Establishment of using serum YKL-40 and SCCA in combination for the diagnosis of patients with esophageal squamous cell carcinoma

Purine salvage-associated metabolites as biomarkers for early diagnosis of esophageal squamous cell carcinoma: a diagnostic model-based study

Esophageal squamous cell carcinoma (ESCC) remains an important health concern in developing countries. Patients with advanced ESCC have a poor prognosis and survival rate, and achieving early diagnosis remains a challenge. Metabolic biomarkers are gradually gaining attention as early diagnostic biomarkers. Hence, this multicenter study comprehensively evaluated metabolism dysregulation in ESCC through an integrated research strategy to identify key metabolite biomarkers of ESCC. First, the metabolic profiles were examined in tissue and serum samples from the discovery cohort (n = 162; ESCC patients, n = 81; healthy volunteers, n = 81), and ESCC tissue-induced metabolite alterations were observed in the serum. Afterward, RNA sequencing of tissue samples (n = 46) was performed, followed by an integrated analysis of metabolomics and transcriptomics. The potential biomarkers for ESCC were further identified by censoring gene-metabolite regulatory networks. The diagnostic value of the identified biomarkers was validated in a validation cohort (n = 220), and the biological function was verified. A total of 457 dysregulated metabolites were identified in the serum, of which 36 were induced by tumor tissues. The integrated analyses revealed significant alterations in the purine salvage pathway, wherein the abundance of hypoxanthine/xanthine exhibited a positive correlation with HPRT1 expression and tumor size. A diagnostic model was developed using two purine salvage-associated metabolites. This model could accurately discriminate patients with ESCC from normal individuals, with an area under the curve (AUC) (95% confidence interval (CI): 0.680-0.843) of 0.765 in the external cohort. Hypoxanthine and HPRT1 exerted a synergistic effect in terms of promoting ESCC progression. These findings are anticipated to provide valuable support in developing novel diagnostic approaches for early ESCC and enhance our comprehension of the metabolic mechanisms underlying this disease.

Biomarkers for Early Detection, Prognosis, and Therapeutics of Esophageal Cancers

Esophageal cancer (EC) is the deadliest cancer worldwide, with a 92% annual mortality rate per incidence. Esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) are the two major types of ECs, with EAC having one of the worst prognoses in oncology. Limited screening techniques and a lack of molecular analysis of diseased tissues have led to late-stage presentation and very low survival durations. The five-year survival rate of EC is less than 20%. Thus, early diagnosis of EC may prolong survival and improve clinical outcomes. Cellular and molecular biomarkers are used for diagnosis. At present, esophageal biopsy during upper endoscopy and histopathological analysis is the standard screening modality for both ESCC and EAC. However, this is an invasive method that fails to yield a molecular profile of the diseased compartment. To decrease the invasiveness of the procedures for diagnosis, researchers are proposing non-invasive biomarkers for early diagnosis and point-of-care screening options. Liquid biopsy involves the collection of body fluids (blood, urine, and saliva) non-invasively or with minimal invasiveness. In this review, we have critically discussed various biomarkers and specimen retrieval techniques for ESCC and EAC.

N-linked glycoproteomic profiling in esophageal squamous cell carcinoma

BACKGROUND

Mass spectrometry-based proteomics and glycomics reveal post-translational modifications providing significant biological insights beyond the scope of genomic sequencing.

AIM

To characterize the N-linked glycoproteomic profile in esophageal squamous cell carcinoma (ESCC) via two complementary approaches.

METHODS

Using tandem multilectin affinity chromatography for enrichment of N-linked glycoproteins, we performed N-linked glycoproteomic profiling in ESCC tissues by two-dimensional gel electrophoresis (2-DE)-based and isobaric tags for relative and absolute quantification (iTRAQ) labeling-based mass spectrometry quantitation in parallel, followed by validation of candidate glycoprotein biomarkers by Western blot.

RESULTS

2-DE-based and iTRAQ labeling-based quantitation identified 24 and 402 differentially expressed N-linked glycoproteins, respectively, with 15 in common, demonstrating the outperformance of iTRAQ labeling-based quantitation over 2-DE and complementarity of these two approaches. Proteomaps showed the distinct compositions of functional categories between proteins and glycoproteins with differential expression associated with ESCC. Western blot analysis validated the up-regulation of total procathepsin D and high-mannose procathepsin D, and the down-regulation of total haptoglobin, high-mannose clusterin, and GlcNAc/sialic acid-containing fraction of 14-3-3ζ in ESCC tissues. The serum levels of glycosylated fractions of clusterin, proline-arginine-rich end leucine-rich repeat protein, and haptoglobin in patients with ESCC were remarkably higher than those in healthy controls.

CONCLUSION

Our study provides insights into the aberrant N-linked glycoproteome associated with ESCC, which will be a valuable resource for future investigations.

An N-glycoproteomic site-mapping analysis reveals glycoprotein alterations in esophageal squamous cell carcinoma

Background

Aberrant glycosylation has been recognized as a hallmark of cancer and N-glycosylation is one of the main types of glycosylation in eukaryotes. Although N-glycoproteomics has made contributions to the discovery of biomarkers in a variety of cancers, less is known about the abnormal glycosylation signatures in esophageal squamous cell carcinoma (ESCC).

Methods

In this study, we reported the proteomics and N-glycoproteomic site-mapping analysis of eight pairs of ESCC tissues and adjacent normal tissues. With zic-HILIC enrichment, TMT-based isobaric labeling, LC–MS/MS analysis, differentially expressed N-glycosylation was quantitatively characterized. Lectin affinity enrichment combined with western blot was used to validate the potential biomarkers in ESCC.

Results

A series of differentially expressed glycoproteins (e.g., LAMP2, PLOD2) and enriched signaling pathways (e.g., metabolism-related pathway, ECM-receptor interaction, focal adhesion) were identified. Besides that, seven significantly enriched motifs were found from the identified N-glycosylation sites. Three clusters were identified after conducting the dynamic profiling analysis of glycoprotein change during lymph node metastasis progression. Further validation found that the elevated fucosylation level of ITGB1, CD276 contributed to the occurrence and development of ESCC, which might be the potential biomarkers in ESCC.

Conclusion

In summary, we characterized the N-glycosylation and N-glycoprotein alterations associated with ESCC. The typical changes in glycoprotein expression and glycosylation occupancy identified in our study will not only be used as ESCC biomarkers but also improve the understanding of ESCC biology.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03489-2.

A signature of saliva-derived exosomal small RNAs as predicting biomarker for esophageal carcinoma: a multicenter prospective study

BACKGROUND

The tRNA-derived small RNAs (tsRNAs) are produced in a nuclease-dependent manner in responses to variety of stresses that are common in cancers. We focus on a cancer-enriched tsRNA signature to develop a salivary exosome-based non-invasive biomarker for human esophageal squamous cell carcinoma (ESCC).

METHODS

Cancer-enriched small RNAs were identified by RNA sequencing of salivary exosomes obtained from ESCC patients (n = 3) and healthy controls (n = 3) in a pilot study and further validated in discovery cohort (n = 66). A multicenter prospective observational study was conducted in two ESCC high-incidence regions (n = 320 and 200, respectively) using the newly developed biomarker signature.

RESULTS

The tsRNA (tRNA-GlyGCC-5) and a previously undocumented small RNA were specifically enriched in salivary exosomes of ESCC patients, ESCC tissues and ESCC cells. The bi-signature composed of these small RNAs was able to discriminate ESCC patients from the controls with high sensitivity (90.50%) and specificity (94.20%). Based on the bi-signature Risk Score for Prognosis (RSP), patients with high-RSP have both shorter overall survival (OS) (HR 4.95, 95%CI 2.90-8.46) and progression-free survival (PFS) (HR 3.69, 95%CI 2.24-6.10) than those with low-RSP. In addition, adjuvant therapy improved OS (HR 0.47, 95%CI 0.29-0.77) and PFS (HR 0.36, 95%CI 0.21-0.62) only for patients with high but not low RSP. These findings are consistent in both training and validation cohort.

CONCLUSIONS

The tsRNA-based signature not only has the potential for diagnosis and prognosis but also may serve as a pre-operative biomarker to select patients who would benefit from adjuvant therapy.

TRIAL REGISTRATION

A prospective study of diagnosis biomarkers of esophageal squamous cell carcinoma, ChiCTR2000031507 . Registered 3 April 2016 - Retrospectively registered.

CHI3L1 (Chitinase 3 Like 1) upregulation is associated with macrophage signatures in esophageal cancer

Chitinase-3 like-protein-1 (CHI3L1) has been found to be overexpressed in many cancers and increased CHI3L1 level in serum seems to correlate with a poor prognosis in patients with metastatic cancer. However, the expression of CHI3L1 and its potential role in esophageal cancer remains unclear. We retrieved publicly available RNA-seq datasets of esophageal cancer tissues and normal esophageal tissues. We analyzed the correlation between CHI3L1 expression with different clinical parameters (such as T stages, N stage, response to treatment and tumor residues after treatment), the relationship between CHI3L1 expression level and prognosis, and the relationship between CHI3L1 expression and different immune cell signatures in esophageal cancer tissues. A transgenic mouse model of esophageal carcinoma was used to validate CHI3L1 expression and its association with macrophage signature gene expression. The effect of recombinant CHI3L1 on macrophage polarization was assessed in cell model. We showed the upregulation of CHI3L1 in esophageal cancer tissues in comparison to normal esophageal tissues, and its upregulation was positively associated with tumor size. The analysis of immunological signatures and CHI3L1 expression indicated that CHI3L1 level was highly correlated with increased expression of macrophage signature genes in esophageal tumor tissues. CHI3L1 was also upregulated in the esophagus dysplasia tissues in a transgenic mouse model. Recombinant CHI3L1 treatment favored M2 gene expression in LPS-stimulated RAW 264.7 macrophage cell line. CHI3L1 overexpression may favor macrophage recruitment in esophageal tumor tissues. Future studies are needed to delineate the mechanisms of CHI3L1-mediated macrophage recruitment and polarization in tumor tissues.

Evaluation of 2 Commercially Systems for Detection of Serum Squamous Cell Carcinoma Antigen in Pan Squamous Cell Carcinoma

BACKGROUND

This study compared the analytical performance of the Elecsys 602 (Roche Diagnostics) system with the I2000 (Abbott laboratories) system for the quantitative measurement of squamous cell carcinoma antigen (SCCA) to assess its role as an indicator in pan squamous cell carcinoma.

METHODS

435 serum samples included pan squamous cell cancer group (n = 318) and healthy subjects (n = 52) and non-squamous cell group (n = 41) and benign diseases group (n = 24) were measured by 2 systems and compared.

RESULTS

The within-run precision coefficient of variation (CV) for Abbott and Roche systems were 3.34-4.88% and 0.95 -1.96%, and the total precision CV were 2.89-9.48% and 3.97-5.38%, respectively. Good correlation was showed in Abbott and Roche systems (slopes = 0.749, r = 0.9658). Serum SCCA in the groups of nasopharyngeal carcinomas, lung squamous cell carcinoma, esophageal squamous cell carcinoma, bladder cancer and cervical squamous cell carcinoma under the curve area (AUC) was more than 0.5, while the AUC in the non- nasopharyngeal carcinomas head and neck squamous cell carcinoma was less than 0.5. The AUC of 2 systems was statistically different in lung squamous cell carcinoma and nasopharyngeal carcinomas (P < 0.05). The levels of SCCA of 2 systems were similarities in esophageal squamous cell carcinoma(stage IV vs. stage 0a-II)and bladder cancer(stage I vs. stage Oa)and cervical squamous cell carcinoma(stage IIB-III vs. stage I-IIA), which advanced stage had higher level of SCCA than early stage. But the SCCA levels of 2 systems were inconsistent in bladder cancer (stage II-IV vs. stage Oa in Abbott), head and neck squamous cell carcinoma (stage IV vs. stage Oa-I in the Roche) and lung squamous cell carcinoma (stage III vs. stage I-II in the Roche). (P < 0.05).

CONCLUSIONS

2 systems correlated well in SCCA detection of squamous cell carcinoma, but there were individual differences. Serum SCCA may also contribute to the diagnosis of bladder cancer.

Serum Exosomal Dicer Is a Useful Biomarker for Early Detection of Differentiated Gastric Adenocarcinoma

BACKGROUND AND AIM

A recent basic study identified that Dicer is contained in exosomes derived from cancer cells and plays crucial roles in microRNA maturation and cancer development. Based on this novel basic concept, we analyzed the usefulness of serum exosomal Dicer as a diagnostic biomarker for gastrointestinal cancers.

METHODS

Enrolled participants (691) were categorized into 3 groups: gastric cancer (GC) cohort, 183 patients (90 healthy controls (HCs) and 93 GC patients); esophageal cancer (EC) cohort, 115 patients (90 HCs and 25 EC patients); and colorectal cancer (CRC) cohort, 188 patients (92 HCs and 96 CRC patients) after age- and sex matching using the propensity score. The quality of isolated serum exosomes was validated with an electron microscope, particle size analyzer, and exosome marker, CD63.

RESULTS

Serum exosomal Dicer was significantly higher in the GC group than in the HC group (p = 0.004), whereas no significant differences were found in both EC and CRC cohorts. Serum exosomal Dicer was significantly higher in only differentiated gastric adenocarcinoma and not in the undifferentiated type. Moreover, serum exosomal Dicer showed no significant differences regardless of Helicobacter pylori (H. pylori) status. The biomarker panel combining serum exosomal Dicer with H. pylori status distinguished between HC and differentiated GC patients with an area under the curve (AUC) of 0.762. As for early-stage diagnosis, this combination distinguished between HC and stage I differentiated GC with an AUC = 0.758.

CONCLUSIONS

Serum exosomal Dicer is a potential noninvasive diagnostic biomarker for early detection of differentiated gastric adenocarcinoma.

Urinary microRNA biomarkers for detecting the presence of esophageal cancer

Esophageal cancer (EC) including esophageal squamous cell carcinoma (ESCC) and adenocarcinoma (EAC) generally exhibits poor prognosis; hence, a noninvasive biomarker enabling early detection is necessary. Age- and sex-matched 150 healthy controls (HCs) and 43 patients with ESCC were randomly divided into two groups: 9 individuals in the discovery cohort for microarray analysis and 184 individuals in the training/test cohort with cross-validation for qRT-PCR analysis. Using 152 urine samples (144 HCs and 8 EACs), we validated the urinary miRNA biomarkers for EAC diagnosis. Among eight miRNAs selected in the discovery cohort, urinary levels of five miRNAs (miR-1273f, miR-619-5p, miR-150-3p, miR-4327, and miR-3135b) were significantly higher in the ESCC group than in the HC group, in the training/test cohort. Consistently, these five urinary miRNAs were significantly different between HC and ESCC in both training and test sets. Especially, urinary miR-1273f and miR-619-5p showed excellent values of area under the curve (AUC) ≥ 0.80 for diagnosing stage I ESCC. Similarly, the EAC group had significantly higher urinary levels of these five miRNAs than the HC group, with AUC values of approximately 0.80. The present study established novel urinary miRNA biomarkers that can early detect ESCC and EAC.

Identifying Novel Biomarkers Ready for Evaluation in Low-Prevalence Populations for the Early Detection of Upper Gastrointestinal Cancers: A Systematic Review

Introduction

Detecting upper gastrointestinal (GI) cancers in primary care is challenging, as cancer symptoms are common, often non-specific, and most patients presenting with these symptoms will not have cancer. Substantial investment has been made to develop biomarkers for cancer detection, but few have reached routine clinical practice. We aimed to identify novel biomarkers for upper GI cancers which have been sufficiently validated to be ready for evaluation in low-prevalence populations.

Methods

We systematically searched MEDLINE, Embase, Emcare, and Web of Science for studies published in English from January 2000 to October 2019 (PROSPERO registration CRD42020165005). Reference lists of included studies were assessed. Studies had to report on second measures of diagnostic performance (beyond discovery phase) for biomarkers (single or in panels) used to detect pancreatic, oesophageal, gastric, and biliary tract cancers. We included all designs and excluded studies with less than 50 cases/controls. Data were extracted on types of biomarkers, populations and outcomes. Heterogeneity prevented pooling of outcomes.

Results

We identified 149 eligible studies, involving 22,264 cancer cases and 49,474 controls. A total of 431 biomarkers were identified (183 microRNAs and other RNAs, 79 autoantibodies and other immunological markers, 119 other proteins, 36 metabolic markers, 6 circulating tumour DNA and 8 other). Over half (n = 231) were reported in pancreatic cancer studies. Only 35 biomarkers had been investigated in at least two studies, with reported outcomes for that individual marker for the same tumour type. Apolipoproteins (apoAII-AT and apoAII-ATQ), and pepsinogens (PGI and PGII) were the most promising biomarkers for pancreatic and gastric cancer, respectively.

Conclusion

Most novel biomarkers for the early detection of upper GI cancers are still at an early stage of matureness. Further evidence is needed on biomarker performance in low-prevalence populations, in addition to implementation and health economic studies, before extensive adoption into clinical practice can be recommended.

Electronic Supplementary Material

The online version of this article (10.1007/s12325-020-01571-z) contains supplementary material, which is available to authorized users.

Current Achievements and Applications of Transcriptomics in Personalized Cancer Medicine

Over the last decades, transcriptome profiling emerged as one of the most powerful approaches in oncology, providing prognostic and predictive utility for cancer management. The development of novel technologies, such as revolutionary next-generation sequencing, enables the identification of cancer biomarkers, gene signatures, and their aberrant expression affecting oncogenesis, as well as the discovery of molecular targets for anticancer therapies. Transcriptomics contribute to a change in the holistic understanding of cancer, from histopathological and organic to molecular classifications, opening a more personalized perspective for tumor diagnostics and therapy. The further advancement on transcriptome profiling may allow standardization and cost reduction of its analysis, which will be the next step for transcriptomics to become a canon of contemporary cancer medicine.

Optimized Cutoff Value of Serum Squamous Cell Carcinoma Antigen Concentration Accurately Predicts Recurrence After Curative Resection of Squamous Cell Carcinoma of the Esophagus

BACKGROUND

Squamous cell carcinoma antigen (SCC-Ag) and carcinoembryonic antigen (CEA) are widely used in clinical practice to predict the prognosis of patients with esophageal squamous cell carcinoma (ESCC). However, their predictive values for prognosis are controversial. This study determined optimal cutoff values of serum SCC-Ag and CEA concentrations for predicting postoperative recurrence of ESCC, which enabled selection of high-risk patients.

METHODS

The study retrospectively analyzed 427 patients who underwent curative resection for ESCC. The optimal cutoff values of preoperative SCC-Ag and CEA concentrations for predicting postoperative recurrence were determined using combined analysis of hazard ratios and sensitivities for recurrence. Using the optimal cutoff value, the study evaluated survival, recurrence patterns, and temporal changes in marker concentrations.

RESULTS

The preoperative SCC-Ag concentration of 1.1 ng/ml was the optimal cutoff value for predicting postoperative recurrence, whereas precise cutoff values could not be determined for preoperative CEA concentrations. High preoperative SCC-Ag concentrations (> 1.1 ng/ml), which were significantly associated with more aggressive tumor phenotypes and shorter disease-free survival, were identified as an independent prognostic factor in the multivariable analysis. High preoperative SCC-Ag concentrations were significantly associated with greater prevalence of lung/pleura and local recurrences. Normalization of serum SCC-Ag concentrations after neoadjuvant treatment or esophagectomy was not associated with a decreased risk of postoperative recurrence.

CONCLUSIONS

The optimal cutoff value of preoperative SCC-Ag concentrations that predicted recurrence of ESCC was 1.1 ng/ml, illuminating the utility of serum SCC-Ag concentrations as an easily measurable tool for selecting a perioperative management strategy.

Etiology, cancer stem cells and potential diagnostic biomarkers for esophageal cancer

Esophageal cancer (EC) has been a leading cause of cancer death worldwide in part due to late detection and lack of precision treatment. EC includes two major malignancies, esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC). Recent studies reveal that ESCC and EAC have distinct cell of origin and contain cancer stem cells (also known as tumor initiating cells) expressing different cell surface markers. These biomarkers have potentially important values for both early detection and finding effective therapy. In this review we summarize the updated findings for cell of origin and provide an overview of cancer cell biomarkers that have been tested for ESCC and EAC. In addition, we also discuss recent progress in the study of molecular mechanisms leading to these malignancies.

The Diagnostic Value of Serum IGFBP7 in Patients with Esophageal Squamous Cell Carcinoma

Esophageal squamous cell cancer (ESCC) is one of the leading malignant cancer in the world and especially in China with high incidence and mortality. The exploration of novel serum biomarkers is required for early detection of ESCC. We investigated the diagnostic value of serum insulin like growth factor binding protein 7 (IGFBP7) in ESCC, evaluating its potential to improve the diagnosis of ESCC. The serum samples of 106 patients with ESCC and 107 normal controls were tested by enzyme-linked immunosorbent assay (ELISA). The levels of IGFBP7 in ESCC group were significantly higher than that in normal controls, compared by the Mann-Whitney U test (P<0.0001). Using receiver operating characteristic (ROC) curve, the diagnostic value of serum IGFBP7 was demonstrated. Versus normal group, the area under the ROC curve (AUC) of all ESCC was 0.794 (95%CI: 0.735-0.853) and early-stage ESCC was 0.725 (95%CI: 0.633-0.817). With optimized cutoff value of 2.993 ng/mL, IGFBP7 showed certain diagnostic value with specificity of 90.7%, sensitivities of 40.6% and 32.4% in ESCC and early-stage ESCC, respectively. Considering the correlation between clinical data and IGFBP7, no significant association was found (all P>0.05). Thus, we supposed that serum IGFBP7 might be a potential biomarker in the diagnosis of ESCC.

Low-density lipoprotein promotes lymphatic metastasis of esophageal squamous cell carcinoma and is an adverse prognostic factor

The purpose of the current study was to investigate the prognostic role of preoperative serum lipid levels in patients with esophageal squamous cell carcinoma (ESCC) and to preliminarily explore the mechanism of serum lipids in this disease. Preoperative lipids, including total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol and triglyceride levels, were assessed in 242 patients with ESCC. To eliminate the influence of nutritional status, all patients had previously undergone esophagectomy. Univariate and multivariate Cox regression analyses were performed to identify predictors of overall survival (OS). Associations between significant lipid targets and clinical features were then analyzed and the results were validated using TE-1 and ECa109 esophageal cancer cell lines. The cell proliferation was evaluated with a Cell Counting Kit-8 (CCK8) assay and the cell cycle was assessed with propidium iodide staining and flow cytometry. Univariate analysis revealed that HDL (P=0.048), LDL (P=0.020), Pathological T-staging status (pT status) (P=0.001), Pathological N-staging status (pN status) (P=0.001) and histological differentiation (P=0.002) were significantly associated with OS. Based on multivariate analysis, LDL [hazard ratio (HR)=2.164, P=0.005], pT status (HR=1.714, P=0.001), pN status (HR=1.966, P=0.001) and histological differentiation (HR=4.083, P=0.002) were risk factors in patients with ESCC. A high LDL level (>3.12 mmol/l) was associated with sex (P=0.001), tumor location (P=0.004) and a higher susceptibility to lymphatic metastasis (P=0.007). A CCK8 assay demonstrated that LDL promoted TE-1 and ECa109 cell proliferation, and flow cytometry analysis revealed that treatment with LDL at an appropriate concentration resulted in an accumulation of cells in G2 phase and decreased the number of cells in G1 phase. In summary, the current study identified that preoperative LDL serum level serves an important role in predicting ESCC outcome as LDL promotes lymphatic metastasis. Furthermore, a preliminary mechanism for this association has been validated in vitro.

Long non-coding RNAs in esophageal cancer: molecular mechanisms, functions, and potential applications

Esophageal cancer (EC) is the sixth leading cause of cancer-related death worldwide. The lack of early diagnostic biomarkers and effective prognostic indicators for metastasis and recurrence has resulted in the poor prognosis of EC. In addition, the underlying molecular mechanisms of EC development have yet to be elucidated. Accumulating evidence has demonstrated that lncRNAs play a vital role in the pathological progression of EC. LncRNAs may regulate gene expression through the recruitment of histone-modifying complexes to the chromatin and through interactions with RNAs or proteins. Recent evidence has demonstrated that the dysregulation of lncRNAs plays important roles in the proliferation, metastasis, invasion, angiogenesis, apoptosis, chemoradiotherapy resistance, and stemness of EC, which suggests potential clinical implications. In this review, we highlight the emerging roles and regulatory mechanisms of lncRNAs in the context of EC and discuss their potential clinical applications as diagnostic and prognostic biomarkers.

Elevated levels of serum nidogen-2 in esophageal squamous cell carcinoma

BACKGROUND

Nidogen-2 (NID2), a secretory basement membrane protein, has been implicated as a potential biomarker in ovarian cancer and hepatocellular carcinoma.

OBJECTIVE

In this study, we aimed to investigate the utility of detecting serum NID2 levels for identification of esophageal squamous cell carcinoma (ESCC) patients and prediction of poor survival outcome.

METHODS

Using an in-house NID2 enzyme-linked immunosorbent assay (ELISA), serum samples from 101 ESCC patients and 50 healthy controls were screened for their NID2 levels.

RESULTS

The serum NID2 levels in ESCC patients (median 24.4 μg/L) are significantly higher (p= 4.3e-09) than that of the healthy controls (median 15.85 μg/L). The receiver operating characteristic (ROC) curve demonstrated an area under the curve of 0.756. At the threshold of 17.95 μg/L, the sensitivity and specificity achieved are 0.76 and 0.63, respectively. Kaplan-Meier survival analysis revealed that patients with high serum NID2 levels (⩾ 32.6 μg/L) have significantly higher risk of death (HR = 1.984, 95% CI: 1.175-3.349; log-rank p-value = 0.012) compared to those with low serum NID2 levels (< 20.0 μg/L).

CONCLUSIONS

In conclusion, we show that detecting the elevation of serum NID2 levels has potential diagnostic and prognostic value for ESCC patients.

The diagnostic value of long non-coding RNA MIR31HG and its role in esophageal squamous cell carcinoma

AIMS

This study aimed to assess plasma lncRNA microRNA-31 hist gene (MIR31HG) as a novel diagnostic and therapeutic biomarker for esophageal squamous cell carcinoma (ESCC) and to investigate its role in ESCC.

MAIN METHODS

The expression of MIR31HG, Furin and MMP1 was examined via quantitative real-time polymerase chain reaction. MIR31HG expression between plasma and ESCC tissues was compared using Pearson correlation analysis; furthermore, the association between Furin/MMP1 levels and MIR31HG levels in ESCC tissues was analyzed. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic value of plasma MIR31HG. A WST-1 assay was performed to assess cell proliferation. The migratability and invasiveness of cells was determined via Transwell assays.

KEY FINDINGS

MIR31HG was significantly upregulated in ESCC tissues and plasma (P < 0.01). A significant positive association was obtained between plasma and tissue MIR31HG expression in ESCC (r = 0.78, P < 0.01). Furthermore, MIR31HG displayed high diagnostic sensitivity and specificity for predicting ESCC occurance. Furthermore, knockdown of MIR31HG suppressed the capacity for proliferation, migration, and invasion of ESCC cells (P < 0.01). In addition, silencing of MIR31HG inhibited the expression of Furin and MMP1 in EC9706 and EC1 and the level of Furin/MMP1 in ESCC tissues displayed a significant positive correlation with MIR31HG (P < 0.01).

SIGNIFICANCE

MIR31HG can be used as a novel potential diagnostic biomarker and a potential therapeutic target for ESCC.

Potential suppressive effects of theophylline on human rectal cancer SW480 cells in vitro by inhibiting YKL-40 expression

Chitinase-3-like-1 protein (YKL-40), a member of the mammalian chitinase-like glycoproteins, serves a key role in the pathogenesis of rectal cancer. The present study examined the antitumor effect of theophylline, a pan-chitinase inhibitor, in rectal cancer in vitro and investigated the mechanism by which it acted. SW480 cell lines were treated with varying theophylline concentrations (10^-2, 10^-3, 10^-4 and 10^-5 mol/l). An MTT assay was used to observe cell proliferation and identify the optimal theophylline concentration. Western blotting was used to analyze YKL-40 expression. The cell cycle distribution of SW480 cell lines treated with theophylline was measured by flow cytometry. The angiopoietin-2 expression level was measured by ELISA. The expression levels of YKL-40 were evidently decreased in theophylline-treated SW480 cell lines. The proliferation of SW480 cells was inhibited following theophylline treatment, which was associated with G₁ phase cell cycle arrest and a decrease in the expression of angiopoietin-2. The mechanism of theophylline action may involve the downregulation of YKL-40 expression, arrest of the cell cycle at G₁ phase and inhibition of angiopoietin-2 expression. These results provide a rationale for the potential use of anti-YKL-40 and anti-angiogenic strategies in treating rectal cancer.

Evaluation of the circulating level of fibroblast activation protein α for diagnosis of esophageal squamous cell carcinoma

To evaluate whether circulating fibroblast activation protein α (FAPα) could serve as a biomarker for the diagnosis of esophageal squamous cell carcinoma (ESCC), enzyme-linked immunosorbent assay (ELISA) was used to detect plasma FAPα in 556 participants including ESCC group, benign esophageal disease group, healthy controls and other cancer controls group. The levels of plasma FAPα were significantly decreased in ESCC patients (P < 0.001) and showed a positive correlation with HDL-C levels (R = 0.372, P < 0.001). The sensitivity and specificity of plasma FAPα were 56.1% and 85.6% based on the optimal cut-off (49.04 ng/ml, AUC = 0.714). The combination of FAPα and the traditional biomarkers (CEA, CYFR211 and SCCA) improved the sensitivity (41.5%) without compromising the specificity (95.0%). Contradictorily, the immunohistochemical staining revealed the overexpression of FAPα in stroma of ESCC tissues. So the source of soluble FAPα was further explored by qRT-PCR, Western blotting, ELISA and immunoprecipitation in fibroblast cell lines and mouse xenograft models. We found that the plasma FAPα was not correlated with the FAPα expressed in tumor, and the multi-organ might contribute to the circulating levels of FAPα including skeletal muscle, liver and bone marrow. These results indicated that the low plasma FAPα level might due to the systemic reaction to the presence of tumor and circulating FAPα level might be a potential indicator for diagnosing ESCC.

Preoperative serum immunoglobulin G and A antibodies to Porphyromonas gingivalis are potential serum biomarkers for the diagnosis and prognosis of esophageal squamous cell carcinoma

Background

The key-stone-pathogen, Porphyromonas gingivalis associates not only with periodontal diseases but with a variety of other chronic diseases such as cancer. We previously reported an association between the presence of Porphyromonas gingivalis in esophageal squamous cell carcinoma (ESCC) and its progression. We now report the diagnostic and prognostic potential of serum immunoglobulin G and A antibodies (IgG/A) against Porphyromonas gingivalis for ESCC.

Methods

An enzyme-linked immunosorbent assay (ELISA) was used to determine the serum levels of Porphyromonas gingivalis IgG and IgA in 96 cases with ESCC, 50 cases with esophagitis and 80 healthy controls.

Results

The median serum levels of IgG and IgA for P. gingivalis were significantly higher in ESCC patients than non-ESCC controls. P. gingivalis IgG and IgA in serum demonstrated sensitivities/specificities of 29.17%/96.90% and 52.10%/70.81%, respectively, and combination of IgG and IgA produced a sensitivity/specificity of 68.75%/68.46%. The diagnostic performance of serum P. gingivalis IgA for early ESCC was superior to that of IgG (54.54% vs. 20.45%). Furthermore, high serum levels of P. gingivalis IgG or IgA were associated with worse prognosis of ESCC patients, in particular for patients with stage 0-IIor negative lymphnode metastasis, and ESCC patients with high levels of both IgG and IgA had the worst prognosis. Multivariate analysis revealed that lymph node status, IgG and IgA were independent prognostic factors.

Conclusions

The IgG and IgA for P. gingivalis are potential serum biomarkers for ESCC and combination of IgG and IgA improves the diagnostic and prognostic performance. Furthermore, serum P. gingivalis IgG and IgA can detect early stage ESCC.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3905-1) contains supplementary material, which is available to authorized users.

Chitinase 3-like 1 secreted by peritumoral macrophages in esophageal squamous cell carcinoma is a favorable prognostic factor for survival

AIM

To identify whether chitinase 3-like 1 (CHI3L1) serves as a suitable biomarker for the prognosis of esophageal squamous cell carcinoma (ESCC) and to analyze this protein’s cellular source.

METHODS

An ELISA was conducted to detect the concentration of CHI3L1 in the serum of 150 ESCC patients diagnosed between January 2001 and February 2005. The prognostic relevance of CHI3L1 was evaluated by a Kaplan-Meier and Cox regression analysis. The immunohistochemistry was reanalyzed, and fluorescent staining was utilized to explore the cellular origins of CHI3L1. We stimulated monocyte-derived macrophages (MDMs) with either IL-6 or the supernatant of the ESCC cell line Eca-109 and later investigated the level of CHI3L1 by qPCR and ELISA.

RESULTS

The level of serum CHI3L1 was higher in older patients (≥ 60) than in patients under the age of 60 (P = 0.001). The patients with higher levels of CHI3L1 had a significantly shorter overall survival, whereas the traditional markers, carcinoembryonic antigen and squamous cell carcinoma antigen, were less effective (P > 0.05). A multivariate Cox analysis (P = 0.001) indicated that CHI3L1 was an independent prognostic factor for ESCC patients. Peritumoral macrophages in ESCC exhibited high levels of CHI3L1. Interleukin-6 (IL-6) and the supernatant of Eca-109 containing IL-6 stimulated MDMs to secrete CHI3L1. The serum concentration of CHI3L1 in the ESCC patients showed a weak correlation with the laboratory inflammatory parameters neutrophil (NEU, P = 0.045), neutrophil/lymphocyte rate (NLR, P = 0.016), and C-reactive protein (CRP, P < 0.001).

CONCLUSION

Our study first established a connection between the pretreated CHI3L1 and patients with ESCC, and the serum CHI3L1 was primarily secreted by ESCC-surrounded macrophages.

Combined detection of Twist1, Snail1 and squamous cell carcinoma antigen for the prognostic evaluation of invasion and metastasis in cervical squamous cell carcinoma

BACKGROUND

Cervical cancer is one of the most common malignant tumours of the female reproductive system, ranking second only to breast cancer in morbidity worldwide. Essential features of the progression of cervical cancer are invasion and metastasis, which are closely related to disease prognosis and mortality rate. At the present time there is no effective method to evaluate cancer invasion and metastasis before surgery. Here we report our study on molecular changes in biopsy tissue for the prognostic evaluation of cancer invasion and metastasis.

PATIENTS AND METHODS

Expression of the epithelial-mesenchymal transition-inducing transcription factors Twist1 and Snail1 was detected by immunohistochemistry in 32 normal, 36 low-grade squamous intraepithelial neoplasia (LSIL), 54 high-grade squamous intraepithelial neoplasia (HSIL) and 320 cervical squamous cell carcinoma (CSCC) samples. The correlation between the expression of Twist1, Snail1 and squamous cell carcinoma antigen (SCCA) in CSCC tissues and clinical pathology results was evaluated. A transwell migration and invasion assay was used to explore the roles of Twist1 and Snail1 in the invasion of cancer cells. Lymph node metastasis and lymphovascular space invasion (LVSI) rates for the following groups were analysed: SCCA(+) group, Twist1(+) group, Snail1(+) group, Twist1(+)Snail1(+)group, Twist1(+)SCCA(+)group, Snail1(+)SCCA(+)group and Twist1(+)Snail1(+)SCCA(+) group.

RESULTS

The expression of Twist1 and Snail1 was significantly upregulated in HSIL and CSCC (p < 0.05). Twist1 and Snail1 expression levels were associated with LVSI, lymph node metastasis and histological grade (p < 0.05) but not with age or FIGO stage (p > 0.05). The expression of SCCA was associated with LVSI, lymph node metastasis, FIGO stage and histological grade (p < 0.05) but not with age (p > 0.05). Twist1 was an independent factor contributing to the invasion ability of cervical cancer cells. In addition, the positive rate of lymph node metastasis and LVSI was higher in the Twist1(+)Snail1(+)SCCA(+) group than in the SCCA(+) group, Twist1(+) group and Snail1(+) group, respectively (p < 0.05).

CONCLUSION

Combined detection of Twist1 and Snail1 in SCCA-positive biopsy specimens may be a potential method for evaluating the invasion and metastasis of CSCC prior to surgery.

Prognostic value of pretreatment serum alanine aminotransferase/aspartate aminotransferase (ALT/AST) ratio and gamma glutamyltransferase (GGT) in patients with esophageal squamous cell carcinoma

BACKGROUND

The levels of liver function tests (LFTs) are often used to assess liver injury and non-liver disease-related mortality. In our study, the relationship between pretreatment serum LFTs and overall survival (OS) was evaluated in esophageal squamous cell carcinoma (ESCC) patients.

METHODS

Our purpose was to investigate the prognostic value of the preoperative alanine aminotransferase/aspartate aminotransferase (ALT/AST) ratio and gamma glutamyltransferase (GGT) in ESCC patients. A retrospective study was performed in 447 patients with ESCC, and follow-up period was at least 60 months until death. The prognostic significance of serum LFTs were determined by univariate and multivariate Cox hazard models.

RESULTS

LFTs including ALT, AST, LSR, GGT, TBA and LDH were analyzed. Serum LSR (HR: 0.592, 95% CI = 0.457-0.768, p < 0.001 and GGT (HR: 1.507, 95% CI = 1.163-1.953, p = 0.002) levels were indicated as significant predictors of OS. The 5-year OS among patients with higher LSR levels was longer compared with those patients with decreased LSR levels, not only in the whole cohort but also in the subgroups stratified by pathological stage (T1-T2 subgroup, T3-T4 subgroup, N0 subgroup and M0 subgroup). We also found that patients with a higher GGT might predict worse OS than patients with a normal GGT, not only in the whole cohort but also in the subgroups stratified by pathological stage (T3-T4 subgroup and N1-N2 subgroup).

CONCLUSIONS

Both increased levels of LSR and decreased levels of GGT might predict shorter overall survival in ESCC patients. Our findings suggest that serum LSR and GGT levels could be used as a key predictor of survival in patients with ESCC.

Development and Validation of a Serum Biomarker Panel for the Detection of Esophageal Squamous Cell Carcinoma through RNA Transcriptome Sequencing

Serum tumor markers for the diagnosis of esophageal squamous cell carcinoma (ESCC) have low sensitivity. This study aims to identify new serum markers for ESCC diagnosis from RNA sequencing (RNA-seq) data.

RNA-seq was performed using six pairs of ESCC and matched normal tissues. The candidates for ESCC were screened from the differentially expressed genes. The candidates were analyzed by ELISA from the serum of a test group and a validation group. Real-time PCR, Western blotting and immunohistochemistry were used to detect the expression of the candidates in tumor cell lines and tumor tissues.

Ten genes were selected from the RNA-seq data. Serum levels of ADAM12, CHI3L1, MMP13 and SPP1 were significantly higher in the ESCC patients than in the healthy controls. A diagnostic model combining CHI3L1, MMP13, and SPP1 was established. The area under the curve (AUC) values for serum CHI3L1, MMP13, and SPP1 and the diagnostic model for discriminating ESCC patients from controls were 0.732, 0.881, 0.661 and 0.928, respectively. In the validation cohort, the AUC values were 0.753, 0.789, 0.696 and 0.843, respectively. Moreover, the AUC of the model for classifying patients with early ESCC was 0.918 in the test group and 0.857 in the validation group. Overexpression of CHI3L1, MMP13 and SPP1 was observed in the tumor cell lines and tissues.

The diagnostic model composed of CHI3L1, MMP13 and SPP1 discriminates ESCC patients with high sensitivity. Our data highlight the potential of this diagnostic model for the noninvasive diagnosis of ESCC.

Role of chitinase-like proteins in cancer

Chitinase-like proteins (CLPs) are lectins combining properties of cytokines and growth factors. Human CLPs include YKL-40, YKL-39 and SI-CLP that are secreted by cancer cells, macrophages, neutrophils, synoviocytes, chondrocytes and other cells. The best investigated CLP in cancer is YKL-40. Serum and plasma levels of YKL-40 correlate with poor prognosis in breast, lung, prostate, liver, bladder, colon and other types of cancers. In combination with other circulating factors YKL-40 can be used as a predictive biomarker of cancer outcome. In experimental models YKL-40 supports tumor initiation through binding to RAGE, and is able to induce cancer cell proliferation via ERK1/2-MAPK pathway. YKL-40 supports tumor angiogenesis by interaction with syndecan-1 on endothelial cells and metastatic spread by stimulating production of pro-inflammatory and pro-invasive factors MMP9, CCL2 and CXCL2. CLPs induce production of pro- and anti-inflammatory cytokines and chemokines, and are potential modulators of inflammatory tumor microenvironment. Targeting YKL-40 using neutralizing antibodies exerts anti-cancer effect in preclinical animal models. Multifunctional role of CLPs in regulation of inflammation and intratumoral processes makes them attractive candidates for tumor therapy and immunomodulation. In this review we comprehensively analyze recent data about expression pattern, and involvement of human CLPs in cancer.

High level of serum apolipoprotein A-I is a favorable prognostic factor for overall survival in esophageal squamous cell carcinoma

Background

Noninvasive prognostic tools for esophageal squamous cell carcinoma (ESCC) are urgently needed. Serum lipids and lipoproteins are used for the prognosis of certain diseases; however, the prognostic value of serum apolipoprotein A-I (ApoA-I) in ESCC has not been described.

Methods

Pre-treatment serum lipids and lipoprotein concentrations (including ApoA-I, Apo-B, HDL-C, LDL-C, TC and TG) were analyzed retrospectively and compared between 210 patients with ESCC and 219 healthy controls. The prognostic significance of serum lipids and lipoproteins was determined by univariate and multivariate Cox hazard models in ESCC.

Results

Clinical characteristics (age, sex, pT status, pN status, pM status, pTNM status, histological differentiation or alcohol index) had no influence on baseline ApoA-I level. Serum ApoA-I, HDL-C, LDL-C, and TC levels were significantly lower and Apo-B was significantly higher in ESCC patients than in normal controls. On univariate analysis, ApoA-I, alcohol index, pT status, pN status and pTNM status were associated with significantly poor survival, and ApoA-I (p = 0.039), alcohol index (p = 0.037) and pTNM status (p = 0.000) were identified as prognostic factors associated with shorter survival in the multivariate analysis.

Conclusions

Overall survival was shorter in ESCC patients with decreased pre-treatment ApoA-I levels. Our findings suggest that serum ApoA-I level should be evaluated as a predictor of survival in patients with ESCC.

Serum miR-1297: a promising diagnostic biomarker in esophageal squamous cell carcinoma

We aimed to value the diagnostic potential of serum miR-1297 in esophageal squamous cell cancer (ESCC). Its expression level was detected in 156 pairs of patients with ESCC and healthy volunteers using quantitative real-time polymerase chain reaction (qRT-PCR) method. It was statistically decreased in ESCC patients compared with healthy controls. AUC based on serum miR-1297 was 0.840 ± 0.035 in discovery group and 0.837 ± 0.034 in validation group. Further analysis on early-stage patients revealed that the AUC was 0.819 ± 0.053 in discovery group and 0.814 ± 0.044 in validation group. Its sensitivity and specificity were promising. In conclusion, serum miR-1297 can serve as an ideal indicator for the diagnosis of ESCC.

Expression of YKL-40 and MIP-1a proteins in exudates and transudates: biomarkers for differential diagnosis of pleural effusions? A pilot study

Background

YKL-40 is an extracellular matrix glycoprotein with a significant role in tissue inflammation and remodeling. MIP-1a has chemotactic and pro-inflammatory properties, and is induced by YKL-40 in several lung disorders. The aim of this study was to determine the levels of YKL-40 and MIP-1a in blood serum and pleural fluids of various pulmonary diseases, and to evaluate their potential role as differential diagnosis biomarkers.

Methods

We recruited 60 patients (age: 62.5 ± 20.6 years) with pleural effusions: 49 exudates and 11 transudates (T). Exudates were further classified based on the underlying disease: ten with tuberculosis (TB), 13 with lung cancer (LCa), 15 with metastatic cancer (MCa) of non-lung origin and 11 with parapneumonic (PN) effusions. YKL-40 and MIP-1a levels were measured by ELISA.

Results

Pleural YKL-40 levels (ng/ml) were similar among all patient groups (TB: 399 ± 36, LCa: 401 ± 112, MCa: 416 ± 34, PN: 401 ± 50, T: 399 ± 42, p = 0.92). On the contrary, YKL-40 was significantly lower in the serum of TB patients (TB: 58 ± 22, LCa: 212 ± 106, MCa: 254 ± 140, PN: 265 ± 140, T: 229 ± 123, p < 0.001). Pleural MIP-1a protein levels (ng/ml) were statistically lower only in patients with LCa (TB: 25.0 ± 20.2, LCa: 7.3 ± 6.0, MCa: 16.1 ± 14.9, PN: 25.4 ± 27.9, T: 18.5 ± 7.9, p = 0.012), a finding also observed in serum MIP-1a levels (TB: 17.1 ± 7.6, LCa: 9.4 ± 7.0, MCa: 28.7 ± 28.7, PN: 33.3 ± 24.0, T: 22.9 ± 8.7, p = 0.003).

Conclusions

Our data suggest that both YKL-40 and MIP-1a, particularly in serum, could prove useful for the differentiation of pleural effusions in clinical practice, especially of TB or LCa origin. However, large-scale studies are needed to validate these findings.

Consensus reference gene(s) for gene expression studies in human cancers: end of the tunnel visible?

BACKGROUND

Gene expression studies are increasingly used to provide valuable information on the diagnosis and prognosis of human cancers. Also, for in vitro and in vivo experimental cancer models gene expression studies are widely used. The complex algorithms of differential gene expression analyses require normalization of data against a reference or normalizer gene, or a set of such genes. For this purpose, mostly invariant housekeeping genes are used. Unfortunately, however, there are no consensus (housekeeping) genes that serve as reference or normalizer for different human cancers. In fact, scientists have employed a wide range of reference genes across different types of cancer for normalization of gene expression data. As a consequence, comparisons of these data and/or data harmonizations are difficult to perform and challenging. In addition, an inadequate choice for a reference gene may obscure genuine changes and/or result in erroneous gene expression data comparisons.

METHODS

In our effort to highlight the importance of selecting the most appropriate reference gene(s), we have screened the literature for gene expression studies published since the turn of the century on thirteen of the most prevalent human cancers worldwide.

CONCLUSIONS

Based on the analysis of the data at hand, we firstly recommend that in each study the suitability of candidate reference gene(s) should carefully be evaluated in order to yield reliable differential gene expression data. Secondly, we recommend that a combination of PPIA and either GAPDH, ACTB, HPRT and TBP, or appropriate combinations of two or three of these genes, should be employed in future studies, to ensure that results from different studies on different human cancers can be harmonized. This approach will ultimately increase the depth of our understanding of gene expression signatures across human cancers.

Identification of the long non-coding RNA POU3F3 in plasma as a novel biomarker for diagnosis of esophageal squamous cell carcinoma

Background

Recent studies have demonstrated that long non-coding RNAs (lncRNAs) were present in the blood of cancer patients and have shown great potential as powerful and non-invasive tumor markers. However, little is known about the value of lncRNAs in the diagnosis of esophageal squamous cell carcinoma (ESCC). We hypothesized that ESCC-related lncRNAs might be released into the circulation during tumor initiation and could be utilized to detect and monitor ESCC.

Methods

Ten lncRNAs (HOTAIR, AFAP1-AS1, POU3F3, HNF1A-AS1, 91H, PlncRNA1, SPRY4-IT1, ENST00000435885.1, XLOC_013104 and ENST00000547963.1) which previously found to be differently expressed in esophageal cancer were selected as candidate targets for subsequent circulating lncRNA assay. A four-stage exploratory study was conducted to test the hypothesis: (1) optimization of detected method to accurately and reproducibly measure ESCC-related lncRNAs in plasma and serum; (2) evaluation of the stability of circulating lncRNAs in human plasma or serum; (3) exploration the origin of ESCC-related lncRNAs in vitro and in vivo; (4) evaluation the diagnostic power of circulating lncRNAs for ESCC.

Results

ESCC-related lncRNAs were detectable and stable in plasma of cancer patients, and derived largely from ESCC tumor cells. Furthermore, plasma levels of POU3F3, HNF1A-AS1 and SPRY4-IT1 were significantly higher in ESCC patients compared with normal controls. By receiver operating characteristic curve (ROC) analysis, among the three lncRNAs investigated, plasma POU3F3 provided the highest diagnostic performance for detection of ESCC (the area under the ROC curve (AUC), 0.842; p < 0.001; sensitivity, 72.8%; specificity, 89.4%). Moreover, use of POU3F3 and SCCA in combination could provide a more effective diagnosis performance (AUC, 0.926, p < 0.001, sensitivity, 85.7%; specificity, 81.4%). Most importantly, this combination was effective to detect ESCC at an early stage (80.8%).

Conclusions

Plasma POU3F3 could serve as a potential biomarker for diagnosis of ESCC, and the combination of POU3F3 and SCCA was more efficient for ESCC detection, in particular for early tumor screening.

Electronic supplementary material

The online version of this article (doi:10.1186/1476-4598-14-3) contains supplementary material, which is available to authorized users.