Consensus on the pathological definition and classification of poorly cohesive gastric carcinoma

Background and aims Clinicopathological characteristics of gastric cancer (GC) are changing, especially in the West with a decreasing incidence of distal, intestinal-type tumours and the corresponding increasing proportion of tumours with Laurén diffuse or WHO poorly cohesive (PC) including signet ring cell (SRC) histology. To accurately assess the behaviour and the prognosis of these GC subtypes, the standardization of pathological definitions is needed. Methods A multidisciplinary expert team belonging to the European Chapter of International Gastric Cancer Association (IGCA) identified 11 topics on pathological classifications used for PC and SRC GC. The topics were debated during a dedicated Workshop held in Verona in March 2017. Then, through a Delphi method, consensus statements for each topic were elaborated. Results A consensus was reached on the need to classify gastric carcinoma according to the most recent edition of the WHO classification which is currently WHO 2010. Moreover, to standardize the definition of SRC carcinomas, the proposal that only WHO PC carcinomas with more than 90% poorly cohesive cells having signet ring cell morphology have to be classified as SRC carcinomas was made. All other PC non-SRC types have to be further subdivided into PC carcinomas with SRC component ( 10% SRCs) and PC carcinomas not otherwise specified (< 10% SRCs). Conclusion The reported statements clarify some debated topics on pathological classifications used for PC and SRC GC. As such, this consensus classification would allow the generation of evidence on biological and prognostic differences between these GC subtypes

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 = 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 = 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 resectio

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