissues with lymphatic metastasis was higher than that in tissues without lymphatic metastasis (P < 0.05). YAP expression is associated with serosal invasion, lymphatic metastasis, lymph node ratio, remote metastasis, Dukes stage, and CEA levels (P < 0.05). YAP and CEA are independent predictors of the survival of CRC patients (P < 0.05 and P < 0.01). YAP predicted CRC prognosis primarily for patients with late-clinical-stage CRC (P=0.002), but not for patients with early-clinical-stage CRC (P=0.083). However, patients with high YAP and high CEA levels exhibited lower overall survival rates than those with low YAP expression in early-clinical-stage CRC (P < 0.001). Conclusion High YAP levels in the cancer tissues combined with high plasma CEA levels are potential biomarkers for predicting CRC prognosis in the early clinical stage.

The biomarkers and potential pathogenesis of lung cancer related cerebral hemorrhage.

Cerebral hemorrhage is one of the common complications in patients with lung cancer (LC). Although cancer related cerebral hemorrhage was aware, the pathogenesis and biomarkers of lung cancer related cerebral hemorrhage (LCRCH) remained not well known. The aim of this study was to investigate the pathogenesis and plasma biomarkers of LCRCH.A retrospective review was conducted on acute cerebral hemorrhage patients with active LC who was admitted to the hospital between January 2007 and December 2017. A total of 56 patients with LCRCH (active LC patients with acute cerebral hemorrhage but without conventional vascular risks) was recruited. Meanwhile, 112 patients with active LC alone and gender, age, and subtype of cancer cell matched were recruited as control group.In LCRCH patients, most of the hemorrhagic lesions were located in lobes. And most of them with adenocarcinoma were in medium to terminal stage with poor prognosis short-term. Moreover, LCRCH patients had a lengthened prothrombin time (PT), elevated plasma carcinoembryonic antigen (CEA), cancer antigen 125 (CA125) and cancer antigen 199 (CA199) levels and decreased platelet (PLT) level than did the patients with LC. Multivariate logistic regression analysis showed that lengthened PT, elevated plasm CEA, and CA199 levels were independent risk factors for LCRCH.It was suggested that lengthened PT, elevated plasm CEA and CA199 levels associated with the pathogenesis of LCRCH, and that the Index derived from independent risks should be serve as a specific biomarker of LCRCH.

Potential diagnostic and prognostic value of plasma long noncoding RNA LINC00086 and miR-214 expression in gastric cancer.

Plasma carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), and cancer antigen 72-4 (CA72-4) are common markers which are useful in the diagnosis and prognosis of GC. However, their sensitivity and specificity in GC remain unsatisfactory. Identification of cancer diagnosed-biomarkers would be of great value. Evaluate the diagnostic and prognostic value of LINC00086 and miR-214 in GC. In this study, we determined the expression of LINC00086 and miR-214 in GC by qRT-PCR. Additionally, we investigated the relationship between various clinicopathological features of GC patients and LINC00086 or miR-214 expression, and evaluated the diagnostic and prognostic value of LINC00086 and miR-214 in GC. In this study, we found that plasma LINC00086 expression was significantly lower, whereas plasma miR-214 expression was significantly higher in GC patients than in normal individuals. LINC00086 and miR-214 exhibited high sensitivity and specificity in diagnosing GC. Additionally, GC patients with low LINC00086 or high miR-214 expression were likely to have larger tumors, lymphatic metastasis, larger TNM stage, and higher CEA and CA19-9 levels. Moreover, GC patients with low LINC00086 or high miR-214 expression showed lower survival rates. Lymphatic metastasis, LINC00086, and miR-214 are independent factors affecting patient diagnosis. LINC00086 and miR-214 are potentially diagnostic and prognostic markers for GC.

CYP2C9 polymorphism is not associated with elevated carcinoembryonic antigen levels

Background: Carcinoembryonic antigen (CEA) is a glycoprotein that can be elevated in a number of benign and malignant conditions. In colorectal cancer, it is used as a prognostic marker and to detect recurrence. However, it lacks specificity and may become elevated in individuals without a history of cancer or other identifiable cause leading to costly and invasive investigation. Objective: The aim of this study was to assess whether genetic polymorphisms in the liver enzyme CYP2C9 could explain high CEA levels in otherwise normal individuals. Design: This is a case-control study. Setting: Individuals were genotyped for the poor metabolizer (PM) alleles CYP2C9*2 and CYP2C9*3 using predesigned TaqMan single nucleotide polymorphisms assays. Patients and Methods: Nineteen individuals with previously clinically unexplained elevated CEA and 567 healthy Caucasian controls were included. Main Outcome Measures: Chi-square analysis was used to test for association of CYP2C9 genotype with plasma CEA concentration. Sample Size: Nineteen individuals with previously clinically unexplained elevated CEA and 567 healthy Caucasian controls were included. Results: Fifteen of the 19 individuals with previously high CEA had elevated plasma CEA (>3.0μg/L) on re-testing. The frequency of CYP2C9 PM alleles in these 15 patients was not significantly higher than the frequency in controls. Conclusion: CEA concentrations do not appear to be influenced by CYP2C9 genotype, so this cannot be used to explain elevated CEA in the absence of an obvious clinical cause. Limitation: Small sample size.

Combination of D-dimer and carcinoembryonic antigen levels as a predictive and prognostic biomarker in advanced colorectal cancer patients.

In view of the controversial findings on the utility of D-dimer and carcinoembryonic antigen (CEA) as biomarkers in advanced colorectal cancer (CRC), we evaluated the predictive and prognostic value of the D-dimer and CEA levels in unresectable advanced CRC patients treated with first-line chemotherapy. A total of 57 previously untreated patients with advanced CRC were enrolled. We assessed both plasma D-dimer and CEA levels at the start (D1 and CEA1) and after two cycles (D2 and CEA2) of chemotherapy. Based on the respective optimal cut-off values of 0.8 and 5.0 ng/mL for D1 and CEA1, respectively, patients were divided into low and high D-dimer or CEA groups. The results show that D1 and CEA1 levels were correlated (r = 0.392, P = 0.003). Mean CEA2 was reduced by 26.24 ng/mL in patients with partial response and stable disease and increased by 165.95 ng/mL in patients with progressive disease relative to the CEA1 level (P < 0.001). However, no correlation was evident between changes in the D-dimer levels and chemotherapy response (P = 0.441). The overall survival (OS) of patients with high D1 was shorter than that of patients with low D1 (median OS, 16 vs 29 months, P = 0.009). Multivariate analyses further demonstrated that D1 (P = 0.042) and chemotherapy response (P = 0.016), but not CEA, were independent prognostic factors for OS in advanced CRC. Taken together, our result found that changes in CEA levels may serve as a predictive biomarker of the chemotherapy response and baseline D-dimer levels as a prognostic biomarker of OS in patients with advanced CRC.

Liquid biopsy: a powerful tool to monitor trastuzumab resistance in HER2-positive metastatic gastric cancer

Human epidermal growth factor receptor 2 (HER2) overexpression/amplification affects about 6.1%–23.0% of gastric cancer patients [1, 2]. All major guidelines recommend HER2 testing to guide the selection for trastuzumab treatment in metastatic gastric cancer (mGC) [3], because doublet chemotherapy with trastuzumab significantly improved overall survival (OS) in the crucial trastuzumab for gastric cancer trial (the ToGA trial) [4]. However, the unsatisfactory gain of median progression-free survival (PFS) stresses important issues of intrinsic and acquired resistance to HER2-targeted therapies [4]. Currently, the underlying molecular mechanism of trastuzumab resistance in mGC is still unclear, and the strategies to real time monitor resistance-specific aberrations are urgently needed. As circulating tumor DNA (ctDNA) carries the same genomic alterations that are present in the primary tumor [5, 6], liquid biopsy-based ctDNA profiling offers a unique opportunity for serially monitoring treatment response in a non-invasive manner, and has opened the door for identification the mechanisms of drug resistance. In a study recently published in Gut, titled “Liquid biopsies to track trastuzumab resistance in metastatic HER2-positive gastric cancer”, Wang et al. [7] demonstrated for the first time that longitudinal ctDNA sequencing could promisingly predict tumor shrinkage and progression in HER2 + mGC patients under trastuzumab treatment. Based on the detected molecular alterations from the ctDNA profiling, they further dissected various mechanisms of trastuzumab resistance (Fig. 1). Longitudinal circulating tumor DNA sequencing provides novel insights into gene alterations underlying trastuzumab resistance in HER2-positive metastatic gastric cancer. HER2+: HER2-positive; mGC: metastatic gastric cancer; ctDNA: circulating tumor DNA: Copy No.: copy number In this study, the authors sequenced 416 clinically relevant genes to determine the genomic profiles of GC patients. The molecular alterations, including copy number alterations, mutations and structural variations, detected in 78 paired plasma and tissue samples (46 from HER2+ patients and 32 from HER2− patients) were used to evaluate the consistency of detection between the “liquid” and “solid” biopsies. As expected, the alterations detected in plasma provided a good representation of the status in the tumor tissues. In particular, HER2 amplification status, the major marker of HER2 + GC, detected by plasma-based ctDNA sequencing was highly consistent with that by tissue-based sequencing and fluorescence in situ hybridisation. These findings indicated that plasma-based ctDNA profiling might provide insights into HER2 amplification in HER2 + GC. Further longitudinal analysis were perform in 97 time-course plasma samples collected from 24 HER2 + mGC patients to track the resistance during trastuzumab treatment. As compared to plasma carcinoembryonic antigen, the copy number variations (CNVs) of HER2 in ctDNA were better at tracking trastuzumab treatment response. Generally, the HER2 copy number decreased during treatment compared with baseline and levels of progressive disease (PD), indicating tumor shrinkage. Additionally, most patients with intrinsic resistance-related progression presented higher HER2 copy numbers at PD than baseline, while the patients with acquired resistance often had lower HER2 copy numbers at PD. From the same ctDNA profiles, the authors found evidence for reported mechanisms of trastuzumab resistance in 76.5% patients. They found that the patients with multiple resistance mechanisms (PIK3CA/R1/C3 and ERBB2/4 mutations) displayed much shorter PFS during trastuzumab treatment. These findings suggested that liquid biopsy-based ctDNA profiling can effectively capture the heterogeneity information about acquired resistance. Furthermore, they also observe several novel resistance mechanisms. One of them is the ERBB4 S774G mutation. This novel mutation can increase the sensitivity to trastuzumab treatment, suggesting for the first time that the mutation of ERBB4 play a critical role in mediating resistance to ERBB2 inhibitors in HER2 + GC. Another novel resistance mechanism is the emergence of NF1 mutations. Using in vitro and in vivo experiments, the authors demonstrated that NF1 was a resistance-related gene and could be used as a potential resistance marker of trastuzumab. NF1 lost (mutation or deletion) contributes to driving resistance of HER2-targeted therapy via elevating pMEK/ERK activation, whereas the combination of HER2 and MEK/ERK inhibitors might overcome trastuzumab resistance. This study has some obvious limitations. First, other rare genomic or even nongenomic mechanisms of trastuzumab resistance may have been missed by the 416-gene panel. Second, the relatively small number of patient enrolled does not allow drawing definitive conclusion on the predictive value of this liquid biopsy approach. Nevertheless, the study provides helpful information to monitor the treatment response of trastuzumab and develop therapeutic strategies for the HER2 + mGC patients with trastuzumab resistance. The author read and approved the final manuscript. Not applicable. The author declares no competing interests. Not applicable. Not applicable. Not applicable. Not applicable.

Biomarkers and potential pathogenesis of colorectal cancer-related ischemic stroke.

AIMTo investigate the specific biomarkers and potential pathogenesis of colorectal cancer-related ischemic stroke (CRCIS).METHODSA retrospective study was conducted on CRCIS patients (colorectal cancer patients with ischemic stroke without conventional stroke risk factors) registered at seven centers between January 2007 and December 2017. Clinical data and laboratory and imaging findings were compared with age- and sex- matched patients with colorectal cancer (CRC) without ischemic stroke that were admitted to the same hospital during the same period. Univariate and multivariate analyses were performed to analyze the independent risk factors for CRCIS. A receiver operator characteristic curve was configured to calculate the optimal cut-off value of the products of the independent risk factors for CRCIS.RESULTSA total of 114 CRCIS patients and 114 CRC patients were included. Multiple lesions in multiple vascular territories were common in CRCIS patients (71, 62.28%). The levels of plasma D-dimer, carcinoembryonic antigen (CEA), cancer antigen 125, and neutrophil count were significantly higher in CRCIS patients than in CRC patients. Multiple logistic regression analysis revealed that plasma D-dimer levels [odds ratio (OR) = 1.002, 95% confidence interval (CI): 1.001-1.003, P < 0.001], CEA levels (OR = 1.011, 95%CI: 1.006-1.015, P < 0.001), and neutrophil count levels (OR = 1.626, 95%CI: 1.268-2.087, P < 0.001) were independent risk factors for CRCIS. In addition, receiver operator characteristic curve revealed that the area under curve for the products of plasma D-dimer, CEA, and neutrophil count was 0.889 ± 0.022 (95%CI: 0.847-0.932, P < 0.001), and the optimal cut-off value for the product was 252.06, which was called the CRCIS Index, with a sensitivity of 86.0% and specificity of 79.8%.CONCLUSIONHypercoagulability induced by elevated CEA and neutrophils may be an important cause of CRCIS. The CRCIS index, which serves as a biomarker of CRCIS, needs further study.

Liquid biopsies to track trastuzumab resistance in metastatic HER2-positive gastric cancer

ObjectiveTo monitor trastuzumab resistance and determine the underlying mechanisms for the limited response rate and rapid emergence of resistance of HER2+ metastatic gastric cancer (mGC).DesignTargeted sequencing of 416 clinically relevant...