Comprehensive RNA dataset of tissue and plasma from patients with esophageal cancer or precursor lesions.

In the past decades, the incidence of esophageal adenocarcinoma has increased dramatically in Western populations. Better understanding of disease etiology along with the identification of novel prognostic and predictive biomarkers are urgently needed to improve the dismal survival probabilities. Here, we performed comprehensive RNA (coding and non-coding) profiling in various samples from 17 patients diagnosed with esophageal adenocarcinoma, high-grade dysplastic or non-dysplastic Barrett's esophagus. Per patient, a blood plasma sample, and a healthy and disease esophageal tissue sample were included. In total, this comprehensive dataset consists of 102 sequenced libraries from 51 samples. Based on this data, 119 expression profiles are available for three biotypes, including miRNA (51), mRNA (51) and circRNA (17). This unique resource allows for discovery of novel biomarkers and disease mechanisms, comparison of tissue and liquid biopsy profiles, integration of coding and non-coding RNA patterns, and can serve as a validation dataset in other RNA landscaping studies. Moreover, structural RNA differences can be identified in this dataset, including protein coding mutations, fusion genes, and circular RNAs.

Evaluation of a marker independent isolation method for circulating tumor cells in esophageal adenocarcinoma.

OBJECTIVE: The enrichment of circulating tumor cells (CTCs) from blood provides a minimally invasive method for biomarker discovery in cancer. Longitudinal interrogation allows monitoring or prediction of therapy response, detection of minimal residual disease or progression, and determination of prognosis. Despite inherent phenotypic heterogeneity and differences in cell surface marker expression, most CTC isolation technologies typically use positive selection. This necessitates the optimization of marker-independent CTC methods, enabling the capture of heterogenous CTCs. The aim of this report is to compare a size-dependent and a marker-dependent CTC-isolation method, using spiked esophageal cells in healthy donor blood and blood from patients diagnosed with esophageal adenocarcinoma. METHODS: Using esophageal cancer cell lines (OE19 and OE33) spiked into blood of a healthy donor, we investigated tumor cell isolation by Parsortix post cell fixation, immunostaining and transfer to a glass slide, and benchmarked its performance against the CellSearch system. Additionally, we performed DEPArray cell sorting to infer the feasibility to select and isolate cells of interest, aiming towards downstream single-cell molecular characterization in future studies. Finally, we measured CTC prevalence by Parsortix in venous blood samples from patients with various esophageal adenocarcinoma tumor stages. RESULTS: OE19 and OE33 cells were spiked in healthy donor blood and subsequently processed using CellSearch (n = 16) or Parsortix (n = 16). Upon tumor cell enrichment and enumeration, the recovery rate ranged from 76.3 ± 23.2% to 21.3 ± 9.2% for CellSearch and Parsortix, respectively. Parsortix-enriched and stained cell fractions were successfully transferred to the DEPArray instrument with preservation of cell morphology, allowing isolation of cells of interest. Finally, despite low CTC prevalence and abundance, Parsortix detected traditional CTCs (i.e. cytokeratin+/CD45-) in 8/29 (27.6%) of patients with esophageal adenocarcinoma, of whom 50% had early stage (I-II) disease. CONCLUSIONS: We refined an epitope-independent isolation workflow to study CTCs in patients with esophageal adenocarcinoma. CTC recovery using Parsortix was substantially lower compared to CellSearch when focusing on the traditional CTC phenotype with CD45-negative and cytokeratin-positive staining characteristics. Future research could determine if this method allows downstream molecular interrogation of CTCs to infer new prognostic and predictive biomarkers on a single-cell level.

FA01.02: THE EFFECT OF POSTOPERATIVE COMPLICATIONS AFTER MIE ON LONG-TERM SURVIVAL: A RETROSPECTIVE, MULTI-CENTER COHORT STUDY.

BACKGROUND: Esophagectomy has a high incidence of postoperative morbidity. Complications lead to a decreased short-term survival, however the influence of those complications on long-term survival is still unclear. Most of the performed studies are small, single center cohort series with inconclusive or conflicting results. Minimally invasive esophagectomy (MIE) has been shown to be associated with a reduced postoperative morbidity. In this study, the influence of complications on long-term survival for patients with esophageal cancer undergoing a MIE were investigated. METHODS: Data was collected from the EsoBenchmark database, a collaboration of 13 high-volume centers routinely performing MIE. Patients were included in this database from June 1, 2011 until May 31, 2016. Complications were scored according to the Clavien-Dindo (CD) classification for surgical complications. Major complications were defined as a CD grade ≥ 3. The data were corrected for 90-day mortality to correct for the short-term effect of postoperative complications on mortality. Overall survival was analyzed using the Kaplan Meier, log rank- and (uni- and multivariable) Cox-regression analyses. RESULTS: A total of 926 patients were eligible for analysis. Mean follow-up time was 30.8 months (SD 17.9). Complications occurred in 543 patients (59.2%) of which 39.3% had a major complication. Anastomotic leakage (AL) occurred in 135 patients (14.5%) of which 9.2% needed an intervention (CD grade ≥ 3). A significant worse long-term survival was observed in patients with any AL (HR 1.73, 95% CI 1.29-2.32, P < 0.001) and for patients with AL CD grade ≥3 (HR 1.86, 95% CI 1.32-2.63, P < 0.001). Major cardiac complications occurred in 18 patients (1.9%) and were related to a decreased long-term survival (HR 2.72, 95% CI 1.38-5.35, p 0.004). For all other complications, no significant influence on long-term survival was found. CONCLUSION: The occurrence and severity of anastomotic leakage and cardiac complications after MIE negatively affect long-term survival of esophageal cancer patients. DISCLOSURE: All authors have declared no conflicts of interest.

Defining Benchmarks for Transthoracic Esophagectomy: A Multicenter Analysis of Total Minimally Invasive Esophagectomy in Low Risk Patients.

OBJECTIVE: To define "best possible" outcomes in total minimally invasive transthoracic esophagectomy (ttMIE). BACKGROUND: TtMIE, performed by experts in patients with low comorbidity, may serve as a benchmark procedure for esophagectomy. PATIENTS AND METHODS: From a cohort of 1057 ttMIE, performed over a 5-year period in 13 high-volume centers for esophageal surgery, we selected a study group of 334 patients (31.6%) that fulfilled criteria of low comorbidity (American Society of Anesthesiologists score ≤2, WHO/ECOG score ≤1, age ≤65 years, body mass index 19-29 kg/m). Endpoints included postoperative morbidity measured by the Clavien-Dindo classification and the comprehensive complication index. Benchmark values were defined as the 75th percentile of the median outcome parameters of the participating centers to represent best achievable results. RESULTS: Benchmark patients were predominantly male (82.9%) with a median age of 58 years (53-62). High intrathoracic (Ivor Lewis) and cervical esophagogastrostomy (McKeown) were performed in 188 (56.3%) and 146 (43.7%) patients, respectively. Median (IQR) ICU and hospital stay was 0 (0-2) and 12 (9-18) days, respectively. 56.0% of patients developed at least 1 complication, and 26.9% experienced major morbidity (≥grade III), mostly related to pulmonary complications (25.7%), anastomotic leakage (15.9%), and cardiac events (13.5%). Benchmark values at 30 days after hospital discharge were ≤55.7% and ≤30.8% for overall and major complications, ≤18.0% for readmission, ≤3.1% for positive resection margins, and ≥23 for lymph node yield. Benchmarks at 30 and 90 days were ≤1.0% and ≤4.6% for mortality, and ≤40.8 and ≤42.8 for the comprehensive complication index, respectively. CONCLUSION: This outcome analysis of patients with low comorbidity undergoing ttMIE may serve as a reference to evaluate surgical performance in major esophageal resection.

Prognostic Relevance of Lymph Node Regression After Neoadjuvant Chemoradiation for Esophageal Cancer.

Prognostic factors after preoperative chemoradiation for patients with advanced esophageal cancer are under discussion. Treatment response measured in the primary tumor is a well-defined prognostic marker. The prognostic relevance of tumor regression in lymph nodes (LNs), eg, histomorphologic characteristics must be evaluated in a larger series of patients. From 1997-2010, 403 patients with cT3N×M0 esophageal cancer underwent preoperative chemoradiation followed by transthoracic esophagectomy. Histopathologic response of the primary tumor was graded in resected specimens as "minor" (≥10% vital residual tumor cells) or "major." The LNs of all patients without LN metastases (ypN0 n = 222, adenocarcinoma n = 129, squamous cell carcinoma n = 93) were reevaluated for central fibrosis. Univariate and multivariate analyses were performed on histomorphologic criteria of examined LNs and used to correlate these with tumor response and prognosis. The 5-year survival rate (5YSR) for all patients was 30%. Overall, 5480 LNs were reevaluated for the existence of central fibrosis in ypN0 cases. The prognostic relevance of the LN regression (LNR) grading system was confirmed for all patients with univariate (P < 0.001) and multivariate (P = 0.02) analyses. In results, the 5YSR for ypN0 patients overall was 37%, for patients with major response by the primary tumor was 42%, and for minor responders was 19% (P < 0.001). Analyzing LNR in major responders, the group with less than 3 LNs with central fibrosis (n = 52) showed significantly better prognosis (5YSR = 63%) compared to those with more (5YSR = 34%), (P = 0.016). Conclusion includes morphologic signs of metastatic LNR after chemoradiation, such as central fibrosis, are of prognostic relevance for patients with advanced esophageal cancer, especially for those with major response of the primary tumor.