Optimising Oncolytic Virotherapy and Immunotherapy for the treatment of Disseminated Colorectal Cancer

Colorectal cancer (CRC) is one of the most prevalent malignancies in the Western world with a 5 year survival rate of patients with metastatic disease of less than 10%. As such, there remains a pressing need for novel treatment strategies and modalities. Established treatments including anti-EGFR antibodies, for example cetuximab, have improved survival although disappointingly only 10-20% of patients obtain an objective clinical response. Advancing treatment modalities include oncolytic viruses (Reovirus, Vaccinia Virus (JX-594)), which preferentially replicate in cancer cells causing cell death and stimulate anti-tumour immunity, and BH3-mimetic inhibitors (ABT- 263), which antagonise the BCL-2 family of pro-survival proteins, may enhance CRC patient survival. Harnessing the potential immune and anti- cancer effects of these treatment modalities, alone and in combination, at primary tumour and sites of metastatic and micrometastatic (for example lymph nodes) disease could form the basis of successful clinical adjuvant strategies. This MD thesis aims to investigate the efficacy of two OV, Reovirus and JX- 594 vaccinia virus against CRC. In particular, the work outlined in this thesis has examined whether i) Reovirus directly kills CRC cell lines with differential mutational status, alone or in combination with BH3-mimetics and ii) can activate immune effector cells to enhance killing of EGFR targeted cells in order to optimise the use of anti-EGFR therapy; iii) delineate the mechanism of cell death induced by JX-594 treated CRC cells, and iv) test the ability of JX-594 to activate and induce an innate immune response in the blood and lymph nodes. Studies investigating Reovirus in combination with ABT-263 and Cetuximab were performed. ABT-263 in combination with Reovirus demonstrated that this strategy did not yield enhanced killing over either agent alone, with only additive effects observed in a single cell line, SW620. However, initial studies combining Cetuximab with OV did reveal the potential of Reovirus to increase EGFR-mediated ADCC against a KRAS mutant cell line, SW480, demonstrating the importance of OV immune activation in combination therapeutic approaches. To date, the immune potential of reovirus is well recognised however, less is known about the immune potential of JX-594, an OV currently in clinical testing at Leeds Teaching Hospitals NHS Trust. To test the ability of JX594 to activate immune cell populations, healthy donor blood, along with blood and lymph nodes from CRC patients, were collected and treated with JX-594. JX-594 treated NK cells from patient blood and lymph nodes demonstrated CD69 activation, enhanced degranulation and increased cytotoxicity against CRC cell line targets. In blood, NK cell activation was dependent on IFN production and the presence of CD14+ve monocytes however in lymph node mononuclear cells this was IFN independent and the mechanism remains to be elucidated. Importantly, OV activation of immune effector cells known to reside in LN is encouraging for targeting distant micrometastatic disease. OV hold promise as a novel treatment modality. Direct tumour-specific lysis, transgene expression and the induction of tumour specific innate immunity in isolation, or in combination with adjunct antitumour treatment modalities, means that they may provide a two-pronged attack against the tumour at different disease sites

Automated analysis of intraoperative phase in laparoscopic cholecystectomy: A comparison of one attending surgeon and their residents

OBJECTIVE: This study compares the intraoperative phase times in laparoscopic cholecystectomy performed by an attending surgeon and supervised residents over 10-years to assess operative times as a marker of performance and any impact of case severity on times. DESIGN: Laparoscopic cholecystectomy videos were uploaded to Touch Surgery™ Enterprise, a combined software and hardware solution for securely recording, storing, and analysing surgical videos, which provide analytics of intraoperative phase times. Case severity and visualisation of the critical view of safety (CVS) were manually assessed using modified 10-point intraoperative gallbladder scoring system (mG10) and CVS scores, respectively. Attending and residents' times were compared unmatched and matched by mG10. SETTING: Secondary analysis of anonymized laparoscopic cholecystectomy video, recorded as standard of care. PARTICIPANTS: Adult patients who underwent elective laparoscopic cholecystectomy a single UK hospital. Cases were performed by one attending and their residents. RESULTS: 159 (attending=96, resident=63) laparoscopic cholecystectomy videos and intraoperative phase times were reviewed on Touch Surgery™ Enterprise and analyzed. Attending cases were more challenging (p=0.037). Residents achieved higher CVS scores (p=0.034) and showed longer dissection of hepatocystic triangle (HCT) times (p=0.012) in more challenging cases. Residents' total operative time (p=0.001) and dissection of HCT (p=0.002) times exceeded the attending's in low-severity matched cases (mG10=1). Residents' total operative times (p<0.001), port insertion/gallbladder exposure (p=0.032), and dissection of HCT (p<0.001) exceeded the attending's in matched cases (mG10=2). Residents' total operative (p<0.001), dissection of HCT (p<0.001), and gallbladder dissection (p=0.010) times exceeded the attendings in unmatched cases. CONCLUSIONS: Residents' total operative and dissection of HCT times significantly exceeded the attending's unmatched cases and low-severity matched cases which could suggest training need, however, also reflects an expected assessment of competence, and validates time as a marker of performance

Oncolytic reovirus as a combined antiviral and anti-tumour agent for the treatment of liver cancer

Objective: Oncolytic viruses (OVs) represent promising, proinflammatory cancer treatments. Here, we explored whether OV-induced innate immune responses could simultaneously inhibit HCV while suppressing hepatocellular carcinoma (HCC). Furthermore, we extended this exemplar to other models of virus-associated cancer. Design and results: Clinical grade oncolytic orthoreovirus (Reo) elicited innate immune activation within primary human liver tissue in the absence of cytotoxicity and independently of viral genome replication. As well as achieving therapy in preclinical models of HCC through the activation of innate degranulating immune cells, Reo-induced cytokine responses efficiently suppressed HCV replication both in vitro and in vivo. Furthermore, Reo-induced innate responses were also effective against models of HBV-associated HCC, as well as an alternative endogenous model of Epstein–Barr virus-associated lymphoma. Interestingly, Reo appeared superior to the majority of OVs in its ability to elicit innate inflammatory responses from primary liver tissue. Conclusions: We propose that Reo and other select proinflammatory OV may be used in the treatment of multiple cancers associated with oncogenic virus infections, simultaneously reducing both virus-associated oncogenic drive and tumour burden. In the case of HCV-associated HCC (HCV-HCC), Reo should be considered as an alternative agent to supplement and support current HCV-HCC therapies, particularly in those countries where access to new HCV antiviral treatments may be limited

Laparoscopic versus open repair of perforated peptic ulcer: a systematic scoping review and in-depth evaluation of existing evidence

BackgroundPerforated peptic ulcer remains a common cause of morbidity and mortality worldwide. Surgical treatment includes a trend towards minimally invasive surgery. To safely implement this, it is important to understand the key steps that have been assessed in clinical trials. The aim of this review is to assess the reporting of intervention steps in laparoscopic and open ulcer repair.MethodsA systematic search was performed of the MEDLINE, EMBASE, &amp; clinical trial databases (PROSPERO (CRD42023404537)). Randomised trials on laparoscopic vs open repair of peptic ulcer were included. Data extracted included study metadata, as well as technical aspects of interventions, use of co-interventions. Study design was assessed using the PRECIS-2 tool, to explore whether trials were predominantly pragmatic or explanatory, and also using the Cochrane Risk of Bias tool.Results408 studies were screened for eligibility, and nine full-texts were included. This included six studies from China, two from India, and one from the Netherlands. Incision, ulcer closure details, and lavage, were the best reported aspects of laparoscopic repair (n=7). Method of access, incision, and ulcer closure were well described in 8 studies. Co-interventions such as antibiotic use, analgesia, and H pylori eradication were poorly described. Interventions were delivered by high volume laparoscopic surgeons. Studies were considered at high risk of bias. PRECIS-2 assessment found studies were neither fully pragmatic nor explanatory.ConclusionsLaparoscopic repair of perforated peptic ulcer is a poorly defined intervention. Standardisation of key steps and co-interventions is required to facilitate a well designed randomised trial

Water-soluble contrast agents in adhesional small bowel obstruction:meta-analysis and PRECIS-2 assessment of trials

Background: Adhesional small bowel obstruction is a common presentation to acute general surgical services. Initial management is typically conservative and includes the use of water-soluble contrast agents. Current trials assessing water-soluble contrast agents are limited by sample size and demonstrate contrasting results. The aim of this review was to systematically appraise the use of water-soluble contrast agents in adhesional small bowel obstruction. Methods: This systematic review and meta-analysis was registered with PROSPERO (CRD42024573136) and conducted in line with PRISMA guidelines. Searches of Medline, Embase and Central databases were undertaken to include randomized clinical trials reporting the use of water-soluble contrast agents in adhesional small bowel obstruction. Searches were last updated on 26 July 2024. The primary outcome was the need for operative intervention. Secondary outcomes included the rate of intestinal ischaemia, the need for bowel resection, and mortality. A random-effects meta-analysis was conducted for outcomes reported in three or more studies. Risk of bias was assessed using the Cochrane Risk-of-Bias tool, and trial methods were appraised using the PRagmatic Explanatory Continuum Indicator Summary (PRECIS-2) tool. Results: In all, 11 randomized controlled trials were included with a median sample size of 88 (range 26-242), nine of which were single-centre studies; only one study used computed tomography imaging to diagnoses adhesional small bowel obstruction. Meta-analysis revealed no significant difference in operative intervention (odds ratio 0.63, 95% confidence interval 0.39 to 1.01; P = 0.053), small bowel ischaemia, small bowel resection, or mortality. Risk of bias raised concerns in several domains. PRECIS-2 assessment showed trials were pragmatic rather than explanatory designs. Conclusion: This review does not support the use of therapeutic water-soluble contrast agents in adhesional small bowel obstruction. Further adequately powered trials are needed. Standardization of diagnostic modality and consideration of explanatory designs should be considered.</p

Surgical experience and identification of errors in laparoscopic cholecystectomy

BACKGROUND: Surgical errors are acts or omissions resulting in negative consequences and/or increased operating time. This study describes surgeon-reported errors in laparoscopic cholecystectomy. METHODS: Intraoperative videos were uploaded and annotated on Touch SurgeryTM Enterprise. Participants evaluated videos for severity using a 10-point intraoperative cholecystitis grading score, and errors using Observational Clinical Human Reliability Assessment, which includes skill, consequence, and mechanism classifications. RESULTS: Nine videos were assessed by 8 participants (3 junior (specialist trainee (ST) 3-5), 2 senior trainees (ST6-8), and 3 consultants). Participants identified 550 errors. Positive relationships were seen between total operating time and error count (r2 = 0.284, P < 0.001), intraoperative grade score and error count (r2 = 0.578, P = 0.001), and intraoperative grade score and total operating time (r2 = 0.157, P < 0.001). Error counts differed significantly across intraoperative phases (H(6) = 47.06, P < 0.001), most frequently at dissection of the hepatocystic triangle (total 282; median 33.5 (i.q.r. 23.5-47.8, range 15-63)), ligation/division of cystic structures (total 124; median 13.5 (i.q.r. 12-19.3, range 10-26)), and gallbladder dissection (total 117; median 14.5 (i.q.r. 10.3-18.8, range 6-26)). There were no significant differences in error counts between juniors, seniors, and consultants (H(2) = 0.03, P = 0.987). Errors were classified differently. For dissection of the hepatocystic triangle, thermal injuries (50 in total) were frequently classified as executional, consequential errors; trainees classified thermal injuries as step done with excessive force, speed, depth, distance, time or rotation (29 out of 50), whereas consultants classified them as incorrect orientation (6 out of 50). For ligation/division of cystic structures, inappropriate clipping (60 errors in total), procedural errors were reported by junior trainees (6 out of 60), but not consultants. For gallbladder dissection, inappropriate dissection (20 errors in total) was reported in incorrect planes by consultants and seniors (6 out of 20), but not by juniors. Poor economy of movement (11 errors in total) was reported more by consultants (8 out of 11) than trainees (3 out of 11). CONCLUSION: This study suggests that surgical experience influences error interpretation, but the benefits for surgical training are currently unclear

Novel Textbook Outcomes following emergency laparotomy: Delphi exercise

Background: Textbook outcomes are composite outcome measures that reflect the ideal overall experience for patients. There are many of these in the elective surgery literature but no textbook outcomes have been proposed for patients following emergency laparotomy. The aim was to achieve international consensus amongst experts and patients for the best Textbook Outcomes for non-trauma and trauma emergency laparotomy. Methods: A modified Delphi exercise was undertaken with three planned rounds to achieve consensus regarding the best Textbook Outcomes based on the category, number and importance (Likert scale of 1–5) of individual outcome measures. There were separate questions for non-trauma and trauma. A patient engagement exercise was undertaken after round 2 to inform the final round. Results: A total of 337 participants from 53 countries participated in all three rounds of the exercise. The final Textbook Outcomes were divided into ‘early’ and ‘longer-term’. For non-trauma patients the proposed early Textbook Outcome was ‘Discharged from hospital without serious postoperative complications (Clavien–Dindo ≥ grade III; including intra-abdominal sepsis, organ failure, unplanned re-operation or death). For trauma patients it was ‘Discharged from hospital without unexpected transfusion after haemostasis, and no serious postoperative complications (adapted Clavien–Dindo for trauma ≥ grade III; including intra-abdominal sepsis, organ failure, unplanned re-operation on or death)’. The longer-term Textbook Outcome for both non-trauma and trauma was ‘Achieved the early Textbook Outcome, and restoration of baseline quality of life at 1 year’. Conclusion: Early and longer-term Textbook Outcomes have been agreed by an international consensus of experts for non-trauma and trauma emergency laparotomy. These now require clinical validation with patient data

Novel Textbook Outcomes following emergency laparotomy:Delphi exercise

Background: Textbook outcomes are composite outcome measures that reflect the ideal overall experience for patients. There are many of these in the elective surgery literature but no textbook outcomes have been proposed for patients following emergency laparotomy. The aim was to achieve international consensus amongst experts and patients for the best Textbook Outcomes for non-trauma and trauma emergency laparotomy. Methods: A modified Delphi exercise was undertaken with three planned rounds to achieve consensus regarding the best Textbook Outcomes based on the category, number and importance (Likert scale of 1–5) of individual outcome measures. There were separate questions for non-trauma and trauma. A patient engagement exercise was undertaken after round 2 to inform the final round. Results: A total of 337 participants from 53 countries participated in all three rounds of the exercise. The final Textbook Outcomes were divided into ‘early’ and ‘longer-term’. For non-trauma patients the proposed early Textbook Outcome was ‘Discharged from hospital without serious postoperative complications (Clavien–Dindo ≥ grade III; including intra-abdominal sepsis, organ failure, unplanned re-operation or death). For trauma patients it was ‘Discharged from hospital without unexpected transfusion after haemostasis, and no serious postoperative complications (adapted Clavien–Dindo for trauma ≥ grade III; including intra-abdominal sepsis, organ failure, unplanned re-operation on or death)’. The longer-term Textbook Outcome for both non-trauma and trauma was ‘Achieved the early Textbook Outcome, and restoration of baseline quality of life at 1 year’. Conclusion: Early and longer-term Textbook Outcomes have been agreed by an international consensus of experts for non-trauma and trauma emergency laparotomy. These now require clinical validation with patient data.</p

Two years later:Is the SARS-CoV-2 pandemic still having an impact on emergency surgery? An international cross-sectional survey among WSES members

Background: The SARS-CoV-2 pandemic is still ongoing and a major challenge for health care services worldwide. In the first WSES COVID-19 emergency surgery survey, a strong negative impact on emergency surgery (ES) had been described already early in the pandemic situation. However, the knowledge is limited about current effects of the pandemic on patient flow through emergency rooms, daily routine and decision making in ES as well as their changes over time during the last two pandemic years. This second WSES COVID-19 emergency surgery survey investigates the impact of the SARS-CoV-2 pandemic on ES during the course of the pandemic.Methods: A web survey had been distributed to medical specialists in ES during a four-week period from January 2022, investigating the impact of the pandemic on patients and septic diseases both requiring ES, structural problems due to the pandemic and time-to-intervention in ES routine. Results: 367 collaborators from 59 countries responded to the survey. The majority indicated that the pandemic still significantly impacts on treatment and outcome of surgical emergency patients (83.1% and 78.5%, respectively). As reasons, the collaborators reported decreased case load in ES (44.7%), but patients presenting with more prolonged and severe diseases, especially concerning perforated appendicitis (62.1%) and diverticulitis (57.5%). Otherwise, approximately 50% of the participants still observe a delay in time-to-intervention in ES compared with the situation before the pandemic. Relevant causes leading to enlarged time-to-intervention in ES during the pandemic are persistent problems with in-hospital logistics, lacks in medical staff as well as operating room and intensive care capacities during the pandemic. This leads not only to the need for triage or transferring of ES patients to other hospitals, reported by 64.0% and 48.8% of the collaborators, respectively, but also to paradigm shifts in treatment modalities to non-operative approaches reported by 67.3% of the participants, especially in uncomplicated appendicitis, cholecystitis and multiple-recurrent diverticulitis. Conclusions: The SARS-CoV-2 pandemic still significantly impacts on care and outcome of patients in ES. Well-known problems with in-hospital logistics are not sufficiently resolved by now; however, medical staff shortages and reduced capacities have been dramatically aggravated over last two pandemic years.</p