A senior surgical resident can safely perform complex esophageal cancer surgery after surgical mentoring program-experience of a European high-volume center

Previous studies have shown that surgical residents can safely perform a variation of complex abdominal surgeries when provided with adequate training, proper case selection, and appropriate supervision. Their outcomes are equivalent when compared to experienced board-certified surgeons. Our previously published training curriculum for robotic assisted minimally invasive esophagectomy already demonstrated a possible reduction in time to reach proficiency. However, esophagectomy is a technically challenging procedure and comes with high morbidity rates of up to 60%, making it difficult to provide opportunities to train surgical residents. We aimed to investigate if a surgical resident could safely perform complex esophageal surgery when a structured modular teaching curriculum is applied. A structured teaching program based on our previously published modular step-up approach was applied by two experienced board-certified esophageal surgeons. Our IRB-approved (Institutional Review Board) database was searched to identify all Ivor-Lewis esophagectomies performed by the selected surgical resident from August 2019 to July 2021. The cumulative sum method was used to analyze the learning curve of the surgical resident. Outcomes of patients operated by the resident were then compared to our overall cohort of open, hybrid, and robotic Ivor-Lewis esophagectomies from May 2016 to May 2020. The total cohort included 567 patients, of which 65 were operated by the surgical resident and 502 patients were operated by experienced esophageal cancer surgeons as the control group. For baseline characteristics, a significant difference for BMI (Body mass index) was observed, which was lower in the resident's group (25.5 kg/m2 vs. 26.8 kg/m2 (P = 0.046). A significant difference of American Society of Anesthesiologists- and Eastern Cooperative Oncology Group-scores was seen, and a subgroup analysis including all patients with American Society of Anesthesiologists I and Eastern Cooperative Oncology Group 0 was performed revealing no significant differences. Postoperative complications did not differ between groups. The anastomotic leak rate was 13.8% in the resident's cohort and 12% in the control cohort (P = 0.660). Major complications (Clavien-Dindo ≥ IIIb) occurred in 16.9% of patients in both groups. Oncological outcome, defined by harvested lymph nodes (35 vs. 32.33, P = 0.096), proportion of lymph node compliant performed operations (86.2% vs. 88.4%, P = 0.590), and R0-resection rate (96.9% vs. 96%, P = 0.766), was not compromised when esophagectomies were performed by the resident. The resident completed the learning curves after 39 cases for the total operating time, 38 cases for the thoracic operating time, 26 cases for the number of harvested lymph nodes, 29 cases for anastomotic leak rate, and finally 58 cases for the comprehensive complication index. For postoperative complications, no significant difference was seen between patients operated in the resident group versus the control group, with a third of patients being discharged with a textbook outcome in both cohorts. Furthermore, no difference in oncological quality of the resection was found, emphasizing safety and feasibility of our training program. A structured modular step-up for training a surgical resident to perform complex esophageal cancer surgery can successfully maintain patient safety and outcomes.

cIAPs control RIPK1 kinase activity-dependent and -independent cell death and tissue inflammation

Cellular inhibitor of apoptosis proteins (cIAPs) are RING-containing E3 ubiquitin ligases that ubiquitylate receptor-interacting protein kinase 1 (RIPK1) to regulate TNF signalling. Here, we established mice simultaneously expressing enzymatically inactive cIAP1/2 variants, bearing mutations in the RING domains of cIAP1/2 (cIAP1/2 mutant RING, cIAP1/2MutR ). cIap1/2MutR/MutR mice died during embryonic development due to RIPK1-mediated apoptosis. While expression of kinase-inactive RIPK1D138N rescued embryonic development, Ripk1D138N/D138N /cIap1/2MutR/MutR mice developed systemic inflammation and died postweaning. Cells expressing cIAP1/2MutR and RIPK1D138N were still susceptible to TNF-induced apoptosis and necroptosis, implying additional kinase-independent RIPK1 activities in regulating TNF signalling. Although further ablation of Ripk3 did not lead to any phenotypic improvement, Tnfr1 gene knock-out prevented early onset of systemic inflammation and premature mortality, indicating that cIAPs control TNFR1-mediated toxicity independent of RIPK1 and RIPK3. Beyond providing novel molecular insights into TNF-signalling, the mouse model established in this study can serve as a useful tool to further evaluate ongoing therapeutic protocols using inhibitors of TNF, cIAPs and RIPK1.

Laparoscopic ischemic conditioning of the stomach prior to esophagectomy induces gastric neo-angiogenesis

BACKGROUND

The risk of an anastomotic leakage (AL) following Ivor-Lewis esophagectomy is increased in patients with calcifications of the aorta or a stenosis of the celiac trunc. Ischemic conditioning (ISCON) of the gastric conduit prior to esophagectomy is supposed to improve gastric vascularization at the anastomotic site. The prospective ISCON trial was conducted to proof the safety and feasibility of this strategy with partial gastric devascularization 14 days before esophagectomy in esophageal cancer patients with a compromised vascular status. This work reports the results from a translational project of the ISCON trial aimed to investigate variables of neo-angiogenesis.

METHODS

Twenty esophageal cancer patients scheduled for esophagectomy were included in the ISCON trial. Serum samples (n = 11) were collected for measurement of biomarkers and biopsies (n = 12) of the gastric fundus were taken before and after ISCON of the gastric conduit. Serum samples were analyzed including 62 different cytokines. Vascularization of the gastric mucosa was assessed on paraffin-embedded sections stained against CD34 to detect the degree of microvascular density and vessel size.

RESULTS

Between November 2019 and January 2022 patients were included in the ISCON Trial. While serum samples showed no differences regarding cytokine levels before and after ISCON biopsies of the gastric mucosa demonstrated a significant increase in microvascular density after ISCON as compared to the corresponding gastric sample before the intervention.

CONCLUSION

The data prove that ISCON of the gastric conduit as esophageal substitute induces significant neo-angiogenesis in the gastric fundus which is considered as surrogate of an improved vascularization at the anastomotic site.

Laparoscopic ischemic conditioning prior esophagectomy in selected patients: the ISCON trial

Anastomotic leakage (AL) after esophagectomy is the most impactful complication after esophagectomy. Ischemic conditioning (ISCON) of the stomach >14 days prior to esophagectomy might reduce the incidence of AL. The current trial was conducted to prospectively investigate the safety and feasibility of laparoscopic ISCON in selected patients. This international multicenter feasibility trial included patients with esophageal cancer at high risk for AL with major calcifications of the thoracic aorta or a stenosis in the celiac trunk. Patients underwent laparoscopic ISCON by occlusion of the left gastric and the short gastric arteries followed by esophagectomy after an interval of 12-18 days. The primary endpoint was complications Clavien-Dindo ≥ grade 2 after ISCON and before esophagectomy. Between November 2019 and January 2022, 20 patients underwent laparoscopic ISCON followed by esophagectomy. Out of 20, 16 patients (80%) underwent neoadjuvant treatment. The median duration of the laparoscopic ISCON procedure was 45 minutes (range: 25-230). None of the patients developed intraoperative or postoperative complications after ISCON. Hospital stay after ISCON was median 2 days (range: 2-4 days). Esophagectomy was completed in all patients after a median of 14 days (range: 12-28). AL occurred in three patients (15%), and gastric tube necrosis occurred in one patient (5%). In hospital, the 30-day and 90-day mortalities were 0%. Laparoscopic ISCON of the gastric conduit is feasible and safe in selected esophageal cancer patients with an impaired vascular status. Further studies have to prove whether this innovative strategy aids to reduce the incidence of AL.

Analysis of training pathway to reach expert performance levels based on proficiency-based progression in robotic-assisted minimally invasive esophagectomy (RAMIE)

BACKGROUND

Robotic-assisted minimally invasive esophagectomy (RAMIE) was first introduced in 2003 and has since then shown to significantly improve the postoperative course. Previous studies have shown that a structured training pathway based on proficiency-based progression using individual skill levels as measures of reach of competence can enhance surgical performance. The aim of this study was to evaluate and help understand our pathway to reach surgical expert levels using a proficiency-based approach introducing RAMIE at our German high-volume center.

METHODS

All patients undergoing RAMIE performed by two experienced surgeons for esophageal cancer since the introduction of the robotic technique in 2017 was included in this analysis. Intraoperative outcomes and postoperative outcomes were included in the analysis. The cumulative sum method was used to analyze how many cases are needed to reach expert levels for different performance characteristics and skill sets during robotic-assisted minimally invasive esophagectomy.

RESULTS

From 06/2017 to 03/2022, a total of 154 patients underwent RAMIE at our facility and were included in the analysis. An advancement in performance level was observed for total operating time after 70 cases and for thoracic operative time after 79 cases. Lymph node yield showed an increase up until case 60 in the CUSUM analysis. Length of hospital stay stabilized after case 55. The CCI score inflection point was at case 55 in both CUSUM and regression analyses. Anastomotic leak rate stabilized at case 38 and showed another inflection point after case 83.

CONCLUSION

Our data and analysis showed the progression from proficient to expert performance levels during the implementation of RAMIE at a European high-volume center. Further analysis of surgeons, especially with a different training status has yet to reveal if the caseloads found in this study are universally applicable. However, skill acquisition and respective measures of such are diverse and as a great range of number of cases was observed, we believe that the learning curve and ascent in performance levels cannot be defined by one parameter alone.

X-linked inhibitor of apoptosis protein is a prognostic marker for a favorable outcome in three identified subsets in resectable adenocarcinoma of the pancreas

PURPOSE

Pancreatic ductal adenocarcinoma (PDAC) is currently one of the leading causes of cancer death worldwide. Therefore, building further subgroups as well as enabling individual patient therapy and diagnostics are needed. X-linked inhibitor of apoptosis protein (XIAP) is known to modulate apoptotic and inflammatory pathways. Its expression was found to correlate with patients' survival in other tumor entities. This study aims to examine the role of XIAP in patients with PDAC in relation to the inflammatory microenvironment.

METHODS

The PANCALYZE multicenter study group included 257 patients with PDAC. Paraffin-embedded tumor samples were stained immunohistochemically for CD3, CD20, CD38, CD56, CD66b, CD117, and CD163 and XIAP. These stainings were further analyzed digitally with QuPath and survival analyses were done.

RESULTS

XIAP-positive patients with T-cell, respectively, neutrophil enriched tumors survived significantly longer compared to XIAP-negative patients (CD3: 37.6 vs. 24.6 months, p = 0.028; CD66b: 34.1 vs. 14.9 months, p = 0.027). Additionally, XIAP-positive patients showed better survival in the lymph node-negative population (48.4 vs. 24.2 months, p = 0.019). Regarding the total population, our findings did not show a correlation between XIAP expression and survival. In multivariate cox regression analyzes XIAP proves to be an independent factor for better survival in the identified subgroups (CD3: p = 0.043; CD66b: p = 0.012, N0: p = 0.040).

CONCLUSION

We found XIAP-positive subgroups with significantly better survival in patients with PDAC in T-cell-rich, neutrophil-rich, or lymph node-negative cohorts. This could lead to further individualized cancer treatment with less aggressive therapy protocols for XIAP-positive tumors or more intensive follow-up for XIAP-negative tumors.

Clinical utility and applicability of the,Esophagus Complication Consensus Group' (ECCG) classification of anastomotic leakage following hybrid Ivor-Lewis esophagectomy

BACKGROUND

Anastomotic leakage (AL) remains the leading surgical complication following Ivor-Lewis (IL) esophagectomy. Different treatment options of AL exist but outcome is difficult to compare due to a lack of generally accepted classifications. This retrospective study was conducted to analyze the clinical significance of a recently proposed classification based on the management of AL.

PATIENTS AND METHODS

A cohort of 954 consecutive patients undergoing hybrid IL esophagectomy (laparoscopy/thoracotomy) was analysed. AL was defined according to the,Esophagus Complication Consensus Group' (ECCG) criteria depending on its treatment: conservative (AL type I), interventional endoscopic (AL type II), and surgical (AL type III). Primary outcome was single or multiple organ failure (Clavien-Dindo IVA/B) associated with AL.

RESULTS

Overall morbidity was 63.0% and 8.8% (84/954 patients) developed an AL postoperatively. Three patients (3.5%) had an AL type I, 57 patients (67.9%) an AL type II and 24 patients (28.6%) an AL type III. For patients managed surgically, AL was diagnosed significantly earlier (median days: AL type III: 2 vs AL type II: 6, p < 0.001). Associated organ failure (CD IVA/B) was significantly lower for AL type II as compared to AL type III (21.1% versus 45.8%, p < 0.0001). In-hospital mortality was 3.5% for AL type II and 8.3% for AL type III (p = 0.789). There was no difference for re-admission to ICU and overall length of hospital stay.

CONCLUSION

The proposed ECCG classification is simply to apply and discriminates the post-treatment severity of AL but does not aid to implement a treatment algorithm.

Combined regression score predicts outcome after neoadjuvant treatment of oesophageal cancer

BACKGROUND

Histopathologic regression following neoadjuvant treatment (NT) of oesophageal cancer is a prognostic factor of survival, but the nodal status is not considered. Here, a score combining both to improve prediction of survival after neoadjuvant therapy is developed.

METHODS

Seven hundred and fifteen patients with oesophageal squamous cell (SCC) or adenocarcinoma (AC) undergoing NT and esophagectomy were analysed. Histopathologic response was classified according to percentage of vital residual tumour cells (VRTC): complete response (CR) without VRTC, major response with <10% VRTC, minor response with >10% VRTC. Nodal stage was classified as ypN0 and ypN+. Kaplan-Meier and Cox regression were used for survival analysis.

RESULTS

Survival analysis identified three groups with significantly different mortality risks: (1) low-risk group for CR (ypT0N0) with 72% 5-year overall survival (5y-OS), (2) intermediate-risk group for minor/major responders and ypN0 with 59% 5y-OS, and (3) high-risk group for minor/major responders and ypN+ with 20% 5y-OS (p < 0.001). Median survival in AC and SCC cohorts were comparable (3.8 (CI 95%: 3.1, 5.3) vs. 4.6 years (CI 95%: 3.3, not reached), p = 0.3).

CONCLUSIONS

Histopathologic regression and nodal status should be combined for estimating AC and SCC prognosis. Poor survival in the high-risk group highlights need for adjuvant therapy.

Mapping the Lymphatic Drainage Pattern of Esophageal Cancer with Near-Infrared Fluorescent Imaging during Robotic Assisted Minimally Invasive Ivor Lewis Esophagectomy (RAMIE)-First Results of the Prospective ESOMAP Feasibility Trial

While the sentinel lymph node concept is routinely applied in other surgical fields, no established and valid modality for lymph node mapping for esophageal cancer surgery currently exists. Near-infrared light fluorescence (NIR) using indocyanine green (ICG) has been recently proven to be a safe technology for peritumoral injection and consecutive lymph node mapping in small surgical cohorts, mostly without the usage of robotic technology. The aim of this study was to identify the lymphatic drainage pattern of esophageal cancer during highly standardized RAMIE and to correlate the intraoperative images with the histopathological dissemination of lymphatic metastases. Patients with clinically advanced stage squamous cell carcinoma or adenocarcinoma of the esophagus undergoing a RAMIE at our Center of Excellence for Surgery of the Upper Gastrointestinal Tract were prospectively included in this study. Patients were admitted on the day prior to surgery, and an additional EGD with endoscopic injection of the ICG solution around the tumor was performed. Intraoperative imaging procedures were performed using the Stryker 1688 or the FIREFLY fluorescence imaging system, and resected lymph nodes were sent to pathology. A total of 20 patients were included in the study, and feasibility and safety for the application of NIR using ICG during RAMIE were shown. NIR imaging to detect lymph node metastases can be safely performed during RAMIE. Further analyses in our center will focus on pathological analyses of ICG-positive tissue and quantification using artificial intelligence tools with a correlation of long-term follow-up data.

Time to endoscopic vacuum therapy-lessons learned after > 150 robotic-assisted minimally invasive esophagectomies (RAMIE) at a German high-volume center

OBJECTIVE OF THE STUDY

In esophageal surgery, anastomotic leak (AL) remains one of the most severe and critical adverse events after oncological esophagectomy. Endoscopic vacuum therapy (EVT) can be used to treat AL; however, in the current literature, treatment outcomes and reports on how to use this novel technique are scarce. The aim of this study was to evaluate the outcomes of patients with an AL after IL RAMIE and to determine whether using EVT as an treatment option is safe and feasible.

MATERIAL AND METHODS

This study includes all patients who developed an Esophagectomy Complications Consensus Group (ECCG) type II AL after IL RAMIE at our center between April 2017 and December 2021. The analysis focuses on time to EVT, duration of EVT, and follow up treatments for these patients.

RESULTS

A total of 157 patients underwent an IL RAMIE at our hospital. 21 patients of these (13.4%) developed an ECCG type II AL. One patient died of unrelated Covid-19 pneumonia and was excluded from the study cohort. The mean duration of EVT was 12 days (range 4-28 days), with a mean of two sponge changes (range 0-5 changes). AL was diagnosed at a mean of 8 days post-surgery (range 2-16 days). Closure of the AL with EVT was successful in 15 out of 20 patients (75%). Placement of a SEMS (Self-expandlable metallic stent) after EVT was performed in four patients due to persisting AL. Overall success rate of anastomotic sealing independently of the treatment modality was achieved in 19 out of 20 Patients (95%). No severe EVT-related adverse events occurred.

CONCLUSION

This study shows that EVT can be a safe and effective endoscopic treatment option for ECCG type II AL.

XIAP promotes melanoma growth by inducing tumour neutrophil infiltration

Elevated expression of the X‐linked inhibitor of apoptosis protein (XIAP) has been frequently reported in malignant melanoma suggesting that XIAP renders apoptosis resistance and thereby supports melanoma progression. Independent of its anti‐apoptotic function, XIAP mediates cellular inflammatory signalling and promotes immunity against bacterial infection. The pro‐inflammatory function of XIAP has not yet been considered in cancer. By providing detailed in vitro analyses, utilising two independent mouse melanoma models and including human melanoma samples, we show here that XIAP is an important mediator of melanoma neutrophil infiltration. Neutrophils represent a major driver of melanoma progression and are increasingly considered as a valuable therapeutic target in solid cancer. Our data reveal that XIAP ubiquitylates RIPK2, involve TAB1/RIPK2 complex and induce the transcriptional up‐regulation and secretion of chemokines such as IL8, that are responsible for intra‐tumour neutrophil accumulation. Alteration of the XIAP‐RIPK2‐TAB1 inflammatory axis or the depletion of neutrophils in mice reduced melanoma growth. Our data shed new light on how XIAP contributes to tumour growth and provides important insights for novel XIAP targeting strategies in cancer.

Resistance Mechanisms of the Metastatic Tumor Microenvironment to Anti-Angiogenic Therapy

Angiogenesis describes the formation of blood vessels from an existing vascular network. Anti-angiogenic drugs that target tumor blood vessels have become standard of care in many cancer entities. Though very promising results in preclinical evaluation, anti-angiogenic treatments fell short of expectations in clinical trials. Patients develop resistance over time or are primarily refractory to anti-angiogenic therapies similar to conventional chemotherapy. To further improve efficacy and outcome to these therapies, a deeper understanding of mechanisms that mediate resistance to anti-angiogenic therapies is needed. The field has done tremendous efforts to gain knowledge about how tumors engage tumor cell and microenvironmental mechanisms to do so. This review highlights the current state of knowledge with special focus on the metastatic tumor site and potential therapeutic relevance of this understanding from a translational and clinical perspective.

Robot-assisted minimally invasive esophagectomy (RAMIE) vs. hybrid minimally invasive esophagectomy: propensity score matched short-term outcome analysis of a European high-volume center

INTRODUCTION

Transthoracic esophagectomy is a highly complex and sophisticated procedure with high morbidity rates and a significant mortality. Surgical access has consistently become less invasive, transitioning from open esophagectomy to hybrid esophagectomy (HE) then to totally minimally invasive esophagectomy (MIE), and most recently to robot-assisted minimally invasive esophagectomy (RAMIE), with each step demonstrating improved patient outcomes. Aim of this study with more than 600 patients is to complete a propensity-score matched comparison of postoperative short-term outcomes after highly standardized RAMIE vs. HE in a European high volume center.

PATIENTS AND METHODS

Six hundred and eleven patients that underwent transthoracic Ivor-Lewis esophagectomy for esophageal cancer between May 2016 and May 2021 were included in the study. In January 2019, we implemented an updated robotic standardized anastomotic technique using a circular stapler and ICG (indocyanine green) for RAMIE cases. Data were retrospectively analyzed from a prospectively maintained IRB-approved database. Outcomes of patients undergoing standardized RAMIE from January 2019 to May 2021 were compared to our overall cohort from May 2016-April 2021 (HE) after a propensity-score matching analysis was performed.

RESULTS

Six hundred and eleven patients were analyzed. 107 patients underwent RAMIE. Of these, a total of 76 patients underwent a robotic thoracic reconstruction using the updated standardized circular stapled anastomosis (RAMIE group). A total of 535 patients underwent HE (Hybrid group). Seventy patients were propensity-score matched in each group and analysis revealed no statistically significant differences in baseline characteristics. RAMIE patients had a significantly shorter ICU stay (p = 0.0218). Significantly more patients had no postoperative complications (Clavien Dindo 0) in the RAMIE group [47.1% vs. 27.1% in the HE group (p = 0.0225)]. No difference was seen in lymph node yield and R0 resection rates. Anastomotic leakage rates when matched were 14.3% in the hybrid group vs. 4.3% in the RAMIE group (p = 0.07).

CONCLUSION

Our analysis confirms the safety and feasibility of RAMIE and HE in a large cohort after propensity score matching. A regular postoperative course (Clavien-Dindo 0) and a shorter ICU stay were seen significantly more often after RAMIE compared to HE. Furthermore it shows that both procedures provide excellent short-term oncologic outcomes, regarding lymph node harvest and R0 resection rates. A randomized controlled trial comparing RAMIE and HE is still pending and will hopefully contribute to ongoing discussions.

[Perioperative enhanced recovery after surgery program for Ivor Lewis esophagectomy : First experiences of a high-volume center]

BACKGROUND AND OBJECTIVE

Transthoracic esophagectomy is generally accepted as the standard of surgical care for patients with esophageal cancer. Despite improvements in the perioperative management this surgical procedure is associated with a clinically relevant morbidity. Fast-track protocols (synonym: enhanced recovery after surgery, ERAS) are conceived to perioperatively maintain the physiological homoeostasis and thereby to accelerate postoperative rehabilitation and reduce morbidity. In this prospective observational study the initial experiences of a high-volume center with the implementation of an ERAS protocol after transthoracic esophagectomy were analyzed.

MATERIAL AND METHODS

A total of 26 patients with esophageal cancer and a low index of comorbidities prior to hybrid Ivor Lewis esophagectomy were included in this study. According to an ERAS protocol all patients underwent a standardized perioperative treatment pathway aiming to discharge the patients from the inpatient treatment on postoperative day 10. The primary outcome parameter was the rate of major complications (Clavien-Dindo IIIb/IV), which was compared to a cohort of 52 non-ERAS patients.

RESULTS AND CONCLUSION

The ERAS programs with the various core elements can be implemented in patients scheduled for transthoracic esophagectomy, although the organizational and personnel expenditure of this fast-track protocol is high. The length of hospital stay appears to be reduced without compromising patient safety. The limiting variable of the ERAS protocol remains the early and adequate enteral feeding load of the gastric conduit before discharge on postoperative day 10.

[Evidence in minimally invasive oncological surgery of the esophagus]

BACKGROUND

Thoracoabdominal esophagectomy still plays a major role in the oncological treatment for esophageal cancer. Minimally invasive procedures were developed to reduce the high rate of postoperative morbidity and mortality without negatively affecting the oncological outcome.

OBJECTIVE

What evidence supports minimally invasive oncological surgery of the esophagus? Do patients benefit from minimally invasive esophagectomy compared to an open approach? Is the reduction of surgical access trauma specifically advantageous?

MATERIAL AND METHODS

Review, evaluation and critical analysis of the international literature.

RESULTS

A reduction in postoperative morbidity by decreasing surgical trauma was confirmed by three prospective randomized clinical trials, while showing at least similar oncological outcomes. Diverse retrospective analyses and meta-analyses also came to the same result.

CONCLUSION

A minimization of surgical access trauma during thoracoabdominal esophagectomy reduces postoperative morbidity compared to conventional open surgery. Recent evidence suggests that oncological outcomes are not altered depending on the surgical approach.

Dickkopf-2 (DKK2) as Context Dependent Factor in Patients with Esophageal Adenocarcinoma

Dickkopf-2 (DKK2) has been described as Wnt/beta-catenin pathway antagonist and its expression is mediated by micro RNA-221 (miRNA-221). So far, there is only limited data characterizing the role of DKK2 expression in esophageal cancer. A tissue micro array of 192 patients with esophageal adenocarcinoma was analyzed immunohistochemically for DKK2, miRNA-221 expression by RNA scope, and GATA6 amplification by fluorescence in-situ hybridization. The data was correlated with clinical, pathological and molecular data (TP53, HER2, c-myc, GATA6, PIK3CA, and KRAS amplifications). DKK2 expression was detectable in 21.7% and miRNA-221 expression in 33.5% of the patients. We observed no correlation between DKK2 or miRNA-221 expression and clinico-pathological data DKK2 expression was correlated with TP53 mutations and amplification of GATA6. We did not detect a survival difference in dependence of DKK2 for the total cohort, however, in patients without neoadjuvant treatment DKK2 expression correlated with a prolonged survival (median overall-survival 202 vs. 55 months, p = 0.012) which turned opposite in patients that underwent neoadjuvant treatment. High amounts of miRNA-221 were in trend associated with a prolonged overall-survival (p = 0.070). DKK2 as a Wnt antagonist is associated with prolonged survival in patients without neoadjuvant treatment and changes its prognostic value to the contrary in patients after neoadjuvant therapy. The modulatory effects of neoadjuvant treatment in connection with DKK2 expression are not fully understood, but when considering DKK2 as a tumor marker, it is necessary to see it in the context of neoadjuvant therapy.

Caspase-8 is the molecular switch for apoptosis, necroptosis and pyroptosis

Caspase-8 is the initiator caspase of extrinsic apoptosis^1,2 and inhibits necroptosis mediated by RIPK3 and MLKL. Accordingly, caspase-8 deficiency in mice causes embryonic lethality³, which can be rescued by deletion of either Ripk3 or Mlkl^4-6. Here we show that the expression of enzymatically inactive CASP8(C362S) causes embryonic lethality in mice by inducing necroptosis and pyroptosis. Similar to Casp8^-/- mice^3,7, Casp8^C362S/C362S mouse embryos died after endothelial cell necroptosis leading to cardiovascular defects. MLKL deficiency rescued the cardiovascular phenotype but unexpectedly caused perinatal lethality in Casp8^C362S/C362S mice, indicating that CASP8(C362S) causes necroptosis-independent death at later stages of embryonic development. Specific loss of the catalytic activity of caspase-8 in intestinal epithelial cells induced intestinal inflammation similar to intestinal epithelial cell-specific Casp8 knockout mice⁸. Inhibition of necroptosis by additional deletion of Mlkl severely aggravated intestinal inflammation and caused premature lethality in Mlkl knockout mice with specific loss of caspase-8 catalytic activity in intestinal epithelial cells. Expression of CASP8(C362S) triggered the formation of ASC specks, activation of caspase-1 and secretion of IL-1β. Both embryonic lethality and premature death were completely rescued in Casp8^C362S/C362SMlkl^-/-Asc^-/- or Casp8^C362S/C362SMlkl^-/-Casp1^-/- mice, indicating that the activation of the inflammasome promotes CASP8(C362S)-mediated tissue pathology when necroptosis is blocked. Therefore, caspase-8 represents the molecular switch that controls apoptosis, necroptosis and pyroptosis, and prevents tissue damage during embryonic development and adulthood.

Elevated X-linked inhibitor of apoptosis protein (XIAP) expression uncovers detrimental prognosis in subgroups of neoadjuvant treated and T-cell rich esophageal adenocarcinoma

Background

Molecular markers predicting survival in esophageal adenocarcinoma (EAC) are rare. Specifically, in favorable oncologic situations, e.g. nodal negativity or major neoadjuvant therapy response, there is a lack of additional risk factors that serve to predict patients’ outcome more precisely. This study evaluated X-linked inhibitor of apoptosis protein (XIAP) as a potential marker improving outcome prediction.

Methods

Tissue microarrays from 362 patients that were diagnosed with resectable EAC were included in the study. XIAP was stained by immunohistochemistry and correlated to clinical outcome, molecular markers and markers of the cellular tumor microenvironment.

Results

XIAP did not impact on overall survival (OS) in the whole study collective. Subgroup analyses stratifying for common genetic markers (TP53, ERBB2, ARID1A/SWI/SNF) did not disclose any impact of XIAP expression on survival. Detailed subgroup analyses of [1] nodal negative patients, [2] highly T-cell infiltrated tumors and [3] therapy responders to neoadjuvant treatment revealed a significant inverse role of high XIAP expression in these specific oncologic situations; elevated XIAP expression detrimentally affected patients’ outcome in these subgroups. [1]: OS XIAP low: 202 months (m) vs. XIAP high: 38 m; [2]: OS 116 m vs. 28.2 m; [3]: OS 31 m vs. 4 m).

Conclusions

Our data suggest XIAP expression in EAC as a worthy tool to improve outcome prediction in specific oncologic settings that might directly impact on clinical diagnosis and treatment of EAC in the future.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5722-1) contains supplementary material, which is available to authorized users.

[Resection of advanced esophagogastric adenocarcinoma : Extended indications]

In the current German S3 guidelines surgical treatment is not recommended for metastatic gastric cancer or metastatic adenocarcinoma of the esophagogastric junction; however, in routine practice the indications can be extended so that there may be occasions in which radical surgical intervention for specific individuals may be appropriate as part of a multimodal therapy with curative intent. This article presents the scientific rationale of such an approach based on the available literature considering modern, multimodal therapy concepts including criteria to be met for radical surgery. Currently only retrospective trials and limited current meta-analysis data are available for justifying surgical treatment for metastatic adenocarcinoma. The recently published initial results of the FLOT-3 study identified a patient subgroup that benefits from a resection even though metastasis has occurred. Whether surgical therapy will become an integral part of the treatment of limited metastatic adenocarcinoma of the stomach and esophagus in the future, has to be demonstrated by large prospective randomized studies, such as the RENAISSANCE/FLOT-5 study.

Dual targeting of Angiopoetin-2 and VEGF potentiates effective vascular normalisation without inducing empty basement membrane sleeves in xenograft tumours

BACKGROUND

Effective vascular normalisation following vascular endothelial growth factor (VEGF) inhibition is associated with endothelial cell regression leaving empty basement membrane sleeves (BMS). These long-lived BMS permit the rapid regrowth of tumour vasculature upon treatment cessation and promote resistance to VEGF-targeting drugs. Previous attempts at removing BMS have failed. Angiopoietin-2 (Ang2) is a vascular destabilizing factor that antagonises normalisation. We hypothesised that Ang2 inhibition could permit vascular normalisation at significantly reduced doses of VEGF inhibition, avoiding excessive vessel regression and the formation of empty BMS.

METHODS

Mice xenografted with human colorectal cancer cells (LS174T) were treated with low (0.5 mg kg(-1)) or high (5 mg kg(-1)) doses of the VEGF-targeting antibody bevacizumab with or without an Ang2 blocking peptibody L1-10. Tumour growth, BMS formation and normalisation parameters were examined including vessel density, pericyte coverage, adherence junctions, leakiness, perfusion, hypoxia and proliferation.

RESULTS

Dual targeting of VEGF and Ang2 achieved effective normalisation at only one-tenth of the dose required with bevacizumab alone. Pericyte coverage, vascular integrity, adherence junctions and perfusion as prerequisites for improved access of chemotherapy were improved without inducing empty BMS that facilitate rapid vascular regrowth.

CONCLUSIONS

Dual targeting of VEGF and Ang2 can potentiate the effectiveness of VEGF inhibitors and avoid the formation of empty BMS.

Embelin inhibits endothelial mitochondrial respiration and impairs neoangiogenesis during tumor growth and wound healing

In the normal quiescent vasculature, only 0.01% of endothelial cells (ECs) are proliferating. However, this proportion increases dramatically following the angiogenic switch during tumor growth or wound healing. Recent evidence suggests that this angiogenic switch is accompanied by a metabolic switch. Here, we show that proliferating ECs increasingly depend on mitochondrial oxidative phosphorylation (OxPhos) for their increased energy demand. Under growth conditions, ECs consume three times more oxygen than quiescent ECs and work close to their respiratory limit. The increased utilization of the proton motif force leads to a reduced mitochondrial membrane potential in proliferating ECs and sensitizes to mitochondrial uncoupling. The benzoquinone embelin is a weak mitochondrial uncoupler that prevents neoangiogenesis during tumor growth and wound healing by exhausting the low respiratory reserve of proliferating ECs without adversely affecting quiescent ECs. We demonstrate that this can be exploited therapeutically by attenuating tumor growth in syngenic and xenograft mouse models. This novel metabolic targeting approach might be clinically valuable in controlling pathological neoangiogenesis while sparing normal vasculature and complementing cytostatic drugs in cancer treatment.