Repeat cytoreductive surgery with HIPEC for colorectal peritoneal metastases: a systematic review

BACKGROUND

Colorectal peritoneal metastases (CRPM) are present in 10-20% of patients at the time of their initial cancer diagnosis, and affects over 20% of those who develop colorectal cancer recurrence. Cytoreductive surgery (CRS) with HIPEC is firmly established as the optimal surgical treatment, but there is very little known about the benefit of repeat or iterative CRS. The aim of this review is to provide a systematic evaluation of the perioperative complications, survival outcomes and quality of life in patients undergoing repeat CRS with HIPEC for CRPM.

METHODS

A systematic review of PubMed, Ovid MEDLINE, EMBASE, Scopus and Cochrane databases was performed to identify all studies that reported outcomes for repeat CRS with or without HIPEC for CRPM.

RESULTS

Four hundred and ninety-three manuscripts were screened, and 15 retrospective studies were suitable for inclusion. Sample sizes ranged from 2 to 30 participants and comprised a total of 229 patients. HIPEC was used in all studies, but exact rates were not consistently stated. Perioperative morbidity was reported in four studies, between 16.7% and 37.5%. Nine studies reported mortality rate which was consistently 0%. The median overall survival after repeat CRS ranged from 20 to 62.6 months. No studies provided quality of life metrics.

CONCLUSION

Repeat CRS for CRPM has perioperative morbidity and mortality rates comparable to initial CRS, and offers a potential survival benefit in selected patients. There is however limited high-quality data in the literature.

Development and Validation of Micro-Azocasein Assay for Quantifying Bromelain

The proteolytic activity of enzymes may be evaluated by a colorimetric method with azocasein. Hence, we developed a micro-assay to quantify bromelain using azocasein. A total of 250 µL of 1.0% azocasein in dH2O was added to 250 µL of test solution, vortexed and incubated at ambient room temperature/30 min. The reaction was terminated with 1500 µL of 5% trichloroacetic acid, vortexed and centrifuged. A total of 150 µL of 0.5M NaOH was added to 150 µL of supernatant in triplicates, and absorbance was recorded at 410 nm. The linearity of the calibration curve was tested with 200-800 µg/mL serial dilutions. The detection limit, precision, accuracy, and robustness were tested along with the substrate enzyme reaction time and solvent matrix effect. Good linearity was seen with serially diluted 200 µg/mL bromelain. The limit of quantification and limit of detection were 5.412 and 16.4 µg/mL, respectively. Intra-day and inter-day analyses showed a relative standard deviation below 2.0%. The assay was robust when tested over 400-450 nm wavelengths. The assays performed using dH2O or PBS diluents indicated a higher sensitivity in dH2O. The proteolytic activity of bromelain was enhanced with L-cysteine or N-acetylcysteine. Hence, this micro-azocasein assay is reliable for quantifying bromelain.

When all else fails: the colo-duodenal anastomosis

Total enterectomy is an exceedingly rare procedure performed out of necessity due to massive intestinal infarction, trauma, or peritoneal malignancy. This case describes a 47-year-old patient who has successfully undergone the procedure to manage mesenteric ischaemia. Bowel continuity was achieved with a duodenocolonic anastomosis, and the patient has been transitioned to life-long total parental nutrition. This case highlights that carefully selected patients can achieve long-term survival with good quality of life rather than palliation.

Peritoneal Tuberculosis in Western Countries: A Rare Case With Concurrent Helminthic Infection

This case report presents a rare case of peritoneal tuberculosis (TB) coexisting with a helminthic infection in a 25-year-old female residing in Australia, highlighting the diagnostic challenges posed by abdominal TB. Despite the low incidence of TB in Western countries, abdominal TB remains a diagnostic dilemma due to its nonspecific symptoms and potential mimicry of other abdominal pathologies. The case highlights the importance of considering TB as a differential diagnosis of unexplained abdominal symptoms, particularly in individuals with a history of travel or previous residence in high-endemic regions. A multidisciplinary approach involving infectious disease specialists, radiologists, and surgeons is essential for comprehensive management. Prompt initiation of anti-TB therapy is recommended once diagnosis is confirmed.

Taming the SARS-CoV-2-mediated proinflammatory response with BromAc®

Introduction

In the present study, the impact of BromAc®, a specific combination of bromelain and acetylcysteine, on the SARS-CoV-2-specific inflammatory response was evaluated.

Methods

An in vitro stimulation system was standardized using blood samples from 9 healthy donors, luminex assays and flow cytometry were performed.

Results and discussion

BromAc® demonstrated robust anti-inflammatory activity in human peripheral blood cells upon SARS-CoV-2 viral stimuli, reducing the cytokine storm, composed of chemokines, growth factors, and proinflammatory and regulatory cytokines produced after short-term in vitro culture with the inactivated virus (iSARS-CoV-2). A combined reduction in vascular endothelial growth factor (VEGF) induced by SARS-CoV-2, in addition to steady-state levels of platelet recruitment-associated growth factor-PDGFbb, was observed, indicating that BromAc® may be important to reduce thromboembolism in COVID-19. The immunophenotypic analysis of the impact of BromAc® on leukocytes upon viral stimuli showed that BromAc® was able to downmodulate the populations of CD16+ neutrophils and CD14+ monocytes observed after stimulation with iSARS-CoV-2. Conversely, BromAc® treatment increased steady-state HLA-DR expression in CD14+ monocytes and preserved this activation marker in this subset upon iSARS-CoV-2 stimuli, indicating improved monocyte activation upon BromAc® treatment. Additionally, BromAc® downmodulated the iSARS-CoV-2-induced production of TNF-a by the CD19+ B-cells. System biology approaches, utilizing comprehensive correlation matrices and networks, showed distinct patterns of connectivity in groups treated with BromAc®, suggesting loss of connections promoted by the compound and by iSARS-CoV-2 stimuli. Negative correlations amongst proinflammatory axis and other soluble and cellular factors were observed in the iSARS-CoV-2 group treated with BromAc® as compared to the untreated group, demonstrating that BromAc® disengages proinflammatory responses and their interactions with other soluble factors and the axis orchestrated by SARS-CoV-2.

Conclusion

These results give new insights into the mechanisms for the robust anti-inflammatory effect of BromAc® in the steady state and SARS-CoV-2-specific immune leukocyte responses, indicating its potential as a therapeutic strategy for COVID-19.

Energy and nitrogen utilization of lactating dairy cattle fed increasing inclusion of a high-protein processed corn coproduct

Advancing technologies of the corn dry-milling ethanol production process includes the mechanical separation of fiber-containing particles from a portion of plant- and yeast-based nitrogenous particles. The resulting high-protein processed corn coproduct (HPCoP) contains approximately 52% crude protein (CP), 36% neutral detergent fiber (NDF), 6.4% total fatty acids (TFA). The objective of this experiment was to examine the effects of replacing nonenzymatically browned soybean meal with the HPCoP on dry matter intake (DMI), energy and N utilization, and milk production of lactating Jersey cows. Twelve multiparous Jersey cows were used in a triplicated 4 × 4 Latin square design consisting of four 28-d periods. Cows were blocked by milk yield and assigned randomly to 1 of 4 treatment diets that contained HPCoP (dry matter [DM] basis) at (1) 0%; (2) 2.6%; (3) 5.4%; and (4) 8.0%. Diets were formulated to be isonitrogenous and thus replace nonenzymatically browned soybean meal with HPCoP in the concentrate mix, while forage inclusion remained the same across diets. Increasing the concentration of HPCoP had no effect on DMI (mean ± SE; 19.9 ± 0.62 kg/d), but tended to linearly increase milk yield (27.8, 28.5, 29.8, and 29.0 ± 1.00 kg/d). Although no difference was observed in the concentration of milk protein with increasing inclusion of HPCoP (3.40% ± 0.057%), the concentration of fat linearly increased with the inclusion of HPCoP (5.05%, 5.19%, 5.15%, 5.47% ± 0.18%). No differences were observed in the digestibility of DM, NDF, CP, TFA, and gross energy averaging 66.6% ± 0.68%, 49.0% ± 1.03%, 66.1% ± 0.82%, 73.6% ± 1.73%, 66.3% ± 0.72%, respectively, with increasing HPCoP inclusion. The concentration of dietary gross energy linearly increased with increasing concentrations of HPCoP (4.25, 4.26, 4.28, and 4.31 ± 0.01 Mcal/kg), but no difference was observed in digestible energy and metabolizable energy (ME) across treatments averaging 2.83 ± 0.033 and 2.53 ± 0.043 Mcal/kg, respectively. Concentration of dietary net energy for lactation (NEL) tended to increase with increasing HPCoP (1.61, 1.72, 1.74, 1.72 ± 0.054 Mcal/kg) with the ratio of NEL:ME increasing linearly with increasing HPCoP inclusion (0.648, 0.676, 0.687, 0.677 ± 0.0124). Results of this study suggest that inclusion of the HPCoP can replace nonenzymatically browned soybean meal and support normal milk production.

External validation of prognostic scores and comparison of predictive accuracy for patients with colorectal cancer with peritoneal metastases considered for cytoreductive surgery and intraperitoneal chemotherapy

BACKGROUND AND OBJECTIVES

Prognostic scores are developed to facilitate the selection of patients with colorectal cancer peritoneal metastases (CRPM) for treatment with cytoreductive surgery (CRS) ± intraperitoneal chemotherapy (IPC). Three prominent prognostic scores are the Peritoneal Surface Disease Severity Score (PSDSS), the Colorectal Peritoneal Metastases Prognostic Surgical Score (COMPASS), and the modified COloREctal-Pc (mCOREP). We externally validate these scores and compare their predictive accuracy.

METHODS

Data from consecutive CRPM patients who underwent CRS/IPC from 1996 to 2018 was used to externally validate COMPASS, PSDSS, and mCOREP. Analysis evaluated the efficacy of each score in predicting (1) open-close laparotomy-those found at laparotomy to not be eligible for curative intent CRS/IPC, (2) surgical futility-those who underwent open-close laparotomy, palliative debulking surgery, or had an overall survival of less than 12 months, and (3) overall and recurrence-free survival (OS, RFS).

RESULTS

Prognostic scores were calculated for the 174-patient external validation cohort. COMPASS was most accurate in predicting open-close laparotomy, futile surgery, and survival (OS and RFS). Area under the curve (AUC) for open-close prediction was 0.78 (95% confidence interval, CI: 0.68-0.87), representing useful discrimination. However, AUC for futility prediction was 0.62 (95% CI: 0.52-0.71), and C-statistic for OS was 0.65 indicating only possibly helpful discrimination. C-statistic for RFS was 0.59 indicating poor discrimination.

CONCLUSION

While COMPASS showed the best statistical behavior, accuracy for several clinically relevant outcomes remains low, and thus applicability to clinical practice limited.

Increased Incidence of Liver Metastases in Colorectal Versus Appendiceal Adenocarcinoma Peritonectomy Patients Despite Equivocal Survival

BACKGROUND/AIM

Colorectal adenocarcinoma (CRAdenoCa) and appendiceal adenocarcinoma (AAdenoCa) are diseases of the same histopathological type that metastasise to the liver and peritoneum. In selected subgroups, peritonectomy and heated intraperitoneal chemotherapy (HIPEC) may be indicated as part of the multimodal treatment plan. However, literature comparing the survival outcomes and preoperative tumour activity and burden of CRAdenoCa and AAdenoCa peritonectomy patients without synchronous liver metastases (sLM) is scarce. Little is also known about the comparative incidence of sLM and metachronous LM (mLM) between CRAdenoCa and AAdenoCa peritonectomy patients. This study aimed to clarify the above.

PATIENTS AND METHODS

A retrospective cohort study of 684 CRAdenoCa and AAdenoCa primary peritonectomy patients between 2001-2021 was conducted at St George Hospital in Sydney, Australia.

RESULTS

Median overall survival (years) was equivocal between CRAdenoCa and AAdenoCa peritonectomy patients (1.7 vs. 1.9, p=0.35). Peritoneal cancer index and preoperative carcinoembryonic antigen (CEA) were significantly elevated (25 vs. 9, p<0.0001 and 7.9 vs. 5, p=0.0080) in AAdenoCa versus CRAdenoCa peritonectomy patients without sLM. The incidence of sLM and mLM was increased in CRAdenoCa peritonectomy patients (24% vs. 3.1%, p<0.0001 and 26% vs. 10%, p=0.0001).

CONCLUSION

This study demonstrates similar survival outcomes between CRAdenoCa and AAdenoCa peritonectomy patients. Despite elevated preoperative tumour burden and biological activity in AAdenoCa patients, CRAdenoCa patients had higher rates of sLM and mLM. Further studies are warranted to validate and identify cellular and molecular targets that increase CRAdenoCa's ability to metastasise to the liver.

Effective Use of Bromelain and Acetylcysteine (BromAc®) for Treatment of Perigastric Pseudomyxoma Peritonei: A Case Report

BACKGROUND/AIM

Pseudomyxoma peritonei (PMP) is a rare clinical condition of progressive peritoneal mucin accumulation. PMP has a reasonable survivability but with a notable risk of tumour recurrence. Standard treatment, including for tumour relapse, aims for a cure with complete cytoreductive surgery with hyperthermic intraperitoneal chemotherapy. In the case of tumour recurrence, surgery becomes progressively complex, and some patients are not suitable for surgery either due to patient preference or morbidity and mortality risk. BromAc® is an emerging, novel mucolytic combination therapy composed of bromelain and acetylcysteine which can be administered intratumorally via radiologically guided drains. It represents a minimally invasive treatment for patients who have symptomatic tumour deposits but are not surgical candidates.

CASE REPORT

We report the case of a 64-year-old male with a background of appendiceal PMP who presented with a gastric outlet obstruction from a perigastric tumour deposit. This was managed with BromAc® administration, following which the patient's symptoms resolved. This corresponded with an 80% reduction in the tumour volume radiologically.

CONCLUSION

BromAc® is an emerging minimally invasive treatment for PMP tumour deposits that may be considered as adjunctive or alternative treatment in patients who are not surgical candidates to reduce tumour burden and improve symptomatology and quality of life.

Malignant Peritoneal Mesothelioma: An In-Depth and Up-to-Date Review of Pathogenesis, Diagnosis, Management and Future Directions

Malignant peritoneal mesothelioma (MPM) is an extremely rare malignancy usually confined to the abdominal cavity. With an aggressive natural history, morbidity and mortality are consequences of progressive locoregional effects within the peritoneal cavity. The first reported case was in the early 20th century, however, due to the rare nature of the disease and a large gap in understanding of the clinicopathological effects, the next reported MPM cases were only published half a decade later. Since then, there has been exponential growth in our understanding of the disease, however, there are no prospective data and a paucity of literature regarding management. Traditionally, patients were treated with systemic therapy and the outcomes were very poor, with a median survival of less than one year. However, with the advent of cytoreductive surgery and locoregional chemotherapy, there have been significant improvements in survival. Even more recently, with an improved understanding of the molecular pathogenesis of MPM, there have been reports of improved outcomes with novel therapies. Given the disastrous natural history of MPM, the limited data, and the lack of universal treatment guidelines, an in-depth review of the past, present, and future of MPM is critical to improve treatment regimens and, subsequently, patient outcomes.

The 'Starburst' Sign: A Novel Description of PET Images in Carcinoma of Unknown Primary

BACKGROUND/AIM

Carcinoma of unknown primary (CUP) poses a formidable diagnostic challenge, characterised by high mortality rates and an elusive primary tumour site. While Positron emission tomography (PET) scans are routinely employed in the initial evaluation of CUP patients, identifying the primary tumour remains an ongoing struggle. In light of this, the aim of this case report is to introduce a novel radiological description, termed the 'Starburst' sign, derived from distinctive PET scan appearances associated with CUP.

CASE REPORT

In this report, we present the case of a 47-year-old female patient who presented with abdominal symptoms. Upon investigation, extensive peritoneal disease was observed, yet the primary tumour source remained unidentified. Despite further diagnostic efforts, including a normal gastroscopy, a PET scan was able to confirm the presence of high-volume metastatic disease, without an identifiable primary tumour. Palliative treatment was initiated, but unfortunately, the patient's condition deteriorated rapidly, leading to her demise.

CONCLUSION

The 'Starburst' sign, a unique radiological description of CUP in PET scans, has significant potential in advancing our understanding of the disease. It provides a visual analogy to a dying star, aiding comprehension of complex pathophysiology and implications of metastatic lesions. The introduction of the 'Starburst' sign benefits patients and healthcare professionals, enhancing education, assessment, and treatment of CUP. This novel description contributes to knowledge in the field and can impact clinical management.

A Systematic Review of Microwave Ablation for Colorectal Pulmonary Metastases

BACKGROUND/AIM

Pulmonary metastases are the second most common site of metastasis in colorectal cancer after the liver, and microwave ablation (MWA) for its treatment has grown in popularity in patients who are not suitable for pulmonary metastatectomy. However, its long-term efficacy remains unknown.

MATERIALS AND METHODS

A systematic review was conducted in July 2022 in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, using PubMed, EMBASE, Scopus, and Cochrane databases. Studies adopting MWA for colorectal cancer pulmonary metastases were included.

RESULTS

A total of 488 lesions were ablated in 230 patients across eight studies. The median duration of ablation was 10 minutes. The mean length of stay in hospital was 2.3 days. Complications included pneumothorax in 128 (52%) patients; pneumonia, which occurred in 4 (1.7%) patients, and pulmonary haemorrhage in 23 (10.0%) patients. Complete remission was achieved in 85 (37.0%) patients, local control was achieved in 103 (44.8%) patients, and residual or progressive disease remained in 85 (37.0%). Survival post ablation at 1 year was 89.2% and at 3 years was 40.3%. Post-ablation disease-free survival was 43.2% at 3 years.

CONCLUSION

MWA is an alternative treatment for pulmonary metastases of colorectal cancer. It has competitive theoretical properties and local recurrence rate compared to radiofrequency ablation.

Intraperitoneal BromAc® Does Not Interfere with the Healing of Colon Anastomosis

A combination of bromelain and acetylcysteine, BromAc^®, is an efficient intraperitoneal mucolytic for thick mucus secreted in pseudomyxoma peritonei (PMP). Patients with PMP quite often undergo colon anastomosis. Hence, we investigated the effect of the intraperitoneal delivery of BromAc^® on colon-anastomosis healing in a rat model. Sixteen Wistar rats were divided into two groups (N = 8). The controls received intraperitoneal saline after anastomosis, whilst the other group received BromAc^®. They were monitored for body-weight and general health parameters. Half the rats in each group (N = 4) were culled at 4 or 13 days post-surgery for assessment. The healing process of the tissues was assessed by burst pressure and collagen density with histology to assess the integrity of the internal organs. The results indicated that there was a similar pattern of weight fluctuation during the experiment, although the rats treated with the BromAc^® showed slightly greater weight loss during the first 4 days. Although the burst pressure was similar in both groups, the BromAc^® group at day 13 showed a slightly higher burst pressure, which was complemented by a higher collagen density (albeit not statistically significant). The histology of the internal organs was comparable to those of the controls. This study indicates that the intraperitoneal delivery of BromAc^® in a rat model does not interfere with the healing process of colonic anastomosis.

Cytoreductive Surgery and HIPEC for Regionally Advanced Gallbladder Cancer: a Case Report

Gallbladder cancer is a rare cancer, associated with an extremely poor prognosis. Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy is not commonly performed in gallbladder cancer; however, case series have shown prolonged survival time with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in gallbladder cancer and no increase in morbidity compared to cytoreductive surgery without hyperthermic intraperitoneal chemotherapy. We present a case of gallbladder cancer with peritoneal metastases in a 60-year-old male who was successfully treated with complete cytoreductive surgery and hyperthermic intraperitoneal chemotherapy and survived for 4 years following diagnosis.

Overall survival and morbidity are not associated with advanced age for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: a single centre experience

Objectives

Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) has enabled better prognosis for patients with peritoneal surface malignancies. However, in older age groups, short -and long-term outcomes are still perceived as poor. We evaluated patients aged 70 and over and determine if age is a predictor of morbidity, mortality and overall survival (OS).

Methods

A retrospective cohort analysis was performed on CRS/HIPEC patients and categorised by age. The primary outcome was overall survival. Secondary outcomes included morbidity, mortality, hospital and incentive care unit (ICU) stay and early postoperative intraperitoneal chemotherapy (EPIC).

Results

A total of 1,129 patients were identified with 134 aged 70+ and 935 under 70. There was no difference in OS (p=0.175) or major morbidity (p=0.051). Advanced age was associated with higher mortality (4.48 vs. 1.11 %, p=0.010), longer ICU stay (p<0.001) and longer hospitalisation (p<0.001). The older group was less likely to achieve complete cytoreduction (61.2 vs. 73 %, p=0.004) and receive EPIC (23.9 vs. 32.7 %, p=0.040).

Conclusions

In patients undergoing CRS/HIPEC, age of 70 and above does not impact OS or major morbidity but is associated with increased mortality. Age alone should not be a limiting factor in selecting CRS/HIPEC patients. Careful multi-disciplinary approach is needed when considering those of advanced age.

Enhancement of treatment efficacy of hepatic tumours using Trans-arterial-chemoembolization

This review article examines the basic principle underlying trans-arterial chemoembolization (TACE) used for treating unrespectable liver cancer with discussion on the barriers that are present for efficient drug delivery with suggestions on methods that may be used to overcome these barriers and hence enhance the efficacy of the technique. Current drugs used with TACE along with inhibitors of neovascularisation are briefly discussed. It also compares the conventional method of chemoembolization with TACE and rationalizes why there is not much of a difference between the two methods on treatment efficacy. Further it also suggests alternative methods of drug delivery that may be used instead of TACE. Additionally, it discusses the disadvantages on using non degradable microspheres with recommendations for degradable microspheres within 24 hours to overcome rebound neovascularisation owing to hypoxia. Finally, the review examines some of the biomarkers that are used to assess treatment efficacy with indication that non-invasive and sensitive biomarkers should be identified for routine screening and early detection. The review concludes that, if the current barriers present in TACE can be overcome along with the use of degradable microspheres and efficient biomarkers for monitoring efficacy, then a more robust treatment would emerge that may even serve as a cure.

Bromelain and acetylcysteine (BromAc®): a novel approach to the treatment of mucinous tumours

Mucins are a significant extracellular component of neoplastic entities such as pseudomyxoma peritonei and several gastrointestinal adenocarcinomas. Mucinous tumours present a challenge for systemic treatments due to poor drug penetrance and increased resistance. Therefore, the development of an effective mucolytic therapy has significant therapeutic implications for these tumour types. BromAc® is a novel mucolytic agent consisting of bromelain and acetylcysteine. It has demonstrated significant mucolysis and antitumour effects in vitro and in vivo for several mucinous tumours. It has also exhibited a synergistic potentiation of the effect of several cytotoxic agents on mucinous tumours in preclinical studies. Furthermore, it demonstrates locoregional safety and efficacy in animal and clinical studies. This literature review will summarise the history of BromAc® for mucinous tumours, including its conception, preclinical development in vitro and in vivo, and clinical evidence. The implications of current data and directions for future research are then discussed.

Effect of Nebulized BromAc on Rheology of Artificial Sputum: Relevance to Muco-Obstructive Respiratory Diseases

Respiratory diseases such as cystic fibrosis, COPD, and COVID-19 are difficult to treat owing to viscous secretions in the airways that evade mucocilliary clearance. Earlier studies have shown success with BromAc as a mucolytic agent. Hence, we tested the formulation on two gelatinous airway representative sputa models, to determine whether similar efficacy exist. Sputum lodged in an endotracheal tube was treated to aerosol N-acetylcysteine, bromelain, or their combination (BromAc). After measuring the particle size of aerosolized BromAc, the apparent viscosity was measured using a capillary tube method, whilst the sputum flow was assessed using a 0.5 mL pipette. Further, the concentration of the agents in the sputa after treatment were quantified using chromogenic assays. The interaction index of the different formulations was also determined. Results indicated that the mean particle size of BromAc was suitable for aerosol delivery. Bromelain and N-acetylcysteine affected both the viscosities and pipette flow in the two sputa models. BromAc showed a greater rheological effect on both the sputa models compared to individual agents. Further, a correlation was found between the rheological effects and the concentration of agents in the sputa. The combination index using viscosity measurements showed synergy only with 250 µg/mL bromelain + 20 mg/mL NAC whilst flow speed showed synergy for both combinations of bromelain (125 and 250 µg/mL) with 20 mg/mL NAC. Hence, this study indicates that BromAc may be used as a successful mucolytic for clearing airway congestion caused by thick mucinous immobile secretions.

Use of Prognostic Factors and Scores in Selection of Patients with Colorectal Cancer Peritoneal Metastasis (CRPM) for Cytoreductive Surgery and Intraperitoneal Chemotherapy (CRS/IPC): Results of an International Survey Among Oncologic Clinicians

BACKGROUND

No universally accepted guidelines exist for treatment of patients with colorectal cancer peritoneal metastases (CRPM) undergoing cytoreductive surgery and intraperitoneal chemotherapy (CRS/IPC). Several uncertainties remain concerning almost every aspect of this treatment modality, resulting in marked variability in patient management and likely outcomes. This survey aimed to define variations and trends in clinician decision making more clearly.

METHODS

A 41-question web-based survey was distributed electronically via the Peritoneal Surface Oncology Group International (PSOGI), the International Society for the Study of Pleura and Peritoneum (ISSPP) as well as via social media (particularly Twitter). The survey sought to address and record clinician responses regarding patient workup/assessment, selection for preoperative systemic therapy, preoperative and intraoperative selection for CRS/IPC, and consideration of prognosis and complications.

RESULTS

Complete responses were received from 60 clinicians from 45 centres in 22 countries. Upon assessment of survey responses, several interesting trends were noted in each section of the survey. Significant variability in surgeon practice and opinion were identified concerning almost every aspect of the treatment modality.

CONCLUSION

This international survey provides the most comprehensive insight into clinician decision-making trends regarding patient assessment, selection and management. This should allow areas of variability to be more clearly defined and could potentially prompt development of initiatives for achieving consensus and standardisation of care in the future.

Strangulated interstitial interparietal hernia following lower segment caesarean section: a case report

Interparietal hernias are rare and occur most commonly in the long-term postoperative setting following abdominopelvic surgery. This case report describes the development of a strangulated interparietal hernia through a defect in the posterior rectus sheath 4 days post-lower segment caesarean section (LSCS) in a 36-year-old female. Whilst she had an acute abdomen, she did not have a palpable incisional hernia. Her interparietal hernia was identified via a computed tomography scan of her abdomen and pelvis. She underwent a midline laparotomy where ischaemic small bowel was found within her hernia. This was resected and she had an unremarkable recovery. This case is the first of its kind and highlights the diagnostic challenge of interparietal hernias in acute postoperative patients as well as the importance of having a low threshold for suspicion for complicated interparietal hernias in patients with an acute abdomen following LSCS.

Comparing Survival Outcomes and Impact of EPIC in Patients Undergoing CRS/HIPEC for Mucinous Appendiceal Neoplasm

BACKGROUND/AIM

This study sought to investigate the difference in survival outcomes in patients with complete cytoreduction (CC)-0 or CC-1 mucinous appendiceal cancer undergoing cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC). It also investigated what effect early postoperative intraperitoneal chemotherapy (EPIC) may have on survival based on CC score and histology.

PATIENTS AND METHODS

This was a retrospective single centre study of patients that underwent CRS/HIPEC +/- EPIC for mucinous appendiceal neoplasms from June 2003 to February 2022.

RESULTS

A total of 545 patients were identified. Although there was a survival difference between CC-0 and CC-1 on univariate analyses, this was not statistically significant on multivariate analysis. Histology, peritoneal cancer index, and EPIC status were demonstrated to be independent factors that affected overall survival (OS) on multivariate analysis. Patients with CC-1 that received EPIC had significantly improved OS (mean OS 14 years) when compared to patients that did not receive EPIC (mean OS 6 years). In CC-1, OS was significantly improved in patients that received EPIC in both low-grade (p<0.001) and high-grade (p=0.012) disease. OS for patients that received EPIC at 1, 5, and 10 years was 95%, 80%, and 59%, respectively. OS for patients that did not receive EPIC at 1, 5, and 10 years was 84%, 49%, and 30%, respectively.

CONCLUSION

There was no difference in OS between CC-0 and CC-1. The implementation of EPIC in patients with CC-1 significantly improved OS in both low-grade and high-grade disease and thus we recommend its addition in CC-1 disease to achieve optimal survival outcome.

Perioperative chemotherapy in colorectal cancer with peritoneal metastases: A global propensity score matched study

BACKGROUND

There is a paucity of studies evaluating perioperative systemic chemotherapy in conjunction with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in patients with colorectal cancer peritoneal metastases (CRCPM). The aim was to evaluate neoadjuvant and/or adjuvant systemic therapy in CRCPM.

METHODS

Patients with CRCPM from 39 treatment centres globally from January 1, 1991, to December 31, 2018, who underwent CRS+HIPEC were identified and stratified according to neoadjuvant/adjuvant use. Crude data analysis, propensity score matching (PSM) and Cox-proportional hazard modelling was performed.

FINDINGS

Of 2093 patients, 1613 were included in neoadjuvant crude evaluation with 708 in the PSM cohort (354 patients/arm). In the adjuvant evaluation, 1176 patients were included in the crude cohort with 778 in the PSM cohort (389 patients/arm). The median overall survival (OS) in the PSM cohort receiving no neoadjuvant vs neoadjuvant therapy was 37.0 months (95% CI: 32.6-42.7) vs 34.7 months (95% CI: 31.2-38.8, HR 1.08 95% CI: 0.88-1.32, p = 0.46). The median OS in the PSM cohort receiving no adjuvant therapy vs adjuvant therapy was 37.0 months (95% CI: 32.9-41.8) vs 45.7 months (95% CI: 38.8-56.2, HR 0.79 95% CI: 0.64-0.97, p = 0.022). Recurrence-free survival did not differ in the neoadjuvant evaluation but differed in the adjuvant evaluation - HR 1.04 (95% CI: 0.87-1.25, p = 0.66) and 0.83 (95% CI: 0.70-0.98, p = 0.03), respectively. Multivariable Cox-proportional hazard modelling in the crude cohorts showed hazard ratio 1.08 (95% CI: 0.92-1.26, p = 0.37) for administering neoadjuvant therapy and 0.86 (95% CI: 0.72-1.03, p = 0.095) for administering adjuvant therapy.

INTERPRETATION

Neoadjuvant therapy did not confer a benefit to patients undergoing CRS+HIPEC for CRCPM, whereas adjuvant therapy was associated with a benefit in this retrospective setting.

FUNDING

None.

Genetics of SLE: does this explain susceptibility and severity across racial groups?

The prevalence and severity of systemic lupus erythematosus (SLE) have been found to vary across populations of different ancestries. This review explores whether these differences can be explained by the genetic aetiology of the condition. Large genetic studies suggest that populations of different ancestry share the same risk loci but the individual risk alleles are more common in some, leading to a higher prevalence, severity, and earlier onset of the condition. Despite many of the loci being shared across populations, some have been found to be ancestry-specific and these are hypothesised to have undergone differential selective pressure in recent human history. Additionally, the effectiveness of some of the drugs used in SLE has been found to vary across ancestries, which might affect the progression of the disease, but it is unclear whether these differences are pharmacogenetic. We concluded that to understand the full role of genetics in the risk, presentation and response to treatment of SLE, larger studies including individuals from a wider representation of ancestries will be required.

Peritoneal Oxygenation as a Novel Technique for Extrapulmonary Ventilation; A Review and Discussion of the Literature

The COVID-19 crisis has highlighted the difficulties that might occur when attempting to oxygenate patients who have suffered a severe pulmonary insult, including in the development of acute respiratory distress syndrome (ARDS). Traditional mechanical ventilation (MV) is effective; however, in severe cases of hypoxia, the use of rescue therapy, such as extracorporeal membrane oxygenation (ECMO), may be required but is also associated with significant complexity and complications. In this review, we describe peritoneal oxygenation; a method of oxygenation that exploits the peritoneum's gas exchange properties in a fashion that is similar to peritoneal dialysis and has shown considerable promise in animal models. We have conducted a review of the available literature and techniques, including intraperitoneal perfluorocarbons, intraperitoneal jet ventilation, a continuous low-pressure oxygen system (PEROX) and the use of phospholipid-coated oxygen microbubbles (OMBs) through peritoneal microbubble oxygenation (PMO). We conclude that peritoneal oxygenation is a promising technique that warrants further investigation and might be used in clinical settings in the future.

Comprehensive genetic and functional analyses of Fc gamma receptors influence on response to rituximab therapy for autoimmunity

BACKGROUND

Rituximab is widely used to treat autoimmunity but clinical response varies. Efficacy is determined by the efficiency of B-cell depletion, which may depend on various Fc gamma receptor (FcγR)-dependent mechanisms. Study of FcγR is challenging due to the complexity of the FCGR genetic locus. We sought to assess the effect of FCGR variants on clinical response, B-cell depletion and NK-cell-mediated killing in rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE).

METHODS

A longitudinal cohort study was conducted in 835 patients [RA = 573; SLE = 262]. Clinical outcome measures were two-component disease activity score in 28-joints (2C-DAS28CRP) for RA and British Isles Lupus Assessment Group (BILAG)-2004 major clinical response (MCR) for SLE at 6 months. B-cells were evaluated by highly-sensitive flow cytometry. Single nucleotide polymorphism and copy number variation for genes encoding five FcγRs were measured using multiplex ligation-dependent probe amplification. Ex vivo studies assessed NK-cell antibody-dependent cellular cytotoxicity (ADCC) and FcγR expression.

FINDINGS

In RA, carriage of FCGR3A-158V and increased FCGR3A-158V copies were associated with greater 2C-DAS28CRP response (adjusted for baseline 2C-DAS28CRP). In SLE, MCR was associated with increased FCGR3A-158V, OR 1.64 (95% CI 1.12-2.41) and FCGR2C-ORF OR 1.93 (95% CI 1.09-3.40) copies. 236/413 (57%) patients with B-cell data achieved complete depletion. Homozygosity for FCGR3A-158V and increased FCGR3A-158V copies were associated with complete depletion in combined analyses. FCGR3A genotype was associated with rituximab-induced ADCC, and increased NK-cell FcγRIIIa expression was associated with improved clinical response and depletion in vivo. Furthermore, disease status and concomitant therapies impacted both NK-cell FcγRIIIa expression and ADCC.

INTERPRETATION

FcγRIIIa is the major low affinity FcγR associated with rituximab response. Increased copies of the FCGR3A-158V allele (higher affinity for IgG1), influences clinical and biological responses to rituximab in autoimmunity. Enhancing FcγR-effector functions could improve the next generation of CD20-depleting therapies and genotyping may stratify patients for optimal treatment protocols.

FUNDING

Medical Research Council, National Institute for Health and Care Research, Versus Arthritis.

COVID-19 and systemic lupus erythematosus genetics: A balance between autoimmune disease risk and protection against infection

Genome wide association studies show there is a genetic component to severe COVID-19. We find evidence that the genome-wide genetic association signal with severe COVID-19 is correlated with that of systemic lupus erythematosus (SLE), having formally tested this using genetic correlation analysis by LD score regression. To identify the shared associated loci and gain insight into the shared genetic effects, using summary level data we performed meta-analyses, a local genetic correlation analysis and fine-mapping using stepwise regression and functional annotation. This identified multiple loci shared between the two traits, some of which exert opposing effects. The locus with most evidence of shared association is TYK2, a gene critical to the type I interferon pathway, where the local genetic correlation is negative. Another shared locus is CLEC1A, where the direction of effects is aligned, that encodes a lectin involved in cell signaling, and the anti-fungal immune response. Our analyses suggest that several loci with reciprocal effects between the two traits have a role in the defense response pathway, adding to the evidence that SLE risk alleles are protective against infection.

We observed a correlation between the genetic associations with severe COVID-19 and those with systemic lupus erythematosus (SLE, Lupus), and aimed to discover which genetic loci were shared by these diseases and what biological processes were involved. This resulted in the discovery of several genetic loci, some of which had alleles that were risk for both diseases and some of which were risk for severe COVID-19 yet protective for SLE. The locus with most evidence of shared association (TYK2) is involved in interferon production, a process that is important in response to viral infection and known to be dysregulated in SLE patients. Other shared associated loci contained genes also involved in the defense response and the immune system signaling. These results add to the growing evidence that there are alleles in the human genome that provide protection against viral infection yet are risk for autoimmune disease.

Physical and chemical factors affecting the loading and release of bromelain from DC beads

Doxorubicin loaded DC beads (microspheres) has been used for treating un-resectable tumours by transarterial chemoembolization (TACE). We have shown that bromelain, an enzyme from the pineapple plant, enhances the cytotoxic effect of a number of chemotherapeutic drugs and in an earlier study we have demonstrated that it can be loaded into DC beads. Therefore, in the current study we have investigated how certain physical and chemical parameters affect its loading and release for future development of DC beads in cancer therapy. Aliquots of 40-60 µL of DC beads (100-300 µm) were treated to bromelain in distilled water and various parameters such as pH of solution, bromelain concentration, temperature, loading period, presence/absence of agitation and the cytotoxic effect of bromelain loaded beads were investigated. Further release kinetics was also studied with additional investigation of pH effect on the proteolytic activity of bromelain. Results indicate that higher loading of bromelin was achieved in the beads at lower pH, higher concentration of bromelain, with agitation, 24 hours loading and ambient room temperature. Proteolytic activity of bromelain was maximal at pH 4.5 whilst cytotoxicity was at par if not better in the bromelain loaded DC beads. Release kinetics indicated that bromelain can be delivered over several hours. Hence, we conclude that bromelain can be loaded more efficiently with manipulation of certain parameters with noticeable cytotoxicity in tumour cells.

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) for ovarian cancer in an Australian institution: lessons from 20 years' experience

Objectives

We report the 20-year experience of the largest Australian unit performing cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for ovarian cancer and reflect on learning opportunities.

Methods

A retrospective review of all cases of CRS for ovarian cancer at St George Peritonectomy Unit from Jan 1998 to Jan 2018 was performed. Prospectively collected data include age, stage, histology, disease extent (PCI), completeness of cytoreduction (CC score), HIPEC regime, 30-day surgical morbidity, disease recurrence, and death. Survival was computed using Kaplan–Meier method and analysed using log-rank tests and Cox-proportional hazards models.

Results

Forty-one women with advanced ovarian cancer (11 primary stage III/IV, 30 recurrent) underwent CRS, 29 (71%) with HIPEC. Most (68%) had high-volume disease (PCI > 15). In 98%, CC0/CC1 (residual < 2.5 mm) was achieved. Fourteen (34%) had grade 3/4 complications, 1 patient (2%) died within 30 days and 2 patients (5%) died within 90 days. Progression-free and median overall survival was 30.0 and 67.0 months for primary cancer, and 6.7 and 18.1 months for recurrent cancer. Survival was associated with platinum-sensitivity, PCI ≤ 15, and CC score 0, but not HIPEC.

Conclusion

This study reports outcomes for patients with advanced ovarian cancer patients treated in an Australian centre offering CRS and HIPEC. Whilst survival and morbidity outcomes were good for primary disease, they were poorer than predicted from the literature for cases of recurrent disease. The incorporation of evidence-based predictors of survival and multidisciplinary input are essential to achieve the best survival outcomes.

Outcomes and prognostic factors of cytoreductive surgery and perioperative intraperitoneal chemotherapy in high-volume peritoneal carcinomatosis

BACKGROUND AND OBJECTIVES

The management of patients with extensive appendiceal mucinous neoplasms and mesothelioma is controversial. Our aims were to analyze overall survival (OS), disease-free survival (DFS) and independent prognostic factors associated with high peritoneal cancer index (PCI) status in patients who underwent cytoreductive surgery (CRS) and perioperative intraperitoneal chemotherapy (PIC).

METHODS

A prospectively-maintained database for patients with appendiceal neoplasms and mesothelioma undergoing CRS/PIC from year 1996 to 2018 was retrospectively analyzed. Patients who achieved complete cytoreduction were stratified into limited (PCI < 30) and extensive (PCI ≥ 30) disease groups.

RESULTS

260 female and 235 male patients were identified. The 5-year survival for low-grade appendiceal mucinous neoplasms (LAMN) was significantly higher in the low PCI group (96.2% vs. 63.5%, p < 0.001). There was no difference in the OS across both groups in high-grade appendiceal mucinous neoplasms (HAMN) (63 vs. 69 months; p = 0.942) and mesothelioma (72 vs. 42 months; p = 0.058). Overall mortality was 2%. Grade III/IV complications were significantly higher in extensive disease (68% vs. 36.6%, p < 0.001). On multivariate analysis, use of EPIC and blood transfusion (>8 units) were independent positive and negative prognostic factors, respectively, associated with OS. Meanwhile, use of EPIC conferred benefit in DFS while increased blood transfusion (>8 units) and elevated preoperative CA125 were predictive of a poor DFS.

CONCLUSION

Long-term survivals following CRS/PIC are achievable with acceptable mortality and higher morbidity rates in extensive appendiceal mucinous neoplasms and mesothelioma. High PCI status does not preclude treatment with CRS/PIC.

Cytoreductive Surgery and HIPEC for Malignant Peritoneal Mesothelioma: Outcomes and Survival From an Australian Centre

BACKGROUND/AIM

The aim of the study was to determine outcomes and overall survival (OS) in patients undergoing cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC) for malignant peritoneal mesothelioma (MPM).

PATIENTS AND METHODS

This was a retrospective cohort study from a prospectively maintained database of patients that underwent CRS/HIPEC for MPM from April 1999 to December 2021.

RESULTS

A total of 81 patients were identified with MPM. Median OS was 53 months with a 1-, 3- and 5-year OS of 76%, 55% and 49% respectively. Multivariate analysis identified lymph node status, PCI and CC score as statistically significant prognostic factors that impact survival. Median OS for PCI 0-20 was 103 months vs. 33 months for PCI 21-39 (p=0.005). Median OS for CC0, CC1 and CC2 were 104, 30 and 2.7 months respectively (p<0.001). Hazard ratio for node-positive disease over node-negative was 2.14 (95% CI=1.07-4.31, p<0.033). Grade III/IV complication rate was 43.2% and mortality 4.9%.

CONCLUSION

CRS/HIPEC remains the gold standard for treating patients with MPM with excellent patient OS. Lymph node status, PCI and CC score were independent prognostic factors that affect OS.

Long term survival after multiple microwave ablations for colorectal cancer lung metastases: A case report

Colorectal cancer is one of the leading causes of cancer-associated morbidity and mortality in the world, with lower survival rates when metastases are present. We present a case of a 69-year-old man, diagnosed with metastatic rectal cancer to the lungs in 2015. Over the course of 5 years, he was treated with 4 microwave ablation procedures to both his lungs. Despite this, he does not have any local recurrence or any symptoms since he was first diagnosed 7 years ago. This case highlights the potential for microwave ablation to be used for curative intent in pulmonary metastases in colorectal cancer as an alternative to more invasive and complex procedures such as metastasectomies or lung resection, as well as the benefit of using microwave ablation for disease control to improve patients’ quality of life.

A novel method for potentiation of chemotherapy in soft tissue sarcomas with BromAc

Single-agent doxorubicin currently forms part of standard care for patients with sarcomas. However, efficacy is limited by the presence of dose-dependent cardiotoxicity and toxicity to renal, hepatic, and neurological systems. Therefore, there is a pressing need for novel drug regimens which can provide increased efficacy and safety. BromAc is a novel drug combination developed as a mucolytic agent which has demonstrated anticancer activity both in vitro and in vivo in several cancers. Here, we investigated the efficacy of BromAc in combination with doxorubicin for four subtypes of sarcoma. Cell proliferation, alongside western blot for a variety of cell cycle, apoptosis, and autophagy biomarkers assays was performed following treatment of cell lines in vitro at various concentrations of BromAc and doxorubicin. The impact of drug treatment on MUC1 and MUC4 levels was assessed through immune-cytological methods. Drug agent synergy was assessed through the Chou-Talalay framework. BromAc treatment in combination with doxorubicin was more efficacious than single-agent doxorubicin, with synergistic effects observed. The immuno-cytological analysis demonstrated significant mucin depletion following treatment with BromAc and doxorubicin used in combination, providing a potential mechanistic underpinning for the observed anticancer effects.

Sodium thiosulfate during cisplatin-based hyperthermic intraperitoneal chemotherapy is associated with transient hypernatraemia without clinical sequelae

Objectives

Cisplatin is commonly used during intraperitoneal chemotherapy however has well-established nephrotoxic side-effects. Sodium thiosulfate is often added to cisplatin-based hyperthermic intraperitoneal chemotherapy (HIPEC) protocols to mitigate this, however evidence regarding risk of hypernatraemia is scarce as of yet.

Methods

We retrospectively identified patients undergoing cytoreductive surgery (CRS) for peritoneal surface malignancies of any origin at a single high-volume unit between April 2018 and December 2020. Patients were included if they received cisplatin-based HIPEC with intravenous sodium thiosulfate. Blood tests were collected pre-surgery and then daily during admission. Hypernatraemia was defined as serum sodium >145 mmol/L. Renal impairment was defined using the RIFLE criteria.

Results

Eleven CRSs met inclusion criteria, the majority of which were indicated for ovarian cancer (72.7%). One (9.1%) patient with mesothelioma received mitomycin C as an additional chemotherapy agent. The incidence of hypernatraemia was 100% but all cases were transient, with no clinical sequelae observed. The rate of AKI was 36.4%, with three (27.3%) patients classified as risk and one (9.1%) instance of failure. No long-term renal impairment was observed.

Conclusions

Despite biochemical evidence of mild hypernatraemia but with the absence of clinical sequelae, sodium thiosulfate appears to be safe when used in adjunct to cisplatin-based HIPEC during CRS. These findings should be evaluated with further comparative studies. When describing renal impairment, it is important that standardisation in reporting occurs, with the RIFLE and Acute Kidney Injury Network criteria now the preferred consensus definitions.

Cost-effectiveness of Iterative Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for the Treatment of Peritoneal Carcinomatosis

BACKGROUND

Iterative cytoreduction (iCRS) and hyperthermic intraperitoneal chemotherapy is a treatment for recurrence of peritoneal carcinomatosis. There are considerable upfront costs for this approach for which the cost-effectiveness has not been evaluated.

PATIENTS AND METHODS

We used a prospectively maintained database of patients having undergone primary and iterative cytoreduction at St. George Hospital between January 1, 2014, and December 31, 2017, which was linked with financial data. Cost effectiveness and survival outcomes were used to compare primary cytoreduction (pCRS) and iterative cytoreduction (iCRS) in addition to comparison with other treatment modalities.

RESULTS

The average cost per patient in Australian dollars was $69,295 ($14,691-$696,002) and the average cost per life-year was $15,842. There was no difference in cost-effectiveness between those who had undergone pCRS and those who had undergone iCRS. The overall survival was 52.5 months (95% confidence interval=49.7-55.2 months) with no difference in survival between pCRS and iCRS groups. The median length of hospital stay was significantly longer for patients in the pCRS treatment group (25.51 days) when compared to the iCRS treatment group (21.15 days, p=0.034).

CONCLUSION

iCRS is a cost-effective treatment in the management of recurrent peritoneal carcinomatosis.

OA13 Comprehensive genetic and functional analyses of Fc gamma receptors explain response to rituximab therapy for autoimmune rheumatic diseases

Background/Aims

Rituximab is widely used to treat rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) but clinical response varies. Efficacy is determined by the efficiency of depletion, which may depend on a variety of Fc gamma receptor (FcγR)-dependent mechanisms. Previous research was limited by complexity of the FCGR locus, not integrating copy number variation with functional SNP, and small sample size. Here, we aimed to assess the effect of the full range of FcγRs variants on depletion, clinical response and functional effect on NK-cell-mediated killing in two rheumatic diseases with a view to personalised B-cell depleting therapies.

Methods

A prospective longitudinal study was conducted in 873 patients (RA = 611; SLE=262) from four cohorts (BSRBR-RA, BILAG-BR, Leeds RA and Leeds SLE Biologics). For RA, the outcome measures were 3C-DAS28CRP and 2C-DAS28CRP at 6 (+/-3) months post-rituximab (adjusted for baseline DAS28). For SLE, major clinical response (MCR) was defined as improvement of active BILAG-2004 domains to grade C/better at 6 months. B-cell depletion was evaluated by highly-sensitive flow cytometry. Qualitative and quantitative polymorphisms for five major FcγRs were measured using a commercial multiplex ligation-dependent probe amplification. Median NK cell FcγRIIIa expression (CD3-CD56+CD16+) and NK-cell degranulation (CD107a) in the presence of rituximab-coated Daudi/Raji B-cell lines were assessed using flow cytometry.

Results

In RA, for FCGR3A, carriage of V allele (coefficient -0.25 [SE 0.11]; p = 0.02) and increased copies of V allele (-0.20 [0.09]; p = 0.02) were associated with better 2C-DAS28 response. Irrespective of FCGR3A genotype, increased gene copies were associated with a better response. In SLE, 177/262 (67.6%) achieved BILAG response (MCR=34.4%; Partial=33.2%). MCR was associated with increased copies of FCGR3A-158V allele, OR 1.64 (95% CI 1.12-2.41) and FCGR2C-ORF allele 1.93 (1.09-3.40). Of patients with B-cells data in the combined cohort, 236/413 (57%) achieved complete depletion post-rituximab. Only homozygosity for V allele and higher copies of FCGR3A V allele were associated with increased odds of depletion. Patients with complete depletion had higher NK cell FcγRIIIa expression at rituximab initiation than those with incomplete depletion (p = 0.04) and this higher expression was associated with improved EULAR response in RA. Moreover, for FCGR3A, degranulation activity was increased in V allele carriers vs FF genotype in the combined cohort; p = 0.02.

Conclusion

FcγRIIIa is the major low affinity FcγR and increased copies of the FCGR3A-158V allele, encoding the allotype with a higher affinity for IgG1, was associated with clinical and biological responses to rituximab in two autoimmune diseases. This was supported by functional data on NK cell-mediated cytotoxicity. In SLE, increased copies of the FCGR2C-ORF allele was also associated with improved response. Our findings indicate that enhancing FcγR-effector functions could improve the next generation of CD20-depleting therapies and genotyping could stratify patients for optimal treatment protocols.

Disclosure

M. Md Yusof: None. J. Robinson: None. V. Davies: None. D. Wild: None. M. Morgan: None. J. Taylor: None. Y. El-Sherbiny: None. D. Morris: None. L. Liu: None. A. Rawstron: None. M. Buch: None. D. Plant: None. H. Cordell: None. J. Isaacs: None. I. Bruce: None. P. Emery: Grants/research support; PE has received consultancy fees and funding for research from Roche within the last 3 years. A. Barton: None. T. Vyse: None. J. Barrett: None. E. Vital: Grants/research support; EMV has received consultancy fees and funding for research from Roche within the last 3 years. A. Morgan: None.

Ex-vivo mucolytic and anti-inflammatory activity of BromAc in tracheal aspirates from COVID-19

COVID-19 is a lethal disease caused by the pandemic SARS-CoV-2, which continues to be a public health threat. COVID-19 is principally a respiratory disease and is often associated with sputum retention and cytokine storm, for which there are limited therapeutic options. In this regard, we evaluated the use of BromAc®, a combination of Bromelain and Acetylcysteine (NAC). Both drugs present mucolytic effect and have been studied to treat COVID-19. Therefore, we sought to examine the mucolytic and anti-inflammatory effect of BromAc® in tracheal aspirate samples from critically ill COVID-19 patients requiring mechanical ventilation.

Method

Tracheal aspirate samples from COVID-19 patients were collected following next of kin consent and mucolysis, rheometry and cytokine analysis using Luminex kit was performed.

Results

BromAc® displayed a robust mucolytic effect in a dose dependent manner on COVID-19 sputum ex vivo. BromAc® showed anti-inflammatory activity, reducing the action of cytokine storm, chemokines including MIP-1alpha, CXCL8, MIP-1b, MCP-1 and IP-10, and regulatory cytokines IL-5, IL-10, IL-13 IL-1Ra and total reduction for IL-9 compared to NAC alone and control. BromAc® acted on IL-6, demonstrating a reduction in G-CSF and VEGF-D at concentrations of 125 and 250 µg.

Conclusion

These results indicate robust mucolytic and anti-inflammatory effect of BromAc® ex vivo in tracheal aspirates from critically ill COVID-19 patients, indicating its potential to be further assessed as pharmacological treatment for COVID-19.

Positive selection acts on regulatory genetic variants in populations of European ancestry that affect ALDH2 gene expression

ALDH2 is a key enzyme in alcohol metabolism that protects cells from acetaldehyde toxicity. Using iHS, iSAFE and FST statistics, we identified regulatory acting variants affecting ALDH2 gene expression under positive selection in populations of European ancestry. Several SNPs (rs3184504, rs4766578, rs10774625, rs597808, rs653178, rs847892, rs2013002) that function as eQTLs for ALDH2 in various tissues showed evidence of strong positive selection. Very large pairwise FST values indicated high genetic differentiation at these loci between populations of European ancestry and populations of other global ancestries. Estimating the timing of positive selection on the beneficial alleles suggests that these variants were recently adapted approximately 3000-3700 years ago. The derived beneficial alleles are in complete linkage disequilibrium with the derived ALDH2 promoter variant rs886205, which is associated with higher transcriptional activity. The SNPs rs4766578 and rs847892 are located in binding sequences for the transcription factor HNF4A, which is an important regulatory element of ALDH2 gene expression. In contrast to the missense variant ALDH2 rs671 (ALDH2*2), which is common only in East Asian populations and is associated with greatly reduced enzyme activity and alcohol intolerance, the beneficial alleles of the regulatory variants identified in this study are associated with increased expression of ALDH2. This suggests adaptation of Europeans to higher alcohol consumption.

Bromelain and acetylcysteine (BromAc®) alone and in combination with gemcitabine inhibit subcutaneous deposits of pancreatic cancer after intraperitoneal injection

Gemcitabine (GEM) is commonly chosen for treating pancreatic cancer. However, its use is limited by toxicity. Earlier in vitro studies with GEM in combination with Bromelain (Brom) and Acetylcysteine (Ac) indicated a substantial reduction in IC₅₀. In this study, immunocytochemistry and Western blot were used to explore the mechanistic effects of Brom and Ac (BromAc^®) in vitro. Then, we explored the efficacy and safety of BromAc^® only and with GEM in a pancreatic cancer model in vivo. Immunocytochemistry results revealed a reduction in both MUC1 and MUC4 post-treatment. There was a decrease in VEGF, MMP-9, NF-κβ and cleavage of PARP. There was also a decrease in the cell cycle regulators Cyclin B and D as well as TGF-β and the anti-apoptotic Bcl-2. In vivo, the low and high doses of BromAc^® alone and with chemotherapy agents were safe. A very significant reduction in pancreatic tumour volume, weight, and ki67 were seen with BromAc^® therapy and was equal to treatment with GEM alone and better than treatment with 5-FU. In addition, tumour density was significantly reduced by BromAc^®. In conclusion, the anticancer effect of BromAc^® is probably related to its mucin depletion activity as well as its effect on proteins involved in cell cycle arrest, apoptosis and modulation of the tumour microenvironment. The in vivo results are encouraging and are considered the first evidence of the efficacy of BromAc^® in pancreatic cancer. These results also provide some mechanistic leads of BromAc^®.

Peritoneal Spread of Low-grade Appendiceal Tumours - 2 Days of Early Postoperative Intra-peritoneal Chemotherapy Are Enough

BACKGROUND/AIM

While controversial, cytoreductive surgery (CRS) with heated intra-peritoneal chemotherapy (HIPEC) and early postoperative intra-peritoneal chemotherapy (EPIC) remains the mainstay of treatment for low grade appendiceal neoplasm with pseudomyxoma peritonei (PMP). Our study aimed to investigate the difference in survival when administering HIPEC alone vs. HIPEC + EPIC. Additionally, we examined whether the duration of EPIC affects survival.

PATIENTS AND METHODS

We compared the difference in survival in 238 patients who underwent CRS + HIPEC alone vs. CRS + HIPEC/EPIC combination for low grade appendiceal cancer. We also compared short course (1-2 days) vs. long course (3-5 days) of EPIC.

RESULTS

HIPEC/EPIC combination group (n=179) showed a significantly better 5-year survival of 95% compared to 71% in HIPEC alone (n=59). There was no statistically significant difference in 5-year survival between short course (n=22) and long course of EPIC (n=157).

CONCLUSION

Combined use of HIPEC and EPIC improves 5-year survival in low-grade appendiceal neoplasm. Two days of EPIC are sufficient.

Postoperative Pancreatic Fistula After Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy: An Update on Incidence, Risk Factors, Management, and Clinical Sequelae in 1,141 Patients

BACKGROUND/AIM

An update on the incidence, risk factors, clinical sequalae, and management of postoperative pancreatic fistula (POPF) following cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC).

PATIENTS AND METHODS

Retrospective analysis of prospectively collected data from the St George CRS/HIPEC database.

RESULTS

Sixty-five (5.7%) out of 1,141 patients developed a POPF. Patients with POPFs were older, had a higher peritoneal cancer index, longer operation time, and required more units of blood intraoperatively. Splenectomy and distal pancreatectomy were significant risk factors for developing POPFs. While there was no effect on overall long-term survival in POPF patients, they did suffer higher rates of Clavien-Dindo grade 3/4 complications, in-hospital deaths, and longer hospital length of stay. Of the 65 POPF patients, 23 were taken back to theatre, 48 required radiological drains and 7 underwent endoscopic retrograde cholangiopancreatography.

CONCLUSION

There are multiple risk factors for developing POPFs that are non-modifiable. While POPFs are associated with increased postoperative morbidity, long-term survival does not appear to be affected.

Role of human nucleoside transporters in pancreatic cancer and chemoresistance

The prognosis of pancreatic cancer is poor with the overall 5-year survival rate of less than 5% changing minimally over the past decades and future projections predicting it developing into the second leading cause of cancer related mortality within the next decade. Investigations into the mechanisms of pancreatic cancer development, progression and acquired chemoresistance have been constant for the past few decades, thus resulting in the identification of human nucleoside transporters and factors affecting cytotoxic uptake via said transporters. This review summaries the aberrant expression and role of human nucleoside transports in pancreatic cancer, more specifically human equilibrative nucleoside transporter 1/2 (hENT1, hENT2), and human concentrative nucleoside transporter 1/3 (hCNT1, hCNT3), while briefly discussing the connection and importance between these nucleoside transporters and mucins that have also been identified as being aberrantly expressed in pancreatic cancer. The review also discusses the incidence, current diagnostic techniques as well as the current therapeutic treatments for pancreatic cancer. Furthermore, we address the importance of chemoresistance in nucleoside analogue drugs, in particular, gemcitabine and we discuss prospective therapeutic treatments and strategies for overcoming acquired chemoresistance in pancreatic cancer by the enhancement of human nucleoside transporters as well as the potential targeting of mucins using a combination of mucolytic compounds with cytotoxic agents.