The tight junction protein claudin 6 is a potential target for patient-individualized treatment in esophageal and gastric adenocarcinoma and is associated with poor prognosis.

BACKGROUND: The prognosis of esophageal adenocarcinoma (EAC) and gastric adenocarcinoma (GAC) remains poor, and new therapeutic approaches are urgently needed. Claudin 6 (CLDN6) is an oncofetal antigen that is largely absent in healthy tissues and upregulated in several cancers, making it a promising therapeutical target. In this study, the expression of CLDN6 was assessed in an large Caucasian EAC and GAC cohort. METHODS: RNA-Seq data from 89 EACs and 371 GACs were obtained from The Cancer Genome Atlas project and EAC/GAC cases were stratified by CLDN6 mRNA expression based on a survival-associated cutoff. For groups with CLDN6 expression above or below this cutoff, differential gene expression analyses were performed using DESeq, and dysregulated biological pathways were identified using the Enrichr tool. Additionally, CLDN6 protein expression was assessed in more than 800 EACs and almost 600 GACs using a CLDN6-specific immunohistochemical antibody (clone 58-4B-2) that is currently used in Phase I/II trials to identify patients with CLDN6-positive tumors (NCT05262530; NCT04503278). The expression of CLDN6 was also correlated with histopathological parameters and overall survival (OS). RESULTS: EACs and GACs with high CLDN6 mRNA levels displayed an overexpression of pathways regulating the cell cycle, DNA replication, and receptor / extracellular matrix interactions. CLDN6 protein expression was associated with shorter OS in EAC and GAC, both in treatment-naïve subgroups and cohorts receiving neoadjuvant therapy. In multivariate analysis, CLDN6 protein expression was an independent adverse prognostic factor in EAC associated with a shorter OS (HR: 1.75; p = 0.01) and GAC (HR: 2.74; p = 0.028). CONCLUSIONS: High expression of CLDN6 mRNA is associated with the dysregulation of distinct biological pathways regulating cell growth, proliferation, and cell-matrix interactions. Clinically, the expression of CLDN6 protein is a valuable adverse prognostic marker in EAC and GAC.

The Impact of the COVID Pandemic on Adrenal Surgery at an Academic Endocrine Surgery Unit.

COVID-19 has severely affected the delivery of surgical care worldwide. The aim of the present study was to evaluate its impact on adrenal surgery at our academic endocrine center. All primary adrenal surgeries performed at the University Hospital of Cologne, Germany between 01.01.2019 and 31.07.2022 were included. This time frame was divided into pre-Covid (before 02/20), acute Covid (until 05/21), and post acute period (after 05/2021). Demographics, clinic-pathologic characteristics and treatment of these patients were analyzed. One hundred adrenalectomies were included: 22 before, 30 during, and 48 after the acute phase. The percentage of Conn adenomas and pheochromocytomas decreased during the acute phase (from 45.4 to 26.6% and from 18 to 10%, respectively) in favor of Cushing adenomas and suspicious tumors (from 4.5 to 20% and from 31.8 to 36.6%). About 90.9% of tumors resected for suspicion of malignancy were confirmed malignant by final histopathology, as opposed to 71.4% and 52.6% before and after the acute phase. The operative technique was similar during the three phases (63% retroperitoneoscopic, 34% laparoscopic and 2% open resections), with a significantly shorter operative time for retroperitoneoscopy (p=0.04). ICU monitoring demand increased during the acute phase (from 13.6% to 43.3%), according to the increase in Cushing adenomas and malignant tumors. During the acute phase of COVID-19 pandemic adrenal surgery for Cushing and malignant tumors increased, while a delay in pheochromocytoma surgery to the post acute phase was observed. The suspicion of malignancy formulated by the endocrine tumor board was accurate in 90.9% of cases.

Outcome of endoscopic vacuum therapy for duodenal perforation.

BACKGROUND: Duodenal defects are complex clinical situations, and their management is challenging and associated with high mortality. Besides surgery, endoscopic treatment options exist, but the size and location of the perforation can limit their application. We present a retrospective study, demonstrating a successful application of endoscopic vacuum therapy (EVT) for duodenal leaks. METHODS: We performed a retrospective study of all patients who underwent EVT for duodenal perforations between 2016 and 2021 at two tertiary centers. We analyzed demographic and clinical patient characteristics, surgical outcomes, leak characteristics, sponge-related complications, and success rate. RESULTS: Indications for treatment with EVT in the duodenum consisted of leak after duodenal suture of a perforated ulcer (n = 4), iatrogenic perforation after endoscopic resection (n = 2), iatrogenic perforation during surgery (n = 2), and anastomotic leak after upper gastrointestinal surgery (n = 2). EVT was used as a first-line treatment in seven patients and as a second-line treatment in three patients. EVT was successfully applied in all interventions (n = 10, 100%). Overall, EVT lead to definitive closure of the defects in eight out of ten patients (80%). No severe EVT-related adverse events occurred. CONCLUSION: EVT is safe and technically feasible, so it emerges as a promising endoscopic treatment option for duodenal leaks. However, multidisciplinary collaboration and management are important to reduce the occurrence of postoperative complications, and to improve recovery rates.

Assessment of pyloric sphincter physiology after Ivor-Lewis esophagectomy using an endoluminal functional lumen imaging probe.

OBJECTIVE OF THE STUDY: The most common functional complication after Ivor-Lewis esophagectomy is the delayed emptying of the gastric conduit (DGCE) for which several diagnostic tools are available, e.g. chest X-ray, upper esophagogastroduodenoscopy (EGD) and water-soluble contrast radiogram. However, none of these diagnostic tools evaluate the pylorus itself. Our study demonstrates the successful measurement of pyloric distensibility in patients with DGCE after esophagectomy and in those without it. METHODS AND PROCEDURES: Between May 2021 and October 2021, we performed a retrospective single-centre study of all patients who had an oncological Ivor-Lewis esophagectomy and underwent our post-surgery follow-up programme with surveillance endoscopies and computed tomography scans. EndoFlip™ was used to perform measurements of the pylorus under endoscopic control, and distensibility was measured at 40 ml, 45 ml and 50 ml balloon filling. RESULTS: We included 70 patients, and EndoFlip™ measurement was feasible in all patients. Successful application of EndoFlip™ was achieved in all interventions (n = 70, 100%). 51 patients showed a normal postoperative course, whereas 19 patients suffered from DGCE. Distensibility proved to be smaller in patients with symptoms of DGCE compared to asymptomatic patients. For 40 ml, 45 ml and 50 ml, the mean distensibility was 6.4 vs 10.1, 5.7 vs 7.9 and 4.5 vs 6.3 mm2/mmHg. The differences were significant for all three balloon fillings. No severe EndoFlip™ treatment-related adverse events occurred. CONCLUSION: Measurement with EndoFlip™ is a safe and technically feasible endoscopic option for measuring the distensibility of the pylorus. Our study shows that the distensibility in asymptomatic patients after esophagectomy is significantly higher than that in patients suffering from DGCE. However, more studies need to be conducted to demonstrate the general use of EndoFlip™ measurement of the pylorus after esophagectomy.

Adrenal Surgery in the Era of Multidisciplinary Endocrine Tumor Boards.

Work up of adrenal masses includes assessment of endocrine activity and malignancy risk. There is no indication for surgical removal of nonfunctional adrenal adenomas, according to the guidelines. In the present study, we aimed at evaluating the impact of a university endocrine tumor board on the quality of the indications for adrenal surgery at our institution. One hundred consecutive patients receiving primary adrenal surgery at the University Hospital of Cologne, Germany were included. Their demographics, clinic-pathologic characteristics, treatment and outcome were analyzed. In 55 (55%) cases, indication for surgery consisted in functional benign tumors, including Conn, Cushing adenomas and pheochromocytomas. Forty (40%) tumors were referred to surgery for malignancy suspicion and 5 (5%) myelolipomas were removed due to their size. Eighty-nine percent of surgeries were performed as minimally invasive procedures. Overall morbidity included two (2%) self-limiting pancreatic fistulas after left laparoscopic adrenalectomy for pheochromocytoma. All functional tumors were confirmed benign by final histology. Only 33 (82.5%) of 40 suspicious cases turned out to be malignant. Consequently, nonfunctional benign adenomas were "unnecessarily" removed in only 7 (7%) patients, with 6 (85.7%) of them having a history of extra-adrenal cancer and all of them fulfilling criteria for surgery, according to the international guidelines. In conclusion, the endocrine tumor board provided an excellent adherence to the guidelines with most surgeries being performed either for functional or malignant tumors. In nonfunctional tumors with history of extra adrenal cancer, CT guided biopsy might be considered for obviating surgery.

There is no correlation between a delayed gastric conduit emptying and the occurrence of an anastomotic leakage after Ivor-Lewis esophagectomy.

INTRODUCTION: Esophagectomy is the gold standard in the surgical therapy of esophageal cancer. It is either performed thoracoabdominal with a intrathoracic anastomosis or in proximal cancers with a three-incision esophagectomy and cervical reconstruction. Delayed gastric conduit emptying (DGCE) is the most common functional postoperative disorder after Ivor-Lewis esophagectomy (IL). Pneumonia is significantly more often in patients with DGCE. It remains unclear if DGCE anastomotic leakage (AL) is associated. Aim of our study is to analyze, if AL is more likely to happen in patients with a DGCE. PATIENTS AND METHODS: 816 patients were included. All patients have had an IL due to esophageal/esophagogastric-junction cancer between 2013 and 2018 in our center. Intrathoracic esophagogastric end-to-side anastomosis was performed with a circular stapling device. The collective has been divided in two groups depending on the occurrence of DGCE. The diagnosis DGCE was determined by clinical and radiologic criteria in accordance with current international expert consensus. RESULTS: 27.7% of all patients suffered from DGCE postoperatively. Female patients had a significantly higher chance to suffer from DGCE than male patients (34.4% vs. 26.2% vs., p = 0.040). Pneumonia was more common in patients with DGCE (13.7% vs. 8.5%, p = 0.025), furthermore hospitalization was longer in DGCE patients (median 17 days vs. 14d, p < 0.001). There was no difference in the rate of type II anastomotic leakage, (5.8% in both groups DGCE). All patients with ECCG type II AL (n = 47; 5.8%) were treated successfully by endoluminal/endoscopic therapy. The subgroup analysis showed that ASA ≥ III (7.6% vs. 4.4%, p = 0.05) and the histology squamous cell carcinoma (9.8% vs. 4.7%, p = 0.01) were independent risk factors for the occurrence of an AL. CONCLUSION: Our study confirms that DGCE after IL is a common finding in a standardized collective of patients in a high-volume center. This functional disorder is associated with a higher rate of pneumonia and a prolonged hospital stay. Still, there is no association between DGCE and the occurrence of an AL after esophagectomy. The hypothesis, that an DGCE results in a higher pressure on the anastomosis and therefore to an AL in consequence, can be refuted. DGCE is not a pathogenetic factor for an AL.

A new hybrid stent using endoscopic vacuum therapy in treating esophageal leaks: a prospective single-center experience of its safety and feasibility with mid-term follow-up.

Self-expandable metal stents (SEMS) and endoscopic vacuum therapy (EVT) are endoscopic options for treating leaks of the esophagus. VACStent® is a variant of SEMS that aims to combine the advantages of SEMS and EVT in one device. Due to this unique construction, VACStent® can build a barrier to the leak and facilitate wound healing with EVT, all while maintaining intestinal passage. We present the first prospective feasibility study of VACStent® for treating leaks of the upper gastrointestinal tract. Between September 2019 and November 2020, we performed a prospective, investigator-initiated, single-center study and included all patients who underwent endoscopic stenting with VACStent® for various kinds of esophageal leaks, such as spontaneous, iatrogenic or anastomotic leaks. We included 20 patients, who underwent a total of 24 endoscopic VACStent® implantations. Technical success of the application of the VACStent® was achieved in all interventions (n = 24, 100%). Overall, clinical success in closing the leaks with VACStent® treatment was achieved in 60% of patients (12/20). No severe VACStent® treatment-related adverse events occurred. Oral feeding with supplement high-energy drinks failed in all patients due to clogging of the suction tube. VACStent® is a safe and feasible endoscopic treatment option for leaks of the upper gastrointestinal tract. However, our data could not show the expected advantage of orally feeding the patients during the treatment with the VACStent® in its current form. Efficacy of VACStent® compared to EVT or SEMS needs to be investigated in a further study. ClinicalTrials.gov Identifier: NCT03962179.

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.

Efficacy and feasibility of OverStitch suturing of leaks in the upper gastrointestinal tract.

BACKGROUND: Management of upper gastrointestinal leaks is challenging. A new potential treatment option for this complication is endoscopic suturing with the OverStitch system (Apollo Endosurgery, Texas, USA), which is today mainly used for endoscopic sleeve gastroplasty. The aim of this study was to analyze the efficacy and feasibility of this new treatment option in patients with leaks in the upper gastrointestinal tract. METHODS: We performed a retrospective, single-center study of all patients who underwent endoscopic suturing with OverStitch of leaks in the upper gastrointestinal tract. RESULTS: Endoscopic suturing was performed on 13 patients (mean age, 59.62 ± 16.29 years; mean leak size, 22.31 ± 22.6 mm) over a period of 8 months. Postoperative leaks were detected in 10 patients (76.9%) after foregut surgery. Interventional success was achieved in all endoscopic attempts (n = 16, 100%) with a mean closure time of 28.0 ± 12.36 min per patient. Follow-up technical success rate for each suture was (n = 8, 50.0%). Clinical success, including repeated suture attempts was achieved in 8 of the 13 patients (61.5%). These 8 patients had not received prior treatment for the leak. No immediate or delayed serious complications occurred as a result of OverStitch. The mean follow-up was 95 ± 91.07 days. CONCLUSIONS: Endoscopic suturing with OverStitch for leaks in the upper gastrointestinal tract is feasible and effective in patients who have not received prior treatment. This minimally invasive technique seems to be a promising option especially for patients with large leaks and significant comorbidities.

Tumour-infiltrating neutrophils counteract anti-VEGF therapy in metastatic colorectal cancer.

BACKGROUND: Immune infiltration is implicated in the development of acquired resistance to anti-angiogenic cancer therapy. We therefore investigated the correlation between neutrophil infiltration in metastasis of colorectal cancer (CRC) patients and survival after treatment with bevacizumab. Our study identifies CD177+ tumour neutrophil infiltration as an adverse prognostic factor for bevacizumab treatment. We further demonstrate that a novel anti-VEGF/anti-Ang2 compound (BI-880) can overcome resistance to VEGF inhibition in experimental tumour models. METHODS: A total of 85 metastatic CRC patients were stratified into cohorts that had either received chemotherapy alone (n = 39) or combined with bevacizumab (n = 46). Tumour CD177+ neutrophil infiltration was correlated to clinical outcome. The impact of neutrophil infiltration on anti-VEGF or anti-VEGF/anti-Ang2 therapy was studied in both xenograft and syngeneic tumour models by immunohistochemistry. RESULTS: The survival of bevacizumab-treated CRC patients in the presence of CD177+ infiltrates was significantly reduced compared to patients harbouring CD177- metastases. BI-880 treatment reduced the development of hypoxia associated with bevacizumab treatment and improved vascular normalisation in xenografts. Furthermore, neutrophil depletion or BI-880 treatment restored treatment sensitivity in a syngeneic tumour model of anti-VEGF resistance. CONCLUSIONS: Our findings implicate CD177 as a biomarker for bevacizumab and suggest VEGF/Ang2 inhibition as a strategy to overcome neutrophil associated resistance to anti-angiogenic treatment.

HER2/neu (ERBB2) expression and gene amplification correlates with better survival in esophageal adenocarcinoma.

BACKGROUND: HER2 (ERBB2 or HER2/neu) is a tyrosine-kinase increasing cell proliferation. Overexpression/amplification of HER2 is correlated with worse prognosis in solid malignancies. Consequently, HER2 targeting is established in breast and upper gastrointestinal tract cancer. There are conflicting data concerning the impact of HER2 overexpression on esophageal adenocarcinoma (EAC), as most studies do not differ between cancers of the esophagus/gastroesophageal junction and the stomach. The aim of this study was to analyze the expression/amplification of HER2 in EAC in correlation to clinicopathological data to verify its prognostic impact. METHODS: We analyzed 428 EAC patients that underwent transthoracic thoraco-abdominal esophagectomy between 1997 and 2014. We performed HER2 immunohistochemistry (IHC) according to the guidelines and fluorescence-in-situ-hybridization (FISH) for IHC score2+, using tissue micro arrays (TMA) with up to eight biopsies from the surface and infiltration area of a single tumor for evaluating HER2-heterogeneity and single-spot TMA. The HER2-status was correlated with clinicopathological data. RESULTS: HER2-positivity was found in up to 14.9% in our cohort (IHC score 3+ or IHC score 2+ with gene amplification) and demonstrated a significantly better overall survival (OS) in correlation to HER2-negative tumors (median OS 70.1 vs. 24.6 months, p = 0.006). HER2-overexpression was more frequently seen in lower tumor stages (pT1/pT2, p = 0.038), in the absence of lymphatic metastases (pN0/pN+, p = 0.020), and was significantly associated with better histological grading (G1/G2) (p = 0.041). CONCLUSION: We demonstrated a positive prognostic impact of HER2 overexpression in a large cohort of EAC, contrary to other solid malignancies including gastric cancer and breast cancer, but consistent to the results of a large study on EAC from 2012.

Outcome of Self-Expanding Metal Stents in the Treatment of Anastomotic Leaks After Ivor Lewis Esophagectomy.

BACKGROUND: Esophageal anastomotic leakages after Ivor Lewis esophagectomy are severe and life-threatening complications. We analyzed the outcome of using self-expanding metal stents (SEMS) in the treatment of postoperative leakage after esophagogastrostomy. METHODS: Seventy patients with esophageal anastomotic leakage after Ivor Lewis esophagectomy for esophageal cancer who had received SEMS treatment between January 2006 and December 2015 at our clinic were identified in this retrospective study. The patients were analyzed according to demographic characteristics, risk factors, leakage characteristics, stent characteristics, stent-related complications, sealing success rate and mortality. RESULTS: Over a 10-year period, 70 patients received SEMS as treatment for postoperative anastomotic leakage after esophagectomy. Technical success of esophageal stenting in anastomotic leakage was achieved in 50 out of 70 cases (71.4%). Sealing success rate was 70% (n = 49) with a median treatment of 28 days (range 7-87). In 20 patients (28.6%), stent-related complications, such as stenosis, dislocation, leakage persistence, perforation or esophagotracheal fistula occurred after the SEMS treatment. Sixty-one patients (87.1%) survived SEMS treatment of esophagogastric anastomotic leakage. Mean follow-up for all patients was 38 months (IQR 10-76), and no significant difference was found in a comparison of the long-term survival rate between patients with successful and unsuccessful SEMS treatment. CONCLUSIONS: The management of esophageal anastomotic leaks after Ivor Lewis esophagectomy with SEMS is effective, safe and technically feasible. Aggressive non-surgical management should be considered when developing a treatment plan for stenting.

First reported case of a collision tumor composed of pancreatic adenocarcinoma and retroperitoneal liposarcoma: a case report.

BACKGROUND: Collision tumors are rare cases with two different tumor entities growing synchronously. While adenocarcinoma of the pancreas is the most common pancreatic tumor with an incidence of 10 per 100.000, retroperitoneal liposarcoma remains very rare. This is the first report of a collision tumor between these two tumor entities. CASE PRESENTATION: Demographic details: The tumor was diagnosed in a 64 male Caucasian patient. Besides atrial fibrillation, arterial hypertension and a hypothyroidism there is no relevant medical history especially no history of cancer. Clinical details: During a routine check-up an unclassified tumor of the pancreatic tail was diagnosed. The lab showed no pathologies. Tumor markers were negative for carbohydrate antigen 19-9 and 72-4 (CA 19-9, CA 72-4) and carcinoembryonic antigen (CEA). Alpha-fetoprotein (AFP) and neuron specific enolase (NSE) were both elevated (AFP 97kU/l, (< 5,8kU/l) and NSE 30,0 µg/l (16,4 µg/l)). A computed tomography-guided core needle biopsy was performed which revealed a low-grade liposarcoma (G1). A CT scan showed no metastases. A surgical resection was recommended by the interdisciplinary tumor board. INTERVENTIONS: A systematic left sided retroperitoneal compartment resection including en-bloc-left sided pancreatectomy, splenectomy, nephrectomy, hemicolectomy, adrenalectomy, partial gastrectomy and partial resection of the diaphragm was performed. Pathology revealed a collision tumor consisting of pancreatic adenocarcinoma that was classified pT3, pN2 (11/33 ece+) L1 V0 Pn0, R0; G2 [UICC Stage III] and a liposarcoma pT2, pN0 (0/33) L0 V0 Pn0, G1 [UICC Stage Ib]. The postoperative tumor board recommended an adjuvant chemotherapy with gemcitabine and capecitabine for the locally advanced pancreatic adenocarcinoma. OUTCOME: At the latest follow-up (1 year after surgery) the patient was in good clinical condition and without evidence of tumor recurrence. CONCLUSION: Collision tumors are rare and difficult to diagnose. This is the first description of a collision tumor composed of pancreatic adenocarcinoma and retroperitoneal liposarcoma. The reported case demonstrates that inconsistent diagnostic results (e.g. imaging and pathology) should raise suspicion concerning the diagnosis. Awareness of these rare cases might protect us from underdiagnosing patients and therefore leading to better patient care. There is evolving evidence that will lead to more personalized treatment options for somatic BRCA mutated pancreatic cancer.

Isolated pulmonary metastases define a favorable subgroup in metastatic pancreatic cancer.

PURPOSE: Liver metastasis represents the first site of dissemination in >80% of metastatic pancreatic cancer (PC) patients. Pulmonary metastasis as first site of dissemination in PC is a rare event and might define a biologically distinct subgroup in metastatic PC. METHODS: Consecutive PC patients who were diagnosed or treated with isolated pulmonary metastases at our high-volume comprehensive cancer center were included in a prospectively maintained database between 2002 and 2015. Medical records and correlating computed tomography findings (CT) were retrospectively analyzed. RESULTS: A total of 40 PC patients with isolated pulmonary metastases were identified. Pulmonary metastases represented disease recurrence after initial resection of PC in 22 patients and disease progression of locally advanced pancreatic cancer in 5 patients. 14 out of 27 PC patients (56%) had received chemoradiotherapy for localized disease prior to pulmonary metastasis. Data on 1st-line treatment for pulmonary metastases was available for 38 patients: most patients (71%) received a gemcitabine-based chemotherapy regimen, 5 patients (13%) received best supportive care. After a median follow-up of 37.3 months, median survival after diagnosis of pulmonary metastasis was estimated with 25.5 months (95% CI 19.1-31.8); a significantly improved survival after diagnosis of pulmonary metastasis was observed for patients with less than 10 lung metastases (31.3 vs 18.7 months, p = 0.003) and for an unilateral localization of lung involvement (31.3 vs 21.8 months, p = 0.03). CONCLUSIONS: Our results suggest a favorable outcome of PC patients with isolated pulmonary metastases. Further research is warranted to elucidate the specific molecular characteristics of this rare subgroup.

KRAS exon 2 mutations influence activity of regorafenib in an SW48-based disease model of colorectal cancer.

AIM: To investigate the impact of KRAS mutation variants on the activity of regorafenib in SW48 colorectal cancer cells. MATERIALS & METHODS: Activity of regorafenib was evaluated in isogenic SW48 KRAS wild-type (WT) and mutant cells. Subcutaneous xenografts (KRAS WT and G12C mutant variants) in NOD/SCID mice were analyzed to elucidate the effect of regorafenib treatment in vivo. RESULTS: Compared with KRAS WT cells, all mutant variants seemed associated with some degree of resistance to regorafenib-treatment in vitro. In vivo, activation of apoptosis (TUNEL) and reduction of proliferation (Ki67) after treatment with regorafenib were more pronounced in KRAS WT tumors as compared with G12C variants. CONCLUSION: In SW48 cells, exon 2 mutations of the KRAS gene may influence antitumor effects of regorafenib.

Intraoperative thyroid frozen section: indications, results and consequences.

Background: Frozen section (FS) analysis is strongly influenced by the experience of surgeons and pathologists. We analyzed its performance in a secondary care hospital with surgical and pathologic experience transferred from a university hospital. Methods: Indications, results, and consequences of all thyroid FS performed between January 1, 2021 and December 31, 2022 were critically reviewed. Results: FS was performed in 90 (26.5%) of 340 procedures. Indications consisted in a suspicious fine needle biopsy in 28 (31.1%) cases, (99m) Technetium-Methoxy-Isobutyl-Isonitrile (MIBI) retaining hypofunctional nodules in 25 (27.8%), the intraoperative appearance in 18 (20%), the sonographic appearance in 18 (20%) and a positron emission tomography (PET) positive result in 1 case (1.1%). Malignancy was diagnosed in 21 (23.3%) and confirmed by final histology in all cases (100%). In the remaining 69 (76.7%) FS displaying no positive malignancy criteria, final histology delivered benign in 62 (89.8%) and malignant diagnoses in 7 cases (10.1%). 25% of thyroid carcinomas could not be diagnosed by FS. FS sensitivity was consequently 75% (95% CI: 55.1-89.3%). All missed malignancies were papillary thyroid carcinomas of follicular variant (fvPTC). FS sensitivity was lowest in MIBI positive hypofunctional nodules (33%) and Bethesda III (50%) as opposed to Bethesda V (92.9%) and to those cases with suspicious sonographic or intraoperative appearance (71.4%). Two-staged surgery was necessary in 10 (15.8%) of carcinomas. Conclusions: Sensitivity of FS in a secondary care hospital offering surgical and pathologic experience from a specialized university center is 75% and mainly reduced by the prevalence of fvPTC. Omitting FS in Bethesda III and MIBI positive hypofunctional nodules might improve FS performance.

Dissecting the inflammatory tumor microenvironment of esophageal adenocarcinoma: mast cells and natural killer cells are favorable prognostic factors and associated with less extensive disease.

PURPOSE: Esophageal adenocarcinoma (EAC) remains a challenging and lethal cancer entity. A promising target for new therapeutic approaches, as demonstrated by the success of immune checkpoint inhibitors, are tumor-associated immune cells and the tumor microenvironment (TME). However, the understanding of the TME in esophageal cancer remains limited and requires further investigation. METHODS: Over 900 EAC samples were included, including patients treated with primary surgery and neoadjuvant (radio-)chemotherapy. The immune cell infiltrates of mast cells (MC), natural killer cells (NK cells), plasma cells (PC), and eosinophilic cells (EC) were assessed semi-quantitatively and correlated with histopathological parameters and overall survival (OS). RESULTS: A high presence of all four immune cell types significantly correlated with a less extensive tumor stage and a lower frequency of lymph node metastasis, and, in case of NK cells, with less distant metastasis. The presence of MC and NK cells was favorably associated with a prolonged OS in the total cohort (MC: p < 0.001; NK cells: p = 0.004) and patients without neoadjuvant treatment (MC: p < 0.001; NK cells: p = 0.01). NK cells were a favorable prognostic factor in the total cohort (p = 0.007) and in the treatment-naïve subgroup (p = 0.04). Additionally, MC were a favorable prognostic factor in patients with lymph node metastasis (p = 0.009). CONCLUSION: Our results indicate a complex and important role of mast cells, NK cells, and the other assessed immune cells in the tumor microenvironment of EAC. Therefore, they are one further step to a better understanding of the immune cell environment and the potential therapeutic implications in this cancer entity.

Differentiated Thyroid Cancer in Adolescents: Single Center Experience and Considerations for Surgical Management and Radioiodine Treatment

Objective: Differentiated thyroid cancer (DTC) in adolescents rare but with a favorable outcome, despite higher rates of cervical lymph node and pulmonary metastasis compared to adults. The aim of this study was to critically evaluate treatment of adolescents with DTC at a single center. Methods: Patients receiving postoperative radioiodine treatment (RAIT) for DTC between 2005 and 2020 at our institution were screened to identify adolescents according to the World Health Organization definition (10-19 years of age). Demographics, clinico-pathological characteristics, treatment and outcome were analyzed. Results: Among 1,897 DTC patients, 23 (1.3%) were adolescents with a median (range) age of 16 (10-18) years. The female to male ratio was 3.6:1. Sixty percent had classic papillary thyroid cancer, with follicular variant in 40%, which was higher than previously reported (15-25%) for this age group. pT-status was pT1 in 9 (39.2%), pT2 in 8 (34.8%), pT3 in 3 (13%) and pT4 in 3 (13%) patients. In 19 (82.6%) patients, central lymphadenectomy was performed and metastasis was seen in 57%. All patients received RAIT with initial activities of 1.2 (n=1, 4.3%), 2 (n=12, 52.2%) or 3.7 GBq (n=10, 43.5%). Eighteen (78.2%) patients were free of biochemical and radiologic disease at a median follow-up of 60.7 months. Second-line surgery for lymph node relapse was necessary in 3 (13%) cases. There was one disease-associated death. Conclusion: Despite high rates of metastasis, most patients were cured, and second-line surgery was rarely required. Further prospective studies are needed to determine whether less aggressive surgical management or omitting adjuvant RAIT are feasible in patients with limited stages at diagnosis.