Amplification of KRAS and its heterogeneity in non-Asian gastric adenocarcinomas.

BACKGROUND: Gastric cancer is one of the deadliest cancer entities worldwide. While surgery is the only curative treatment option in early tumors, for locally advanced and metastatic patients further therapeutic targets are needed. Several studies not only reported mutations but also amplifications of the KRAS locus in different cancer entities. More recently, KRAS amplification was discussed as a new therapeutic target. Little is known about the (prognostic) relevance and (heterogenic) distribution of KRAS amplification in gastric adenocarcinomas, especially in Non-Asian patients. METHODS: Amplification of the KRAS locus and corresponding protein expression was analyzed in 582 gastric adenocarcinomas employing fluorescence in-situ hybridization (FISH) and immunohistochemistry. Amplification status was correlated with clinico-pathological features, clinical outcome and molecular tumor data including a correlation to the TCGA subtypes of gastric carcinoma. RESULTS: KRAS amplification was detected in 27 out of 470 analysable tumors (5.7%) and correlated with protein expression of KRAS in all amplified tumors. Within the KRAS amplified gastric tumors 14/27 (51.9%) showed a heterogeneous distribution with also KRAS non-amplified tumor parts. According to TCGA 24 tumors (88.8%) were related to chromosomal instable tumors (CIN). The survival analysis of the entire patient cohort did not show any difference in overall survival in dependence on the KRAS status. However, a significant survival difference with a worse outcome for patients with KRAS amplified tumors was identified when analysing patients without neoadjuvant pre-treatment. CONCLUSIONS: We confirm the unfavorable prognosis of KRAS amplified tumors reported by other studies in (Asian) patient groups, at least in patients without neoadjuvant pre-treatment. Within KRAS amplified tumors we revealed intratumoral heterogeneity that may define a (more aggressive) tumor cell population which is more frequently observed in patients with lymph node metastases. Despite the heterogeneous distribution of KRAS amplified tumor clones, KRAS amplified locally advanced or metastasized gastric adenocarcinomas represent a therapeutically highly relevant tumor subgroup.

The economic burden of endoscopic treatment for anastomotic leaks following oncological Ivor Lewis esophagectomy.

BACKGROUND: Complications after surgery for esophageal cancer are associated with significant resource utilization. The aim of this study was to analyze the economic burden of two frequently used endoscopic treatments for anastomotic leak management after esophageal surgery: Treatment with a Self-expanding Metal Stent (SEMS) and Endoscopic Vacuum Therapy (EVT). MATERIALS AND METHODS: Between January 2012 and December 2016, we identified 60 German-Diagnosis Related Group (G-DRG) cases of patients who received a SEMS and / or EVT for esophageal anastomotic leaks. Direct costs per case were analyzed according to the Institute for Remuneration System in Hospitals (InEK) cost-accounting approach by comparing DRG payments on the case level, including all extra fees per DRG catalogue. RESULTS: In total, 60 DRG cases were identified. Of these, 15 patients were excluded because they received a combination of SEMS and EVT. Another 6 cases could not be included due to incomplete DRG data. Finally, N = 39 DRG cases were analyzed from a profit-center perspective. A further analysis of the most frequent DRG code -G03- including InEK cost accounting, revealed almost twice the deficit for the EVT group (N = 13 cases, € - 9.282 per average case) compared to that for the SEMS group (N = 9 cases, € - 5.156 per average case). CONCLUSION: Endoscopic treatments with SEMS and EVT for anastomotic leaks following oncological Ivor Lewis esophagectomies are not cost-efficient for German hospitals. Due to longer hospitalization and insufficient reimbursements, EVT is twice as costly as SEMS treatment. An adequate DRG cost compensation is needed for SEMS and EVT.

History of Esophagogastric Junction Cancer Treatment and Current Surgical Management in Western Countries.

The incidence of esophagogastric junction (EGJ) cancer has been significantly increasing in Western countries. Appropriate planning for surgical therapy requires a reliable classification of EGJ cancers with respect to their exact location. Clinically, the most accepted classification of EGJ cancers is "adenocarcinoma of the EGJ" (AEG or "Siewert"), which divides tumor center localization into AEG type I (distal esophagus), AEG type II ("true junction"), and AEG type III (subcardial stomach). Treatment strategies in western countries routinely employ perioperative chemotherapy or neoadjuvant chemoradiation for cases of locally advanced cancers. The standard surgical treatment strategies are esophagectomy for AEG type I and gastrectomy for AEG type III cancers. For "true junctional cancers," i.e., AEG type II, whether the extension of resection in the oral or aboral direction represents the most effective surgical therapy remains debatable. This article reviews the history of surgical EGJ cancer treatment and current surgical strategies from a Western perspective.

Multimodal Treatment Strategies in Esophagogastric Junction Cancer: a Western Perspective.

Esophagogastric junction (EGJ) cancer is a solid tumor entity with rapidly increasing incidence in the Western countries. Given the high proportion of advanced cancers in the West, treatment strategies routinely employed include surgery and chemotherapy perioperatively, and chemoradiation in neoadjuvant settings. Neoadjuvant chemoradiation and perioperative chemotherapy are mostly performed in esophageal cancer that extends to the EGJ and gastric as well as EGJ cancers, respectively. Recent trials have tried to combine both strategies in a perioperative context, which might have beneficial outcomes, especially in patients with EGJ cancer. However, it is difficult to recruit patients for trials, exclusively for EGJ cancers; therefore, the results have to be carefully reviewed before establishing a standard protocol. Trastuzumab was the first drug for targeted therapy that was positively evaluated for this tumor entity, and there are several ongoing trials investigating more targeted drugs in order to customize effective therapies based on tissue characteristics. The current study reviews the multimodal treatment concept for EGJ cancers in the West and summarizes the latest reports.

Gastric cancer treatment in the world: Germany.

Epidemiologically, around 15,500 persons per year contract gastric cancer with continuously decreasing incidence and a 5-year survival rate of only 30% to 35%. Contrary to the Asian countries, there are no prevention programs for gastric cancer in Germany, which leads to the disease frequently being diagnosed in locally advanced stages and predominantly being treated with multimodal therapy concepts. Complete (R0) resection is the therapy of choice for resectable gastric cancer. Special forms of gastric cancer that are limited to the mucosa can be endoscopically resected with a curative intent. Systematic D2 lymphadenectomy (LAD) plays a decisive role in the management of local advanced tumors because it significantly contributes to the reduction of tumor-related death and both local and regional relapse rates. Perioperative chemotherapy improves prognosis in the advanced stages, whereas palliative chemotherapy is normally indicated for metastatic diseases. Standardized resection procedures and the use of individualized multimodal therapy concepts have led to improvement in the 5-year survival rate.

Third international conference of the European Union Network of Excellence on gastric and esophagogastric junction cancer, Cologne, Germany, June 2012.

In 2012 the European Union Network of Excellence on gastric and esophagogastric junction cancer (EUNE) held its third conference in Cologne, Germany. The main themes discussed included translational research, standard and audit, early diagnosis, development of surgical treatment, adequate surgery for EGJ cancer, adjuvant and neoadjuvant treatment, prevention of peritoneal carcinomatosis and finally education and training. The meeting was attended by 150 experts from 18 different countries.