Integrative genomic analyses of European intrahepatic cholangiocarcinoma: Novel ROS1 fusion gene and PBX1 as prognostic marker.

BACKGROUND: Cholangiocarcinoma (CCA) is a fatal cancer of the bile duct with a poor prognosis owing to limited therapeutic options. The incidence of intrahepatic CCA (iCCA) is increasing worldwide, and its molecular basis is emerging. Environmental factors may contribute to regional differences in the mutation spectrum of European patients with iCCA, which are underrepresented in systematic genomic and transcriptomic studies of the disease. METHODS: We describe an integrated whole-exome sequencing and transcriptomic study of 37 iCCAs patients in Germany. RESULTS: We observed as most frequently mutated genes ARID1A (14%), IDH1, BAP1, TP53, KRAS, and ATM in 8% of patients. We identified FGFR2::BICC1 fusions in two tumours, and FGFR2::KCTD1 and TMEM106B::ROS1 as novel fusions with potential therapeutic implications in iCCA and confirmed oncogenic properties of TMEM106B::ROS1 in vitro. Using a data integration framework, we identified PBX1 as a novel central regulatory gene in iCCA. We performed extended screening by targeted sequencing of an additional 40 CCAs. In the joint analysis, IDH1 (13%), BAP1 (10%), TP53 (9%), KRAS (7%), ARID1A (7%), NF1 (5%), and ATM (5%) were the most frequently mutated genes, and we found PBX1 to show copy gain in 20% of the tumours. According to other studies, amplifications of PBX1 tend to occur in European iCCAs in contrast to liver fluke-associated Asian iCCAs. CONCLUSIONS: By analyzing an additional European cohort of iCCA patients, we found that PBX1 protein expression was a marker of poor prognosis. Overall, our findings provide insight into key molecular alterations in iCCA, reveal new targetable fusion genes, and suggest that PBX1 is a novel modulator of this disease.

Extension of resection after positive intraoperative pathology during surgery for gastric and gastroesophageal junction adenocarcinoma: a retrospective cohort study.

BACKGROUND: Residual tumor at the resection margins after surgery for gastric and gastroesophageal junction (GEJ) adenocarcinoma is a known prognostic factor. In this single-center, retrospective cohort study in a tertiary referral center, the authors aimed to evaluate the relevance of intraoperative pathology consultation (IOC) and consecutive extension of surgery on patient survival. STUDY DESIGN: Of 737 consecutive patients undergoing (sub)total gastrectomy for gastric or GEJ adenocarcinoma, 679 cases with curative intent surgery between 05/1996 and 03/2019 were included. Patients were categorized into: R0 without further resection (direct R0), R0 after positive IOC and extension of resection (converted R0), and R1. RESULTS: IOC was performed in 242 (35.6%) patients, in 216 (89.3%) at the proximal resection margin. Direct R0-status was achieved in 598 (88.1%), converted R0 in 26 (3.8%) of 38 (5.6%) patients with positive IOC and R1 in 55 (8.1%) patients. The median follow-up was 29 months for surviving patients. 3-year survival rate (3-YSR) was significantly higher for direct R0 compared to converted R0 with 62.3% compared to 21.8% (hazard ratio=0.298; 95% CI=0.186-0.477, P <0.001). 3-YSR was similar between converted R0 and R1 (21.8 vs. 13.3%; hazard ratio =0.928; 95% CI=0.526-1.636, P =0.792). In multivariate analysis, advanced T ( P <0.001), N ( P <0.001), R ( P =0.003), and M1 status ( P <0.001) were associated with worse overall survival. CONCLUSION: IOC and consecutive extended resection for positive resection margins in gastrectomy for the proximal gastric and GEJ adenocarcinoma does not achieve long-term survival benefits in advanced tumor stages.

Long-Term Postsurgical Outcomes of Neoadjuvant Chemoradiation (CROSS) Versus Chemotherapy (FLOT) for Multimodal Treatment of Adenocarcinoma of the Esophagus and the Esophagogastric Junction.

BACKGROUND: The question of the ideal neoadjuvant therapy for locally advanced esophagogastric adenocarcinoma has not been answered to date. Multimodal treatment has become a standard treatment for these adenocarcinomas. Currently, perioperative chemotherapy (FLOT) or neoadjuvant chemoradiation (CROSS) is recommended. METHODS: A monocentric retrospective analysis compared long-term survival after CROSS versus FLOT. The study enrolled patients with adenocarcinoma of the esophagus (EAC) or the esophagogastric junction type I or II undergoing oncologic Ivor-Lewis esophagectomy between January 2012 and December 2019. The primary objective was to determine the long-term outcome in terms of overall survival. The secondary objectives were to determine differences regarding the histopathologic categories after neoadjuvant treatment and the histomorphologic regression. RESULTS: The findings showed no survival advantage for one or the other treatment in this highly standardized cohort. All the patients underwent open (CROSS: 9.4% vs. FLOT: 22%), hybrid (CROSS: 82% vs. FLOT: 72%), or minimally invasive (CROSS: 8.9% vs. FLOT: 5.6%) thoracoabdominal esophagectomy. The median post-surgical follow-up period was 57.6 months (95% confidence interval [CI] 23.2-109.7 months), and the median survival was longer for the CROSS patients (54 months) than for the FLOT patients (37.2 months) (p = 0.053). The overall 5-years survival was 47% for the entire cohort (48% for the CROSS and 43% for the FLOT patients). The CROSS patients showed a better pathologic response and fewer advanced tumor stages. CONCLUSION: The improved pathologic response after CROSS cannot be translated into longer overall survival. To date, the choice of which neoadjuvant treatment to use can be made only on the basis of clinical parameters and the patient's performance status.

Two decades of gastric and gastroesophageal junction cancer surgery.

PURPOSE: Diagnosis and treatment of gastric and gastroesophageal junction cancer have undergone many critical changes during the last two decades. We addressed the question of how clinical reality outside of clinical trials has changed for gastric and gastroesophageal junction cancer patients in a European center for upper gastrointestinal surgery. METHODS: In this retrospective cohort study, patients undergoing (sub)total gastrectomy for gastric or gastroesophageal junction adenocarcinoma between 1996 and 2017 in a tertiary upper gastrointestinal center were included. The time was divided into a) before (1996-2006) (pre-CTx) and b) after (2006-2017) (CTx) the MAGIC trial. Data were comprehensively analyzed for demographics, tumor stage, perioperative treatment, surgery, histopathology, and survival rates (SR). RESULTS: 737 patients (32% female) underwent gastrectomy, 255 patients in the pre-CTx era and 482 patients in the CTx era. The median age was 65 years and the median follow-up was 27.5 months for surviving patients. Around 16.9% of patients received neoadjuvant treatment in the pre-CTx era versus 46.3% in the CTx era. The 3-year survival rate (3-YSR) was 46.4% in the pre-CTx and 60.9% in the CTx era (p < 0.001). For pretreated patients, 3-YSR was 39.0% (pre-CTx) versus 55.3% (CTx) (p = 0.168). Survival rate (SR) for locally advanced tumor stages (cT3/cT4) was higher when neoadjuvant therapy was administered (3-YSR: 56.7% vs 40.6%; p = 0.022). There were no significant differences according to sex (p = 0.357), age (p = 0.379), pT category (p = 0.817), pN stage (p = 0.074), cM stage (p = 0.112), Laurén classification (p = 0.158), and SRs (3-YSR: 60.3% vs 59.4%; p = 0.898) between the MAGIC and FLOT regimens. CONCLUSIONS: Survival rates have dramatically improved for gastric cancer patients during the last two decades. MAGIC and FLOT regimens showed similar results in the postsurgical follow-up.

Placental growth factor promotes tumour desmoplasia and treatment resistance in intrahepatic cholangiocarcinoma.

OBJECTIVE: Intrahepatic cholangiocarcinoma (ICC)-a rare liver malignancy with limited therapeutic options-is characterised by aggressive progression, desmoplasia and vascular abnormalities. The aim of this study was to determine the role of placental growth factor (PlGF) in ICC progression. DESIGN: We evaluated the expression of PlGF in specimens from ICC patients and assessed the therapeutic effect of genetic or pharmacologic inhibition of PlGF in orthotopically grafted ICC mouse models. We evaluated the impact of PlGF stimulation or blockade in ICC cells and cancer-associated fibroblasts (CAFs) using in vitro 3-D coculture systems. RESULTS: PlGF levels were elevated in human ICC stromal cells and circulating blood plasma and were associated with disease progression. Single-cell RNA sequencing showed that the major impact of PlGF blockade in mice was enrichment of quiescent CAFs, characterised by high gene transcription levels related to the Akt pathway, glycolysis and hypoxia signalling. PlGF blockade suppressed Akt phosphorylation and myofibroblast activation in ICC-derived CAFs. PlGF blockade also reduced desmoplasia and tissue stiffness, which resulted in reopening of collapsed tumour vessels and improved blood perfusion, while reducing ICC cell invasion. Moreover, PlGF blockade enhanced the efficacy of standard chemotherapy in mice-bearing ICC. Conclusion PlGF blockade leads to a reduction in intratumorous hypoxia and metastatic dissemination, enhanced chemotherapy sensitivity and increased survival in mice-bearing aggressive ICC.

Tumor Microenvironment of Esophageal Cancer.

Esophageal cancer is among the top ten most deadly cancers worldwide with adenocarcinomas of the esophagus showing increasing incidences over the last years. The prognosis is determined by tumor stage at diagnosis and in locally advanced stages by response to (radio-)chemotherapy followed by radical surgery. Less than a third of patients with esophageal adenocarcinomas completely respond to neoadjuvant therapies which urgently asks for further strategies to improve these rates. Aiming at the tumor microenvironment with novel targeted therapies can be one strategy to achieve this goal. This review connects experimental, translational, and clinical findings on each component of the esophageal cancer tumor microenvironment involving tumor angiogenesis, tumor-infiltrating immune cells, such as macrophages, T-cells, myeloid-derived suppressor cells, and cancer-associated fibroblasts. The review evaluates the current state of already approved concepts and depicts novel potentially targetable pathways related to esophageal cancer tumor microenvironment.

[Influence of molecular pathology on oncological surgery of tumors of the upper gastrointestinal tract]. / Einfluss der Molekularpathologie auf die onkologische Chirurgie von Tumoren des oberen Gastrointestinaltraktes.

BACKGROUND: In the recent past tumors of the upper gastrointestinal (GI) tract, e.g. esophageal squamous cell carcinoma (ESCC), esophageal adenocarcinoma (EAC) and gastric adenocarcinoma, have been increasingly characterized by molecular genetics. The resulting subtypes provide potential targets for novel targeted treatment based on the biological characteristics. OBJECTIVE: This article summarizes the current state of molecular subtyping in all three tumor entities and the individualized treatment strategies derived from these categories are discussed. MATERIAL AND METHODS: A selective literature search was performed focusing on molecular subtyping, current targeted treatment and the impact on the oncological treatment concepts. Databases such as PubMed were used. RESULTS: Based on molecular characteristics ESCC is nowadays categorized into three subtypes. Genetically, at least one subgroup resembles oropharyngeal carcinomas rather than those of the upper GI tract. In contrast, EAC is characterized by its high tumor burden and large chromosomal instability. In gastric carcinoma 4 subtypes are distinguished: 1) Epstein-Barr virus (EBV) positive, 2) microsatellite instability (MSI), 3) genomically stable (GS) and 4) chromosomally unstable (CIN) tumors. CONCLUSION: To date, only a few targeted therapeutic options have been successfully transferred into daily routine derived from the genetic characterization of the three tumor entities. These include selective ERBB2 inhibition, immunotherapy using PD-L1 inhibition or combined blockade of ERBB2/VEGF.

Aldo-Keto Reductase 1C3 Mediates Chemotherapy Resistance in Esophageal Adenocarcinoma via ROS Detoxification.

Esophageal adenocarcinoma (EAC) is one of the most lethal malignancies, and limits promising treatments. AKR1C3 represents a therapeutic target to combat the resistance in many cancers. However, the molecular mechanism of AKR1C3 in the chemotherapy resistance of EAC is still unclear. We found that the mRNA level of AKR1C3 was higher in EAC tumor tissues, and that high AKR1C3 expression might be associated with poor overall survival of EAC patients. AKR1C3 overexpression decreased cell death induced by chemotherapeutics, while knockdown of AKR1C3 attenuated the effect. Furthermore, we found AKR1C3 was inversely correlated with ROS production. Antioxidant NAC rescued chemotherapy-induced apoptosis in AKR1C3 knockdown cells, while the GSH biosynthesis inhibitor BSO reversed a protective effect of AKR1C3 against chemotherapy. AKT phosphorylation was regulated by AKR1C3 and might be responsible for eliminating over-produced ROS in EAC cells. Intracellular GSH levels were modulated by AKR1C3 and the inhibition of AKT could reduce GSH level in EAC cells. Here, we reported for the first time that AKR1C3 renders chemotherapy resistance through controlling ROS levels via AKT signaling in EAC cells. Targeting AKR1C3 may represent a novel strategy to sensitize EAC cells to conventional chemotherapy.

Linking Cancer Stem Cell Plasticity to Therapeutic Resistance-Mechanism and Novel Therapeutic Strategies in Esophageal Cancer.

Esophageal cancer (EC) is an aggressive form of cancer, including squamous cell carcinoma (ESCC) and adenocarcinoma (EAC) as two predominant histological subtypes. Accumulating evidence supports the existence of cancer stem cells (CSCs) able to initiate and maintain EAC or ESCC. In this review, we aim to collect the current evidence on CSCs in esophageal cancer, including the biomarkers/characterization strategies of CSCs, heterogeneity of CSCs, and the key signaling pathways (Wnt/ß-catenin, Notch, Hedgehog, YAP, JAK/STAT3) in modulating CSCs during esophageal cancer progression. Exploring the molecular mechanisms of therapy resistance in EC highlights DNA damage response (DDR), metabolic reprogramming, epithelial mesenchymal transition (EMT), and the role of the crosstalk of CSCs and their niche in the tumor progression. According to these molecular findings, potential therapeutic implications of targeting esophageal CSCs may provide novel strategies for the clinical management of esophageal cancer.

Cell type-specific transcriptomics of esophageal adenocarcinoma as a scalable alternative for single cell transcriptomics.

Single-cell transcriptomics have revolutionized our understanding of the cell composition of tumors and allowed us to identify new subtypes of cells. Despite rapid technological advancements, single-cell analysis remains resource-intense hampering the scalability that is required to profile a sufficient number of samples for clinical associations. Therefore, more scalable approaches are needed to understand the contribution of individual cell types to the development and treatment response of solid tumors such as esophageal adenocarcinoma where comprehensive genomic studies have only led to a small number of targeted therapies. Due to the limited treatment options and late diagnosis, esophageal adenocarcinoma has a poor prognosis. Understanding the interaction between and dysfunction of individual cell populations provides an opportunity for the development of new interventions. In an attempt to address the technological and clinical needs, we developed a protocol for the separation of esophageal carcinoma tissue into leukocytes (CD45+), epithelial cells (EpCAM+), and fibroblasts (two out of PDGFRα, CD90, anti-fibroblast) by fluorescence-activated cell sorting and subsequent RNA sequencing. We confirm successful separation of the three cell populations by mapping their transcriptomic profiles to reference cell lineage expression data. Gene-level analysis further supports the isolation of individual cell populations with high expression of CD3, CD4, CD8, CD19, and CD20 for leukocytes, CDH1 and MUC1 for epithelial cells, and FAP, SMA, COL1A1, and COL3A1 for fibroblasts. As a proof of concept, we profiled tumor samples of nine patients and explored expression differences in the three cell populations between tumor and normal tissue. Interestingly, we found that angiogenesis-related genes were upregulated in fibroblasts isolated from tumors compared with normal tissue. Overall, we suggest our protocol as a complementary and more scalable approach compared with single-cell RNA sequencing to investigate associations between clinical parameters and transcriptomic alterations of specific cell populations in esophageal adenocarcinoma.

Identification of targeted therapy options for gastric adenocarcinoma by comprehensive analysis of genomic data.

BACKGROUND: So far only trastuzumab, pembrolizumab and ramucirumab have been approved by the FDA for targeted therapy in gastric cancer (GC). Here we report on potential targeted therapy options for gastric adenocarcinoma based on a novel analysis of "The Cancer Genome Atlas (TCGA)" database. METHODS: One hundred two FDA-approved targeted cancer drugs were compiled and molecular targets defined. Drugs were considered as potentially effective if targeted genes showed (1) an increase in copy number, (2) gain of function with oncogene activation, (3) specific alterations responsive to approved drugs. Additionally, genetic changes that confer drug resistance and/or sensitivity were evaluated. RESULTS: Fifty percentage of patients with GC may be treatable with non-GC but FDA-approved targeted cancer therapies. The major drug identified in our in silico study for GC is copanlisib, a PI3K inhibitor. In the TCGA patient database, our genetically based drug response prediction identified more patients with alterations sensitive to copanlisib compared to the already-GC-approved drug trastuzumab (20%, 78 out of 393 patients, vs. trastuzumab: 13%, 52 of 393 patients), which is mainly due to the high incidence of PIK3CA gain of function mutations within mutation hot spots. CONCLUSION: Our results demonstrate that various currently FDA-approved drugs might be candidates for targeted therapy of GC. For clinical trials, cancer patients should be selected based on the genomic profile of their tumor.

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.

Total minimally invasive esophagectomy for esophageal adenocarcinoma reduces postoperative pain and pneumonia compared to hybrid esophagectomy.

BACKGROUND: The impact of total minimally invasive esophagectomy (MIE) on early postoperative outcome and patient's survival is a matter of recent discussion. METHODS: We performed a 1:2 propensity score-matched comparison of 20 patients who underwent 3D-MIE and high intrathoracic esophagogastrostomy with 40 patients who underwent hybrid esophagectomy (HYBRID) with laparoscopic gastric mobilization and open transthoracic esophagectomy and the same anastomosis for esophageal adenocarcinoma in 2014 and 2015. Matching criteria were tumor localization, age, gender, and neoadjuvant treatment. RESULTS: Both groups did not differ regarding overall postoperative complications (MIE 55% vs. HYBRID 50%, p = 0.715) and anastomotic leakage (MIE 15% vs. HYBRID 5%, p = 0.186). A significant difference was seen regarding the rate of postoperative pneumonia (MIE 5% vs. HYBRID 27.5%; p = 0.040) and the postoperative ICU stay (MIE median 1 day vs. HYBRID median 2 days, p < 0.001). The R0-resection rate was 100% in both groups and median number of dissected lymph nodes was 32 for MIE and 35 for HYBRID (p = 0.236). Significant differences between both groups were noticed for postoperative number of patients with use of opiate demand medication and numeric rating scale for pain (NRSP maximum pain, median) both in favor of the MIE group (MIE 25%, NRSP 2 vs. HYBRID 60%, NRSP 4; p = 0.011, p < 0.001). Overall 2-year survival rate was 85% in both groups. CONCLUSION: Total minimally invasive esophagectomy is superior to hybrid esophagectomy in regard of postoperative pain and rate of pneumonia. No differences exist for postoperative surgical complications or short-term prognosis.

Oligometastatic Disease in Upper Gastrointestinal Cancer - How to Proceed?

BACKGROUND: In the present study we review and discuss the current evidence and suggest how to proceed in the management of oligometastatic disease in upper gastrointestinal cancer. METHODS: An electronic search of the PubMed database for relevant articles was performed. RESULTS: Both the search for 'oligometastasis', 'oligometastases', 'oligometastatic', 'oligometastatic disease' as well as 'esophageal' and 'esophageal cancer' and the search for 'oligometastasis', 'oligometastases', 'oligometastatic', 'oligometastatic disease' as well as 'gastric', 'gastric cancer', 'stomach', and 'stomach cancer' yielded very few studies. Most data need to be extrapolated in general studies on oligometastatic diseases of different origins. No randomized controlled trial could be found. CONCLUSION: In the absence of data to formulate recommendations on how to proceed in the treatment of oligometastatic disease in upper gastrointestinal cancer, a more aggressive treatment of oligometastatic disease can be considered in patients whose tumors show a more favorable neoplastic behavior after the 'test of time'. The RENAISSANCE study will certainly deliver important data regarding this aspect.

Molecular markers predicting lymph node metastasis in early esophageal cancer.

AIMS: The aim of this study was to identify molecular markers predicting depth of tumor infiltration and presence of lymph node metastasis in early esophageal cancer. METHODS: Between 1996 and 2004, 67 patients with pT1 esophagus cancer underwent esophagectomy. Resected tumors and lymph nodes were analyzed by immunohistochemistry for tissue infiltration, lymph node metastasis (LNM), micrometastasis and extracapsular lymph node infiltration (ELNI). We focused on MMP-2 (matrix-metalloproteinase-2), TIMP-2 (tissue inhibitor of metalloproteinase-2), PIM-1 and survivin as the most promising marker candidates. The data was correlated with the patients' long term follow-up (median follow-up time 11.4 years). RESULTS: We found 22 pT1a and 45 pT1b carcinomas. None of the mucosal carcinomas, but 58% (26 patients) of the submucosal carcinomas showed lymph node metastasis or micrometastasis. The rate of LNM positively correlated with the depth of tumor infiltration (23% LNM in sm1 tumors and 82% LNM in sm3 tumors). Low grade PIM-1 expression (<30%) was significantly associated with occurrence of LNM (p=0.034) while high expression TIMP-2 (>70%) were detected in submucosal tumors. Logistic regression analysis revealed PIM-1 and Grading G3 as independent risk factors for LNM (p<0.001). Survival of patients with micrometastasis was comparable to those with LNM (median survival: 5.05 years versus 5.52 years). Patients with ELNI had the worst prognosis (median survival: 1.7 years). CONCLUSIONS: PIM-1 is a promising marker for prediction of lymph node metastasis in early esophagus cancer. Extracapsular lymph node infiltration has an independent worse prognostic impact.

Novel diagnostic and prognostic biomarkers in esophageal cancer.

INTRODUCTION: This article provides an overview of actual biomarkers with an impact on improvement of diagnosis and treatment of esophageal cancer patients. AREAS COVERED: Recent literature has been analyzed and provides information regarding the potential role of molecular markers as a diagnostic or prognostic factor in esophageal cancer. EXPERT OPINION: Until now, the role of molecular markers is far from being firmly established for routine use and is not without obstacles. However, with reliable standardized methods, established cut-off values and promising candidates in marker panels with markers of genetic, epigenetic and proteomic origin might result in a marker tool worthwhile of being validated in large, prospective, randomized trials. Novel validated marker combinations have to be clinically applied to prove their putative role in complementing clinical techniques within the development of better detection concepts of esophageal cancer, improving patients' long-term prognosis by early and purposive therapy within individualized treatment concepts.

pT2 Adenocarcinoma of the esophagus: early or advanced cancer?

BACKGROUND: There is an increasing trend to include patients with esophageal carcinoma invading the muscularis propria (pT2) in neoadjuvant therapy regimens. But it is unclear which patients have prognostic benefit from this strategy. The aim of this study was to assess the prognosis and prognostic factors in patients with pT2 esophageal adenocarcinoma to further optimize treatment strategies. METHODS: Included were patients with pT2 esophageal adenocarcinoma treated operatively at three centers specializing in upper gastrointestinal surgery. There were 159 patients (139 male) without induction therapy; median age was 64.5 years. Survival was analyzed by univariate and multivariate analysis. RESULTS: In 37% of patients (n = 59), no lymph node involvement (pN0) was detected. Overall 5-year survival rate for all patients was 37%; for pN0 patients it was 62%, and for patients with lymph node metastases (pN+) it was 24%. Median number of examined lymph nodes was 26. Extracapsular lymph node involvement (ELNI) was evident in 55 of 100 pN+ patients with a 5-year survival rate of 14%. Patients without ELNI had a 5-year survival rate of 36% (p = 0.041). Results were comparable in all participating hospitals. Thirty-day and 90-day mortality rates of the entire collective were 2.6% and 3.8%, respectively. Multivariate analysis of prognosis revealed the lymph node ratio (p < 0.001) and the pN-ELNI category (p = 0.005) as significant parameters (pN0 hazard ratio 1 [reference]; pN+ without ELNI hazard ratio 2.2, 95% confidence interval: 1.2 to 3.8); pN+ with ELNI hazard ratio 2.5, 95% confidence interval: 1.5 to 4.5). CONCLUSIONS: The prognosis of patients with esophageal adenocarcinoma invading the muscularis propria without lymph node metastasis is very good. However, in this study, about 30% had extracapsular lymph node involvement, which reflects particularly aggressive biological tumor behavior.