Tissue resident iNKT17 cells facilitate cancer cell extravasation in liver metastasis via interleukin-22.

During metastasis, cancer cells invade, intravasate, enter the circulation, extravasate, and colonize target organs. Here, we examined the role of interleukin (IL)-22 in metastasis. Immune cell-derived IL-22 acts on epithelial tissues, promoting regeneration and healing upon tissue damage, but it is also associated with malignancy. Il22-deficient mice and mice treated with an IL-22 antibody were protected from colon-cancer-derived liver and lung metastasis formation, while overexpression of IL-22 promoted metastasis. Mechanistically, IL-22 acted on endothelial cells, promoting endothelial permeability and cancer cell transmigration via induction of endothelial aminopeptidase N. Multi-parameter flow cytometry and single-cell sequencing of immune cells isolated during cancer cell extravasation into the liver revealed iNKT17 cells as source of IL-22. iNKT-cell-deficient mice exhibited reduced metastases, which was reversed by injection of wild type, but not Il22-deficient, invariant natural killer T (iNKT) cells. IL-22-producing iNKT cells promoting metastasis were tissue resident, as demonstrated by parabiosis. Thus, IL-22 may present a therapeutic target for prevention of metastasis.

Challenges in the interdisciplinary treatment of leakages after left-sided colorectal surgery: endoscopic negative pressure therapy, open-pore film drainage therapy and beyond.

PURPOSE: The treatment of anastomotic leakage after left colorectal surgery remains challenging. Since its introduction, endoscopic negative pressure therapy (ENPT) has proven to be advantageous, reducing the necessity of surgical revision. The aim of our study is to present our experience with endoscopic treatment of colorectal leakages and to identify potential factors influencing treatment outcome. METHODS: Patients who underwent endoscopic treatment of colorectal leakage were retrospectively analyzed. Primary endpoint was the healing rate and success of endoscopic therapy. RESULTS: We identified 59 patients treated with ENPT between January 2009 and December 2019. The overall closure rate was 83%, whereas only 60% of the patients were successfully treated with ENPT and 23% needed further surgery. The time between diagnosis of leakage and uptake of endoscopic treatment did not influence the closure rate, but patients with chronic fistula (> 4 weeks) showed a significantly higher reoperation rate than those with an acute fistula (94% vs 6%, p = 0.01). CONCLUSION: ENPT is a successful treatment option for colorectal leakages, which appears to be more favorable when started early. Further studies are still needed to better describe its healing potential, but it deserves an integral role in the interdisciplinary treatment of anastomotic leakages.

Possible tumour cell reimplantation during curative endoscopic therapy of superficial Barrett's carcinoma.

BACKGROUND AND AIMS: Endoscopic resection has been established as curative therapy for superficial cancer arising from Barrett's oesophagus (BE); recurrences are very rare. Based on a case series with unusual and massive early recurrences, we analyse the issue of tumour cell reimplantation. METHODS: This hypothesis was developed on the basis of two out of seven patients treated by circumferential (n=6) or nearly circumferential (n=1) en bloc and R0 endoscopic resection of T1 neoplastic BE. Subsequently, a prospective histocytological analysis of endoscope channels and accessories was performed in 2 phases (cytohistological analysis; test for cell viability) in 22 different oesophageal carcinoma patients undergoing endoscopy. Finally, cultures from two oesophageal adenocarcinoma cell lines were incubated with different triamcinolone concentrations (0.625-10 mg/mL); cell growth was determined on a Multiwell plate reader. RESULTS: Cancer regrowth in the two suspicious cases (male, 78/71 years) occurred 7 and 1 months, respectively, after curative tumour resection. Subsequent surgery showed advanced tumours (T2) with lymph node metastases; one patient died. On cytohistological examinations of channels and accessories, suspicious/neoplastic cells were found in 4/10 superficial and in all 5 advanced cancers. Further analyses in seven further advanced adenocarcinoma cases showed viable cells in two channel washing specimens. Finally, cell culture experiments demonstrated enhanced tumour cell growth by triamcinolone after 24 hours compared with controls. CONCLUSIONS: Tumour cell reimplanation from contaminated endoscopes and accessories is a possible cause of local recurrence after curative endoscopic therapy for superficial Barrett carcinoma; also, corticosteroid injection could have promoted tumour regrowth in these cases.

IL22BP Mediates the Antitumor Effects of Lymphotoxin Against Colorectal Tumors in Mice and Humans.

BACKGROUND & AIMS: Unregulated activity of interleukin (IL) 22 promotes intestinal tumorigenesis in mice. IL22 binds the antagonist IL22 subunit alpha 2 (IL22RA2, also called IL22BP). We studied whether alterations in IL22BP contribute to colorectal carcinogenesis in humans and mice. METHODS: We obtained tumor and nontumor tissues from patients with colorectal cancer (CRC) and measured levels of cytokines by quantitative polymerase chain reaction, flow cytometry, and immunohistochemistry. We measured levels of Il22bp messenger RNA in colon tissues from wild-type, Tnf-/-, Lta-/-, and Ltb-/- mice. Mice were given azoxymethane and dextran sodium sulfate to induce colitis and associated cancer or intracecal injections of MC38 tumor cells. Some mice were given inhibitors of lymphotoxin beta receptor (LTBR). Intestine tissues were analyzed by single-cell sequencing to identify cell sources of lymphotoxin. We performed immunohistochemistry analysis of colon tissue microarrays from patients with CRC (1475 tissue cores, contained tumor and nontumor tissues) and correlated levels of IL22BP with patient survival times. RESULTS: Levels of IL22BP were decreased in human colorectal tumors, compared with nontumor tissues, and correlated with levels of lymphotoxin. LTBR signaling was required for expression of IL22BP in colon tissues of mice. Wild-type mice given LTBR inhibitors had an increased tumor burden in both models, but LTBR inhibitors did not increase tumor growth in Il22bp-/- mice. Lymphotoxin directly induced expression of IL22BP in cultured human monocyte-derived dendritic cells via activation of nuclear factor κB. Reduced levels of IL22BP in colorectal tumor tissues were associated with shorter survival times of patients with CRC. CONCLUSIONS: Lymphotoxin signaling regulates expression of IL22BP in colon; levels of IL22BP are reduced in human colorectal tumors, associated with shorter survival times. LTBR signaling regulates expression of IL22BP in colon tumors in mice and cultured human dendritic cells. Patients with colorectal tumors that express low levels of IL22BP might benefit from treatment with an IL22 antagonist.

Anti-inflammatory microenvironment of esophageal adenocarcinomas negatively impacts survival.

OBJECTIVE: Reflux promotes esophageal adenocarcinomas (EACs) creating a chronic inflammatory environment. Survival rates are low due to early local recurrences and distant metastasis. Hence, there is a need for new potential treatment options like immunotherapies. However, the inflammatory microenvironment in EACs and its impact on patient outcome remain to be fully understood. METHODS: mRNA expression levels of pro- and anti-inflammatory markers in 39 EAC patients without neoadjuvant radio-chemotherapy were measured. Data were confirmed using flow cytometric analysis of freshly resected surgical specimens. Inflammatory alterations in premalignant lesions of Barrett's esophagus were analyzed by immunohistochemistry. RESULTS: Expression levels of IL22 were reduced in EAC, while expression levels of FOXP3, IL10 and CTLA4 were increased. Flow cytometry demonstrated a strong infiltration of CD4+ T cells with a reduction in CD4+ T cells producing IL-22 or IL-17A. We also observed an increase in CD4+CD127lowFOXP3+ cells producing IL-10. Accumulation of FOXP3+ T cells occurred prior to malignant changes. High expression of IL10 and low expression of IL22 in EAC were associated with reduced overall survival. Moreover, increased expression of IL10, CTLA4 and PD1 in the unaltered esophageal mucosa distant to the EAC was also linked with an unfavorable prognosis. CONCLUSION: EAC shows an anti-inflammatory environment, which strongly affects patient survival. The microscopically unaltered peritumoral tissue shows a similar anti-inflammatory pattern indicating an immunological field effect, which might contribute to early local recurrences despite radical resection. These data suggest that using checkpoint inhibitors targeting anti-inflammatory T cells would be a promising therapeutic strategy in EAC.

Endoscopic vacuum therapy versus stenting for postoperative esophago-enteric anastomotic leakage: systematic review and meta-analysis.

BACKGROUND: Esophageal anastomotic leakage still represents a challenging complication after esophageal surgery. Endoscopically placed self-expandable metal stents (SEMS) are the treatment of choice, but since the introduction of endoscopic vacuum therapy (EVT) for esophageal leakage 10 years ago, increasing evidence has demonstrated that EVT might be a superior alternative. Therefore, we performed a systematic review and meta-analysis to compare the effectiveness and related morbidity of SEMS and EVT in the treatment of esophageal leak. METHODS: We systematically searched for studies comparing SEMS and EVT to treat anastomotic leakage after esophageal surgery. Predefined end points including outcome, treatment success, endoscopy, treatment duration, hospitalization time, morbidity, and mortality were assessed and included in the meta-analysis. RESULTS: Five retrospective studies including 274 patients matched the inclusion criteria. Compared with stenting, EVT was significantly associated with a higher rate of leak closure (odds ratio [OR] 3.14, 95 % confidence interval [CI] 1.23 to 7.98), more endoscopic device changes (pooled median difference of 3.09; 95 %CI 1.54 to 4.64]), a shorter duration of treatment (pooled median difference -11.90 days; 95 %CI -18.59 to -5.21 days), and a lower mortality rate (OR 0.39, 95 %CI 0.18 to 0.83). There were no significant differences in short-term and major complications. CONCLUSIONS: Owing to the retrospective quality of the studies with potential biases, the results of the meta-analysis must be interpreted with caution. However, the analysis indicates the potential benefit of EVT, which should be further investigated with standardized and prospectively collected data.

Surgical Management of Non-Malignant Esophageal Perforations: A Single-Center Analysis Over a 15-Year Period.

PURPOSE: Esophageal perforations are associated with high morbidity and mortality. Different nonoperative and operative treatment options have been proposed. This study focuses on the impact of different surgical treatments in nonmalignant esophageal perforations and tries to identify predictors of mortality in a single tertiary center over a 15-year period. METHODS: From 2002 to 2017, patients with surgically managed esophageal perforation were identified from our database. Patients with esophageal malignancies were excluded. Etiology, clinical data, treatment, and outcome were analyzed. A multivariate logistic regression analysis was performed to investigate the impact on mortality. RESULTS: A total of 72 patients were identified. The majority of perforations were iatrogenic (54.2%) followed by Boerhaave's syndrome (23.6%). Most ruptures were found in the distal third of the esophagus (59.7%) measuring <3 cm (61.1%). Patients were treated with exploration and drainage (8.3%), primary suture and patch reinforcement (36.1%), resection and restoration of continuity (25.0%), or resection without restoration of continuity (30.6%). Delayed therapy significantly correlated with sepsis (p < 0.0001) and mortality (p = 0.032). A correlation between an increasing perforation length with sepsis (p = 0.012) was observed. A higher Perforation Severity Score (PSS; OR 4.430; 95% CI 1.143-17.174; p = 0.031) and a higher American Society of Anesthesiologists (ASA) score (OR 2.923; 95% CI 1.011-8.448; p = 0.048) were associated with mortality in multivariate analysis. CONCLUSION: Esophageal perforations are associated with high mortality, and larger ruptures are associated with worse outcome. Rapid diagnosis and treatment are crucial for patient survival. Hence, PSS and ASA score help to identify high-risk patients. The advantage of surgical management lies in the rapid control of the septic focus in an already critically ill patient. Though, the kind of surgical technique needs to be adjusted to the individual situation.

The decrease of BMI and albumin levels influences the rate of anastomotic leaks in patients following reconstruction after emergency diverting esophagectomy.

OBJECTIVES: Diverting esophagectomies in cases of benign esophageal perforations remain rare but potentially life saving procedures. Usually, an esophagostoma and a feeding jejunostomy or gastrostomy are created, and patients are given time to recover from the emergency situation. However, little is known about morbidity and mortality as well as the optimal timing for a staged reconstruction. METHODS: Patients with benign esophageal perforations were selected from our retrospective database. Perforations in esophageal malignancies were excluded to avoid bias on patients' general outcome. Clinical parameters and especially, the influence of the nutritional status indicated by the BMI (Body Mass Index) as well as serum albumin levels (g/l) were analyzed. RESULTS: A total of 24 patients with diverting esophagectomies were identified. Of these, 13 (54.2%) patients received a staged reconstruction after a median of 143.0 days. Patients presenting for their staged reconstruction demonstrated a significantly decreased level of their BMI (p = 0.026) as compared to their prior hospitalization. Interestingly, the relative decrease of BMI (8.5 kg/m2 vs. 4.3 kg/m2) and albumin levels (6.5 g/l vs. 0.0 g/l) was significantly different in patients with or without anastomotic leaks between both surgeries (p = 0.021; p = 0.034, respectively). In addition, higher rates of overall complications were associated with an increased rate of malnutrition. CONCLUSIONS: The relative amount of malnutrition indicated by BMI or serum albumin levels influences the rate of anastomotic leaks and general complications in patients with staged reconstruction after diverting esophagectomy for non-malignant esophageal perforations. Hence, reconstruction should be done as fast as possible to reduce the amount of malnutrition and a frequent assessment of the nutritional status must be done during recovery from the emergency surgery.

Does the Margin Matter in Esophageal Cancer.

BACKGROUND: The prognostic impact of circumferential resection margin (CRM) involvement in resected esophageal cancer (EC) is controversial discussed. The College of American Pathologists (CAP) and the Royal College of Pathologists (RCP) provide 2 different definitions of CRM involvement. The aim of this systematic review was to evaluate the clinical significance of CRM involvement on patients' survival following esophagectomy due to EC. METHODS: PubMed, Science Direct, and Google scholar were searched for studies analyzing the clinical impact of CRM in EC. SUMMARY: A total of 28 studies analyzed the prognostic effect of a positive CRM in EC. A wide range of CRM involvement (8.6-83.1%) was reported. Both available meta-analyses found a significant association between a positive CRM and patients' survival irrespective of RCP (OR 2.52 [95% CI 1.96-3.25; p < 0.001]) or CAP (OR 4.02 [95% CI 2.25-7.20; p < 0.001]) criteria. The influence of neoadjuvant therapy on the CRM remains unclear. Key Messages: CRM involvement is a useful parameter for EC patients' prognosis. The application of CAP criteria should be preferred since patients with a poor prognosis can be identified more sufficiently. Neoadjuvant therapy and en bloc transthoracic esophagectomy show favorable results for achievement of negative CRM.

A Comprehensive Analysis of Tn and STn Antigen Expression in Esophageal Adenocarcinoma.

Differential glycosylation, marked by the presence of truncated O-glycans, is a distinctive feature of epithelial-derived cancers. However, there is a notable gap in research regarding the expression of Tn and STn antigens in esophageal adenocarcinoma (EAC). To address this, we employed commercially available antibodies, previously validated for Tn and STn antigens, to analyze two cohorts of EAC tissues. Initially, large-area tissue sections from formalin-fixed paraffin-embedded (FFPE) EAC and corresponding healthy tissues were subjected to immunohistochemistry (IHC) staining and scoring. Subsequently, we evaluated the RNA expression levels of crucial O-glycosylation related genes-C1GALT1 and C1GALT1C1-using a quantitative real-time polymerase chain reaction (qRT-PCR). In a comprehensive analysis, a substantial cohort of EAC tissues (n = 311 for Tn antigen, n = 351 for STn antigen) was investigated and correlated with clinicopathological data. Our findings revealed that Tn and STn antigens are highly expressed (approximately 71% for both) in EAC, with this expression being tumor-specific. Notably, Tn antigen expression correlates significantly with the depth of tumor cell infiltration (p = 0.026). These antigens emerge as valuable markers and potential therapeutic targets for esophageal adenocarcinoma.

Risk Factor Analysis for Developing Major Complications Following Esophageal Surgery-A Two-Center Study.

BACKGROUND: Esophagectomy carries a high risk of morbidity and mortality compared to other major surgeries. With the aim of creating an easy-to-use clinical preoperative risk assessment tool and to validate previously described risk factors for major complications following surgery, esophagectomies at two tertiary medical centers were analyzed. METHODS: A total of 450 patients who underwent esophagectomy for esophageal carcinoma at the University Medical Centre, Hamburg, or at the Medical Center University Duisburg-Essen, Germany (January 2008 to January 2020) were retrospectively analyzed. Epidemiological and perioperative data were analyzed to identify the risk factors that impact major complication rates. The primary endpoint of this study was to determine the incidence of major complications. RESULTS: The mean age of the patients was 63 years with a bimodal distribution. There was a male predominance across the cohort (81% vs. 19%, respectively). Alcohol abuse (p = 0.0341), chronic obstructive pulmonary disease (p = 0.0264), and cardiac comorbidity (p = 0.0367) were associated with a significantly higher risk of major complications in the multivariate analysis. Neoadjuvant chemotherapy significantly reduced the risk of major postoperative complications (p < 0.0001). CONCLUSIONS: Various patient-related risk factors increased the rate of major complications following esophagectomy. Patient-tailored prehabilitation programs before esophagectomy that focus on minimizing these risk factors may lead to better surgical outcomes and should be analyzed in further studies.

Multicytokine-producing CD4+ T cells characterize the livers of patients with NASH.

A role of CD4+ T cells during the progression from nonalcoholic fatty liver disease (NAFLD) to nonalcoholic steatohepatitis (NASH) has been suggested, but which polarization state of these cells characterizes this progression and the development of fibrosis remain unclear. In addition, a gut-liver axis has been suggested to play a role in NASH, but the role of CD4+ T cells in this axis has just begun to be investigated. Combining single-cell RNA sequencing and multiple-parameter flow cytometry, we provide the first cell atlas to our knowledge focused on liver-infiltrating CD4+ T cells in patients with NAFLD and NASH, showing that NASH is characterized by a population of multicytokine-producing CD4+ T cells. Among these cells, only those with a Th17 polarization state were enriched in patients with advanced fibrosis. In parallel, we observed that Bacteroides appeared to be enriched in the intestine of NASH patients and to correlate with the frequency of multicytokine-producing CD4+ T cells. In short, we deliver a CD4+ T cell atlas of NAFLD and NASH, providing the rationale to target CD4+ T cells with a Th17 polarization state to block fibrosis development. Finally, our data offer an early indication to test whether multicytokine-producing CD4+ T cells are part of the gut-liver axis characterizing NASH.

Combined endoscopic-percutaneous treatment of upper gastrointestinal enterocutaneous fistula using vacuum therapy and resorbable plug insertion (Vac-Plug).

After gastrointestinal resections, leakages can occur, persist despite conventional therapy and result in enterocutaneous fistulae. We developed a combination method using flexible endoscopic techniques to seal the enteric orifice with an absorbable plug in addition to a percutaneously and fistuloscopically guided open-pore film drainage (Vac-Plug method). We retrospectively searched our endoscopy database to identify patients treated with the outlined technique. The clinical and pathological data were assessed, the method analyzed and characterized and the technical and clinical success determined. We identified 14 patients that were treated with the Vac-Plug method (4 females, 10 males with a mean age of 56 years, range 50-74). The patients were treated over a time period of 23 days (range 4-119) in between one to thirteen interventions (mean n = 5). One patient had to be excluded due to short follow-up after successful closure. Seventy-seven percent (10/13) were successfully treated with a median follow-up of 453 days (range 35-1246) thereafter. No treatment related complications occurred during the therapy. The data of the analysis showed that the Vac-Plug therapy is safe and successful in a relevant proportion of the patients. It is easy to learn and to apply and is well tolerated. In our opinion, it is a promising addition to the armamentarium of interventional methods of these difficult to treat patients. Of course, its usefulness must be further validated in larger prospective studies.

Completion of FLOT Therapy, Regardless of Tumor Regression, Significantly Improves Overall Survival in Patients with Esophageal Adenocarcinoma.

Esophageal cancer is the eighth most common cancer worldwide, with poor prognosis and high mortality. The combination of surgery and systemic therapy provide the best chances for long-term survival. The purpose of this study was to analyze the impact of the FLOT protocol on the overall survival of patients following surgery for esophageal adenocarcinoma, with a focus on the patients who did not benefit in terms of pathological remission from the neoadjuvant therapy. A retrospective analysis of all the patients who underwent esophagectomies from 2012 to 2017 for locally advanced adenocarcinomas of the esophagus at a tertiary medical center was performed. The results show that the completion of systemic therapy, regardless of the tumor regression grading, had a significant positive impact on the overall survival. The patients with complete regression and complete systemic therapy showed the best outcomes. Anastomotic insufficiency did not negatively impact the long-term survival, while complications of the systemic therapy led to significantly reduced overall survival. We conclude that adjuvant systemic therapy should, when possible, always be completed, regardless of the tumor regression, following an esophagectomy.

Endoscopic vacuum therapy versus stent treatment of esophageal anastomotic leaks (ESOLEAK): study protocol for a prospective randomized phase 2 trial.

BACKGROUND: Intrathoracic anastomotic leaks represent a major complication after Ivor Lewis esophagectomy. There are two promising endoscopic treatment strategies in the case of leaks: the placement of self-expanding metal stents (SEMS) or endoscopic vacuum therapy (EVT). Up to date, there is no prospective data concerning the optimal endoscopic treatment strategy. This is a protocol description for the ESOLEAK trial, which is a first small phase 2 randomized trial evaluating the quality of life after treatment of anastomotic leaks by either SEMS placement or EVT. METHODS: This phase 2 randomized trial will be conducted at two German tertiary medical centers and include a total of 40 patients within 2 years. Adult patients with histologically confirmed esophageal cancer, who have undergone Ivor Lewis esophagectomy and show an esophagogastric anastomotic leak on endoscopy or present with typical clinical signs linked to an anastomotic leak, will be included in our study taking into consideration the exclusion criteria. After endoscopic verification of the anastomotic leak, patients will be randomized in a 1:1 ratio into two treatment groups. The intervention group will receive EVT whereas the control group will be treated with SEMS. The primary endpoint of this study is the subjective quality of life assessed by the patient using a systematic and validated questionnaire (EORTC QLQ C30, EORTC QLQ-OES18 questionnaire). Important secondary endpoints are healing rate, period of hospitalization, treatment-related complications, and overall mortality. DISCUSSION: The latest meta-analysis comparing implantation of SEMS with EVT in the treatment of esophageal anastomotic leaks suggested a higher success rate for EVT. The ESOLEAK trial is the first study comparing both treatments in a prospective manner. The aim of the trial is to find suitable endpoints for the treatment of anastomotic leaks as well as to enable an adequate sample size calculation and evaluate the feasibility of future interventional trials. Due to the exploratory design of this pilot study, the sample size is too small to answer the question, whether EVT or SEMS implantation represents the superior treatment strategy. TRIAL REGISTRATION: ClinicalTrials.gov NCT03962244 . Registered on May 23, 2019. DRKS-ID DRKS00007941.

Prognostic value of preoperative circulating tumor cells counts in patients with UICC stage I-IV colorectal cancer.

Colorectal cancer (CRC) is one of the leading causes of cancer death worldwide. There is an urgent need to identify prognostic markers for patients undergoing curative resection of CRC. The detection of circulating tumor cells in peripheral blood is a promising approach to identify high-risk patients with disseminated disease in colorectal cancer. This study aims to evaluate the prognostic relevance of preoperative CTCs using the Cellsearch® system (CS) in patients, who underwent resection with curative intent of different stages (UICC I-IV) of colorectal cancer. Out of 91 Patients who underwent colorectal resection, 68 patients were included in this study. CTC analysis was performed in patients with CRC UICC stages I-IV immediately before surgery. Data were correlated with clinicopathological parameters and patient outcomes. One or more CTCs/7.5 mL were detected in 45.6% (31/68) of patients. CTCs were detected in all stages of the Union of International Cancer Control (UICC), in stage I (1/4, 25%), in stage II (4/12, 33.3%), in stage III (5/19, 26.3%) and in stage IV (21/33, 63.6%). The detection of ≥ 1 CTCs/ 7.5ml correlated to the presence of distant overt metastases (p = 0.014) as well as with shorter progression-free (p = 0.008) and overall survival (p = 0.008). Multivariate analyses showed that the detection of ≥ 1 CTCs/ 7.5ml is an independent prognostic indicator for overall survival (HR, 3.14; 95% CI, 1.18-8.32; p = 0.021). The detection of CTCs is an independent and strong prognostic factor in CRC, which might improve the identification of high-risk patients in future clinical trials.

Oesophageal Adenocarcinomas: Where Do We Stand Today?

Oesophageal cancers (oesophageal squamous cell carcinomas and adenocarcinomas) haven been responsible for more than one million deaths worldwide in 2018 [...].

Clinical Significance of Circulating Tumor Cells in Gastrointestinal Carcinomas.

The idea of a liquid biopsy to screen, surveil and treat cancer patients is an intensively discussed and highly awaited tool in the field of oncology. Despite intensive research in this field, the clinical application has not been implemented yet and further research has to be conducted. However, one component of the liquid biopsy is circulating tumor cells (CTCs) whose potential for clinical application is evaluated in the following. CTCs can shed from primary tumors to the peripheral blood at any time point during the progress of a malignant disease. Following, one single CTC can be the origin for distant metastasis at later cancer stage. Thus, CTCs have great potential to either be used in cancer diagnostics and patient stratification or to function as a target for new therapeutic approaches to stop tumor dissemination and metastasis at the very early beginning. Due to the biological fundamental role of CTCs in tumor progression, here, we provide an overview of CTCs in gastrointestinal cancers and their potential use in the clinical setting. In particular, we discuss the usage of CTC for screening and stratifying patients' risk. Moreover, we will discuss the potential role of CTCs for treatment specification and treatment monitoring.

Lymph Node and Bone Marrow Micrometastases Define the Prognosis of Patients with pN0 Esophageal Cancer.

BACKGROUND: Pathological routine lymph node staging is postulated to be the main oncological prognosticator in esophageal cancer (EC). However, micrometastases in lymph nodes (LNMM) and bone marrow (BNMM) are discussed as the key events in tumor recurrence. We assessed the prognostic significance of the LNMM/BNMM status in initially pN0 staged patients with curative esophagectomy. METHODS: From 110 patients bone marrow aspirates and lymph node tissues were analyzed. For LNMM detection immunohistochemistry was performed using the anticytokeratin antibody AE1/AE3. To detect micrometastases in the bone marrow a staining with the pan-keratin antibody A45-B/B3 was done. Results were correlated with clinicopathologic parameters as well as recurrence and death during follow-up time. RESULTS: Thirty-eight (34.5%) patients showed LNMM, whereas in 54 (49.1%) patients BNMM could be detected. LNMM and BNMM positive patients showed a correlation to an increased pT category (p = 0.017). Univariate and multivariate analyses revealed that the LNMM/BNMM status and especially LNMM skipping the anatomical lymph node chain were significant independent predictors of overall survival and recurrence-free survival. CONCLUSIONS: This study indicates that routine pathological staging of EC is insufficient. Micrometastases in lymph nodes and the bone marrow seem to be the main reason for tumor recurrence and they are a strong prognosticator following curative treatment of pN0 EC.

Expression and serum levels of the neural cell adhesion molecule L1-like protein (CHL1) in gastrointestinal stroma tumors (GIST) and its prognostic power.

INTRODUCTION: Diagnosis of gastrointestinal stroma tumors (GIST) is based on the histological evaluation of tissue specimens. Reliable systemic biomarkers are lacking. We investigated the local expression of the neural cell adhesion molecule L1-like protein (CHL1) in GIST and determined whether soluble CHL1 proteoforms could serve as systemic biomarkers. MATERIAL AND METHODS: Expression of CHL1 was analyzed in primary tumor specimens and metastases. 58 GIST specimens were immunohistochemically stained for CHL1 on a tissue microarray (TMA). Systemic CHL1 levels were measured in sera derived from 102 GIST patients and 91 healthy controls by ELISA. Results were statistically correlated with clinicopathological parameters. RESULTS: CHL1 expression was detected in GIST specimens. Reduced tissue expression was significantly associated with advanced UICC stages (p = 0.036) and unfavorable tumor localization (p = 0.001). CHL1 serum levels are significantly elevated in GIST patients (p < 0.010). Elevated CHL1 levels were significantly associated with larger tumors (p = 0.023), advanced UICC stage (p = 0.021), and an increased Fletcher score (p = 0.041). Moreover, patients with a higher CHL1 serum levels displayed a significantly shortened recurrence free survival independent of other clinicopathological variables. CONCLUSION: Local CHL1 expression and serum CHL1 levels show a reverse prognostic behavior, highlighting the relevance of proteolytic shedding of the molecule. The results of the study indicate a potential role of serum CHL1 as a diagnostic and prognostic marker in GIST.