International consensus on the management of metastatic gastric cancer: step by step in the foggy landscape : Bertinoro Workshop, November 2022

BACKGROUND

Many gastric cancer patients in Western countries are diagnosed as metastatic with a median overall survival of less than twelve months using standard chemotherapy. Innovative treatments, like targeted therapy or immunotherapy, have recently proved to ameliorate prognosis, but a general agreement on managing oligometastatic disease has yet to be achieved. An international multi-disciplinary workshop was held in Bertinoro, Italy, in November 2022 to verify whether achieving a consensus on at least some topics was possible.

METHODS

A two-round Delphi process was carried out, where participants were asked to answer 32 multiple-choice questions about CT, laparoscopic staging and biomarkers, systemic treatment for different localization, role and indication of palliative care. Consensus was established with at least a 67% agreement.

RESULTS

The assembly agreed to define oligometastases as a "dynamic" disease which either regresses or remains stable in response to systemic treatment. In addition, the definition of oligometastases was restricted to the following sites: para-aortic nodal stations, liver, lung, and peritoneum, excluding bones. In detail, the following conditions should be considered as oligometastases: involvement of para-aortic stations, in particular 16a2 or 16b1; up to three technically resectable liver metastases; three unilateral or two bilateral lung metastases; peritoneal carcinomatosis with PCI ≤ 6. No consensus was achieved on how to classify positive cytology, which was considered as oligometastatic by 55% of participants only if converted to negative after chemotherapy.

CONCLUSION

As assessed at the time of diagnosis, surgical treatment of oligometastases should aim at R0 curativity on the entire disease volume, including both the primary tumor and its metastases. Conversion surgery was defined as surgery on the residual volume of disease, which was initially not resectable for technical and/or oncological reasons but nevertheless responded to first-line treatment.

Antitumor Immunity Mediated by Photodynamic Therapy Using Injectable Chitosan Hydrogels for Intratumoral and Sustained Drug Delivery

Photodynamic therapy (PDT) is an anticancer therapy with proven efficacy; however, its application is often limited by prolonged skin photosensitivity and solubility issues associated with the phototherapeutic agents. Injectable hydrogels which can effectively provide intratumoral delivery of photosensitizers with sustained release are attracting increased interest for photodynamic cancer therapies. However, most of the hydrogels for PDT applications are based on systems with high complexity, and often, preclinical validation is not provided. Herein, we provide a simple and reliable pH-sensitive hydrogel formulation that presents appropriate rheological properties for intratumoral injection. For this, Temoporfin (m-THPC), which is one of the most potent clinical photosensitizers, was chemically modified to introduce functional groups that act as cross-linkers in the formation of chitosan-based hydrogels. The introduction of -COOH groups resulted in a water-soluble derivative, named PS2, that was the most promising candidate. Although PS2 was not internalized by the target cells, its extracellular activation caused effective damage to the cancer cells, which was likely mediated by lipid peroxidation. The injection of the hydrogel containing PS2 in the tumors was monitored by high-frequency ultrasounds and in vivo fluorescence imaging which confirmed the sustained release of PS2 for at least 72 h. Following local administration, light exposure was conducted one (single irradiation protocol) or three (multiple irradiation protocols) times. The latter delivered the best therapeutic outcomes, which included complete tumor regression and systemic anticancer immune responses. Immunological memory was induced as ∼75% of the mice cured with our strategy rejected a second rechallenge with live cancer cells. Additionally, the failure of PDT to treat immunocompromised mice bearing tumors reinforces the relevance of the host immune system. Finally, our strategy promotes anticancer immune responses that lead to the abscopal protection against distant metastases.

Visceral adipose tissue secretome from early and late-stage oesophageal cancer patients differentially affects effector and regulatory T cells

AIM

Visceral obesity is a key risk factor in the development of oesophagogastric junctional adenocarcinoma (OGJ), predominantly via generation of systemic low grade inflammation. Obesity-induced inflammation promotes resistance to current standards of care, enhancing tumour cell growth and survival. This study investigates the effect of the visceral adipose tissue secretome from OGJ patients with early versus advanced tumours on T-cell immunity and the role of immune checkpoint blockade in enhancing anti-tumour immunity.

METHODS AND RESULTS

Visceral adipose conditioned media (ACM) from both early and late-stage OGJ patients significantly altered T cell activation status, upregulating co-stimulatory marker CD27 on T cells. ACM from both early and late-stage OGJ patients significantly altered immune checkpoint expression profiles downregulating immune checkpoints (ICs) on the surface of dual Th1/17-like and Th17-like cells and upregulating ICs on the surface of Th1-like cells and Treg cells. ACM derived from early-stage OGJ patients but not late-stage OGJ patients increased IFN-γ production by T cells. The addition of immune checkpoint blockers (ICBs) did not increase IFN-γ production by T cells in the presence of late-stage ACM, collectively highlighting the dichotomous immunostimulatory effect of early-stage ACM and immune-inhibitory effect of late-stage ACM. Interestingly, ACM from early-stage OGJ patients was more pro-inflammatory than ACM from late-stage patients, reflected by decreased levels of IL-17A/F, TNF-α, IL-1RA and IL-5.

CONCLUSION

The ACM-induced upregulation of ICs on T cells highlights a therapeutic vulnerability that could be exploited by ICBs to harness anti-cancer immunity and improve clinical outcomes for OGJ patients. Schematic workflow - (A) visceral adipose tissue was taken from OAC patients at time of surgery and cultured for 72 h in media. (B) The harvested ACM was co-cultured with healthy donor PBMCs that were concurrently activated with anti-CD3/28 for 48 h and T cell immunophenotyping was carried out by flow cytometry. Key findings - (A) Early and late stage ACM enhanced a Th1-like phenotype and upregulated CTLA-4 on Th1-like cells. A Th17-like phenotype was also enhanced in addition with a Treg-like phenotype. CTLA-4 and PD-L1 were upregulated on the surface of Treg-like cells. (B) ICB-attenuated IL-17 production by T cells. However, ACM attenuated ICB-mediated reduction in IL-10 production by T cells. Higher levels of pro-inflammatory factors were found in early stage ACM compared with late stage ACM.

Nutrient deprivation and hypoxia alter T cell immune checkpoint expression: potential impact for immunotherapy

Aim

Use of immune checkpoint blockade to enhance T cell-mediated immunity within the hostile tumour microenvironment (TME) is an attractive approach in oesophageal adenocarcinoma (OAC). This study explored the effects of the hostile TME, including nutrient deprivation and hypoxia, on immune checkpoint (IC) expression and T cell phenotypes, and the potential use of nivolumab to enhance T cell function under such conditions.

Methods and Results

ICs were upregulated on stromal immune cells within the tumour including PD-L2, CTLA-4 and TIGIT. OAC patient-derived PBMCs co-cultured with OE33 OAC cells upregulated LAG-3 and downregulated the co-stimulatory marker CD27 on T cells, highlighting the direct immunosuppressive effects of tumour cells on T cells. Hypoxia and nutrient deprivation altered the secretome of OAC patient-derived PBMCs, which induced upregulation of PD-L1 and PD-L2 on OE33 OAC cells thus enhancing an immune-resistant phenotype. Importantly, culturing OAC patient-derived PBMCs under dual hypoxia and glucose deprivation, reflective of the conditions within the hostile TME, upregulated an array of ICs on the surface of T cells including PD-1, CTLA-4, A2aR, PD-L1 and PD-L2 and decreased expression of IFN-γ by T cells. Addition of nivolumab under these hostile conditions decreased the production of pro-tumorigenic cytokine IL-10.

Conclusion

Collectively, these findings highlight the immunosuppressive crosstalk between tumour cells and T cells within the OAC TME. The ability of nivolumab to suppress pro-tumorigenic T cell phenotypes within the hostile TME supports a rationale for the use of immune checkpoint blockade to promote anti-tumour immunity in OAC.

Graphical abstract

Study schematic: (A) IC expression profiles were assessed on CD45+ cells in peripheral whole blood and infiltrating tumour tissue from OAC patients in the treatment-naïve setting. (B) PBMCs were isolated from OAC patients and expanded ex vivo for 5 days using anti-CD3/28 + IL-2 T cell activation protocol and then co-cultured for 48 h with OE33 cells. T cell phenotypes were then assessed by flow cytometry. (C) PBMCs were isolated from OAC patients and expanded ex vivo for 5 days using anti-CD3/28 + IL-2 T cell activation protocol and then further cultured under conditions of nutrient deprivation or hypoxia for 48 h and T cell phenotypes were then assessed by flow cytometry. Key findings: (A) TIGIT, CTLA-4 and PD-L2 were upregulated on CD45+ immune cells and CTLA-4 expression on CD45+ cells correlated with a subsequent decreased response to neoadjuvant regimen. (B) Following a 48 h co-culture with OE33 cells, T cells upregulated LAG-3 and decreased CD27 co-stimulatory marker. (C) Nutrient deprivation and hypoxia upregulated a range of ICs on T cells and decreased IFN-γ production by T cells. Nivolumab decreased IL-10 production by T cells under nutrient deprivation-hypoxic conditions.

Prevalence, nature and trajectory of dysphagia postoesophageal cancer surgery: a prospective longitudinal study protocol

INTRODUCTION

Dysphagia is a common problem following oesophagectomy, and is associated with aspiration pneumonia, malnutrition, weight loss, prolonged enteral feeding tube dependence, in addition to an extended in-hospital stay and compromised quality of life (QOL). To date, the prevalence, nature and trajectory of post-oesophagectomy dysphagia has not been systematically studied in a prospective longitudinal design. The study aims (1) to evaluate the prevalence, nature and trajectory of dysphagia for participants undergoing an oesophagectomy as part of curative treatment, (2) to determine the risk factors for, and post-operative complications of dysphagia in this population and (3) to examine the impact of oropharyngeal dysphagia on health-related QOL across time points.

METHODS AND ANALYSIS

A videofluoroscopy will be completed and analysed on both post-operative day (POD) 4 or 5 and at 6-months post-surgery. Other swallow evaluations will be completed preoperatively, POD 4 or 5, 1-month and 6-month time points will include a swallowing screening test, tongue pressure measurement, cough reflex testing and an oral hygiene evaluation. Nutritional measurements will include the Functional Oral Intake Scale to measure feeding tube reliance, Malnutrition Screening Tool and the Strength, Assistance With Walking, Rise From a Chair, Climb Stairs and Falls questionnaire. The Reflux Symptom Index will be administered to investigate aerodigestive symptoms commonly experienced by adults post-oesophagectomy. Swallowing-related QOL outcome measures will be determined using the European Organisation for Research and Treatment of Cancer QLQ-18, MD Anderson Dysphagia Inventory and the Swallowing Quality of Life Questionnaire.

ETHICS AND DISSEMINATION

Ethical approval has been granted by the Tallaght University Hospital/St. James' Hospital Research Ethics Committee (JREC), Dublin, Ireland (Ref. No. 2021-Jul-310). The study results will be published in peer-reviewed journals and presented at national and international scientific conferences.

Unraveling the Pivotal Role of Atropisomerism for Cellular Internalization

The intrinsic challenge of large molecules to cross the cell membrane and reach intracellular targets is a major obstacle for the development of new medicines. We report how rotation along a single C-C bond, between atropisomers of a drug in clinical trials, improves cell uptake and therapeutic efficacy. The atropisomers of redaporfin (a fluorinated sulfonamide bacteriochlorin photosensitizer of 1135 Da) are separable and display orders of magnitude differences in photodynamic efficacy that are directly related to their differential cellular uptake. We show that redaporfin atropisomer uptake is passive and only marginally affected by ATP depletion, plasma proteins, or formulation in micelles. The α₄ atropisomer, where meso-phenyl sulfonamide substituents are on the same side of the tetrapyrrole macrocycle, exhibits the highest cellular uptake and phototoxicity. This is the most amphipathic atropisomer with a conformation that optimizes hydrogen bonding (H-bonding) with polar head groups of membrane phospholipids. Consequently, α₄ binds to the phospholipids on the surface of the membrane, flips into the membrane to adopt the orientation of a surfactant, and eventually diffuses to the interior of the cell (bind-flip mechanism). We observed increased α₄ internalization by cells of the tumor microenvironment in vivo and correlated this to the response of photodynamic therapy when tumor illumination was performed 24 h after α₄ administration. These results show that properly orientated aryl sulfonamide groups can be incorporated into drug design as efficient cell-penetrating motifs in vivo and reveal the unexpected biological consequences of atropisomerism.

Abstract 1990: Exploring the immune-metabolic mechanisms of adipose tissue in oesophageal adenocarcinoma

Background: Oesophageal Adenocarcinoma (OAC) is the most strongly associated cancer with obesity. Approximately 75% of OAC patients are obese which results in chronic systemic low-grade inflammation, which is believed to drive carcinogenesis as well as influencing radiation treatment response. Adipose tissue is a regulatory organ with many downstream effects which are still not understood. This study aims to elucidate what influence adipose tissue metabolism and secretome have in treatment resistance and whether obesity alters this response.

Methods: Following patient consent, ex-vivo Visceral Adipose Tissue (VAT) explants were exposed to increasing doses of radiation with/without Palmitate and Oleate. Agilent Seahorse Xfe24 was used to measure oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) in VAT explants and mitochondrial metabolic parameters in dendritic cells (DCs) following treatment with Adipose Conditioned Media (ACM). Levels of DC maturation following irradiated ACM exposure and Macrophage (Mɸ) polarisation following ACM or Tumour Conditioned Media (TCM) exposure were analyzed by flow cytometry. Irradiated ACM and TCM were analyzed via MSD 54plex ELISA to assess secreted factors on angiogenic, chemokine, cytokine, inflammatory, TH17 or vascular injury panels.

Results: VAT explant energy metabolism showed a significant increase for OCR and ECAR with obesity and increasing radiation exposure however OCR was significantly decreased following Palmitate treatment compared with untreated and Oleate treated adipose explants (p<0.05). DCs treated with iACM showed decreased expression of CD11c, CD80, CD86, HLA-DR, CD40 and PD-L1 with increasing radiation in a dose-dependent manner and decreased HLA-DR and CD54 following ACM exposure from obese versus non-obese patients (p<0.05). Mɸ showed increased expression of pro-inflammatory and anti-inflammatory markers following ACM exposure but following TCM exposure only anti-inflammatory markers were increased (p<0.05). DCs showed altered Proton Leak, Basal and ATP linked respiration following exposure to ACM (p<0.05). Altered secretion of proinflammatory mediators was observed from the obese adipose secretome compared with non-obese patients and with increasing radiation doses (p<0.05).

Conclusion: We have demonstrated that obesity and increasing radiation doses can significantly alter the immune-metabolic influences of adipose tissue and further studies are profiling the lipidomic and metabolomic landscape of the adipose secretome. Alterations in the secretome of adipose tissue could potentiate the tumor microenvironment and deleteriously affect immune cell function therefore further interrogation is required to fully elucidate the influence adipose tissue may have in treatment response.

Citation Format: Fiona O'Connell, Eimear Mylod, Ailsing B. Heeran, Noel E. Donlon, Maria Davern, Christine Butler, Anshul Bhardwaj, Claire Donohoe, Narayanasamy Ravi, John V. Renyolds, Margaret R. Dunne, Helen M. Roche, Jacintha O'Sullivan. Exploring the immune-metabolic mechanisms of adipose tissue in oesophageal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1990.

Impact of radiotherapy on the immune landscape in oesophageal adenocarcinoma

BACKGROUND

In the contemporary era of cancer immunotherapy, an abundance of clinical and translational studies have reported radiotherapy (RT) and immunotherapies as a viable option for immunomodulation of many cancer subtypes, with many related clinical trials ongoing. In locally advanced disease, chemotherapy or chemoradiotherapy followed by surgical excision of the tumour remain the principal treatment strategy in oesophageal adenocarcinoma (OAC), however, the use of the host immune system to improve anti-tumour immunity is rapidly garnering increased support in the curative setting.

AIM

To immunophenotype OAC patients’ immune checkpoint (IC) expression with and without radiation and evaluate the effects of checkpoint blockade on cell viability.

METHODS

In the contemporary era of cancer immunotherapy, an abundance of studies have demonstrated that combination RT and IC inhibitors (ICIs) are effective in the immunomodulation of many cancer subtypes, with many related clinical trials ongoing. Although surgical excision and elimination of tumour cells by chemotherapy or chemoradiotherapy remains the gold standard approach in OAC, the propagation of anti-tumour immune responses is rapidly garnering increased support in the curative setting. The aim of this body of work was to immunophenotype OAC patients’ IC expression with and without radiation and to establish the impact of checkpoint blockade on cell viability. This study was a hybrid combination of in vitro and ex vivo models. Quantification of serum immune proteins was performed by enzyme-linked immunosorbent assay. Flow cytometry staining was performed to evaluate IC expression for in vitro OAC cell lines and ex vivo OAC biopsies. Cell viability in the presence of radiation with and without IC blockade was assessed by a cell counting kit-8 assay.

RESULTS

We identified that conventional dosing and hypofractionated approaches resulted in increased IC expression (PD-1, PD-L1, TIM3, TIGIT) in vitro and ex vivo in OAC. There were two distinct subcohorts with one demonstrating significant upregulation of ICs and the contrary in the other cohort. Increasing IC expression post RT was associated with a more aggressive tumour phenotype and adverse features of tumour biology. The use of anti-PD-1 and anti-PD-L1 immunotherapies in combination with radiation resulted in a significant and synergistic reduction in viability of both radiosensitive and radioresistant OAC cells in vitro. Interleukin-21 (IL-21) and IL-31 significantly increased, with a concomitant reduction in IL-23 as a consequence of 4 Gray radiation. Similarly, radiation induced an anti-angiogenic tumour milieu with reduced expression of vascular endothelial growth factor-A, basic fibroblast growth factor, Flt-1 and placental growth factor.

CONCLUSION

The findings of the current study demonstrate synergistic potential for the use of ICIs and ionising radiation to potentiate established anti-tumour responses in the neoadjuvant setting and is of particular interest in those with advanced disease, adverse features of tumour biology and poor treatment responses to conventional therapies.

Cooperation between chemotherapy and immune checkpoint blockade to enhance anti-tumour T cell immunity in oesophageal adenocarcinoma

Response rates to immune checkpoint blockade (ICB) remain low in oesophageal adenocarcinoma (OAC). Combining ICB with immunostimulatory chemotherapies to boost response rates is an attractive approach for converting 'cold' tumours into 'hot' tumours. This study profiled immune checkpoint (IC) expression on circulating and tumour-infiltrating T cells in OAC patients and correlated these findings with clinical characteristics. The effect of first-line chemotherapy regimens (FLOT and CROSS) on anti-tumour T cell immunity was assessed to help guide design of ICB and chemotherapy combinations in the first-line setting. The ability of ICB to enhance lymphocyte-mediated cytolysis of OAC cells in the absence and presence of post-FLOT and post-CROSS chemotherapy tumour cell secretome was assessed by a CCK-8 assay. Expression of ICs on T cells positively correlated with higher grade tumours and a subsequent poor response to neoadjuvant treatment. First-line chemotherapy regimens substantially altered IC expression profiles of T cells increasing PD-1, A2aR, KLRG-1, PD-L1, PD-L2 and CD160 and decreasing TIM-3 and LAG-3. In addition, pro-inflammatory T cell cytokine profiles were enhanced by first-line chemotherapy regimens. T cell activation status was significantly altered; both chemotherapy regimens upregulated co-stimulatory markers ICOS and CD69 yet downregulated co-stimulatory marker CD27. However, ICB attenuated chemotherapy-induced downregulation of CD27 on T cells and promoted differentiation of effector memory T cells into a terminally differentiated state. Importantly, dual nivolumab-ipilimumab treatment increased lymphocyte-mediated cytolysis of OAC cells, an effect further enhanced in the presence of post-FLOT tumour cell secretome. These findings justify a rationale to administer ICBs concurrently with first-line chemotherapies.

OUP accepted manuscript

Background

Healthcare requires patient feedback to improve outcomes and experience. This study undertook a systematic review of the depth, variability, and digital suitability of current patient-reported outcome measures (PROMs) in patients undergoing laparoscopic cholecystectomy.

Methods

A PROSPERO-registered (registration number CRD42021261707) systematic review was undertaken for all relevant English language articles using PubMed version of MEDLINE, Scopus, and Web of Science electronic databases in June 2021. The search used Boolean operators and wildcards and included the keywords: laparoscopic cholecystectomy AND patient outcome OR patient-reported outcome OR patient-reported outcome measure OR PRO OR PROM. Medical Subjects Heading terms were used to search PubMed and Scopus. Articles published from 1 January 2011 to 2 June 2021 were included.

Results

A total of 4960 individual articles were reviewed in this study, of which 44 were found to evaluate PROMs in patients undergoing laparoscopic cholecystectomy and underwent methodological index for non-randomized studies (MINORS) grading. Twenty-one articles spanning 19 countries and four continents met all inclusion criteria and were included in the qualitative data synthesis. There was significant heterogeneity in PROMs identified with eight different comprehensive PROM tools used in the 21 studies. There was wide variation in the time points at which PROMs were recorded. Fourteen of 21 studies recorded PROMs before and after surgery, and 7 of 21 recorded PROMs only after surgery. Follow-up intervals ranged from 3 days to 2 years after surgery.

Conclusions

This study identified that while post-laparoscopic cholecystectomy PROMs are infrequently measured currently, tools are widely available to achieve this in clinical practice. PROMs may not capture all the outcomes but should be incorporated into future cholecystectomy outcome research. The EQ-5D™ (EuroQoL Group, Rotterdam, the Netherlands) provides a simple platform for the modern digital era.

P-O02 Management Experiences of Post-gastrectomy Severe Alkaline Reflux Oesophagitis

Background

Alkaline reflux oeosphagitis is a recognized complication of procedures that compromise the lower oesophageal sphincter (LES), including gastrectomy. Incidence of reflux is dependent on the reconstructive procedure with Roux-en-Y esophagojejunostomy commonly accepted as the optimal method. The authors report their experience of 6 patients who underwent remedial intervention for severe alkaline reflux esophagitis following gastric surgery.  

Methods

A retrospective review of 6 patients who had underwent a previous gastric procedure and developed symptoms of gastroesophageal reflux disease, over a 6-year period (2014-2020). Reflux symptoms were diagnosed by clinical history, radiology, endoscopy and esophageal manometry prior to proceeding to surgical reflux control. Post-operative outcomes following anti-reflux surgery were assessed by means of serial outpatient assessments and endoscopy. 

Results

Six patients were included in this report, 4 males and 2 females with an average age of 73 years (range 58-91). Primary diagnoses encompassed; 4 gastric adenocarcinomas, 1 gastric neuroendocrine tumour and 1 patient with debilitating gastric antral vascular ectasia (GAVE) syndrome. Four patients underwent total gastrectomy and 2 subtotal gastrectomy with Roux-en-Y reconstruction. Onset of post-operative reflux symptoms ranged from 2-weeks to 3-years. Failing medical management, all patients underwent jejunojejunal anastomosis and Roux limb length revision with surgical jejunostomy. At follow up 5 patients had some degree of symptom resolution; 3 complete resolution, 2 initial resolution and 1 with unresolved symptoms.

Conclusions

Severe alkaline reflux oesophagitis is a recognized complication of gastric procedures compromising the LES. The authors report our experience of managing this complication following gastrectomy with jejunojejunal anastomosis and Roux limb length revision, with a majority of patients having improvement in if not complete resolution of reflux symptoms.

P-OGC11 Vitamin B12 supplementation post gastrectomy. A service audit in St. James’s hospital, Dublin

Background

Vitamin B12 deficiency is a well described complication post gastrectomy. It is caused by the loss of parietal cell mass leading to megaloblastic anaemia and possible long term neurological symptoms. Treatment can be with standardised replacement regimens or to monitor B12 levels and replace as required.  This study assesses patient understanding of and compliance with B12 supplementation guidelines post total and subtotal gastrectomy. 

Methods

125 patients who underwent gastrectomy between 2010-2020 were available for study (86 total gastrectomies, 39 subtotal gastrectomies).  Patient data was collected by review of the hospital electronic records and individual phone calls. Patients were asked standardised questions to elicit knowledge of the importance of B12 supplementation and compliance with supplementation.

Results

92% (79/86) of total gastrectomy patients reported compliance in regular parenteral B12 supplementation.  Compliance was significantly lower for subtotal gastrectomies  for checking and/or replacing their vitamin B12 at 53.8% (21/39) (p < 0.001). 62.6% of patients stated that they knew it was important to supplement B12 post gastrectomy.  37.8% of participants could explain why this was important and 14.8% had any knowledge of the complications of vitamin B12 deficiency. Patients who were compliant with B12 supplementation had an improved understanding of why supplementation was important compared to those who did not.

Conclusions

Regular monitoring and supplementation of vitamin B12 levels is important post gastrectomy.  This study demonstrates good compliance in those undergoing total gastrectomy.  Patient understanding correlates with compliance, suggesting that patient education and knowledge reinforcement may be key to compliance with vitamin B12 supplementation.

Steric Repulsion Induced Conformational Switch in Supramolecular Structures

Inspired by the rigidified architecture of ‘picket‐fence’ systems, we propose a strategy utilizing strain to impose intramolecular tension in already peripherally overcrowded structures leading to selective atropisomeric conversion. Employing this approach, tuneable shape‐persistent porphyrin conformations were acquired exhibiting distinctive supramolecular nanostructures based on the orientation of the peripheral groups. The intrinsic assemblies driven by non‐covalent bonding interactions form supramolecular polymers while encapsulating small molecules in parallel channels or solvent‐accessible voids. The developed molecular strain engineering methodologies combined with synthetic approaches have allowed the introduction of the pivalate units creating a highly strained molecular skeleton. Changes in the absorption spectrum indicated the presence of severe steric repulsions between the peripheral groups which were confirmed by single crystal X‐ray analysis. To release the steric strain introduced by the peripheral units, thermal equilibration strategies were used to selectively convert the most abundant atropisomer to the desirable minor one.

C-Reactive Protein and C-Reactive Protein-Based Scores to Predict Survival in Esophageal and Junctional Adenocarcinoma: Systematic Review and Meta-Analysis

BACKGROUND

Esophageal adenocarcinoma (EAC) has a poor prognosis; predictive markers of prognosis would facilitate advances in personalized therapy. C-reactive protein (CRP) and CRP-based scores are increasingly recommended across oncology; however, their role and value in EAC is unclear. This systematic review and meta-analysis examined CRP cut-point and scores and how they may best be applied in predicting survival in EAC.

METHODS

A systematic literature search was conducted in EMBASE, Medline, Web of Science, Cochrane, Scopus and CINAHL databases, from inception to 1st October 2020. Studies reporting data from adults with EAC including adenocarcinoma of the gastro-esophageal junction (AEG), pre-treatment CRP or CRP-based score and Hazard Ratio (HR) for survival were included. QUIPS tool assessed risk of bias. Meta-analysis was undertaken.

RESULTS

A total of 819 records were screened. Eight papers were included, with data for 1475 people. CRP cut-points ranged from 2.8 to 10 mg/L. The Glasgow Prognostic Score (GPS) and modified GPS were the most commonly reported scores. On meta-analysis, elevated preoperative GPS/mGPS was significantly associated with worse overall survival (hazards ratio [HR] 1.81, 95% confidence interval [CI] 1.25-2.62, p = 0.002); results were similar in subgroup analyses of multimodal treatment, M0 disease, and R0 resection.

CONCLUSIONS

This is the first review to evaluate comprehensively the evidence for CRP and CRP-based scores in EAC. Meta-analysis demonstrated that elevated preoperative GPS or mGPS was significantly associated with reduced overall survival in EAC, including AEG. There is insufficient evidence to support use of CRP alone. Future studies should examine GPS/mGPS in EAC prospectively, alone and combined with other prognostic markers.

SP5.1.11 The immune landscape of the Tumour draining lymph node and the Tumour Microenvironment in oesophageal; A novel therapeutic target

Aim

The tumour microenvironment (TME) and tumour-draining lymph node microenvironment (LNME) remain poorly understood. Our study profiles the immune, angiogenic and inflammatory environment of the LNME and the TME of oesophagogastric patients.

Methods

The prognositc value of nodal status, clinical stage and tumour regression grade (TRG) was evaluated using a cohort of OAC patients (n = 702). Immune checkpoints (ICs) on tumour-draining lymph nodes(TDLNs, n = 6) and tumour tissue(n = 9) at surgical resection was assessed by flow cytometry. We also screened for cytokines, angiogenic mediators and chemokines. Using The Cancer Genome Atlas (TCGA), protein and mRNA levels (n = 72) and mutated versus non-mutated copies(n = 87) of this panel was correlated with survival.

Results

The frequency of CD3+TIM-3 and PD-1+T cells in TDLNs positively correlated with clinical tumour status as did CD8 + PD-1+TIGIT + T cells with nodal burden. Pro-angiogenic factor bFGF was significantly higher within the TME compared with the LNME. PIGF and SAA mediators of tumour growth were significantly higher in the LNME and levels of SAA in LNME positively correlated with adverse features. High levels of pro inflammatory IL-8,IL-6 and Flt1, mutations in pro-inflammatory genes CCL26,IL-31 and IL-17C and anti-tumour IL-1RN and CCL22 correlated with reduced overall survival.

Conclusions

The TME is more immunosuppressive than the TDLN, however, certain pro-angiogenic factors were enriched in TDLNs suggesting the priming of a pre-metastatic niche. Given the association of ICs with clinical features and tumour biology this may help to inform novel therapeutic approaches.

Comparison of Esophagectomy outcomes between a National Center, a National Audit Collaborative, and an International database using the Esophageal Complications Consensus Group (ECCG) standardized definitions

The ECCG developed a standardized platform for reporting operative complications, with consensus definitions. The Dutch Upper Gastrointestinal Cancer Audit (DUCA) published a national comparison against these benchmarks. This study compares ECCG data from the Irish National Center (INC) with both published benchmark studies. All patients undergoing multimodal therapy or surgery with curative intent from 2014 to 2018 inclusive were studied, with data recorded prospectively and entered onto a secure online database (Esodata.org). 219 patients (mean age 67; 77% male) underwent open resection, 66.6% via transthoracic en bloc resection. 30-day and 90-day mortality were 0.0 and 0.9%,nrespectively. Anastomotic leak rate was 5.4%, pneumonia 18.2%, respiratory failure 10%, ARDS 2.7%, atrial dysrhythmia 22.8%, recurrent nerve injury 3%, and delirium in 5% of patients. Compared with both ECCG and DUCA, where MIE constituted 47 and 86% of surgical approaches, respectively, overall complications were similar, as were severity of complications; however, anastomotic leak rate was several-fold less, and mortality was significantly lower (P < 0.001). In this consecutive series and comparative audit with benchmark averages from the ECCG and DUCA publications, a low mortality and anastomotic leak rate were the key differential findings. Although not risk stratified, the severity of complications from this 'open' series is consistent with series containing large numbers of total or hybrid MIE, highlighting a need to adhere to these strictly defined definitions in further prospective research and randomized studies.

Ligand-Targeted Delivery of Photosensitizers for Cancer Treatment

Photodynamic therapy (PDT) is a promising cancer treatment which involves a photosensitizer (PS), light at a specific wavelength for PS activation and oxygen, which combine to elicit cell death. While the illumination required to activate a PS imparts a certain amount of selectivity to PDT treatments, poor tumor accumulation and cell internalization are still inherent properties of most intravenously administered PSs. As a result, common consequences of PDT include skin photosensitivity. To overcome the mentioned issues, PSs may be tailored to specifically target overexpressed biomarkers of tumors. This active targeting can be achieved by direct conjugation of the PS to a ligand with enhanced affinity for a target overexpressed on cancer cells and/or other cells of the tumor microenvironment. Alternatively, PSs may be incorporated into ligand-targeted nanocarriers, which may also encompass multi-functionalities, including diagnosis and therapy. In this review, we highlight the major advances in active targeting of PSs, either by means of ligand-derived bioconjugates or by exploiting ligand-targeting nanocarriers.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Cell death in photodynamic therapy: From oxidative stress to anti-tumor immunity

Photodynamic therapy is a promising approach for cancer treatment that relies on the administration of a photosensitizer followed by tumor illumination. The generated oxidative stress may activate multiple mechanisms of cell death which are counteracted by cells through adaptive stress responses that target homeostasis rescue. The present renaissance of PDT was leveraged by the acknowledgment that this therapy has an immediate impact locally, in the illumination volume, but that subsequently it may also elicit immune responses with systemic impact. The investigation of the mechanisms of cell death under the oxidative stress of PDT is of paramount importance to understand how the immune system is activated and, ultimately, to make PDT a more appealing/relevant therapeutic option.

The physiotherapist and the esophageal cancer patient: from prehabilitation to rehabilitation

Esophageal cancer is a serious malignancy often treated with multimodal interventions and complex surgical resection. As treatment moves to centers of excellence with emphasis on enhanced recovery approaches, the role of the physiotherapist has expanded. The aim of this review is to discuss the rationale behind both the evolving prehabilitative role of the physiotherapist and more established postoperative interventions for patients with esophageal cancer. While a weak association between preoperative cardiopulmonary fitness and post-esophagectomy outcome is reported, cardiotoxicity during neoadjuvant chemotherapy and/or radiotherapy may heighten postoperative risk. Preliminary studies suggest that prehabilitative inspiratory muscle training may improve postoperative outcome. Weight and muscle loss are a recognized sequelae of esophageal cancer and the functional consequences of this should be assessed. Postoperative physiotherapy priorities include effective airway clearance and early mobilization. The benefits of respiratory physiotherapy post-esophagectomy are described by a small number of studies, however, practice increasingly recognizes the importance of early mobilization as a key component of postoperative recovery. The benefits of exercise training in patients with contraindications to mobilization remain to be explored. While there is a strong basis for tailored physiotherapy interventions in the management of patients with esophageal cancer, this review highlights the need for studies to inform prehabilitative and postoperative interventions.

Near-peer bedside clinical teaching: example of a successful programme

BACKGROUND

Traditionally, the formalised teaching of medical students has begun at senior trainee level, with teaching from junior trainees being very limited and informal. A pilot programme was set up in a large university teaching hospital for interns to provide structured bedside clinical teaching to final-year medical students as an adjunct to their formal teaching. Derived from the success of this, a similar programme was run the following year.

METHODS

Feedback from the pilot programme and its successor was evaluated using a five-point Likert scale, and open illustrative comments were also collected.

RESULTS

There was a highly positive response to the initial programme, with final-year students being very positive about participating as teachers the following year. Some proceeded to run the programme the following year, providing feedback to suggest improvements on the pilot programme.

DISCUSSION

Junior trainees can organise and provide an additional option to traditional formal undergraduate clinical bedside teaching, which is well received by students. It also provides a forum through which trainees can hone teaching methods and improve clinical skills. A programme was set up for interns to provide structured bedside clinical teaching to final-year medical students.

The diagnostic accuracy of endoscopic ultrasound in suspected biliary obstruction and its impact on endoscopic retrograde cholangiopancreatography burden in real clinical practice: a consecutive analysis

BACKGROUND AND AIMS

Performing endoscopic ultrasound (EUS) before endoscopic retrograde cholangiopancreatography (ERCP) has been described to be useful in cases of suspected biliary obstruction where EUS can triage patients for ERCP. We aimed to determine the diagnostic accuracy of EUS and its impact on ERCP burden in real clinical practice. We also evaluated the safety and efficacy of EUS+ERCP in a single endoscopic session.

PATIENTS AND METHODS

Four hundred and eighteen consecutive patients with suspected but unexplained biliary obstruction referred for EUS before possible ERCP were evaluated. The diagnostic accuracy of EUS and its value in predicting the need for ERCP were determined. EUS established whether pancreaticobiliary disorder (PBD) was present and whether therapeutic ERCP was required. These decisions were matched with ERCP findings, histology, clinical course, and follow-up. Where ERCP was indicated, it was performed in the same endoscopic session.

RESULTS

EUS was performed in 412/418 patients (feasibility 98.5%), and ERCP was considered necessary in 64% (ERCP avoided in 36%). The single-session EUS and ERCP was safe and effective (264 patients). The diagnostic accuracy of EUS was as follows: choledocholithiasis 99%, malignant strictures 90%, and benign strictures 92%. EUS showed pathology in 42% of patients who had a nondilated biliary system at initial investigations. When EUS indicated a normal common bile duct (n=119), this had a 100% positive predictive value for non-necessity for ERCP. The median overall follow-up period was 12 months (range 6-34 months).

CONCLUSION

EUS demonstrated high diagnostic accuracy in this mixed group of PBD. This accurately guided ERCP need and avoided unnecessary ERCP in 36%. EUS and ERCP in the same endoscopic session for the evaluation and management of PBD is technically feasible, with safety and efficacy profiles equivalent to that of each procedure performed independently in different sessions.

Modern oncologic and operative outcomes for oesophageal cancer treated with curative intent

The curative approach to oesophageal cancer carries significant risks and a cure is achieved in approximately 20 per cent. There has been a recent trend internationally to observe improved operative and oncological outcomes. This report audits modern outcomes from a high volume centre with a prospective database for the period 2004-08. 603 patients were referred and 310 (52%) were treated with curative intent. Adenocarcinoma represented 68% of the cohort, squamous cell cancer 30%. Of the 310 cases, 227 (73%) underwent surgery, 105 (46%) underwent surgery alone, and 122 (54%) had chemotherapy or combination chemotherapy and radiation therapy. The postoperative mortality rate was 1.7%. The median and 5-year survival of the 310 patients based on intention to treat was 36 months and 36%, respectively, and of the 181 patients undergoing R0 resection, 52 months and 42%, respectively. An in-hospital postoperative mortality rate of less than 2 per cent, and 5-year survival of between 35 and 42% is consistent with benchmarks from international series.

Abstract 1556: Adipose tissue upregulates MMP9 expression in oesophageal cancer promoting invasion and migration in vitro and correlates with obesity status and poor differentiation in vivo

Introduction: Obesity is an independent risk-factor for oesophageal adenocarcinoma. Adipose tissue is an endocrine organ secreting numerous factors with different biological activities. We aimed to investigate the molecular mechanisms linking obesity and cancer in oesophageal cancer.

Methods: Adipose conditioned media (ACM) was prepared from omental adipose tissue of oesophageal adenocarcinoma patients. Proliferation of oesophageal adenocarcinoma cells(OE33, OE19) in response to ACM was examined by BrdU. OE33 cell line was co-culture with visceral adipose tissue and gene expression pathways assessed by Cancer-Pathway-Finder and Affymetrix arrays. Identified genes were assessed in 50 resected oesophageal tumours and related to clinic-pathological data. Migration and invasion following culture with ACM was assessed in oesophageal cell lines.

Results: Culture of both the OE33 and OE19 cell lines with ACM from omental adipose tissue increased proliferation by 142% and 145% respectively. Co-culture of OE33 with adipose tissue increased the expression of genes regulating invasion and metastasis between 10-5000 fold, with MMP9 the most upregulated gene and TP53 down-regulated 2-fold. Altered genes were validated in an independent cohort. Functionally, co-culture of adipose tissue with tumour cells increased both mingration and invasion of tumour cells. Notably, adipose tissue from viscerally obese patients had a significantly higher effect. Markers of focal adhesions(SPP1, integrins), endothelial mesenchymal transition(SNAI2, Laminins) and thrombosis (pai-1) were also significantly upregulated. Expression of pai-1 and MMP9 was significantly (p&lt;0.05) higher in tumours from centrally obese patients.

Conclusion: Omental adipose tissue promoted oesophageal cancer aggressiveness by increasing proliferative, migratory and invasive capacity via upregulation of MMP2, MMP9, SERPINE1, PAI-1, SPP1 and SNAI2. Upregulation of genes in tumours from obese patients suggest a molecular progression of cancer associated with excess adipose tissue.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1556. doi:10.1158/1538-7445.AM2011-1556

Abstract 2283: The role of insulin-like growth factor-1 and insulin like growth factor-1 receptor in obesity and oesophageal cancer

Introduction: The insulin-like growth factor pathway, which is involved in cell proliferation, differentiation and protection against apoptosis, has been implicated in esophageal cancer progression. This study examined the role of insulin-like growth factor-1 (IGF-1) and insulin-like growth factor-1 receptor (IGF-1R) as a potential mechanism linking obesity with esophageal cancer.

Methods: IGF-1R expression in esophageal squamous cell carcinoma (KYSE, OE21) and adenocarcinoma (OE19, OE33) cell lines was measured by Western analysis and the effect of IGF-1 (0.1 − 1000 ng/ml) on survival of cell lines in relation to their expression of IGF-1R was assessed by MTT assay. Circulating levels of IGF-I were measured in 50 human serum samples by ELISA and immunohistochemistry determined IGF-1R expression in human tumor sections. Results were related to tumor type, BMI and survival.

Results: Higher IGF-1R expression was observed in squamous cell carcinoma cell lines, however only adenocarcinoma cell lines showed significantly increased cell survival in response to IGF-1 (p &lt;0.001). Significantly higher circulating levels of IGF-1 were observed in patients with adenocarcinoma (p = 0.02). In resected esophageal tumor sections, no statistical difference between intensity of IGF-1R expression and BMI or survival was observed, however reduced survival was observed in patients with moderate-strong compared to weak-negative IGF-1R expression. Higher intensity IGF-1R staining was observed in the ‘immune cell rich’ leading edge of adenocarcinomas.

Conclusion: This study suggests an important role for IGF-1 in esophageal adenocarcinoma cell survival. Novel findings relating to high IGF-1R expression in the leading edge of esophageal adenocarcinoma and possible associations with obesity are also presented.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2283.

Differences in SMN1 allele frequencies among ethnic groups within North America

Background:

Spinal muscular atrophy (SMA) is the most common inherited lethal disease of children. Various genetic deletions involving the bi-allelic loss of SMN1 exon 7 are reported to account for 94% of affected individuals. Published literature places the carrier frequency for SMN1 mutations between 1 in 25 and 1 in 50 in the general population. Although SMA is considered to be a pan-ethnic disease, carrier frequencies for many ethnicities, including most ethnic groups in North America, are unknown.

Objectives and methods:

To provide an accurate assessment of SMN1 mutation carrier frequencies in African American, Ashkenazi Jewish, Asian, Caucasian, and Hispanic populations, more than 1000 specimens in each ethnic group were tested using a clinically validated, quantitative real-time polymerase chain reaction (PCR) assay that measures exon 7 copy number.

Results:

The observed one-copy genotype frequency was 1 in 37 (2.7%) in Caucasian, 1 in 46 (2.2%) in Ashkenazi Jew, 1 in 56 (1.8%) in Asian, 1 in 91 (1.1%) in African American, and 1 in 125 (0.8%) in Hispanic specimens. Additionally, an unusually high frequency of alleles with multiple copies of SMN1 was identified in the African American group (27% compared to 3.3–8.1%). This latter finding has clinical implications for providing accurate adjusted genetic risk assessments to the African American population.

Conclusions:

Differences in the frequency of SMA carriers were significant among several ethnic groups. This study provides an accurate assessment of allele frequencies and estimates of adjusted genetic risk that were previously unavailable to clinicians and patients considering testing.

Health-related quality of life in long-term survivors of pediatric liver transplantation

The purpose of this study is to measure the health-related quality of life (HRQOL) in children who are long-term survivors of liver transplantation and to pilot the Liver Transplant Disability Scale (LTDS), a newly developed 12-point scale that quantifies chronic medical disability related to liver transplantation. This study is a cross-sectional survey of 51 children surviving liver transplantation by at least 2 years, with a median age of 4.94 years. Functional capacity and utility scores were measured by the Health Utilities Index Mark II (HUI2), and chronic disease-specific medical disability was measured by the LTDS. HUI2 results were compared with a reference population. LTDS scores were compared with utility scores and patient survival 3 years later. Ninety percent of the study patients had functional deficits compared with 50% of controls. Functional impairment was typically mild. The resulting mean utility score, 0.86 +/- 0.13 (0 = dead, 1 = perfect health), was significantly less than that of the reference population, 0.95 +/- 0. 07 (P <.001). LTDS scores ranged from 0 (no disability) to 6 (moderate disability). Seventy-one percent of the children had mild disability (scores 0 to 3), and 29% had moderate disability (scores 4 to 6). LTDS scores did not correlate with utility scores but were predictive of survival. The majority of pediatric liver transplant recipients have mild functional deficits. Their utility scores reflected a high level of HRQOL but were significantly less than those of a reference population. The majority also had mild medical disability, predominantly delayed growth. Medical disability did not correlate with HRQOL but predicted survival 3 years later.