CEA-antigen and SCC-antigen mRNA expression in peripheral blood predict hematogenous recurrence after resection in patients with esophageal cancer

Multigene Profiling of Circulating Tumor Cells in Esophageal Squamous Cell Carcinoma Identifies Prognostic Cancer Driver Genes Associated with Epithelial-Mesenchymal-Transition Progression and Chemoresistance

We investigated the clinical significance of CTCs in cancer progression by detecting multiple cancer driver genes associated with epithelial-to-mesenchymal transition (EMT) at the transcript level. The 10-gene panel, comprising CCND1, ECT2, EpCAM, FSCN1, KRT5, KRT18, MET, TFRC, TWIST1, and VEGFC, was established for characterizing CTCs from mouse ESCC xenograft models and clinical ESCC peripheral blood (PB) samples. Correlations between gene expression in CTCs from PB samples (n = 77) and clinicopathological features in ESCC patients (n = 55) were examined. The presence of CTCs at baseline was significantly correlated with tumor size (p = 0.031). The CTC-high patients were significantly correlated with advanced cancer stages (p = 0.013) and distant metastasis (p = 0.029). High mRNA levels of TWIST1 (Hazard Ratio (HR) = 5.44, p = 0.007), VEGFC (HR = 6.67, p < 0.001), TFRC (HR = 2.63, p = 0.034), and EpCAM (HR = 2.53, p = 0.041) at baseline were significantly associated with a shorter overall survival (OS) in ESCC patients. This study also revealed that TWIST1 facilitates EMT and enhances malignant potential by promoting tumor migration, invasion, and cisplatin chemoresistance through the TWIST1-TGFBI-ZEB1 axis in ESCC, highlighting the prognostic and therapeutic potential of TWIST1 in clinical ESCC treatment.

Circulating Tumor Cell Enumeration for Serial Monitoring of Treatment Outcomes for Locally Advanced Esophageal Squamous Cell Carcinoma

We aim to reveal the clinical significance and potential usefulness of dynamic monitoring of CTCs to track therapeutic responses and improve survival for advanced ESCC patients. Peripheral blood (PB) (n = 389) and azygos vein blood (AVB) (n = 13) samplings were recruited prospectively from 88 ESCC patients undergoing curative surgery from 2017 to 2022. Longitudinal CTC enumeration was performed with epithelial (EpCAM/pan-cytokeratins/MUC1) and mesenchymal (vimentin) markers at 12 serial timepoints at any of the pre-treatment, all of the post-treatments/pre-surgery, post-surgery follow-ups for 3-year, and relapse. Longitudinal real-time CTC analysis in PB and AVB suggests more CTCs are released early at pre-surgery and 3-month post-surgery into the circulation from the CTRT group compared to the up-front surgery group. High CTC levels at pre-treatments, 1-/3-month post-surgery, unfavorable changes of CTC levels between all post-treatment/pre-surgery and 1-month or 3-month post-surgery (Hazard Ratio (HR) = 6.662, p < 0.001), were independent prognosticators for curative treatment. The unfavorable pre-surgery CTC status was independent prognostic and predictive for neoadjuvant treatment efficacy (HR = 3.652, p = 0.035). The aggressive CTC clusters were more frequently observed in AVB compared to PB. Its role as an independent prognosticator with relapse was first reported in ESCC (HR = 2.539, p = 0.068). CTC clusters and longitudinal CTC monitoring provide useful prognostic information and potential predictive biomarkers to help guide clinicians in improving disease management.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Circulating Tumor Cells in Esophageal Squamous Cell Carcinoma - Mini Review

Esophageal cancer has high incidence and mortality rates and a low five-year survival rate of <15% owing to its strong capabilities of invasion, relapse and metastasis. The classic view holds that metastasis and diffusion is an advanced event during cancer progression, but recent studies show that distant diffusion of primary cancer cells may actually be an early event. Detection of circulating tumor cells (CTCs) in the circulation may indicate tumor spread, so CTCs are considered to be the key factor of metastatic cascade. In recent years, despite research progress on CTCs, there is a lack of systematic and important evidence to confirm the diagnostic, monitoring and prognostic values of CTCs in esophageal squamous cell carcinoma (ESCC). In this review, we clarify the relationship between CTC values and ESCC and provide more reliable evidence to improve the management and treatment of ESCC.

Postoperative pneumonia in the acute phase is an important prognostic factor in patients with esophageal cancer

BACKGROUND

The impact of pneumonia on prognosis is controversial, and no report has focused on its onset. This study aimed to examine the impact of pneumonia according to its onset on prognosis and its associated risk factors after esophagectomy.

METHODS

In total, 484 patients who underwent curative resection for esophageal squamous cell carcinoma were retrospectively reviewed. Patients with pneumonia were divided into two groups by the date of onset: pneumonia in the acute phase within 7 days after surgery (n = 59) and pneumonia in the subacute phase 8 days after surgery (n = 49).

RESULTS

The disease-free survival of patients with acute pneumonia was significantly lower than that of those without pneumonia (P = .0002), whereas the disease-free survival of patients with subacute pneumonia was similar to that of patients without pneumonia (P = .5363). In multivariate analysis for disease-free survival, P-stage III to IV (hazard ratio [HR], 3.344; P < .0001), transfusion (HR, 1.4078; P = .0291), and acute pneumonia (HR, 1.8463; P = .0009) were independent prognostic factors. Multivariate analysis revealed that age >75 years (odds ratio [OR], 2.1746; P = .0232), respiratory disease comorbidity (OR, 4.3869; P = .0002), cT3-4 (OR, 2.0143; P = .0477), extended surgery duration (OR, 2.3406; P = .0152), and posterior mediastinal reconstruction (OR, 0.1432; P = .0439) were independent risk factors for acute pneumonia.

CONCLUSION

Post-esophagectomy pneumonia in the acute phase was an independent prognostic factor, whereas advanced age, respiratory disease comorbidity, and extended surgery duration were risk factors for acute pneumonia.

Thoracic Duct Resection Has a Favorable Impact on Prognosis by Preventing Hematogenous Spread of Esophageal Cancer Cells: A Multi-institutional Analysis of 2269 Patients

BACKGROUND

The impact of thoracic duct (TD) resection on prognosis is controversial. This study aimed to examine the impact of TD resection.

METHODS

In this six-institution, matched-cohort study, 2269 consecutive patients with esophageal squamous cell carcinoma who underwent esophagectomy between 2000 and 2017 were enrolled for analysis of long-term outcomes, including overall survival (OS), disease-free survival (DFS), cause-specific survival (CSS), and recurrence patterns.

RESULTS

Based on a propensity score, 642 TD-resected and 642 TD-preserved patients with all stages of disease were selected. At 5 years, the TD-resected group had an OS of 57.7%, a DFS of 50.9%, and a CSS of 62.2%. These rates were significantly higher than the corresponding rates of 48.7% (p = 0.0078), 41.0% (p = 0.0297), and 55.3% (p = 0.0473) in the TD-preserved group. The OS in the TD-preserved and TD-resected groups was similar for the patients with cStage 1 or 2 (p = 0.6265), but it was significantly higher in the TD-resected group for the patients with cStage 3 or 4 (p = 0.0052). The incidence of total recurrence did not differ between the two groups. However, the incidence of hematogenous recurrence in the TD-resected group (19.0%) was significantly lower than in the TD-preserved group (26.2%) (p = 0.0021). For cT4a tumors, the incidence of local recurrence in the TD-resected group (2.4%) was significantly lower than in the TD-preserved group (18.4%) (p = 0.0183).

CONCLUSIONS

Performance of TD resection may help to improve prognosis, especially for patients with advanced esophageal squamous cell carcinoma, by reducing hematogenous and local recurrence. Prospective trials are needed to determine whether prophylactic TD resection has a positive impact on the prognosis of patients with esophageal cancer.

Clinical Significance of Serum Squamous Cell Carcinoma Antigen for Patients with Recurrent Esophageal Squamous Cell Carcinoma

BACKGROUND

Squamous cell carcinoma antigen (SCC-Ag) is a widely used tumor marker of SCC. However, the clinical significance of serum SCC-Ag levels in recurrent esophageal SCC (ESCC) remains unclear. This study aimed to investigate the clinical relevance of serum SCC-Ag levels in patients with recurrent ESCC after surgery.

METHODS

This study retrospectively analyzed 208 patients who experienced recurrence after curative resection for ESCC. Serum SCC-Ag levels at the time of recurrence were collected from the patients' records. The patients were classified into tertiles based on the serum SCC-Ag values (low, middle, and high), and the clinical characteristics and outcomes were compared among the groups.

RESULTS

Significant differences in sex (p = 0.001), pathologic T (p = 0.034), and N stages of primary cancer (p = 0.015) were observed among the groups. Although the recurrence patterns did not differ significantly, a high SCC-Ag was significantly associated with multiple recurrences (p = 0.019). The high-SCC-Ag group patients demonstrated a shorter time to recurrence than the other groups (p = 0.044). The SCC-Ag levels were significantly associated with overall survival after recurrence (p = 0.036). Multivariate analysis showed that serum SCC-Ag value at recurrence was an independent poor prognosticator (p = 0.031).

CONCLUSION

Elevated serum SCC-Ag levels at recurrence were significantly associated with a reduced time to recurrence, multiple recurrences, and a poor prognosis after recurrence. An alternative to the current standard treatment is required to improve the outcome for patients with high serum SCC-Ag levels at recurrence.

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

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

The Diagnostic and Prognostic Value of a Liquid Biopsy for Esophageal Cancer: A Systematic Review and Meta-Analysis

Simple Summary

The “liquid biopsy” is a novel concept for detecting circulating biomarkers in the peripheral blood of patients with various cancers, including esophageal cancer. There are two main methods to identify circulating cancer related biomarkers such as morphological techniques or molecular biological techniques. There are some differences in the sensitivity and specificity for detecting circulating tumor cells (CTCs) or circulating markers between each method. Although it is still challenging to determine strong candidates for early diagnosis and predicting prognosis in patients with esophageal cancer, our meta-analysis might be a milestone for the future development of liquid biopsies in use with esophageal cancer.

Abstract

Esophageal cancer is among the most aggressive diseases, and circulating tumor cells (CTCs) have been recognized as novel biomarkers for various cancers over the past two decades, including esophageal cancer. CTCs might provide crucial clinical information for predicting cancer prognosis, monitoring therapeutic responses or recurrences, or elucidating the mechanism of metastasis. The isolation of CTCs is among the applications of a “liquid biopsy”. There are various technologies for liquid biopsies, and they are classified into two main methods: cytometric or non-cytometric techniques. Here, we review a total of 57 eligible articles to summarize various technologies for the use of a liquid biopsy in esophageal cancer and perform a meta-analysis to assess the clinical utility of liquid biopsies as a prognostic and diagnostic biomarker technique. For prognostic evaluation, the pooled hazard ratio in the cytometric assay is relatively higher than that of the non-cytometric assay. On the other hand, a combination of multiple molecules, using a non-cytometric assay, might be a favorable biomarker technique for the early diagnosis of esophageal cancer. Although determining strong evidence for a biomarker by using a liquid biopsy is still challenging, our meta-analysis might be a milestone for the future development of liquid biopsies in use with esophageal cancer.

A Model Shows Utility in Predicting Postoperative Recurrence and Distant Metastasis in Curatively Resected Esophageal Squamous Cell Cancer

After curative treatment of esophageal squamous cell cancer (ESCC), patients are at high risk for recurrence. The objective of this study was to develop an index with a high sensitivity and specificity to predict ESCC patients’ recurrence and prognosis. A retrospective analysis was conducted on consecutive patients with EC who underwent esophagectomy. In total, 1417 patients were included in the current investigation. In total, 770 patients were included in the current study’s exploratory group. Alcohol consumption, TNM classification, number of lymph node station metastases, and number of lymph node metastases were significantly correlated with recurrence. Multivariate logistical regression analysis resulted in the development of an equation for predicting recurrence and prognosis (REEC). When using the REEC value to predict recurrence, the cutoff value was 1.095, the area under the curve (AUC) values of the REEC were 0.68 (p < 0.001) in the Exploratory Group and 0.65 (p < 0.001) in the Validation Group, and the sensitivity and specificity were 76.68% and 51.18%, respectively. When using the REEC value to predict prognosis, the cutoff value was 1.215, the AUC values of the REEC were 0.65 (p < 0.001) in the Exploratory Group and 0.64 (p < 0.001) in the Validation Group, and the sensitivity and specificity were 73.12% and 50.67%, respectively. In the Exploratory Group, when the REEC value was >1.095, patients had a longer median overall survival (OS) and median disease-free survival (DFS) than those whose REEC value was < 1.095 (70.01±2.01 months versus 50.92±2.85 months and 75.66±1.35 months versus 53.68±2.81 months, respectively, p < 0.001). The differences were confirmed to still exist in the Validation Group (48.12±1.47 vs 32.68±2.53 months and 55.61±1.32 vs 35.68±2.73 months respectively, p < 0.001).This study reported an index that can predict esophageal cancer recurrence and prognosis, and its use can benefit patients.

Elevated Pretreatment CEA and CA19-9 Levels are Related to Early Treatment Failure in Esophageal Adenocarcinoma

INTRODUCTION

Chemoradiotherapy and surgery are the basis of the potentially curative treatment for esophageal cancer. Approximately 1 in 5 patients, however, do not benefit from this intensive treatment due to early treatment failure. The aim of this study was to evaluate levels of carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 at diagnosis, in relation to survival and early treatment failure (disease recurrence or death within 1 year after surgery).

METHODS

Patients with esophageal adenocarcinoma scheduled for chemoradiotherapy followed by surgery between 1998 and 2014 were selected from a retrospectively collected database if both CEA and CA19-9 levels were measured before the start of treatment.

RESULTS

Pretreatment CEA and CA19-9 levels were known in 102 patients. Median overall survival differed (P<0.001) between patients with normal levels of both CEA and CA19-9 (n=59; 51 mo), patients with elevated CEA only (n=13; 43 mo), patients with elevated CA19-9 only (n=19; 24 mo), and those with elevated levels of both CEA and CA19-9 (n=11; 11 mo). Elevation of both CEA and CA19-9 was associated with early treatment failure (odds ratio: 10.4; 95% confidence interval: 2.4-45.5, P=0.002). Median time to tumor recurrence was 34 months in patients with normal CEA and CA19-9 levels, and 7 months in those with elevated levels of both (P=0.003).

CONCLUSIONS

Pretreatment elevated CEA and CA19-9 levels were significantly associated with early treatment failure and decreased overall survival in this esophageal adenocarcinoma patient cohort treated with curative intent. Until prospective validation, CEA and CA19-9 might play a role in identifying high-risk patients before the start of intensive locoregional therapy.

Clinicopathological and prognostic significance of circulating tumor cells in patients with esophageal cancer: a meta-analysis

Background

The aim of this meta-analysis was to assess the clinicopathological and prognostic significance of circulating tumor cells (CTCs) in patients with esophageal cancer (EC).

Methods

We searched PubMed, EMBASE, Science Citation Index Expanded, Cochrane library (from inception to July 2018) with the keywords “esophageal cancer”, “circulating tumor cells”, “prognosis”, and “peripheral blood”. HR, risk ratio (RR), OR, and their 95% CIs were set as effect measures. All analyses were performed by STATA 12.0.

Results

Eighteen studies were retrieved; CTC-positive patients were significantly associated with poor progression-free survival (PFS) (HR=2.61; 95% CI=2.08–3.28) and overall survival (OS) (HR=2.50; 95% CI=2.12–2.94). CTC-positive patients were also associated with high recurrence (OR=2.84; 95% CI=1.81–4.44) and poor response of chemoradiotherapy (RR=0.64; 95% CI=0.43–0.96). For clinicopathological characteristics, CTC-positive patients were significantly associated with TNM staging, depth of infiltration, regional lymph nodes metastasis, distant metastasis, lymphatic invasion, and venous invasion.

Conclusion

The meta-analysis has confirmed the significant clinicopathological and prognostic value of CTC-positive patients for both PFS and OS in patients with EC.

Subclinical cancer cell dissemination in peritoneal lavage fluid detected by reverse-transcription polymerase chain reaction identifies patients at high risk for peritoneal recurrence and consequent impaired survival in the setting of preoperative chemoradiation therapy for pancreatic cancer

BACKGROUND

Preoperative chemoradiation therapy is a promising strategy for pancreatic cancer. Peritoneal recurrence is a major recurrence pattern after surgery for pancreatic cancer following preoperative chemoradiation therapy, even in patients with negative peritoneal lavage fluid cytology. Previous reports have indicated that the detection of carcinoembryonic antigen mRNA by reverse transcription polymerase chain reaction is useful for evaluating subclinical tumor cell dissemination in peritoneal lavage fluid.

METHODS

Patients with resectable and borderline resectable pancreatic cancer treated with preoperative gemcitabine-based chemoradiation therapy and subsequent surgery were enrolled in this study. In all patients, a conventional cytologic examination of peritoneal lavage fluid from laparotomy confirmed the negative peritoneal cytology status. Carcinoembryonic antigen mRNA was detected in the peritoneal lavage fluid at laparotomy using reverse transcription polymerase chain reaction. Recurrence patterns and survival were evaluated in association with the carcinoembryonic antigen mRNA status in the peritoneal lavage fluid.

RESULTS

The peritoneal lavage fluid from 57 of the 237 patients (24%) was carcinoembryonic antigen mRNA(+). The carcinoembryonic antigen mRNA(+) patients had a significantly higher incidence of peritoneal recurrence than the carcinoembryonic antigen mRNA(-) patients (36% vs. 15%, P < .001). The 5-year survival rates of the carcinoembryonic antigen mRNA(+) and carcinoembryonic antigen mRNA(-) patients were 31% and 51%, respectively (P = .037). A multivariable analysis for survival revealed that borderline resectability, positive nodal status, and positive carcinoembryonic antigen mRNA status were independent variables for impaired survival.

CONCLUSION

Carcinoembryonic antigen mRNA(+) status was associated with a significantly increased incidence of peritoneal recurrence in patients with pancreatic cancer treated with preoperative chemoradiation therapy, resulting in impaired survival.

The Negative Survival Impact of Infectious Complications After Surgery is Canceled Out by the Response of Neoadjuvant Chemotherapy in Patients with Esophageal Cancer

BACKGROUND

This study was designed to investigate whether postoperative infectious complications (ICs) are a risk factor for the prognosis in esophageal cancer patients who receive neoadjuvant chemotherapy by stratifying the response to neoadjuvant chemotherapy.

METHODS

The present study retrospectively examined patients who received neoadjuvant chemotherapy followed by esophagectomy between January 2011 and September 2015. Risk factors for overall survival (OS) were examined by Cox proportional hazard analyses. Pathological responders to neoadjuvant chemotherapy were defined as those with a tumor disappearance of more than one-third of the initial tumor. Postoperative ICs were defined using the Clavien-Dindo classification.

RESULTS

Of the 111 patients examined, 45 (40.5%) developed postoperative ICs. A pathological response to neoadjuvant chemotherapy was observed in 54 (48.6%) patients. The multivariate analysis demonstrated that postoperative ICs were a significant independent risk factor for the OS (hazard ratio [HR] 2.359; 95% confidence interval [CI] 1.057-5.263, p = 0.036). In the subset analysis, postoperative ICs were a marginally significant independent risk factor for OS in the nonresponders (HR 2.862; 95% CI 0.942-8.696, p = 0.063) but not in the responders (HR 0.867; 95% CI 0.122-6.153, p = 0.886).

CONCLUSIONS

These results suggested that the negative survival impact of postoperative ICs can be canceled out in esophageal cancer patients who respond to neoadjuvant chemotherapy.

Significant prognostic value of circulating tumor cells in esophageal cancer patients: A meta-analysis

Esophageal cancer is the sixth leading cause of cancer death worldwide. Detection of circulating tumor cells (CTCs) is emerging as a novel strategy for predicting cancer patient prognosis. Here we performed a comprehensive literature search to identify relevant articles in EMbase, PubMed, EBSCO, OVID, Cochrane Database, CNKI, WanFangdata and VIPdata. Meta-analysis was conducted using Stata12.0 software, according to the inclusion and exclusion criteria, extracted data and assessment methodology. Thirteen eligible literature studies were included with a total of 979 esophageal squamous cell carcinoma patients, including 424 CTC-positive and 684 CTC-negative cases. Meta-analysis showed that the presence of CTCs was associated with both worse progression-free/disease-free survival [hazard ration (HR) = 2.32, 95% confidence interval (CI) = 1.57 - 3.43, p < 0.001] and poorer overall survival [HR = 2.64, 95% CI = 1.69 - 4.14, p < 0.001]. Further subgroup analyses demonstrated that CTC-positive patients also showed worse progression-free/disease-free survival and poorer overall survival in different subsets. In summary, our meta-analysis provides strong evidence that detection of CTCs in the peripheral blood is an independent prognostic indicator of poor outcome for esophageal squamous cell carcinoma patients.

Prognostic value of circulating tumor cells in esophageal cancer

AIM

To perform a meta-analysis of the related studies to assess whether circulating tumor cells (CTCs) can be used as a prognostic marker of esophageal cancer.

METHODS

PubMed, Embase, Cochrane Library and references in relevant studies were searched to assess the prognostic relevance of CTCs in patients with esophageal cancer. The primary outcome assessed was overall survival (OS). The meta-analysis was performed using the random effects model, with hazard ratio (HR), risk ratio (RR) and 95% confidence intervals (95%CIs) as effect measures.

RESULTS

Nine eligible studies were included involving a total of 911 esophageal cancer patients. Overall analyses revealed that CTCs-positivity predicted disease progression (HR = 2.77, 95%CI: 1.75-4.40, P < 0.0001) and reduced OS (HR = 2.67, 95%CI: 1.99-3.58, P < 0.00001). Further subgroup analyses demonstrated that CTCs-positive patients also had poor OS in different subsets. Moreover, CTCs-positivity was also significantly associated with TNM stage (RR = 1.48, 95%CI: 1.07-2.06, P = 0.02) and T stage (RR = 1.44, 95%CI: 1.13-1.84, P = 0.003) in esophageal cancer.

CONCLUSION

Detection of CTCs at baseline indicates poor prognosis in patients with esophageal cancer. However, this finding relies on data from observational studies and is potentially subject to selection bias. Prospective trials are warranted.

Circulating tumor cells and circulating tumor DNA: What surgical oncologists need to know?

As a result of recent progress in detection techniques, circulating tumor DNA (ctDNA) and circulating tumor cells (CTC) can now be accurately detected in the blood of most cancer patients. While these new biomarkers can provide a better understanding of key biological mechanisms underlying cancer growth and dissemination, they also open up a wide range of possible clinical applications in medical oncology, radiation oncology and surgical oncology. In this review, we summarize the results obtained with ctDNA and CTC together with their potential future clinical applications in the field of surgical oncology, with particular focus on the perioperative setting of various types of cancer. These applications include, but are not limited to, cancer screening, early diagnosis, prognostic assessment, evaluation and management of preoperative systemic or local therapies, post-surgical detection of minimal residual disease and early detection of cancer relapse.

Prognostic significance of circulating tumor cells in esophageal carcinoma: a meta-analysis

PURPOSE

The prognostic significance of circulating tumor cells (CTCs) in esophageal carcinoma (EC) is controversial. We aim to assess its association with clinicopathological and prognostic relevance in EC by using a meta-analysis.

METHODS

We searched PubMed, Cochrane Database, Embase databases, and the references in relevant studies that assessed the clinicopathological or prognostic relevance of CTCs in peripheral blood of patients with EC. Statistical analyses were conducted by using Stata software to calculate the pooled odds ratio (OR), hazard ratio (HR), and 95% confidence intervals (CIs) using fixed or random-effects models according to the heterogeneity of included studies. The subgroup analyses were performed according to ethnicity, histological type, and detection method.

RESULTS

Sixteen trials containing 1,260 patients were included for analysis. Pooled results showed that presence of CTCs was significantly associated with poor overall survival (HR =1.71, 95% CI [1.30, 2.12], P<0.001) and progression-free survival (HR =1.67, 95% CI [1.19, 2.15], P<0.001) in EC patients. Subgroup analysis indicated that presence of CTCs was closely associated with worse overall survival (Asian: HR =1.66, 95% CI [1.24, 2.08], P<0.001; squamous cell carcinoma [SCC]: HR =1.66, 95% CI [1.24, 2.08], P<0.001; no polymerase chain reaction [PCR]: HR =2.08, 95% CI [1.40, 2.76], P<0.001) and progression-free survival (Asian: HR =1.63, 95% CI [1.15, 2.12], P<0.001; SCC: HR =1.63, 95% CI [1.15, 2.12], P<0.001; PCR: HR =1.63, 95% CI [1.15, 2.12], P<0.001). Additionally, ORs showed that presence of CTCs was significantly correlated with tumor node metastasis (TNM) staging (overall: OR = 1.96, 95% CI [1.34, 2.87], P=0.001; Asian: OR =2.09, 95% CI [1.37, 3.19], P=0.001; SCC: OR =1.97, 95% CI [1.21, 3.07], P=0.003; PCR: OR =2.23, 95% CI [1.43, 3.47], P<0.001), venous invasion (overall: OR =2.23, 95% CI [1.46, 3.40], P<0.001; Asian: OR =2.23, 95% CI [1.46, 3.40], P<0.001; SCC: OR =2.23, 95% CI [1.46, 3.40], P<0.001; PCR: OR =2.23, 95% CI [1.46, 3.40], P<0.001), lymph node metastasis (overall: OR =2.41, 95% CI [1.50, 3.86], P<0.001; Asian: OR =2.89, 95% CI [1.80, 4.65], P<0.001; SCC: OR =2.44, 95% CI [1.47, 4.07], P=0.001; PCR: OR =2.89, 95% CI [1.80, 4.65], P<0.001) and distant metastasis (Asian: OR =2.68, 95% CI [1.01, 7.08], P=0.047) in patients with EC.

CONCLUSION

The presence of CTCs indicates a poor prognosis in EC patients, especially in Asian and SCC patients. Further well-designed prospective studies are recommended to explore the clinical applications of CTCs in patients with EC.

[Prognostic value of circulating tumor cells and disseminated tumor cells in patients with esophageal cancer: a meta-analysis]

OBJECTIVE

To explore the correlations of circulating tumor cells (CTCs) and disseminated tumor cells (DTCs) with the clinicopathological characteristics, prognostic events, and survival outcomes in esophageal cancer (EC) patients.

METHODS

The PubMed, Web of Science, Embase database and Cochrane database were searched for studies reporting the outcomes of interest. The studies were selected according to established inclusion/exclusion criteria. Meta-analysis of the studies was performed using Review Manager 5.3 and Stata12.0 software with the odds ratio (OR), risk ratio (RR) , hazard ratio (HR) , and 95% confidence interval (95% CI) as the effect indexes.

RESULTS

Nineteen studies involving a total of 1766 patients were included in the analysis. Significant correlations of CTCs and DTCs were found with the clinicopathological parameters including the tumor stage (OR=1.95), depth of invasion (OR=1.99), lymph node metastasis (OR=2.44_SEN), distal metastasis (OR=5.98_SEN), histological differentiation (OR=1.67) and lymphovascular invasion (OR=4.48). CTCs and DTCs were also correlated with the prognostic events including relapse (RR=6.86_SEN) and metastasis (RR=3.22) and with the survival outcomes including the overall survival (OS) overall analysis (HR=3.46) and disease-free survival/progression-free survival (DFS/PFS) overall analysis (HR=3.00).

CONCLUSION

CTCs and DTCs are significantly associated with an advanced tumor stage, depth of tumor invasion, lymph node metastasis, distant metastasis before therapy, differentiation, lymphovascular invasion, relapse and metastasis in patients with EC. They are also significantly correlated with a poorer survival for OS and DFS/PFS to serve as clinical and prognostic predictors in patients with EC.

Circulating Tumor Cells in Gastrointestinal Cancer: Current Practices and Future Directions

GI cancers are the leading cause of cancer-related death worldwide primarily due to a combination of late presentation and aggressive biology. The lack of adequate biomarkers for screening, diagnosis, staging, and prognosis confounds clinical decision-making and delays potentially effective therapies. Circulating tumor cells (CTCs) are a new biomarker with particular promise in GI cancers, potentially offering clinicians and researchers real-time access to tumor tissue in a reliable, safe, and cost-effective manner. Preliminary studies have investigated the potential clinical utility of CTCs for all GI cancer types with promising results. Furthermore, advances in single cell analytics have been successfully applied to CTCs, allowing for exciting new clinical and research applications. In this chapter, we will review the current state of CTC research in GI cancers as well as the potential future applications that are currently being developed.

Circulating Tumor Cell Analyses in Patients With Esophageal Squamous Cell Carcinoma Using Epithelial Marker-Dependent and -Independent Approaches

In several epithelial malignancies, detection of circulating tumor cells (CTCs) in the peripheral blood has diagnostic, prognostic, and therapeutic implications. However, the clinical relevance of CTCs in esophageal squamous cell carcinoma (ESCC) has not yet been ascertained. The study was conducted with the aim of determining the clinical significance of CTCs in patients with ESCC by using 2 CTC detection systems, one epithelial marker-dependent and the other epithelial marker-independent. Paired peripheral blood samples were prospectively obtained from 61 ESCC patients before treatment and were analyzed for CTCs isolated by the CellSearch system (CS) and the method of isolation by size of epithelial tumor (ISET). Blood samples from 22 healthy volunteers were used as controls. Out of 61 study subjects, CTCs were detected in 20 patients (32.8%) by the ISET method and in only 1 patient (1.6%) by the CS method. Circulating tumor microemboli (CTM) were observed in 3 of 61 (4.9%) patients using ISET, but were undetectable in any of the patient by CS method. No CTCs/CTM were detected by either method in control groups. By ISET method, the presence of CTCs appeared to correlate with the stage of ESCC and with the baseline median platelet levels. No correlation with any other relevant clinicopathological variables was observed. Our results clearly indicate the ability of both CS and ISET methods to detect CTCs in peripheral blood samples from ESCC patients. However, the CellSearch system appears to have a poorer sensitivity as compared with the ISET method. Further studies are essential for assessing the role of such technologies in ESCC.

Prognostic Role of a Multimarker Analysis of Circulating Tumor Cells in Advanced Gastric and Gastroesophageal Adenocarcinomas

OBJECTIVE

We aimed to assess the prognostic value of circulating tumor cells (CTC) in patients with advanced gastric and gastroesophageal adenocarcinomas.

METHODS

The presence of CTC was evaluated in 62 patients with advanced gastric and gastroesophageal adenocarcinomas before systemic therapy and at follow-up through immunomagnetic enrichment for mucin 1- and epithelial cell adhesion molecule (EpCAM)-positive cells, followed by real-time RT-PCR of the tumor-associated genes KRT19, MUC1, EPCAM, CEACAM5 and BIRC5.

RESULTS

The patients were stratified into groups according to CTC detection (CTC negative: with all marker genes negative; CTC positive: with at least 1 of the marker genes positive). Patients who were CTC positive at baseline had a significantly shorter median progression-free survival (PFS; 3.5 months, 95% CI: 2.9-4.2) and overall survival (OS; 5.8 months, 95% CI: 4.5-7.0) than patients lacking CTC (PFS 10.7 months, 95% CI: 6.9-14.4, p<0.001; OS 13.3 months, 95% CI: 8.0-18.6, p=0.003). Alterations in the marker profile during the course of chemotherapy were not predictive of clinical outcome or response to therapy. Yet, a favorable clinical response depended significantly on CTC negativity (p=0.03).

CONCLUSION

Our data suggest that the presence of CTC is a major predictor of outcome in patients with gastric and gastroesophageal malignancies.

Circulating mRNA Profiling in Esophageal Squamous Cell Carcinoma Identifies FAM84B As A Biomarker In Predicting Pathological Response to Neoadjuvant Chemoradiation

Esophageal cancer patients with pathological complete response (pCR) to neoadjuvant chemoradiation (CRT) have favorable outcomes. Currently, there was no reliable biomarker predicting the response to CRT. Perioperative circulating mRNA may be associated with prognosis, but its application for predicting treatment response is unclear. We prospectively assessed the value of circulating messenger RNA (mRNA) profiling in predicting pCR for esophageal squamous cell carcinoma (ESCC). Patients with ESCC completing CRT followed by surgery were enrolled for analysis. Venous peripheral blood was obtained before and after CRT, and total RNA was extracted for hybridization-based whole genome expression analysis and quantitative RT-PCR. We found circulating expression profiling was significantly altered after CRT. Altered FAM84B expression was significantly predictive of pCR. The decrease of serum FAM84B protein level after CRT was also associated with pCR. Immunohistochemistry and western blot confirmed that FAM84B protein was overexpressed in the majority of patients and ESCC cell lines. Furthermore, knockdown of FAM84B delayed tumor growth in ectopic xenografts. We demonstrated the decreased of circulating FAM84B mRNA and protein after neoadjuvant CRT may predict pCR, and FAM84B protein is overexpressed in ESCC. The potential of FAM84B as a novel predictive biomarker, and its biological functions deserve further investigation.

Combining proteomics, serum biomarkers and bioinformatics to discriminate between esophageal squamous cell carcinoma and pre-cancerous lesion

OBJECTIVE

Biomarker assay is a noninvasive method for the early detection of esophageal squamous cell carcinoma (ESCC). Searching for new biomarkers with high specificity and sensitivity is very important for the early detection of ESCC. Serum surface-enhanced laser desorption/ionization-time of flight mass spectrometry (SELDI-TOF-MS) is a high throughput technology for identifying cancer biomarkers using drops of sera.

METHODS

In this study, 185 serum samples were taken from ESCC patients in a high incidence area and screened by SELDI. A support vector machine (SVM) algorithm was adopted to analyze the samples.

RESULTS

The SVM patterns successfully distinguished ESCC from pre-cancerous lesions (PCLs). Also, types of PCL, including dysplasia (DYS) and basal cell hyperplasia (BCH), and healthy controls (HC) were distinguished with an accuracy of 95.2% (DYS), 96.6% (BCH), and 93.8% (HC), respectively. A marker of 25.1 kDa was identified in the ESCC patterns whose peak intensity was observed to increase significantly during the development of esophageal carcinogenesis, and to decrease obviously after surgery.

CONCLUSIONS

We selected five ESCC biomarkers to form a diagnostic pattern which can discriminate among the different stages of esophageal carcinogenesis. This pattern can significantly improve the detection of ESCC.

Circulating tumor cells in hepatocellular carcinoma: detection techniques, clinical implications, and future perspectives

Hepatocellular carcinoma (HCC) is a primary liver cancer with a huge challenge in terms of its complex etiology and its management. The fact that the most common site of early tumor recurrence in liver transplantation for HCC is the transplanted allograft strongly suggests that circulating tumor cells (CTCs) are really an active source of HCC metastasis or recurrence. In the past decade, with the tremendous progress in the technology of CTC detection, there is convincing evidence that CTCs have great potential as a marker for metastatic disease and poor prognosis in patients with a malignancy. Currently some interesting and encouraging results have been achieved in HCC CTC detection, although the knowledge about its clinical relevance in HCC is lagging behind other major tumor types. Here we will review existing and developing methodologies for CTC detection, discuss future perspectives, and describe the potential clinical impact of the identification and molecular characterization of CTC subset or circulating cancer stem cells in HCC patients. Particular attention is given to the results based on the HCC CTC study.

Preoperative Cyfra21-1 and SCC-Ag serum titers predict survival in patients with stage II esophageal squamous cell carcinoma

BACKGROUND

The purpose of this study is to evaluate the predictive significance of preoperative serum level of cytokeratin 19 fragments (Cyfra21-1) and squamous cell carcinoma antigen (SCC-Ag) after complete resection in patients with stage II esophageal squamous cell carcinoma (ESCC).

METHODS

Between 1995 and 2006, a total of 379 patients in stage II ESCC who underwent complete resection were consecutively recruited. Statistical analyses were applied to test the associations between preoperative serum titers of Cyfra21-1 and SCC-Ag, clinicopathological factors and prognoses.

RESULTS

Preoperative high and normal serum level of Cyfra21-1 and SCC-Ag were found in 47.8%, 52.2% and 72.8%, 27.2%, respectively. The 1-, 3-, 5-year overall survival rate for the entire cohort of patients was 95%, 78%, and 56%, respectively. Median overall survival (OS) was 45.3 months longer in patients with low preoperative serum level of Cyfra21-1 (91.9 months) than those with high preoperative serum level of Cyfra21-1 (46.6 months) (P < 0.001). Median OS among patients with SCC-Ag-low level was also longer than those with SCC-Ag-high level (89.7 vs. 63.7 months, P < 0.001), especially for those with stage IIB (P < 0.001). After multivariate analysis, along with pTNM stage, preoperative serum level of Cyfra21-1 and SCC-Ag were independently and significantly predictive factors (P < 0.001, P < 0.001). Furthermore, the five-year survival rate in double-low subset, either-low subset and double-high subset was 100%, 83% and 27%, respectively (P < 0.001).

CONCLUSIONS

The preoperative serum level of Cyfra21-1 and SCC-Ag are independently significant predictors which negatively affected the survivals of patients with stage II ESCC.

Prognostic and predictive roles for circulating biomarkers in gastrointestinal cancer

Circulating tumor cells (CTCs) and circulating free DNA (cfDNA) have been studied as promising prognostic and predictive tumor-derived biomarkers in the bloodstream of patients with gastrointestinal malignancies because they may be an alternative noninvasive tool to tumor tissue biopsies. Quantification and molecular characterization of CTCs and cfDNA may provide additional insights into cancer biology, potentially revealing novel targets to individualize cancer care. The present article aims to review the biology and current methods to assess CTCs and cfDNA, and the efforts to establish both tumor-derived biomarkers as prognostic and predictive factors in esophageal, gastric and colorectal cancer.

Clinical significance of carcinoembryonic antigen-, cytokeratin 19-, or survivin-positive circulating tumor cells in the peripheral blood of esophageal squamous cell carcinoma patients treated with radiotherapy

Circulating tumor cells (CTCs) have been associated with clinical outcome in various malignancies. The aim of this study was to examine CTC status in the peripheral blood of patients with esophageal squamous cell carcinoma (ESCC) before and after radiotherapy, and to evaluate its clinical significance. A total of 72 ESCC patients treated with radical radiotherapy were enrolled in this study. The nested reverse-transcriptase polymerase chain reaction was used to detect the three representative markers of CTCs, namely carcinoembryonic antigen, cytokeratin 19, and survivin. The results showed that CTC(+), a status with positive expression of at least one of these three markers, in patients with ESCC pre- and post-radiotherapy were 54.2% (39/72) and 38.9% (28/72), respectively (P= 0.059). Furthermore, CTC (+) in patients pre- or post-radiotherapy was both correlated with lymph metastasis and adverse 2-year progression-free survival. It was also found that changes in CTC status after radiotherapy could reflect patients' response to radiotherapy. The response rates in cases with CTC status pre-radiotherapy(+)/post-radiotherapy(+), pre-radiotherapy(-)/post-radiotherapy(+), pre-radiotherapy(-)/post-radiotherapy(-), pre-radiotherapy(+)/post-radiotherapy(-) were 58.3% (21/36), 0% (0/3), 73.7% (14/19), and 85.7% (12/14), respectively. In a multivariate analysis of Cox proportional hazard model, only CTC (+) post-radiotherapy was an independent unfavorable prognostic factor for ESCC apart from subsequent chemotherapy and patients' Karnofsky performance status scores. In conclusion, positive detection of CTCs in patients with ESCC after radiotherapy may be a promising biomarker for radiation efficiency and prognosis assessment in ESCC.