Synergistic treatment of infected burn wound utilizing maggot debridement and acellular fish skin grafting - a case report

Here we report about a patient with a full thickness burn injury of the left lower extremity with approximately 8% of total body surface area affected. Initial therapy consisted of necrosectomy and wound coverage with split thickness graft. The patient developed a wound infection with Pseudomonas aeruginosa, resulting in the failure of the skin graft to achieve complete healing. The case was further complicated by the patient's concurrent presentation of anemia, characterized by a hematocrit level of 19.8% on 11th day after admission. Additionally, the patient refused acceptance of any blood transfusion, adding a significant layer of complexity to the management strategy. In summary, the patient's critical state required an immediate intervention. Due to the contraindication for a further surgical debridement and autograft, we changed the treatment strategy to a conservative approach. First, the wound was debrided employing maggot therapy 17 days after admission. Subsequently, free soft tissue coverage was accomplished using decellularized fish skin dressings on 45th day. This approach yielded satisfactory wound closure. Following an approximately two-month hospitalization period (52nd day after admission), the patient was discharged with a stable wound condition, nearing complete healing.

The radiomorphological appearance of the invasive margin in pancreatic cancer is associated with tumor budding

PURPOSE

Pancreatic cancer (PDAC) is characterized by infiltrative, spiculated tumor growth into the surrounding non-neoplastic tissue. Clinically, its diagnosis is often established by magnetic resonance imaging (MRI). At the invasive margin, tumor buds can be detected by histology, an established marker associated with poor prognosis in different types of tumors.

METHODS

We analyzed PDAC by determining the degree of tumor spiculation on T2-weighted MRI using a 3-tier grading system. The grade of spiculation was correlated with the density of tumor buds quantified in histological sections of the respective surgical specimen according to the guidelines of the International Tumor Budding Consensus Conference (n = 28 patients).

RESULTS

64% of tumors revealed intermediate to high spiculation on MRI. In over 90% of cases, tumor buds were detected. We observed a significant positive rank correlation between the grade of radiological tumor spiculation and the histopathological number of tumor buds (rs = 0.745, p < 0.001). The number of tumor buds was not significantly associated with tumor stage, presence of lymph node metastases, or histopathological grading (p ≥ 0.352).

CONCLUSION

Our study identifies a readily available radiological marker for non-invasive estimation of tumor budding, as a correlate for infiltrative tumor growth. This finding could help to identify PDAC patients who might benefit from more extensive peripancreatic soft tissue resection during surgery or stratify patients for personalized therapy concepts.

N-cadherin: A diagnostic marker to help discriminate primary liver carcinomas from extrahepatic carcinomas

Distinguishing primary liver cancer (PLC), namely hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA), from liver metastases is of crucial clinical importance. Histopathology remains the gold standard, but differential diagnosis may be challenging. While absent in most epithelial, the expression of the adherens junction glycoprotein N-cadherin is commonly restricted to neural and mesenchymal cells, or carcinoma cells that undergo the phenomenon of epithelial-to-mesenchymal transition (EMT). However, we recently established N- and E-cadherin expression as hallmarks of normal hepatocytes and cholangiocytes, which are also preserved in HCC and iCCA. Therefore, we hypothesized that E- and/or N-cadherin may distinguish between carcinoma derived from the liver vs carcinoma of other origins. We comprehensively evaluated E- and N-cadherin in 3359 different tumors in a multicenter study using immunohistochemistry and compared our results with previously published 882 cases of PLC, including 570 HCC and 312 iCCA. Most carcinomas showed strong positivity for E-cadherin. Strong N-cadherin positivity was present in HCC and iCCA. However, except for clear cell renal cell carcinoma (23.6% of cases) and thyroid cancer (29.2%), N-cadherin was only in some instances faintly expressed in adenocarcinomas of the gastrointestinal tract (0%-0.5%), lung (7.1%), pancreas (3.9%), gynecological organs (0%-7.4%), breast (2.2%) as well as in urothelial (9.4%) and squamous cell carcinoma (0%-5.6%). As expected, N-cadherin was detected in neuroendocrine tumors (25%-75%), malignant melanoma (46.2%) and malignant mesothelioma (41%). In conclusion, N-cadherin is a useful marker for the distinction of PLC vs liver metastases of extrahepatic carcinomas (P < .01).

Persister cell phenotypes contribute to poor patient outcomes after neoadjuvant chemotherapy in PDAC

Neoadjuvant chemotherapy can improve the survival of individuals with borderline and unresectable pancreatic ductal adenocarcinoma; however, heterogeneous responses to chemotherapy remain a significant clinical challenge. Here, we performed RNA sequencing (n = 97) and multiplexed immunofluorescence (n = 122) on chemo-naive and postchemotherapy (post-CTX) resected patient samples (chemoradiotherapy excluded) to define the impact of neoadjuvant chemotherapy. Transcriptome analysis combined with high-resolution mapping of whole-tissue sections identified GATA6 (classical), KRT17 (basal-like) and cytochrome P450 3A (CYP3A) coexpressing cells that were preferentially enriched in post-CTX resected samples. The persistence of GATA6hi and KRT17hi cells post-CTX was significantly associated with poor survival after mFOLFIRINOX (mFFX), but not gemcitabine (GEM), treatment. Analysis of organoid models derived from chemo-naive and post-CTX samples demonstrated that CYP3A expression is a predictor of chemotherapy response and that CYP3A-expressing drug detoxification pathways can metabolize the prodrug irinotecan, a constituent of mFFX. These findings identify CYP3A-expressing drug-tolerant cell phenotypes in residual disease that may ultimately inform adjuvant treatment selection.

Farnesoid X receptor activation inhibits pancreatic carcinogenesis

Farnesoid X receptor (FXR), a member of the nuclear receptor superfamily that controls bile acid (BA) homeostasis, has also been proposed as a tumor suppressor for breast and liver cancer. However, its role in pancreatic ductal adenocarcinoma (PDAC) tumorigenesis remains controversial. We recently found that FXR attenuates acinar cell autophagy in chronic pancreatitis resulting in reduced autophagy and promotion of pancreatic carcinogenesis. Feeding Kras-p48-Cre (KC) mice with the BA chenodeoxycholic acid (CDCA), an FXR agonist, attenuated pancreatic intraepithelial neoplasia (PanIN) progression, reduced cell proliferation, neoplastic cells and autophagic activity, and increased acinar cells, elevated pro-inflammatory cytokines and chemokines, with a compensatory increase in the anti-inflammatory response. Surprisingly, FXR-deficient KC mice did not show any response to CDCA, suggesting that CDCA attenuates PanIN progression and decelerate tumorigenesis in KC mice through activating pancreatic FXR. FXR is activated in pancreatic cancer cell lines in response to CDCA in vitro. FXR levels were highly increased in adjuvant and neoadjuvant PDAC tissue compared to healthy pancreatic tissue, indicating that FXR is expressed and potentially activated in human PDAC. These results suggest that BA exposure activates inflammation and suppresses autophagy in KC mice, resulting in reduced PanIN lesion progression. These data suggest that activation of pancreatic FXR has a protective role by reducing the growth of pre-cancerous PDAC lesions in response to CDCA and possibly other FXR agonists.

Oncological Outcome of Conversion Surgery After Preoperative Chemotherapy for Metastatic Pancreatic Cancer

OBJECTIVE

To investigate the outcome of conversion surgery in patients with metastatic pancreatic cancer (mPDAC) and to identify patients who may benefit from this approach.

BACKGROUND

The role of conversion surgery in patients with mPDAC and exceptional response to chemotherapy remains unclear.

METHODS

Patients who underwent surgical exploration for mPDAC following chemotherapy between 2006 and 2019 were included. Data on demographics, oncologic treatment, pathology, and postoperative outcomes were analyzed. Univariate and multivariate survival analyses were performed.

RESULTS

Some 173 patients received preoperative chemotherapy and underwent surgical exploration. Ninety-three patients underwent resection of the primary tumor and metastatic sites, 80 patients underwent exploration only. In the resection subgroup, 45 patients had complete pathological response of metastases (ypM0) and 48 patients had residual metastases (ypM1). ypM0 status was associated with lower carcinoembryonic antigen levels and lower ypN stage. Overall survival after resection was 25.5 months in ypM0, 10.7 months in ypM1, and 8.1 months in patients without resection ( P <0.001). Additional adjuvant chemotherapy was significantly associated with prolonged survival in resected patients (29.0 vs 14.8 mo, P =0.024) as well as in ypM0 (29.1 vs 19.2 mo, P =0.047). Multivariable analysis identified conversion surgery, carbohydrate antigen 19-9 (CA19-9) and time of resection as independent prognostic markers for the entire cohort. CA19-9, ypM0 and adjuvant treatment were independent predictors of survival in the resection subgroup.

CONCLUSION

In patients with mPDAC and ypM0 status after chemotherapy, surgical resection is associated with encouraging survival. mPDAC patients with exceptional response to chemotherapy may be candidates for exploration and for resection in ypM0. Adjuvant chemotherapy may provide an additional survival advantage.

A fast and sensitive high-throughput assay to assess polysorbate-degrading hydrolytic activity in biopharmaceuticals

Hydrolysis of polysorbate in biopharmaceutical products has been ascribed to the enzymatic activity from trace levels of residual host cell proteins. In recent years, significant efforts to identify the causative enzymes typically used elaborate, material-intensive and time-consuming approaches. Therefore, the lack of fast and sensitive assays to monitor their activity remains a major bottleneck for supporting process optimization and troubleshooting activities where time and sample throughput are crucial constraints. To address this bottleneck, we developed a novel Electrochemiluminescence-based Polysorbase Activity (EPA) assay to measure hydrolytic activities in biotherapeutics throughout the drug substance manufacturing process. By combining the favorable features of an in-house designed surrogate substrate with a well-established detection platform, the method yields fast (∼36 h turnaround time) and highly sensitive readouts compatible with high-throughput testing. The assay capability for detecting substrate conversion in a precise and reliable manner was demonstrated by extensive qualification studies and by employing a number of recombinant hydrolases associated with polysorbate hydrolysis. In addition, high assay sensitivity and wide applicability were confirmed for in-process pool samples of three different antibody products by performing a head-to-head comparison between this method and an established liquid chromatography - mass spectrometry based assay for the quantification of free fatty acids. Overall, our results suggest that this new approach is well-suited to resolve differences in hydrolytic activity through all stages of purification.

Abstract 6225: SERPINB3 promotes the aggressive basal-like/squamous subtype and correlates with poor prognosis in pancreatic ductal adenocarcinoma through metabolic reprogramming

In this study, we aimed to find genes with a key function in the development of molecular subtypes in pancreatic ductal adenocarcinoma (PDAC). Through transcriptome analysis, we discovered that the endogenous serine/cysteine proteinase inhibitor SERPINB3 (squamous cell carcinoma antigen 1, SCCA1) was distinctively upregulated in the basal-like/squamous subtype, known as an aggressive subtype, and this upregulation associated with decreased patient survival in both a test (N=123) and a validation cohort (N=84). In additional investigations of the tumor metabolome and transcriptome using PDAC patient tumors and cell lines, SERPINB3 and the basal-like/squamous subtype showed a robust relationship with upregulated levels of amino acids (e.g., hydroxyproline) whereas SERPINB3 promoted a gene signature indicative of the basal-like/squamous subtype. Additional mechanistic studies revealed that SERPINB3 and hydroxyproline promoted the migration/invasion of PDAC cells. Moreover, SERPINB3 also promoted metastasis in an orthotopic mouse model of PDAC through stromal factors that increased tumor microvessel density. To conclude, inhibiting SERPINB3 function may attenuate disease progression of the basal-like/squamous subtype in PDAC through changes to the tumor stroma and tumor metabolism.

Citation Format: Yuuki Ohara, Wei Tang, Liu Huaitian, Shouhui Yang, Peijun He, Helen Cawley, Paloma Valenzuela, Lin Zhang, Jochen Gaedcke, B. Michael Ghadimi, Matthias M. Gaida, Frank Bergmann, H. Richard Alexander, Nader Hanna, Stefan Ambs, S. Perwez Hussain. SERPINB3 promotes the aggressive basal-like/squamous subtype and correlates with poor prognosis in pancreatic ductal adenocarcinoma through metabolic reprogramming [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6225.

A Stepped Health Services Intervention to Improve Care for Mental and Neurological Diseases: Protocol for a Prospective Cohort Trial

BACKGROUND

Mental and neurological disorders cause a large proportion of morbidity burden and require adequate health care structures. However, deficits in the German health care system like long waiting times for access to specialized care and a lack of coordination between health care providers lead to suboptimal quality of care and elevated health care costs.

OBJECTIVE

To overcome these deficits, we implement and evaluate a unique stepped and coordinated model of care (the Neurologisch-psychiatrische und psychotherapeutische Versorgung [NPPV] program) for patients with mental and neurological diseases.

METHODS

Patients included in the program receive an appropriate treatment according to medical needs in a multiprofessional network of ambulatory health care providers. The therapy is coordinated by a managing physician and complemented by additional therapy modules, such as group therapy, internet-based cognitive behavioral therapy, and a case management. Statutory health insurance (SHI) routine data and data from a longitudinal patient survey will be used to compare the program with regular care and evaluate SHI expenditures and patient-related outcomes. A health care provider survey will evaluate the quality of structure and processes and provider satisfaction. Finally, an analysis of ambulatory claims data and drug prescription data will be used to evaluate if health care providers follow a needs-led approach in therapy. Ethics approval for this trial was obtained from the ethics committee of the chamber of physicians in North Rhine (September 13, 2017, reference No. 2017287).

RESULTS

Patient enrollment of NPPV ended in September 2021. Data analysis has been completed in 2022. The results of this study will be disseminated through scientific publications, academic conferences, and a publicly available report to the German Federal Joint Committee, which is expected to be available in the first half of 2023.

CONCLUSIONS

The NPPV program is the first intervention to implement a stepped model of care for both mental and neurological diseases in Germany. The analysis of several data sources and a large sample size (more than 14,000 patients) enable a comprehensive evaluation of the NPPV program.

TRIAL REGISTRATION

German Clinical Trials Register DRKS00022754; https://tinyurl.com/3mx9pz5z.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/37569.

Presence of low-grade IPMN at the pancreatic transection margin does not have prognostic significance after resection of IPMN-associated pancreatic adenocarcinoma

INTRODUCTION

Resection margin status is a well-established prognosticator in pancreatic cancer. The prognostic impact of IPMN dysplasia at the pancreatic transection margin in IPMN-associated carcinoma (IPMN-Ca) remains unclear, hence institutional practices on additional resections vary.

METHODS

Patients undergoing partial pancreatectomy or attempted partial pancreatectomy converted to total pancreatectomy for IPMN-Ca between 04/2002 and 12/2018 were identified. Final pathology of the definitive pancreatic transection margin was identified. The association between the presence of IPMN dysplasia at the margin and overall survival (OS) was assessed.

RESULTS

Of 302 patients with IPMN-Ca, 181 (59.9%) patients received partial pancreatoduodenectomy, 61 (20.2%) distal pancreatectomy, and 60 (19.9%) were converted to total pancreatectomy. Median OS was 98.6 months in R0 (≥1 mm), 39.3 months in R1 (<1 mm), and 22.0 months in R1(direct) resected patients, respectively (p < 0.0001). No IPMN dysplasia at the definitive margin was present in 103 (34.1%), low-grade in 131 (43.4%), and high-grade/R1 in 8 (2.6%) patients. Low-grade dysplasia or total pancreatectomy were not associated with shorter OS compared to dysplasia-free margin across the entire cohort. Sensitivity analyses confirmed a lack of prognostic relevance of low-grade IPMN dysplasia at the pancreatic margin in R0 resected IPMN-Ca and in R0 resected UICC stage IA/IB IPMN-Ca.

CONCLUSIONS

Low-grade IPMN at the transection margin is not associated with shorter overall survival after partial pancreatectomy for IPMN-Ca. Additional resections for low-grade dysplasia, up to total pancreatectomy do not result in a survival benefit and should be omitted. Due to limited sample size, high-grade dysplasia could not be analyzed.

Abstract A010: Persister cell phenotypes contribute to poor patient outcomes after neoadjuvant chemotherapy in PDAC

The impact of neoadjuvant chemotherapy on tumor cells is largely unknown with resistance to therapy remaining a significant challenge. We analyzed 171 chemo-naïve and post-chemotherapy resected patient samples (chemoradiotherapy excluded) using RNAseq and multiplexed immunofluorescence. Neoadjuvant chemotherapy enriched for distinct neoplastic persister phenotypes expressing Classical and Basal-like biomarkers GATA6 and KRT17. The enrichment of GATA6HiClassical-like and KRT17Hi Basal-like cells in post-chemotherapy patient samples was associated with poor survival after mFOLFIRINOX, but not gemcitabine. CYP3A subfamily enzymes (CYP3A4 and CYP3A5) were expressed in GATA6Hi and KRT17Hi persister cells and can degrade mFOLFIRINOX constituent irinotecan. Taken together these data support a model in which pre-existing subpopulations of GATA6Hi (Classical) and/or KRT17Hi (Basal) neoplastic cells emerge after mFOLFIRINOX treatment by expressing CYP3A. The identification of CYP3A-enabled persister cell phenotypes is an important step in the design of effective therapies to overcome drug-tolerance and prevent recurrence after neoadjuvant therapy.

Citation Format: Xu Zhou, Roma Kurilov, John P. Neoptolemos, Benedikt Brors, Kai Hu, Teresa Peccerella, Jing-Yu An, Stephanie Roessler, Katrin Pfütze, Angela Schulz, Stephan Wolf, Nicolas Hohmann, Ulrike Heger, Oliver Strobel, Simon T Barry, Christoph Springfeld, Christine Tjaden, Frank Bergmann, Markus Büchler, Thilo Hackert, Franco Fortunato, Peter Bailey. Persister cell phenotypes contribute to poor patient outcomes after neoadjuvant chemotherapy in PDAC [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr A010.

IPMN-associated pancreatic cancer: Survival, prognostic staging and impact of adjuvant chemotherapy

BACKGROUND

Intraductal papillary mucinous neoplasm (IPMN)-associated carcinoma is a subtype of pancreatic cancer for which prognostic factors, the validity of the AJCC/UICC staging system and the role of adjuvant chemotherapy remain unknown.

MATERIALS AND METHODS

Clinicopathological, treatment and follow-up data of patients with IPMN-associated carcinoma undergoing resection between 2002 and 2018 were analyzed. Uni- and multivariable survival analyses were performed to identify prognostic factors.

RESULTS

Of 424 patients undergoing resection for IPMN-associated carcinoma, 77% patients had pancreatic ductal adenocarcinoma (IPMN-PDAC) and 23% had colloid carcinoma (IPMN-CC). Compared to IPMN-CC, IPMN-PDAC was diagnosed at more advanced tumor stages, more frequently involved lymph nodes, more frequently showed poor differentiation and were associated with higher rates of R1 resections. Resected IPMN-PDAC showed markedly shorter median overall survival than IPMN-CC (26.7 months vs. 91.3 months). The current AJCC/UICC staging system was validated for IPMN-associated carcinoma and for both of its subtypes. In multivariable analysis age ≥70 years, diabetes mellitus, high levels of Ca 19-9, IPMN-PDAC subtype, G3 tumors and higher AJCC/UICC stage were independently associated with shorter survival. Adjuvant therapy was not associated with improved survival in IPMN-associated carcinoma. Overall survival was comparable in patients receiving vs. not receiving adjuvant therapy.

CONCLUSIONS

Survival after resection of IPMN-associated carcinoma depends on tumor stage, on histologic tumor subtype, grading, and Ca 19-9 levels. The current 8th edition of the AJCC/UICC staging system is applicable for IPMN-associated carcinoma and for both of its subtypes IPMN-PDAC and IPMN-CC. The role of adjuvant therapy for IPMN-associated carcinoma remains unclear.

Actual Five-year Survival After Upfront Resection for Pancreatic Ductal Adenocarcinoma: Who Beats the Odds?

OBJECTIVE

To determine actual five-year survival (5YS) rates associated with a strategy of upfront surgery and adjuvant therapy in pancreatic ductal adenocarcinoma (PDAC).

BACKGROUND

The rate of actual 5YS in PDAC remains controversial. Available data is restricted to cohorts acquired over several decades and series of resection after patient selection by neoadjuvant therapy.

METHODS

All patients undergoing upfront resection for resectable and borderline-resectable PDAC from 10/2001 to 12/2011 were identified from a prospective database. Actual overall survival was assessed after a follow-up of at least 5 years. Uni- and multivariable logistic regression analyses were performed.

RESULTS

Median survival of 937 patients was 22.1 months. The actual 5YS rate was 17.0% (n = 159) including 89 (9.5%) patients without evidence of disease >5 years after resection. 5YS rates in patients with or without adjuvanttherapy were 18.8% vs. 12.2%, respectively. Tumorgrading, number of positive lymph nodes, a context of intraductal papillary mucinous neoplasia, and vascular resections were independently associated with 5YS. Patient-related parameters and CA 19-9 levels were associated with observed survival up to 3 years, but lost relevance thereafter. The extent of lymph node involvement was the strongest predictor of 5YS. Patients with pN0R0 had a 5YS rate of 38.2%. in patients with exclusively favorable factors the observed 5YS rate was above 50%.

CONCLUSIONS

This is the largest series of long-term survivors with histologically confirmed PDAC. With upfront resection and adjuvant therapy an actual overall 5YS rate of 18.8% can be expected. in favorable subgroups actual 5YS is above 50%.

The link between menin and pleiotrophin in the tumor biology of pancreatic neuroendocrine neoplasms

MEN1, which encodes menin protein, is the most frequently mutated gene in pancreatic neuroendocrine neoplasms (pNEN). Pleiotrophin (PTN) was reported being a downstream factor of menin and to promote metastasis in different tumor entities. In this study, the effect of menin and its link to PTN were assessed on features of pNEN cells and outcome of pNEN patients. The expression of menin and PTN in pNEN patient tissues were examined by qRT-PCR and western blot and compared to their metastasis status. Functional assays, including transwell migration/invasion and scratch wound healing assays, were performed on specifically designed CRISPR/Cas9-mediated MEN1-knockout (MEN1-KO) pNEN cell lines (BON1^MEN1-KO and QGP1^MEN1-KO ) to study the metastasis of pNEN. Among 30 menin negative pNEN patients, 21 revealed a strong protein expression of PTN. This combination was associated with metastasis and shorter disease-free survival. Accordingly, in BON1^MEN1-KO and QGP1^MEN1-KO cells, PTN protein expression was positively associated with enhanced cell migration and invasion, which could be reversed by PTN silencing. PTN is a predicting factor of metastatic behavior of menin-deficient-pNEN. In vitro, menin is able to both promote and suppress the metastasis of pNEN by regulating PTN expression depending on the tumoral origin of pNEN cells.

[Rare pancreatic tumors]

Beyond pancreatic ductal adenocarcinoma, which is by far the most frequent pancreatic neoplasm, a great variety of tumors occur in the pancreas. They include solid and cystic masses and epithelial and nonepithelial neoplasms, and they show a great diversity in their biological behavior, ranging from benign tumors to highly aggressive neoplasms. As examples of rare pancreatic tumors, clinical, morphological, and molecular aspects of acinar cell carcinoma, pancreatoblastoma, solid pseudopapillary neoplasm, and serous cystic neoplasms are presented and discussed.

Refined prognostic staging for resected pancreatic cancer by modified stage grouping and addition of tumour grade

BACKGROUND

With changes in T and N categories the 8th edition of the AJCC/UICC TNM staging system for pancreatic cancer resulted in improved prognostic staging, but inconsistencies were observed with specific stage groups. Tumour grading remains disregarded in prognostic staging. We aimed to validate the current staging system and to investigate the possibility of further optimization by integration of grading.

METHODS

1946 patients undergoing upfront surgical resection for pancreatic adenocarcinoma from 10/2001 to 12/2015 were identified from a prospective institutional database. Survival analyses based on the 8th UICC TNM edition were performed and rare TNM subgroups were reallocated based on survival. The impact of tumour grade on stage-specific survival was assessed and a TNMG staging system was developed.

RESULTS

The 8th UICC staging system accurately stratified prognosis except for comparable survival in stages IB (pT2N0M0) and IIA (pT3N0M0). Regrouping of pT3N0M0 and pT1N1M0 to IB and of pT1N2M0 to II resulted in a modified staging system with higher consistency. High tumour grade (G3&G4 vs G1&G2) was associated with a significantly shorter survival in all new stage groups except for stage IV modified UICC. A TNMG-based prognostic stage grouping in which high tumour grade results in grouping with tumours of the next higher pTNM-stage resulted in improvement of prognostication in non-metastatic pancreatic cancer.

CONCLUSIONS

The 8th edition of the UICC TNM staging system leaves room for improvement. A TNMG staging system with adjustments in group-allocation of specific rarely occurring pTNM subgroups and integration of tumour grade results in improved prognostic stratification.

Collagen Organization Does Not Influence T-Cell Distribution in Stroma of Human Pancreatic Cancer

Simple Summary

The excessive desmoplasia is the hallmark of human pancreatic cancer that influences the local T-cell-based immune response. In the present work, the stromal collagen organization in normal and malignant pancreatic tissues as well as its relationsship to T-cell distribution in pancreatic cancer were studied. It was found that differences in collagen organization do not change the spatial orientation of T-cell migration and do not influence the availability of tumor cells for T-cells. The results of the study do not support the concept of use of stroma collagen organization for improvement of spatial T-cell distribution in the tumor.

Abstract

The dominant intrastromal T-cell infiltration in pancreatic cancer is mainly caused by the contact guidance through the excessive desmoplastic reaction and could represent one of the obstacles to an effective immune response in this tumor type. This study analyzed the collagen organization in normal and malignant pancreatic tissues as well as its influence on T-cell distribution in pancreatic cancer. Human pancreatic tissue was analyzed using immunofluorescence staining and multiphoton and SHG microscopy supported by multistep image processing. The influence of collagen alignment on activated T-cells was studied using 3D matrices and time-lapse microscopy. It was found that the stroma of malignant and normal pancreatic tissues was characterized by complex individual organization. T-cells were heterogeneously distributed in pancreatic cancer and there was no relationship between T-cell distribution and collagen organization. There was a difference in the angular orientation of collagen alignment in the peritumoral and tumor-cell-distant stroma regions in the pancreatic ductal adenocarcinoma tissue, but there was no correlation in the T-cell densities between these regions. The grade of collagen alignment did not influence the directionality of T-cell migration in the 3D collagen matrix. It can be concluded that differences in collagen organization do not change the spatial orientation of T-cell migration or influence stromal T-cell distribution in human pancreatic cancer. The results of the present study do not support the rationale of remodeling of stroma collagen organization for improvement of T-cell–tumor cell contact in pancreatic ductal adenocarcinoma.

Abstract 2860: NOSTRIN-induced inhibition of pancreatic cancer progression involves CCBE1 in an eNOS-independent manner

NOSTRIN represses disease aggressiveness in pancreatic cancer by suppressing eNOS-mediated NO production. We have further explored the NOSTRIN-mediated eNOS-independent pathways that contribute to its tumor inhibitory function. Gene expression analysis identified CCBE1 as a target of NOSTRIN. We provide experimental and clinical evidence that NOSTRIN functions a negative regulator in pancreatic cancer progression through inhibiting the expression of CCBE1. Furthermore, CCBE1 expression is regulated by NOSTRIN independent of eNOS. NOSTRIN attenuates protein-protein interaction between ABL1 and PKD2 resulting in the suppression of PKD2 and NFkB p50 activation. Inhibition of PKD2 and NFkB p50 activation results in the suppression of CTCF, which is as a transcription factor of CCBE1. CCBE1 expression is decreased as the down-stream gene of CTCF. Taken together, CCBE1 may be a potential therapeutic target in pancreatic cancer.

Citation Format: Lin Zhang, Shouhui Yang, Limin Wang, Peijun He, Ohara Yuuki, Paloma Valenzuela, Wei Tang, Jochen Gaedcke, B. Michael Ghadim, Matthias M. Gaida, Frank Bergmann, H. Richard Alexander, Nader Hanna, Brid M Ryan, S. Perwez Hussain. NOSTRIN-induced inhibition of pancreatic cancer progression involves CCBE1 in an eNOS-independent manner [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2860.

Impact of EGFR and EGFR ligand expression on treatment response in patients with metastatic colorectal cancer

Up to 50% of patients with colorectal cancer (CRC) have either synchronous or metachronous hepatic metastases in the course of their disease. Patients with metastatic CRC (mCRC) whose tumors express wild-type KRAS benefit from treatment with monoclonal antibodies (such as cetuximab or panitumumab) that target the epidermal growth factor receptor (EGFR). However, the therapeutic response to these antibodies is variable, and further predictive models are required. The present study examined whether expression of different EGFRs or their ligands in tumors was associated with the response to cetuximab treatment. Tumor tissues, collected during liver resection in 28 patients with mCRC, were analyzed. The protein expression levels of EGFR/ErbB1, ErbB2, ErbB3 and the EGFR ligands heregulin and amphiregulin were determined using Luminex 200^® and enzyme-linked immunosorbent assays. Computed tomography or magnetic resonance imaging was performed 4 weeks before and 6-8 weeks after treatment with cetuximab. Response to treatment was assessed using the response evaluation criteria for solid tumors (RECIST). The association between the protein expression levels of different EGFRs and their ligands with RECIST criteria was then analyzed to determine whether these protein levels could predict the treatment response to cetuximab. A total of 12 patients exhibited a partial response, 9 exhibited stable disease and 7 exhibited progressive disease after cetuximab therapy according to RECIST. The expression levels of EGFRs (EGFR/ErbB1, ErbB2 and ErbB3) and their ligands (heregulin and amphiregulin) were not significantly associated with the response to cetuximab therapy. Therefore, the present study indicated that EGFR or EGFR ligand expression did not predict treatment response in patients with CRC with liver metastases following cetuximab therapy.

KRAS/GNAS-testing by highly sensitive deep targeted next generation sequencing improves the endoscopic ultrasound-guided workup of suspected mucinous neoplasms of the pancreas

Pancreatic cysts or dilated pancreatic ducts are often found by cross-sectional imaging, but only mucinous lesions can become malignant. Therefore, distinction between mucinous and non-mucinous lesions is crucial for adequate patient management. We performed a prospective study including targeted next generation sequencing (NGS) of cell-free DNA in the diagnostic endoscopic ultrasound (EUS)-guided workup. Pancreatic cyst(s) or main duct fluid obtained by EUS-guided FNA was analysed by carcinoembryonic antigen (CEA), cytology and deep targeted NGS of 14 known gastrointestinal cancer genes (AKT1, BRAF, CTNNB1, EGFR, ERBB2, FBXW7, GNAS, KRAS, MAP2K1, NRAS, PIK3CA, SMAD4, TP53, APC) with a limit of detection down to variant allele frequency of 0.01%. Results were correlated to histopathology and clinical follow-up. One hundred and thirteen patients with pancreatic cyst(s) and/or a dilated pancreatic main duct (≥5 mm) were screened. Sixty-six patients had to be excluded, mainly due to inoperability or small cyst size (≤10 mm). Forty-seven patients were enrolled for further analysis. A final diagnosis was available in 27 cases including 8 negative controls. In 43/47 (91.5%) of patients a KRAS- and/or GNAS-mutation was diagnosed by NGS. 27.0% of the KRAS-mutated and 10.0% of the GNAS-mutated lesions harbored multiple mutations. KRAS/GNAS-testing by NGS, cytology, and CEA had a sensitivity and specificity of 94.7/100%, 38.1/100%, and 42.1/75.0%, respectively. KRAS/GNAS-testing was significantly superior to CEA (P = .0209) and cytology (P = .0016). In conclusion, KRAS/GNAS-testing by deep targeted NGS is a suitable method to distinguish mucinous from non-mucinous pancreatic lesions, suggesting its usage as a single diagnostic test. Results must be confirmed in a larger cohort.

Self-Assembled Pyrene Stacks and Peptide Monolayers Tune the Electronic Properties of Functionalized Electrolyte-Gated Graphene Field-Effect Transistors

Aromatic molecules such as pyrenes are a unique class of building units for graphene functionalization, forming highly ordered π-π stacks while peptides provide more complex, biocompatible linkers. Understanding the adsorption and stacking behavior of these molecules and their influence on material properties is an essential step in enabling highly repeatable 2D material-based applications, such as biosensors, gas sensors, and solar cells. In this work, we characterize pyrene and peptide self-assembly on graphene substrates using fluorescence microscopy, atomic force microscopy and electrolyte-gated field-effect measurements supported by quantum mechanical calculations. We find distinct binding and assembly modes for pyrenes versus peptides with corresponding distinct electronic signatures in their characteristic charge neutrality point and field-effect slope responses. Our data demonstrates that pyrene- and peptide-based self-assembly platforms can be highly beneficial for precisely customizing graphene electronic properties for desired device technologies such as transport-based biosensing graphene field-effect transistors.

Radiological evaluation of pancreatic cancer: What is the significance of arterial encasement >180° after neoadjuvant treatment?

PURPOSE

This study aimed to evaluate contrast-enhanced computed tomography (CE-CT) features for prediction of arterial tumor invasion in pancreatic cancer (PDAC) patients in the event of arterial encasement >180° after neoadjuvant (radio-)chemotherapy (NAT).

METHODS

Seventy PDAC patients with seventy-five arteries showing encasement >180° after completion of NAT were analyzed. All patients underwent surgical exploration with either tumor resection including arterial resection, periadventitial dissection (arterial divestment) or confirmation of locally irresectable disease. CE-CT scans were assessed regarding tumor extent and artery-specific imaging features. The results were analyzed on a per-artery basis. Based on the intraoperative and histopathological findings, encased arteries were classified as either invaded or non-invaded.

RESULTS

Eighteen radiologically encased arteries were resected; of these, nine had pathologic evidence for tumor invasion. In 42 encased arteries, the tumor could be removed by arterial divestment. In 13 patients with 15 encased arteries, the tumor was deemed technically irresectable. Median tumor size, length of solid soft tissue contact, and degree of circumferential contiguity by solid soft tissue along the artery in CE-CT were significantly lower in the non-invaded than in the invaded artery group (p ≤ 0.017). Imaging features showed moderate accuracies for prediction of arterial invasion (≤72.0 %). The thresholds ≤26 mm for post-NAT solid soft tissue contact and ≤270° for circumferential contiguity by solid soft tissue had high negative predictive values (≥87.5 %).

CONCLUSION

Although post-NAT prediction of arterial invasion remains difficult, arteries with ≤270° contiguity by soft tissue and arteries with ≤26 mm length of solid soft tissue contact are unlikely to be invaded, with possible implications for surgical planning.

Epithelial-to-Mesenchymal Transition in Pancreatic Cancer is associated with Restricted Water Diffusion in Diffusion-Weighted Magnetic Resonance Imaging

Purpose: This study aimed to evaluate the potential of diffusion-weighted magnetic resonance imaging (DW-MRI) as imaging biomarker for epithelial-to-mesenchymal transition (EMT) in pancreatic ductal adenocarcinoma (PDAC).

Methods: In forty-two patients, preoperative apparent diffusion coefficient (ADC) values of therapy-naive PDAC were compared with immunohistochemical expression profiles of the epithelial marker E-cadherin as well as mesenchymal transcription factors Runt-related transcription factor 2 (Runx2) and Zinc finger E-box-binding homeobox 1 (Zeb1), as determined by Allred immunoreactivity score.

Results: We observed a significant positive rank correlation between the ADC and the E-cadherin Allred score (ρ = 0.553, p < 0.001) and significant negative rank correlations between the ADC and the Runx2 Allred score (ρ = -0.526, p < 0.001) as well as the Zeb1 Allred score (ρ = -0.710, p < 0.001). Compared to tumors with low ADC values < 1.3 µm²/s, tumors with ADC values ≥ 1.3 µm²/s had significantly higher Allred scores for E-cadherin (median, 4 versus 5; p < 0.001) and significantly lower Allred scores for Runx2 (median, 3 versus 2; p = 0.003) as well as Zeb1 (median, 4 versus 0; p < 0.001).

Conclusion: In PDAC, tumor plasticity in terms of EMT is well reflected by ADC values from DW-MRI. In the near future, DW-MRI could be beneficial for identification of PDAC patients that might profit from personalized EMT-targeted therapies.