Detection of Multiple HPV Types in Liquid Biopsies of Cervical Neoplasia.

BACKGROUND: More than 95% of cervical cancers and their precancerous lesions are caused by human papillomavirus (HPV). Cell-free (cf) HPV DNA detection in blood samples may serve as a monitoring tool for cervical cancer. METHODS: In our methodological study, an HPV panel for simultaneous detection of 24 types using mass spectrometry-based analysis was developed for liquid biopsy approaches and tested on HPV positive cell lines, plasmid controls, and cervical high-grade squamous intraepithelial lesions (HSIL) in positive smear samples (n = 52). It was validated in cfDNA blood samples (n = 40) of cervical cancer patients. RESULTS: The HPV panel showed proficient results in cell lines and viral plasmids with a limit of detection of 1 IU (international units)/µL for HPV16/18 and 10GE/µL for HPV11/31/33/39/45/51/52/58/59 and a specificity of 100% for the tested HPV types. In cervical smear samples, HPV DNA was detected with a sensitivity of 98.14%. The overall agreement between the new HPV panel and clinical records was 97.2% (κ = 0.84). In cervical cancer cfDNA, 26/40 (65.0%) tested positive for any HPV type, with most infections due to hrHPV (24/26). HPV positive samples were found in all FIGO stages, with the highest positivity ratio in FIGO III and IV. Even the lowest stage, FIGO I, had 12/23 (52.2%) patients with a positive HPV plasma status. CONCLUSIONS: This proof-of-concept paper shows that the described assay produces reliable results for detecting HPV types in a multiplex mass spectrometry-based assay in cervical smear and cfDNA with high specificity and sensitivity in both cohorts. The assay shows potential for liquid biopsy-based applications in monitoring cervical cancer progression.

Combined Liquid Biopsy Methylation Analysis of CADM1 and MAL in Cervical Cancer Patients.

Cervical cancer is the fourth most common cancer in women, which is associated in >95% with a high-risk human papillomavirus (HPV) infection. Methylation of specific genes has been closely associated with the progress of cervical high-grade dysplastic lesions to invasive carcinomas. Therefore, DNA methylation has been proposed as a triage for women infected with high-risk HPV. Methylation analyses of cervical cancer tissue have shown that cell adhesion molecule 1 (CADM1) and myelin and lymphocyte protein (MAL) methylation are present in over 90% of all cervical high-grade neoplasias and invasive cervical cancers. Here, we established a liquid biopsy-based assay to detect MAL and CADM1 methylation in cell free (cf)DNA of cervical cancer. Methylation of the target gene was validated on bisulfite converted smear-DNA from cervical dysplasia patients and afterward applied to cfDNA using quantitative real-time PCR. In 52 smears, a combined analysis of CADM1 and/or MAL (CADM1/MAL) showed methylation in 86.5% of the cases. In cfDNA samples of 24 cervical cancer patients, CADM1/MAL methylation was detected in 83.3% of the cases. CADM1/MAL methylation was detected already in 81.8% of stage I-II patients showing the high sensitivity of this liquid biopsy assay. In combination with a specificity of 95.5% towards healthy donors (HD) and an area under the curve (AUC) of 0.872 in the receiver operating characteristic (ROC) analysis, CADM1/MAL cfDNA methylation detection might represent a novel and promising liquid biopsy marker in cervical cancer.

Clinical applications and utility of cell-free DNA-based liquid biopsy analyses in cervical cancer and its precursor lesions.

Human papilloma virus (HPV) is an infectious carcinogenic agent. Nearly all cervical cancers are positive for one of the high-risk HPV subtypes. Although the introduction of the HPV vaccines in many countries have shown tremendous positive effects on the incidence of both cervical intraepithelial lesions (CIN) and invasive cancer, the large majority of females worldwide are still not vaccinated. Patients with diagnosed high-grade CIN need a lifelong close monitoring of possible relapse or development of invasive cancer. Different blood-based liquid biopsy approaches have shown great promise as an easily obtainable minimally invasive tool for early detection and monitoring of disease. Among the different liquid biopsy approaches the clinical relevance of cell-free DNA (cfDNA) in cervical cancer has been best investigated. In cervical cancer, the DNA fragments can be of both, human as well as viral origin. Thus, the mutation and methylation status of genes related to carcinogenesis as well as the HPV status can be analysed in plasma from cervical cancer patients. This review describes recent advances in different cfDNA approaches for early detection and monitoring of cervical cancer and its precursor lesions.

Evaluation of the Hamburg-Glasgow Classification in Pancreatic Cancer: Preoperative Staging by Combining Disseminated Tumor Load and Systemic Inflammation.

This study aims to compare the Hamburg Glasgow Classification (HGC) to Union for International Cancer Control (UICC) classification in patients with pancreatic ductal adenocarcinoma (PDAC). As adequate tumor classification is only possible after tumor resection and histological evaluation, only 20% of patients with PDAC receive accurate tumor staging. Thus, an accurate preoperative staging system is still missing but urgently needed. Systemic inflammation and tumor dissemination are important factors regarding the oncological outcome. HGC integrates both into a preoperative staging system, by combining C-reactive protein (CRP), albumin, and disseminated tumor cells (DTC) in the bone marrow. In this prospective study, 109 patients underwent surgical exploration for suspected PDAC. All patients underwent a preoperative bone marrow aspiration for DTC detection. HGC showed significant preoperative risk stratification for overall survival (OS) (p-value < 0.001) and progression-free survival (PFS) (p-value < 0.001). These results were comparable to the UICC survival stratification for OS and PFS (p-value = 0.001 and 0.006). Additionally, in non-metastatic PDAC, HGC III-IV was associated with shorter OS and PFS (p-value < 0.001, respectively) when compared to HGC I-II. Therefore, the HGC is a promising preoperative prognostic staging classification for accurate and simple outcome stratification in patients with PDAC.

Prospective Comparison of the Prognostic Relevance of Circulating Tumor Cells in Blood and Disseminated Tumor Cells in Bone Marrow of a Single Patient's Cohort With Esophageal Cancer.

OBJECTIVE: Aim of this prospective study was to evaluate the prognostic significance of disseminated tumor cells (DTCs) and circulating tumor cells (CTCs) in 1 cohort of patients with esophageal cancer (EC). BACKGROUND: Hematogenous tumor cell dissemination is a key event in tumor progression, and clinical significance of DTCs and CTCs are controversially discussed in the literature. However, evaluation of both biomarker in 1 patient's cohort has not been described before. METHODS: In this prospective, single-center study, 76 patients with preoperatively nonmetastatic staged EC were included. The CellSearch system was used to enumerate CTCs. Bone marrow was aspirated from the iliac crest and cells were enriched by Ficoll density gradient centrifugation. DTCs were immunostained with the pan-keratin antibody A45-B/B3. RESULTS: Fifteen of 76 patients (19.7%) harbored CTCs, whereas in 13 of 76 patients (17.1%), DTCs could be detected. In only 3 patients (3.9%), CTCs and DTCs were detected simultaneously, whereas concordant results (DTC/CTC negative and DTC/CTC positive) were found in 54 patients (71.1%). Surprisingly, only patients with CTCs showed significant shorter overall and relapse-free survival (P = 0.038 and P = 0.004, respectively). Multivariate analyses revealed that only the CTC status was an independent predictor of overall and relapse-free survival (P = 0.007 and P < 0.001, respectively). CONCLUSIONS: This is the first study analyzing CTC and DTC status in 1 cohort of nonmetastatic patients with EC. In this early disease stage, only the CTC status was an independent, prognostic marker suitable and easy to use for clinical staging of patients with EC.

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.

Clinical Relevance of Circulating Tumor Cells in Esophageal Cancer Detected by a Combined MACS Enrichment Method.

INTRODUCTION: Current modalities to predict tumor recurrence and survival in esophageal cancer are insufficient. Even in lymph node-negative patients, a locoregional and distant relapse is common. Hence, more precise staging methods are needed. So far, only the CellSearch system was used to detect circulating tumor cells (CTC) with clinical relevance in esophageal cancer patients. Studies analyzing different CTC detection assays using advanced enrichment techniques to potentially increase the sensitivity are missing. METHODS: In this single-center, prospective study, peripheral blood samples from 90 esophageal cancer patients were obtained preoperatively and analyzed for the presence of CTCs by Magnetic Cell Separation (MACS) enrichment (combined anti-cytokeratin and anti-epithelial cell adhesion molecules (EpCAM)), with subsequent immunocytochemical staining. Data were correlated with clinicopathological parameters and patient outcomes. RESULTS: CTCs were detected in 25.6% (23/90) of the patients by combined cytokeratin/EpCAM enrichment (0-150 CTCs/7.5 mL). No significant correlation between histopathological parameters and CTC detection was found. Survival analysis revealed that the presence of more than two CTCs correlated with significantly shorter overall survival (OS) and progression-free survival (PFS). CONCLUSION: With the use of cytokeratin as an additional enrichment target, the CTC detection rate in esophageal cancer patients can be elevated and displays the heterogeneity of cytokeratin (CK) and EpCAM expression. The presence of >2CTCs correlated with a shorter relapse-free and overall survival in a univariate analysis, but not in a multivariate setting. Moreover, our results suggest that the CK7/8+/EpCAM+ or CK7/8+/EpCAM- CTC subtype does not lead to an advanced tumor staging tool in non-metastatic esophageal cancer (EC) patients.

Absence of HER2 Expression of Circulating Tumor Cells in Patients with Non-Metastatic Esophageal Cancer.

BACKGROUND/AIM: The clinical significance of circulating tumor cells (CTC) in non-metastatic esophageal cancer (EC) remains controversial and the cellular and molecular characteristics of CTCs are poorly understood. Especially the frequency and oncological impact of HER2 expression in CTCs in patients with EC have not been evaluated until now. MATERIALS AND METHODS: In this single-center, prospective study, peripheral blood samples were obtained preoperatively from 45 patients who were diagnosed with resectable EC. CTC detection and HER2 expression were performed using the CellSearch System. Data were correlated with clinicopathological parameters and patient outcomes. RESULTS: The study included 13 patients with squamous cell carcinomas (SCC) and 32 patients with adenocarcinomas (AC). HER2 gene amplification in the primary tumor was detected in 9.1% of patients. One or more CTCs were detected in 15.6% (SCC 1/13; AC 6/32) of the patients. None of the detected CTCs showed HER2 expression. Patients with CTCs showed significantly shorter relapse-free (p<0.001) and overall survival (p=0.015) than CTC-negative patients. CONCLUSION: This is the first study analyzing HER2 expression and the clinical significance of CTCs in patients with non-metastatic EC using an automated immunomagnetic detection system. HER2 expression in CTCs is very rare in patients with non-metastatic EC and seems to have a low clinical and oncological impact.

Improved Risk Stratification by Circulating Tumor Cell Counts in Pancreatic Cancer.

Purpose: Pancreatic cancer is one of the most devastating diseases with a 5-year survival rate of 3% to 5%. Here, we investigated whether circulating tumor cells (CTC) may predict metastatic spread and survival in pancreatic cancer patients.Experimental Design: In a prospective study, we enrolled 69 pancreatic cancer patients. In peripheral blood, CTCs were identified by MACS enrichment (anti-cytokeratin/anti-EpCam) and subsequent automated analysis after combined anti-cytokeratin/anti-CD45/DAPI staining. CTC results were correlated to established clinicopathologic risk factors, detection of disseminated tumor cells (DTC) in bone marrow, and clinical outcome (follow-up time: 48 months).Results: Median patient survival was 11 months (0-48 months). Thirty-eight patients were male and 31 were female, and the majority received gemcitabine (58/69). CTCs were present in 23 of 69 patients (33.3%) ranging from 1 to 19 cells (17 with >1 CTC). Although clinicopathologic parameters and DTC status did not correlate with CTC incidence, progression-free survival (PFS) and overall survival (OS) were significantly reduced in CTC-positive patients in univariate (P = 0.009, PFS; P = 0.030, OS, both log rank) and multivariate analysis [HR = 4.543; confidence interval (CI), 1.549-13.329; P = 0.006, PFS; HR = 2.093; CI, 1.081-4.050; P = 0.028, OS, both Cox regression). Also within patients receiving chemotherapy, PFS was significantly reduced in CTC-positive patients in univariate (P = 0.013) and multivariate (HR = 4.203; CI, 1.416-12.471; P = 0.010) analysis.Conclusions: CTCs affect the outcome of patients with pancreatic cancer independent from other risk factors, including patients receiving (adjuvant) cytotoxic therapy. CTC stratification may allow a better upfront identification of patients with a longer lifespan who might profit from new adjuvant therapies. Clin Cancer Res; 24(12); 2844-50. ©2018 AACR.

Circulating Tumor Cells as a Biomarker for Preoperative Prognostic Staging in Patients With Esophageal Cancer.

OBJECTIVE: We evaluated the prognostic significance of circulating tumor cells (CTCs) in patients with esophageal cancer (EC). BACKGROUND: Despite the availability of several preoperative diagnostic techniques, accurate pretreatment staging of EC remains challenging. METHODS: In this single-center, prospective study, peripheral blood samples for CTC analyses were obtained preoperatively from 100 patients who were judged to have resectable EC. CTC detection was performed using the CellSearch System. Data were correlated with clinicopathological parameters and patient outcomes. RESULTS: CTCs were detected in 18% (18/100) of all eligible patients. Patients with CTCs showed significantly shorter relapse-free (P < 0.001) and overall survival (P < 0.001) than CTC-negative patients. Even in patients with lymph node invasion and without distant metastases (pN+, M0, N = 45), CTC detection indicated significantly worse relapse-free (P < 0.001) and overall survival (P = 0.007). Multivariate analyses of eligible patients identified CTCs as a strong, independent, prognostic indicator of tumor recurrence (hazard ratio, 5.063; 95% confidence interval, 2.233-11.480; P < 0.001) and overall survival (hazard ratio, 3.128; 95% confidence interval, 1.492-6.559; P = 0.003). CONCLUSIONS: This is the first study to report that CTCs detected by an automated immunomagnetic detection system are independent, prognostic indicators of patients' outcome in EC. Thus, implementation of CTCs may improve accuracy of preoperative staging in EC.

Identification of HERC5 and its potential role in NSCLC progression.

For better lung cancer diagnosis and therapy, early detection markers of tumor dissemination are urgently needed, as most lung cancers do not show symptoms until extensive metastasis formation has already taken place. Our previous studies showed that in non-small cell lung cancer (NSCLC) early tumor dissemination is associated with a loss of chromosome 4q12-q32 and the presence of disseminated tumor cells (DTC) in the bone marrow. In order to identify the potential target gene in this region, a screen for methylation-dependent expression was performed. Lung cancer cell lines showing a loss of 4q as well as a normal bronchial epithelial cell line as control were treated with 5-aza-2'-deoxycytidine (5-aza-CdR) followed by expression profiling. Seven genes within the 4q target region, which have been associated with a positive DTC status before were found to be regulated by hypermethylation. QRT-PCR in an independent sample set identified HERC5 as a potential target gene. Quantitative methylation analysis of these lung tissue samples revealed that HERC5 promoter hypermethylation was significantly associated with positive DTC status (p = 0.020) and occurrence of brain metastases (p = 0.015). In addition, hypermethylation of the HERC5 promoter in NSCLC was identified as a predictor for poor survival for Stage I adenocarcinoma patients (p = 0.022) and also for poor overall survival in metastatic lung cancer patients (p = 0.028). In conclusion, HERC5 may function as a prognostic marker and is associated with tumor dissemination in lung cancer.

Loss of 4q21.23-22.1 is a prognostic marker for disease free and overall survival in non-small cell lung cancer.

This study was performed to assess the prognostic relevance of genomic aberrations at chromosome 4q in NSCLC patients. We have previously identified copy number changes at 4q12-q32 to be significantly associated with the early hematogenous dissemination of non-small cell lung cancer (NSCLC), and now aim to narrow down potential hot-spots within this 107 Mb spanning region. Using eight microsatellite markers at position 4q12-35, allelic imbalance (AI) analyses were performed on a preliminary study cohort (n = 86). Positions indicating clinicopathological and prognostic associations in AI analyses were further validated in a larger study cohort using fluorescence in situ hybridization (FISH) in 209 NSCLC patients. Losses at positions 4q21.23 and 4q22.1 were shown to be associated with advanced clinicopathological characteristics as well as with shortened disease free (DFS) and overall survival (OS) (DFS: P = 0.019; OS: P = 0.002). Multivariate analyses identified the losses of 4q21.23-22.1 to be an independent prognostic marker for both DFS and OS in NSCLC (HR 1.64-2.20, all P<0.04), and especially in squamous cell lung cancer (P<0.05). A case report study of a lung cancer patient further revealed a loss of 4q21.23 in disseminated tumor cells (DTCs). Neither gains at the latter positions, nor genomic aberrations at 4q12, 4q31.2 and 4q35.1, indicated a prognostic relevance. In conclusion, our data indicate that loss at 4q21.23-22.1 in NSCLC is of prognostic relevance in NSCLC patients and thus, includes potential new tumor suppressor genes with clinical relevance.

Prognostic relevance of circulating tumor cells in blood and disseminated tumor cells in bone marrow of patients with squamous cell carcinoma of the oral cavity.

PURPOSE: Current staging methods for squamous cell carcinomas (SCC) of the oral cavity (OSCC) need to be improved to predict the risk of individual patients. Because hematogenous tumor cell dissemination is a key event in tumor progression, we assessed the prognostic significance of disseminated tumor cells (DTC) in bone marrow and circulating tumor cells (CTC) in peripheral blood from patients with OSCC. EXPERIMENTAL DESIGN: From 110 patients with OSCC, tumors were surgically resected (R0) without neoadjuvant therapy. The CellSearch system was used to enumerate CTCs. Bone marrow was aspirated from the iliac crest, and mononuclear cells (MNC) were enriched by Ficoll density gradient centrifugation. To detect DTCs, MNCs were immunostained with the pan-keratin antibody A45-B/B3. Results were correlated with clinicopathologic parameters and clinical outcome such as recurrence and death during follow-up time (mean 916 days). RESULTS: Ten of 80 patients (12.5%) harbored CTCs in peripheral blood, whereas in 18 of 90 patients (20.0%) DTCs in bone marrow could be detected. Surprisingly, in only 2 patients (1.8%) CTCs and DTCs were detected simultaneously. Significant correlations could be found for CTCs and tumor size (P = 0.04), nodal status and DTCs (P = 0.02), and distant metastasis with CTCs (P = 0.004) and DTCs (P = 0.005). Univariate and multivariate analyses revealed that CTCs and DTCs were significant and independent predictors of recurrence-free survival (P < 0.001). CONCLUSIONS: Both DTCs and CTCs are independent prognostic markers in patients with OSCC, predicting relapse with higher sensitivity at various disease stages than routine staging procedures. Bone marrow might be an interesting target organ for future therapeutic interventions.

Involvement of CXCR4 chemokine receptor in metastastic HER2-positive esophageal cancer.

A functional linkage of the structurally unrelated receptors HER2 and CXCR4 has been suggested for breast cancer but has not been evaluated for esophageal carcinoma. The inhibition of HER2 leads to a reduction of primary tumor growth and metastases in an orthotopic model of esophageal carcinoma. The chemokine receptor CXCR4 has been implicated in metastatic dissemination of various tumors and correlates with poor survival in esophageal carcinoma. The aim of this study was to investigate a correlation between the expression levels of HER2 and CXCR4 and to evaluate the involvement of CXCR4-expression in HER2-positive esophageal carcinoma. The effects of HER2-inhibition with trastuzumab and of CXCR4-inhibition with AMD3100 on primary tumor growth, metastatic homing, and receptor expression were evaluated in vitro and in an orthotopic model of metastatic esophageal carcinoma using MRI for imaging. The clinical relevance of HER2- and CXCR4-expression was examined in esophageal carcinoma patients. A significant correlation of HER2- and CXCR4-expression in primary tumor and metastases exists in the orthotopic model. Trastuzumab and AMD3100 treatment led to a significant reduction of primary tumor growth, metastases and micrometastases. HER2-expression was significantly elevated under AMD3100 treatment in the primary tumor and particularly in the metastases. The positive correlation between HER2- and CXCR4-expression was validated in esophageal cancer patients. The correlation of CXCR4- and HER2-expression and the elevation of HER2-expression and reduction of metastases through CXCR4-inhibition suggest a possible functional linkage and a role in tumor dissemination in HER2-positive esophageal carcinoma.

Disseminated tumor cells in bone marrow and the natural course of resected esophageal cancer.

OBJECTIVE: To assess the impact of disseminated tumor cells (DTC) in bone marrow on recurrence and survival in complete resected esophageal cancer (EC). BACKGROUND: Current modalities to predict tumor recurrence and survival in EC are insufficient. Here, we evaluated in a prospective study the prognostic relevance of DTC in bone marrow for the natural postoperative course of EC. METHODS: We enrolled 370 consecutive EC patients (1995-2009). All tumors, 189 squamous cell carcinomas and 181 adenocarcinomas, were completely surgically resected (R0), and patients received neither neoadjuvant nor adjuvant therapy. Disseminated tumor cells were detected by an immunocytochemical cytokeratin assay in preoperatively taken bone marrow aspirates. The results were correlated with clinic-pathological parameters and clinical outcome. RESULTS: Overall 120 (32.4%) patients harbored DTC in their bone marrow. Presence of DTC significantly correlated with aggressive tumor biology as indicated by increased tumor size (P = 0.026), regional (P = 0.002) and distant (P = 0.012) lymph node metastases, and higher relapse rate (P < 0.001, χ test). A gradual decrease in disease-free (P < 0.001) and overall (P < 0.001, log-rank test) survival was observed between DTC-negative and DTC-positive patients and was evident in subgroup analysis stratified for nodal status, lymph node yield, lymph node ratio, and tumor subtypes. Disseminated tumor cells were identified as a strong independent prognosticator of tumor recurrence (hazard ratio [HR] 4.0, 95% confidence interval [CI]: 2.96-5.45, P < 0.001) and overall survival (HR 3.1, 95% CI: 2.37-4.09, P < 0.001, Cox regression analysis). CONCLUSIONS: The presence of DTC in bone marrow is a strong and independent prognostic factor in patients with resectable EC.

VEGFR-1 expression levels predict occurrence of disseminated tumor cells in the bone marrow of patients with esophageal carcinoma.

Blocking angiogenesis by inhibiting VEGF represents an established therapeutic strategy in many cancers. The role of placental growth factor (PlGF) and of its receptor VEGFR-1 in tumor biology remain more elusive. Currently, humanized monoclonal antibodies against PlGF are studied in early phase clinical trials because PlGF inhibition blocked murine tumor growth and angiogenesis. In contrast to mice exclusively expressing one PlGF isoform (PlGF-2), humans can produce four PlGF isoforms (PlGF1-4). Surprisingly nothing is yet known about expression of all four PlGF isoforms in human cancer, because until now mostly total PlGF levels or PlGF-1/2 were analyzed without discriminating further. In this study we determined mRNA expression levels of PlGF1-4 and of VEGFR-1 by QRT-PCR in human esophageal tumor tissue and investigated whether gene expression levels correlate with clinical data. PlGF-1 and -2 were expressed in virtually all analyzable tumors, whereas PlGF-3 and -4 were present in tumors of 59 and 74 % of patients, respectively. MRNA Expression levels of all four splice variants correlated with each other. In contrast, PlGF-1 and -2 mRNA expression was lower in esophageal control tissue and PlGF-3 and -4 mRNA were undetectable. VEGFR-1 was expressed by more than 80 % of patients. Interestingly, VEGFR-1 expression levels significantly correlate with presence of disseminated tumor cells (DTCs) in bone marrow. Patients with DTCs exhibit lower VEGFR-1 mRNA expression than patients without DTCs. Pending validation in other types of cancer, expression levels of VEGFR-1 might be useful as surrogate marker for DTCs.

Disseminated tumor cells in pancreatic cancer-an independent prognosticator of disease progression and survival.

Pancreatic cancer is one of the most devastating cancers with a 6-month median survival and a 5-year survival rate of 3-5%. Still important aspects of its aggressive biology remain elusive and advanced therapeutic regimens have not been substantially successful. We investigated the prognostic role of disseminated tumor cells (DTC) in bone marrow, a reservoir for early DTC potentially contributing to metastatic progression, of pancreatic cancer patients. After exclusion of patients with different postsurgery diagnosis or missing DTC status (n = 40) a total of 175 patients remained for final analyses. One-hundred and nineteen patients were male and 96 female with a median age of 67 years, 96 patients underwent complete resection. Bone marrow aspirates taken at primary surgery were analyzed for DTC by an immunocytochemical cytokeratin assay and correlated to survival data. Overall 13.7% of patient samples (24/175) harbored DTC in their bone marrow. Histopathological parameters did not correlate significantly. Univariate survival analysis revealed a borderline significant correlation between DTC and decreased progression-free survival (p = 0.069), and was significant for overall survival (p = 0.036). Regarding patients with resected tumors, the respective p-values were 0.058 for progression-free and 0.016 for overall survival. Importantly, the prognostic influence was independent from other risk factors as shown by multivariate analyses for progression-free (p = 0.030, HR: 2.057; CI (95%): 1.073-3.943) and overall survival (p = 0.006, HR: 2.283; CI (95%): 1.260-4.135). The presence of DTC in bone marrow is a strong and independent prognostic factor of survival in patients with pancreatic cancer. Thus, bone-targeting may be a new future therapeutic option for DTC-positive patients.

ALCAM (CD166) expression and serum levels are markers for poor survival of esophageal cancer patients.

The expression of the activated leukocyte cell adhesion molecule (ALCAM and CD166) is increased in various types of cancer. We aimed to evaluate its role as a prognostic marker for esophageal cancer (EC). We retrospectively analyzed ALCAM expression in 299 primary lesions, 147 lymph node and 46 distant metastases from EC patients, on a tissue microarray using immunohistochemistry. Bone marrow samples from representative cancer patients (n = 16), taken before primary surgery, were stained by double-immunofluorescence for ALCAM and cytokeratins (CK). Blood serum samples from 236 cancer patients and 127 controls were analyzed for serum ALCAM (s-ALCAM) by ELISA. The immunohistochemical analysis showed increased ALCAM expression in the majority of lesions (primary tumor 71%, lymph node 76% and distant metastases 80%). ALCAM expression was not associated with histopathological parameters except for tumor grading (p = 0.015). ALCAM-positive patients had significantly worse recurrence-free and overall survival (OS; p = 0.002). Disseminated tumor cells (DTC) in bone marrow showed two phenotypes, ALCAM+/CK+ (36%) and ALCAM-/CK+ (64%). Multivariate analysis revealed that ALCAM expression and elevated s-ALCAM serum values are powerful prognostic variables for OS in patients with EC (hazard ratio [HR] 3.987, 95% confidence interval [95%CI] 1.906-8.340, p < 0.001 and HR 1.915, 95%CI 1.021-3.592, p = 0.043). The results of our study provide preliminary evidence for the potential clinical utility of ALCAM as a prognostic biomarker for EC, which might be a basis for future clinical application. In addition, ALCAM expression in a subset of DTC of the bone marrow indicates a potential function in the metastatic cascade of EC.

Notch signaling activated by replication stress-induced expression of midkine drives epithelial-mesenchymal transition and chemoresistance in pancreatic cancer.

The incidence of pancreatic ductal adenocarcinoma (PDAC) nearly equals its mortality rate, partly because most PDACs are intrinsically chemoresistant and thus largely untreatable. It was found recently that chemoresistant PDAC cells overexpress the Notch-2 receptor and have undergone epithelial-mesenchymal transition (EMT). In this study, we show that these two phenotypes are interrelated by expression of Midkine (MK), a heparin-binding growth factor that is widely overexpressed in chemoresistant PDAC. Gemcitabine, the front-line chemotherapy used in PDAC treatment, induced MK expression in a dose-dependent manner, and its RNAi-mediated depletion was associated with sensitization to gemcitabine treatment. We identified an interaction between the Notch-2 receptor and MK in PDAC cells. MK-Notch-2 interaction activated Notch signaling, induced EMT, upregulated NF-κB, and increased chemoresistance. Taken together, our findings define an important pathway of chemoresistance in PDAC and suggest novel strategies for its clinical attack.

Prognostic impact of CXCR4 and CXCR7 expression in pancreatic adenocarcinoma.

BACKGROUND: Chemokines and their receptors are known to play important roles in the tumorigenesis of many malignancies. The aim of this study was to evaluate the prognostic impact of the expression of the chemokine receptors CXCR4 and CXCR7 in patients with pancreatic adenocarcinoma (PAC). METHODS: Expression of CXCR4 and CXCR7 in specimens from 249 patients with PAC was evaluated by immunohistochemistry on a tissue microarray and matched with clinicopathological parameters and overall survival. RESULTS: Expression of CXCR4 was detected in 215 patients (86.4%) and CXCR7 in 47 patients (18.9%). No association between CXCR4 and CXCR7 expression was evident, although all the CXCR7 positive tumors were also CXCR4 positive. pT1/2 tumors showed a higher frequency of CXCR7 expression than pT3/4 tumors (P = 0.018), while more dedifferentiated tumors had elevated CXCR7 expression (P = 0.036). Overall and disease-free survival revealed no association with either CXCR4 or CXCR7 expression. CONCLUSION: CXCR7 is associated with tumor grade and inversely associated with tumor size and may play a potential role in tumor progression and differentiation. In contrast to previously reported data our results revealed no significant association between CXCR4 expression and clinical or pathological data.