Surgery (Austin & Northern Health) - Research Publications
Permanent URI for this collection
Search Results
1 - 10 of 15
-
ItemSAR131675, a VEGRF3 Inhibitor, Modulates the Immune Response and Reduces the Growth of Colorectal Cancer Liver Metastasis(MDPI, 2022-06)Most patients with colorectal cancer (CRC) develop metastases, predominantly in the liver (CLM). Targeted therapies are being investigated to improve current CLM treatments. This study tested the effectiveness of SAR131675, a selective VEGFR-3 tyrosine kinase inhibitor, to inhibit CLM in a murine model. Following intrasplenic induction of CLM, mice were treated daily with SAR131675. Tumor growth and immune infiltrates into tumor and liver tissues were assessed at 10-, 16- and 22-days post tumor induction by stereology, IHC and flow cytometry. SAR151675 treatment significantly reduced tumor burden and F4/80+ macrophages in the liver tissues. Analysis of immune cell infiltrates in liver showed tissue that at day 22, had the proportion of CD45+ leukocytes significantly reduced, particularly myeloid cells. Analysis of myeloid cells (CD11b+ CD45+) indicated that the proportion of F4/80- Ly6Clow was significantly reduced, including a predominate PD-L1+ subset, while CD3+ T cells increased, particularly CD8+ PD1+, reflected by an increase in the CD8+:CD4+ T cell ratio. In the tumor tissue SAR11675 treatment reduced the predominant population of F4/80+ Ly6Clo and increased CD4+ T cells. These results suggest that SAR131675 alters the immune composition within tumor and the surrounding liver in the later stages of development, resulting in a less immunosuppressive environment. This immunomodulation effect may contribute to the suppression of tumor growth.
-
ItemCaptopril, a Renin-Angiotensin System Inhibitor, Attenuates Tumour Progression in the Regenerating Liver Following Partial Hepatectomy(MDPI, 2022-05)(1) Liver regeneration following partial hepatectomy for colorectal liver metastasis (CRLM) has been linked to tumour recurrence. Inhibition of the renin−angiotensin system (RASi) attenuates CRLM growth in the non-regenerating liver. This study investigates whether RASi exerts an antitumour effect within the regenerating liver following partial hepatectomy for CRLM and examines RASi-induced changes in the tumour immune microenvironment; (2) CRLM in mice was induced via intrasplenic injection of mouse colorectal tumour cells, followed by splenectomy on Day 0. Mice were treated with RASi captopril (250 mg/kg/day), or saline (control) from Day 4 to Day 16 (endpoint) and underwent 70% partial hepatectomy on Day 7. Liver and tumour samples were characterised by flow cytometry and immunofluorescence; (3) captopril treatment reduced tumour burden in mice following partial hepatectomy (p < 0.01). Captopril treatment reduced populations of myeloid-derived suppressor cells (MDSCs) (CD11b+Ly6CHi p < 0.05, CD11b+Ly6CLo p < 0.01) and increased PD-1 expression on infiltrating hepatic tissue-resident memory (TRM)-like CD8+ (p < 0.001) and double-negative (CD4-CD8-; p < 0.001) T cells; (4) RASi reduced CRLM growth in the regenerating liver and altered immune cell composition by reducing populations of immunosuppressive MDSCs and boosting populations of PD-1+ hepatic TRMs. Thus, RASi should be explored as an adjunct therapy for patients undergoing partial hepatectomy for CRLM.
-
ItemCaptopril, a Renin-Angiotensin System Inhibitor, Attenuates Features of Tumor Invasion and Down-Regulates C-Myc Expression in a Mouse Model of Colorectal Cancer Liver Metastasis(MDPI, 2021-06)(1) Background: Recent clinical and experimental data suggests that the liver's regenerative response following partial hepatectomy can stimulate tumor recurrence in the liver remnant. The Wnt/β-catenin pathway plays important roles in both colorectal cancer carcinogenesis and liver regeneration. Studies have shown that the Wnt/β-catenin pathway regulates multiple renin-angiotensin system (RAS) genes, whilst RAS inhibition (RASi) reduces tumor burden and progression. This study explores whether RASi attenuates features of tumor progression in the regenerating liver post-hepatectomy by modulating Wnt/β-catenin signaling. (2) Methods: Male CBA mice underwent CRLM induction, followed one week later by 70% partial hepatectomy. Mice were treated daily with captopril, a RASi, at 250 mg/kg/day or vehicle control from experimental Day 4. Tumor and liver samples were analyzed for RAS and Wnt signaling markers using qRT-PCR and immunohistochemistry. (3) Results: Treatment with captopril reduced the expression of down-stream Wnt target genes, including a significant reduction in both c-myc and cyclin-D1, despite activating Wnt signaling. This was a tumor-specific response that was not elicited in corresponding liver samples. (4) Conclusions: We report for the first time decreased c-myc expression in colorectal tumors following RASi treatment in vivo. Decreased c-myc expression was accompanied by an attenuated invasive phenotype, despite increased Wnt signaling.
-
ItemTargeting DNA Damage Response and Replication Stress in Pancreatic Cancer(W B SAUNDERS CO-ELSEVIER INC, 2021-01)BACKGROUND & AIMS: Continuing recalcitrance to therapy cements pancreatic cancer (PC) as the most lethal malignancy, which is set to become the second leading cause of cancer death in our society. The study aim was to investigate the association between DNA damage response (DDR), replication stress, and novel therapeutic response in PC to develop a biomarker-driven therapeutic strategy targeting DDR and replication stress in PC. METHODS: We interrogated the transcriptome, genome, proteome, and functional characteristics of 61 novel PC patient-derived cell lines to define novel therapeutic strategies targeting DDR and replication stress. Validation was done in patient-derived xenografts and human PC organoids. RESULTS: Patient-derived cell lines faithfully recapitulate the epithelial component of pancreatic tumors, including previously described molecular subtypes. Biomarkers of DDR deficiency, including a novel signature of homologous recombination deficiency, cosegregates with response to platinum (P < .001) and PARP inhibitor therapy (P < .001) in vitro and in vivo. We generated a novel signature of replication stress that predicts response to ATR (P < .018) and WEE1 inhibitor (P < .029) treatment in both cell lines and human PC organoids. Replication stress was enriched in the squamous subtype of PC (P < .001) but was not associated with DDR deficiency. CONCLUSIONS: Replication stress and DDR deficiency are independent of each other, creating opportunities for therapy in DDR-proficient PC and after platinum therapy.
-
ItemPopulation-based analysis of treatment patterns and outcomes for pancreas cancer in Victoria(WILEY, 2020-09)BACKGROUND: The Victorian Pancreas Cancer summit 2017 analysed state-wide data on management of Victorians with pancreas cancer between 2011 and 2015 to identify variations in care and outcomes. Pancreas cancer remains a formidable disease but systemic therapies are increasingly effective. Surgery remains essential but insufficient alone for cure. Understanding patterns of care and identifying variations in treatment is critical to improving outcomes. METHODS: This population-based study analysed data collected prospectively by Department of Health and Human services (Victorian state government). Data were extracted from Victorian Cancer Registry (covering all Victorian cancer diagnoses), Victorian Admitted-Episodes Dataset (all inpatient data), Victorian Radiotherapy Minimum Dataset and Victorian Death Index providing demographics, tumour and treatment characteristics, age-standardized incidence, overall and median survival. RESULTS: Of 3962 Victorian patients with any form of pancreatic malignancy, 82% were ductal adenocarcinoma (PDAC), of whom 67% had metastases at diagnosis. One-year overall survival for PDAC was 30% (60% non-metastatic, 15% if metastatic). Median survival with metastases increased from 2.7 to 3.9 months, and from 13.3 to 15.9 months for non-metastatic PDAC between 2011 and 2015. Thirty-one percent of non-metastatic patients underwent pancreatectomy. About 1.5% were treated with neoadjuvant chemotherapy/chemoradiation. Of patients undergoing intended curative resection, 77% proceeded to adjuvant therapy. Fifty-one percent of metastatic PDAC patients never received anti-tumour therapy. CONCLUSIONS: Nearly one-fourth of surgically treated patients never received systemic therapy. More than two-thirds of non-metastatic patients never proceeded to surgery. Further consideration of neoadjuvant therapy should be given to borderline resectable patients. Most patients with PDAC still die soon after diagnosis, but median survival is increasing.
-
ItemHealth costs of post-operative complications following rectal resection: a systematic review(WILEY, 2020-07)BACKGROUND: Post-operative complications following rectal resection pose significant health and cost implications for patients and health providers. The objective of this study is to review the associated cost of complications following rectal resection. This included reporting on the proportion and severity of these complications, associated length of stay and surgical technique used. Studies were sourced from Embase OVID, MEDLINE OVID (ALL) and Cochrane Library databases by utilizing a search strategy. METHODS: This search contained studies from 1 January 2010 until 13 February 2019. Studies were included from the year 2010 to account for the implementation of enhanced recovery after surgery protocols. Studies that reported the financial cost associated with complications were included. Any indication for rectal resection was considered. Data was extracted into a formatted table and a narrative synthesis was performed. RESULTS: We identified 13 eligible studies for inclusion. There was strong evidence to suggest that complications are associated with increased costs. There was considerable variation as to the costs attributable to complications ($1443 (P < 0.001) to $17 831 (P < 0.0012), n = 12). The presence of complications was associated with an increased length of stay (5.54 (P-value not given) to 21.04 (P < 0.0001) days, n = 7). There was significant variation in the proportion of complications (6.41 to 64.71%, n = 8). Weak evidence existed around surgical technique used and the associated cost of complications. There was considerable heterogeneity among included studies. CONCLUSIONS: Complications following rectal resection increased health costs. Costs should be standardized and provide a clear methodology for their calculation. Complications should be standardized and include a grading of severity.
-
ItemOutcomes of inguinal hernia repair in cirrhotics: a single tertiary centre experience(WILEY, 2020-05)BACKGROUND: Patients with liver cirrhosis are at a higher risk of perioperative anaesthetic and surgical complications. Surgical repair of abdominal wall hernias in these patients has been widely discouraged. The main objective of this study was to evaluate the post-operative outcomes of patients with liver cirrhosis after inguinal hernia repair at a single institution. METHODS: A retrospective review of a prospectively maintained database of 31 patients with liver cirrhosis undergoing inguinal hernia repair between 2006 and 2016 was undertaken. Data in relation to patient demographics, clinicopathological characteristics, morbidity and mortality were collected. RESULTS: Thirty-one patients with median Model for End-stage Liver Disease score of 14 (7-36) underwent inguinal hernia repair within a 10-year period of our study. There was one mortality in a patient with Model for End-stage Liver Disease score of 36 who presented with a strangulated hernia. Only one patient required return to theatre for the evacuation of haematoma and one patient developed a recurrent hernia in 1-year follow up. CONCLUSION: Inguinal hernia repair in patients with cirrhosis is a safe procedure to perform in the elective setting. Nevertheless, significant consideration must be given in performing these operations in centres with liver transplant units due to their extensive experience in pre-operative optimization to reduce the risk of hepatic decompensation.
-
ItemWhat makes an article impactful?(WILEY, 2020-01)
-
ItemProcurement-related liver injury for transplantation: an analysis of the risk factors and consequences in an Australian transplant centre(WILEY, 2021-12)BACKGROUND: Liver transplantation is an established treatment for liver failure, and its success relies on the quality of the donated organ amongst other factors. Studies on procurement-related liver injury (PRLI) are few and some may not apply to modern-day practice. This is the first Australian study examining risk factors and consequences of PRLI. METHOD: The Victorian Liver Transplant Unit database was examined for deceased liver donors from 2010 to 2017. Information regarding the donor, retrieval and subsequent transplantation was obtained. PRLI details were sought from the 'organ retrieval report form'. PRLI risk factors and their complications were analysed. RESULTS: A total of 420 transplants were included, with 45 injuries in 44 livers (10%), and significant injuries were observed in 4%. Variant anatomy was associated with an increased risk of PRLI (11% vs. 2%, p < 0.001). Complication rates were not significantly different between livers with and without PRLI however a reduction in early graft survival was observed. CONCLUSION: This study shows that PRLI is common, and that variant anatomy is associated with an increased risk of injury. Appropriate feedback and benchmarking are important to maintain a high quality in donor surgery.
-
ItemThe financial burden of complications following rectal resection A cohort study(Lippincott, Williams & Wilkins, 2020-05-01)To investigate the costs associated with postoperative complications following rectal resection. Rectal resection is a major surgical procedure that carries a significant risk of complications. The occurrence of complications following surgery has both health and financial consequences. There are very few studies that examine the incidence and severity of complications and their financial implications following rectal resection. We identified 381 consecutive patients who underwent a rectal resection within a major university hospital. Patients were included using the International Classification of Diseases (ICD) codes. Complications in the postoperative period were reported using the validated Clavien-Dindo classification system. Both the number and severity of complications were recorded. Activity-based costing methodology was used to report financial outcomes. Preoperative results were also recorded and assessed. A 76.9% [95% CI: 68.3:86.2] of patients experienced one or more complications. Patients who had a complication had a median total cost of $22,567 [IQR 16,607:33,641]. Patients who did not have a complication had a median total cost of $15,882 [IQR 12,971:19,861]. The adjusted additional median cost for patients who had a complication was $5308 [95% CI: 2938:7678] (P < .001). Patients who experienced a complication tended to undergo an open procedure (P = .001), were emergent patients (P = .003), preoperatively had lower albumin levels (36 vs 38, P = .0003) and were anemic (P = .001). Complications following rectal resection are common and are associated with increased costs. Our study highlights the importance of evaluating and preventing complications in the postoperative period.