O-OGC07 Endoscopically derived oesophageal adenocarcinoma organoids to assess potential response to neo-adjuvant therapy and virotherapy

Background Organoids are 3D models that retain the architecture and function of the organ from which they are derived. Culture of oesophageal adenocarcinoma organoids from individual’s standard endoscopic biopsies to assess response to therapy could dramatically alter the neo-adjuvant treatment paradigm, giving clarity over who will benefit from therapy, including novel treatment methodologies. Immune checkpoint blockade (ICB) has been shown to be effective in oesophageal adenocarcinoma. Combining Oncolytic Virotherapy with ICB could enhance the action of ICB alone, through selective infection of tumour cells accompanied by immunogenic cell death, with release of neo-tumour antigens and alteration of the tumour microenvironment. Methods This study uses organoids derived from endoscopic biopsies to assess the viability of an oncolytic herpes simplex virus in the treatment of oesophageal adenocarcinoma. Samples were taken at staging endoscopy using standard biopsy forceps. Tissue specimens were dissociated using the Miltenyi tumour dissociation kit before being suspended in Matrigel in conditioned media. Media was changed every 48 hours with domes being split every 7-10 days. After >6 passages organoids were incubated with an oncolytic herpes simplex virus lacking ICP 34.5 and 47. Growth was monitored, and green fluorescence protein expression measured using the Incucyte SX5 Live Cell Analysis system. Results Organoids were successfully established and cultured beyond 6 passages for patients with oesophageal adenocarcinoma. Organoids incubated with an oncolytic herpes simplex virus demonstrated significantly reduced growth compared to untreated organoids with increased expression of green fluorescence protein indicating viral infection. Conclusions We have demonstrated a successful methodology to culture Oesophageal adenocarcinoma organoids from endoscopic biopsies. Further work to determine their responses to standard chemotherapy used in the perioperative phase will help to assess their potential for providing bespoke therapy in the future. Oncolytic herpes simplex virus is able to infect and cause lysis of OAC organoids supporting its potential use in driving an increased inflammatory tumour microenvironment which could be combined with immune checkpoint blockade to induce durable responses for patients.

Histopathological study of endoscopic biopsies of large intestine

The large intestine is a site of a variety of diseases. The lesions tend to occur affecting different age groups ranging from early childhood to late adulthood. Patients may present with very vague clinical symptoms ranging from abdominal pain, loose stools, vomiting, diarrhoea, bleeding per rectum, and change in bowel habit. Patients presenting with repeated symptoms related to lower intestinal pathology are advised to undergo colonoscopic examination.To study clinico-pathological correlation of endoscopic biopsies of large intestine and to study spectrum of large intestinal lesions.The study was conducted at a tertiary care hospital from August 2018 to July 2020. All endoscopic biopsy samples were included in this study. All endoscopic biopsies were performed by high definition colonoscope. Clinical and endoscopic correlation with histopathological diagnosis was performed and results were generated.Total 133 cases were included in this study, out of 133 patients 86 were males and 47 were females. Patients showed wide age range from 11 years to 80 years. There were 25 patients each in age group of 31-40 years and 61-70 years. The most common presenting complaint was loose stools in 66 cases. The most common endoscopic finding was erythema in 82 cases. Out of 133 cases, 105 cases were non neoplastic, 08 cases were benign neoplastic and 20 cases were malignant neoplastic on histopathology.Colonoscopy is very high yielding and safe procedure to perform.Colonoscopic biopsies are proven to be of great importance. Clinical, endoscopic and histopathological correlation is always advisable in large intestinal pathology for early diagnosis and treatment.

Establishment and characterization of patient-derived head and neck cancer models from surgical specimens and endoscopic biopsies

Background Head and neck squamous cell carcinoma (HNSCC) is heterogeneous in etiology, phenotype and biology. Patient-derived xenografts (PDX) maintain morphology and molecular profiling of the original tumors and have become a standard “Avatar” model for human cancer research. However, restricted availability of tumor samples hindered the widespread use of PDX. Most PDX-projects include only surgical specimens because reliable engraftment from biopsies is missing. Therefore, sample collection is limited and excludes recurrent and metastatic, non-resectable cancer from preclinical models as well as future personalized medicine. Methods This study compares the PDX-take rate, -growth, histopathology, and molecular characteristics of endoscopic specimens with surgical specimens. HNSCC samples (n = 55) were collected ad hoc, fresh frozen and implanted into NOD.Cg-PrkdcscidIl2rgtm1Wjl/SzJ mice. Results Engraftment was successful in both sample types. However, engraftment rate was lower (21 vs. 52%) and growth delayed (11.2 vs. 6.7 weeks) for endoscopic biopsies. Following engraftment, growth kinetic was similar. Comparisons of primary tumors and corresponding PDX models confirmed preservation of histomorphology (HE histology) and molecular profile (Illumina Cancer Hotspot Panel) of the patients’ tumors. Accompanying flow cytometry on primary tumor specimens revealed a heterogeneous tumor microenvironment among individual cases and identified M2-like macrophages as positive predictors for engraftment. Vice versa, a high PD-L1 expression (combined positive score on tumor/immune cells) predicted PDX rejection. Conclusion Including biopsy samples from locally advanced or metastatic lesions from patients with non-surgical treatment strategies, increases the availability of PDX for basic and translational research. This facilitates (pre-) clinical studies for individual response prediction based on immunological biomarkers.

Spectrum of esophageal lesions- A study of endoscopic biopsies

Endoscopic biopsies is a very common outpatient procedure in gastroenterology unit. The present article is a study of endoscopic biopsies taken from the esophagus. The gastrointestinal tract cannot be visualized directly and endoscopy is a very important and easy tool for visualization of GI tract lesions directly and helping in the diagnosis in the early stage, there by helping in the overall well being of the patient. To emphasize the utility of endoscopic biopsies in the diagnosis of esophageal lesions. To correlate the endoscopic findings with pathological diagnosis. To study the various pathologies. Endoscopic biopsies taken from the esophagus were studied and analysed in the present study. The biopsies are taken by the gastroenterologist. The biopsies are fixed in 10%formalin.After fixation the biopsy specimen is processed and embedded in paraffin.4 to 5 microns thick sections were cut, stained with Haematoxylin & Eosin and studied. Out of the 118 cases of esophageal biopsies received at the Department of Pathology, Mediciti Institute of Medical Sciences from December 2016 to November, 2018. ,50 were non neoplastic lesions, 68 cases were neoplastic lesions, 50 were non neoplastic lesions, 68 cases were neoplastic lesions. Chronic non specific esophagitis was the commonest non neoplastic esophageal lesion. Squamous cell carcinoma was the commonest neoplastic lesion. The lower one third is the commonest site of pathology for esophagus. Males are mostly effected and predominant age of presentation is around 40-60 years for non neoplastic lesion and 50-70 years for neoplastic region.

The Diagnostic Accuracy of Endoscopic Ultrasound-Guided Fine Needle Aspiration in Patients with Endoscopic Biopsy Negative Upper Gastrointestinal Lesions

Objective To determine the diagnostic accuracy of endoscopic ultrasound guided (EUS) fine needle aspiration in patients who had inconclusive endoscopic biopsies of the same lesion Methodology This retrospective study was conducted at Pak Emirates Military Hospital, Rawalpindi, Pakistan from Jan 2018 to July 2020. Patients who underwent EUS guided FNAC from June 2017 to July 2020 were screened. The FNAC results of patients satisfying the inclusion ciritera were compared with either a surgical biopsy in patients in whom surgeries were done, while in the remaining patients, EUS FNAC results were compared with a 3 months radiological and/or 6 months clinical follow-up. The final diagnosis was defined based on the following criteria: (1) Malignant lesions (n=36), histopathologic diagnosis obtained based on surgery resected samples (n=18) or clinical diagnosis as neoplasm based on clinical follow-up of symptoms (n=30) or radiologic diagnosis based on imaging follow-up at 3 months (n=13) (2) Benign lesions (n=18), benign cytopathologic histopathologic findings and clinical follow-up with no evidence of malignant progression or metastasis. Results EUS-guided FNA cytology turned out to be malignant in 60 percent (n=36) of the specimens. 30 percent of the samples showed benign epithelial cytology ( n=18) while in 10 percent of the cases (n=6), the tissue samples were deemed insufficient for cytological diagnosis. The accuracy came out to be 66.6 percent (n=10 were true negative), sensitivity 93.4 percent, and specificity 100 percent. Conclusion EUS guided-FNA cytology of the sub-mucosal upper GI lesions is highly sensitive and specific for upper GI lesions, which are negative on endoscopic biopsies.