The mechanosensory channel PIEZO1 functions upstream of angiopoietin/TIE/FOXO1 signaling in lymphatic development.

Lymphedema is a debilitating disease with no effective cure and affects an estimated 250 million individuals worldwide. Prior studies have identified mutations in piezo-type mechanosensitive ion channel component 1 (PIEZO1), angiopoietin 2 (ANGPT2), and tyrosine kinase with Ig-like and EGF-like domains 1 (TIE1) in patients with primary lymphedema. Here, we identified crosstalk between these molecules and showed that activation of the mechanosensory channel PIEZO1 in lymphatic endothelial cells (LECs) caused rapid exocytosis of the TIE ligand ANGPT2, ectodomain shedding of TIE1 by disintegrin and metalloproteinase domain-containing protein 17 (ADAM17), and increased TIE/PI3K/AKT signaling, followed by nuclear export of the transcription factor FOXO1. These data establish a functional network between lymphedema-associated genes and provide what we believe to be the first molecular mechanism bridging channel function with vascular signaling and intracellular events culminating in transcriptional regulation of genes expressed in LECs. Our study provides insights into the regulation of lymphatic function and molecular pathways involved in human disease.

Early onset pancreatic cancer-exploring contemporary treatment and outcomes using real-world data.

BACKGROUND: Pancreatic cancer incidence is increasing in younger populations. Differences between early onset pancreatic cancer (EOPC) and later onset pancreatic cancer (LOPC), and how these should inform management warrant exploration in the contemporary setting. METHODS: A prospectively collected multi-site dataset on consecutive pancreatic adenocarcinoma patients was interrogated. Patient, tumour, treatment, and outcome data were extracted for EOPC (≤50 years old) vs LOPC (>50 years old). RESULTS: Of 1683 patients diagnosed between 2016 and 2022, 112 (6.7%) were EOPC. EOPC more frequently had the tail of pancreas tumours, earlier stage disease, surgical resection, and trended towards increased receipt of chemotherapy in the curative setting compared to LOPC. EOPC more frequently received 1st line chemotherapy, 2nd line chemotherapy, and chemoradiotherapy than LOPC in the palliative setting. Recurrence-free survival was improved for the tail of pancreas EOPC vs LOPC in the resected setting; overall survival was superior for EOPC compared to LOPC across the resected, locally advanced unresectable and metastatic settings. CONCLUSIONS: EOPC remains a small proportion of pancreatic cancer diagnoses. The more favourable outcomes in EOPC suggest these younger patients are overall deriving benefits from increased treatment in the curative setting and increased therapy in the palliative setting.

Searching for low phospholipid associated cholelithiasis among patients with post-cholecystectomy biliary pain.

INTRODUCTION: Low phospholipid associated cholelithiasis (LPAC) is associated with variants of the adenosine triphosphate-binding cassette subfamily B, member 4 (ABCB4) gene and is characterized by reduced phosphatidylcholine secretion into bile, impairing the formation of micelles and thus exposing bile ducts to toxic bile acids and increasing cholesterol saturation. LPAC is present in 1% of patients with gallstones and post-cholecystectomy pain is common in this group. LPAC is an under-appreciated cause of post-cholecystectomy pain. The aim of this study is to assess a cohort of patients with post-cholecystectomy pain to identify those with clinical features suggesting that further investigations for LPAC would be beneficial. METHODS: A retrospective chart review was performed of the first 2 years of post-operative follow-up for all patients under 40 years of age undergoing cholecystectomy for symptomatic gallstones at a tertiary centre between January 2016 and December 2017. RESULTS: 258 patients under the age of 40 underwent a cholecystectomy. 50 patients (19.4%) reported abdominal pain post-cholecystectomy. Five patients (1.9%) fulfilled the criteria for suspected LPAC. Family history of gallstones was documented in 33 of 258 (12.8%) of cases. Obstetric history was obtained in 69 of 197 (35%) female patients. None of the five patients identified above who satisfied the criteria of LPAC had the diagnosis of LPAC considered by their treating clinicians. CONCLUSION: LPAC is an under-recognized cause of post-cholecystectomy pain. Treatment can avoid long-term symptoms and complications. Clinicians should take a family history and obstetric history to alert them to the diagnosis of LPAC.

The Specialist Treatment of Inpatients: Caring for Diabetes in Surgery (STOIC-D Surgery) Trial: A Randomized Controlled Trial of Early Intervention With an Electronic Specialist-Led Model of Diabetes Care.

OBJECTIVE: To investigate the effect of early intervention with an electronic specialist-led "proactive" model of care on glycemic and clinical outcomes. RESEARCH DESIGN AND METHODS: The Specialist Treatment of Inpatients: Caring for Diabetes in Surgery (STOIC-D Surgery) randomized controlled trial was performed at the Royal Melbourne Hospital. Eligible participants were adults admitted to a surgical ward during the study with either known diabetes or newly detected hyperglycemia (at least one random blood glucose result ≥11.1 mmol/L). Participants were randomized 1:1 to standard diabetes care or the intervention consisting of an early consult by a specialist inpatient diabetes team using electronic tools for patient identification, communication of recommendations, and therapy intensification. The primary outcome was median patient-day mean glucose (PDMG). The key secondary outcome was incidence of health care-associated infection (HAI). RESULTS: Between 12 February 2021 and 17 December 2021, 1,371 admissions met inclusion criteria, with 680 assigned to early intervention and 691 to standard diabetes care. Baseline characteristics were similar between groups. The early intervention group achieved a lower median PDMG of 8.2 mmol/L (interquartile range [IQR] 6.9-10.0 mmol/L) compared with 8.6 mmol/L (IQR 7.2-10.3 mmol/L) in the control group for an estimated difference of -0.3 mmol/L (95% CI -0.4 to -0.2 mmol/L, P < 0.0001). The incidence of HAI was lower in the intervention group (77 [11%] vs. 110 [16%]), for an absolute risk difference of -4.6% (95% CI -8.2 to -1.0, P = 0.016). CONCLUSIONS: In surgical inpatients, early diabetes management intervention with an electronic specialist-led diabetes model of care reduces glucose and HAI.

How to do a single-stage perforator based nasolabial flap for reconstruction of early-stage tongue cancer.

Tongue cancers are one of the most common subsites of malignancy in the head and neck, of which the majority are squamous cell carcinoma (SCC). Reconstruction following ablative surgery is challenging because of the role of the tongue in articulation, deglutition and protection of the airway. Microvascular free flaps are the current gold standard of reconstruction but are not feasible in all patients. Local and regional flaps provide a less challenging, faster alternative and may be more appropriate in comorbid patients with high anaesthetic risk as well as those with previously irradiated neck and poor vasculature. Nasolabial flaps are not commonly used for tongue reconstruction, requiring a two-staged procedure to allow division of the pedicle. We submit a modification of nasolabial flap as an inferiorly based, islanded perforator flap. This allows for single-stage reconstruction of tongue and floor of the mouth defects following resection of early-stage tongue cancers.

Investigation of N,N,N-Trimethyl-L-alanyl-L-proline Betaine (TMAP) as a Biomarker of Kidney Function.

Glomerular filtration rate (GFR) is the most widely used tool for the measurement of kidney function, but endogenous biomarkers such as cystatin C and creatinine have limitations. A previous metabolomic study revealed N,N,N-trimethyl-L-alanyl-L-proline betaine (TMAP) to be reflective of kidney function. In this study, we developed a quantitative LCMS assay for the measurement of TMAP and evaluated TMAP as a biomarker of GFR. An assay to measure TMAP was developed using liquid chromatography-mass spectrometry. After validation of the method, we applied it to plasma samples from three distinct kidney disease patient cohorts: nondialysis chronic kidney disease (CKD) patients, patients receiving peritoneal and hemodialysis, and living kidney donors. We investigated whether TMAP was conserved in other mammalian and nonmammalian species, by analyzing plasma samples from Wistar rats with diet-induced CKD and searching for putative matches to the m/z for TMAP and its known fragments in the raw sample data repository "Metabolomics Workbench". The assay can measure plasma TMAP at a lower limit of quantitation (100 ng/mL) with an interday precision and accuracy of 12.8 and 12.1%, respectively. In all three patient cohorts, TMAP concentrations are significantly higher in patients with CKD than in controls with a normal GFR. Further, TMAP concentrations are also elevated in rats with CKD and TMAP is present in the sap produced from Acer saccharum trees. TMAP concentration is inversely related to GFR suggesting that it is a marker of kidney function. TMAP is present in nonmammalian species suggesting that it is part of a biologically conserved process.

Use of Temporary Abdominal Closure in Non-Trauma Surgery: A Cohort Study.

BACKGROUND: Damage control surgery in trauma is widely used but the evidence for the use of laparostomy in non-trauma abdominal emergencies is limited. This study aimed to characterise outcomes in emergency abdominal surgery by comparing laparostomy to one-stage laparotomy for patients of similar illness severity. METHODS: A retrospective study of adult patients requiring emergency abdominal surgery and post-operative intensive care stay was performed between 2016 and 2020 at a major Australian metropolitan hospital. Case selection was from a prospectively maintained database, and case notes were reviewed. Patients having delayed abdominal closure were compared with those having one-stage abdominal closure. The primary outcome was odds of in-hospital mortality. The secondary outcomes included intensive care unit length of stay (LOS), overall hospital LOS, definitive stoma rate and discharge destination. Multivariable logistic regression analysis was performed to adjust for potentially confounding variables. RESULTS: Two hundred and eighteen patients met inclusion criteria (80 laparostomy and 138 non-laparostomy). The most common indications for laparostomy were bowel ischaemia (41.3%), sepsis (26.3%) and physiological instability (22.5%). There was no evidence of difference in odds of in-hospital mortality between groups (adjusted OR = 1.67, CI: 0.85-3.28; p = 0.138). Patients requiring laparostomy had a slightly longer median ICU LOS (4 vs. 3 days; p < 0.001), similar median hospital LOS (19 vs. 14 days, p = 0.245) and similar discharge destination. There was no difference in stoma rate (35.0% vs. 35.5%). CONCLUSION: Compared with standard one-stage laparotomy, laparostomy resulted in similar odds of in-hospital mortality in emergency abdominal surgery patients requiring intensive care.

Activation of Angiopoietin-Tie2 Signaling Protects the Kidney from Ischemic Injury by Modulation of Endothelial-Specific Pathways.

SIGNIFICANCE STATEMENT: Ischemia-reperfusion AKI (IR-AKI) is common and causes significant morbidity. Effective treatments are lacking. However, preclinical studies suggest that inhibition of angiopoietin-Tie2 vascular signaling promotes injury, whereas activation of Tie2 is protective. We show that kidney ischemia leads to increased levels of the endothelial-specific phosphatase vascular endothelial protein tyrosine phosphatase (VE-PTP; PTPRB), which inactivates Tie2. Activation of Tie2 through VE-PTP deletion, or delivery of a novel angiopoietin mimetic (Hepta-ANG1), abrogated IR-AKI in mice. Single-cell RNAseq analysis showed Tie2 activation promotes increased Entpd1 expression, downregulation of FOXO1 target genes in the kidney vasculature, and emergence of a new subpopulation of glomerular endothelial cells. Our data provide a molecular basis and identify a candidate therapeutic to improve endothelial integrity and kidney function after IR-AKI. BACKGROUND: Ischemia-reperfusion AKI (IR-AKI) is estimated to affect 2%-7% of all hospitalized patients. The significant morbidity and mortality associated with AKI indicates urgent need for effective treatments. Previous studies have shown activation of the vascular angiopoietin-Tie2 tyrosine kinase signaling pathway abrogates ischemia-reperfusion injury (IRI). We extended previous studies to (1) determine the molecular mechanism(s) underlying kidney injury and protection related to decreased or increased activation of Tie2, respectively, and (2) to test the hypothesis that deletion of the Tie2 inhibitory phosphatase vascular endothelial protein tyrosine phosphatase (VE-PTP) or injection of a new angiopoietin mimetic protects the kidney from IRI by common molecular mechanism(s). METHODS: Bilateral IR-AKI was performed in VE-PTP wild-type or knockout mice and in C57BL/6J mice treated with Hepta-ANG1 or vehicle. Histologic, immunostaining, and single-cell RNA sequencing analyses were performed. RESULTS: The phosphatase VE-PTP, which negatively regulates the angiopoietin-Tie2 pathway, was upregulated in kidney endothelial cells after IRI, and genetic deletion of VE-PTP in mice protected the kidney from IR-AKI. Injection of Hepta-ANG1 potently activated Tie2 and protected the mouse kidney from IRI. Single-cell RNAseq analysis of kidneys from Hepta-ANG1-treated and vehicle-treated mice identified endothelial-specific gene signatures and emergence of a new glomerular endothelial subpopulation associated with improved kidney function. Overlap was found between endothelial-specific genes upregulated by Hepta-ANG1 treatment and those downregulated in HUVECs with constitutive FOXO1 activation, including Entpd1 / ENTPD1 that modulates purinergic receptor signaling. CONCLUSIONS: Our data support a key role of the endothelium in the development of IR-AKI, introduce Hepta-ANG1 as a putative new therapeutic biologic, and report a model to explain how IRI reduces Tie2 signaling and how Tie2 activation protects the kidney. PODCAST: This article contains a podcast at https://dts.podtrac.com/redirect.mp3/www.asn-online.org/media/podcast/JASN/2023_05_23_JSN_Ang_EP23_052323.mp3.

Victoria's surgical response to the COVID-19 pandemic: the first two years.

Victoria suffered three major waves during the first two years of the COVID-19 pandemic. Melbourne became the longest locked down city in the world at 267 days. This narrative review documents the chronological waves of COVID-19 in Victoria and key themes influencing the State-wide surgical response. In 2020, Victoria needed to secure supplies of personal protective equipment (PPE) and later, recognizing the importance of aerosol transmission, introduced a respiratory protection program to protect health care workers (HCWs) with fit-tested N-95 masks. It established routine preoperative PCR testing for periods when community prevalence was high and developed strategies to restrict elective surgery when hospital capacity was limited. In 2021, three short-term outbreaks were contained and eliminated whilst vaccination of HCWs and the vulnerable was taking place. A third major wave (Delta) occurred July to November 2021, succeeded by another involving the Omicron variant from December 2021. Planned surgery waiting list numbers, and waiting times for surgery, doubled between March 2020 and March 2022. In early 2022, almost 300 patients underwent surgery when infected with Omicron, with a low mortality (2.6%), though mortality was significantly higher in the unvaccinated (7.3% versus 1.4%). In conclusion, the Victorian response to COVID-19 involved tight state-wide social restrictions, contact tracing, furlough, escalating PPE guidance and respiratory protection. HCW infections were greatly reduced in 2021 compared with 2020. Pre-operative PCR testing gave confidence for emergency and urgent elective surgery to proceed during pandemic waves. Other elective cases were performed as health system capacity allowed, without compromising outcomes.

Use and outcomes from neoadjuvant chemotherapy in borderline resectable pancreatic ductal adenocarcinoma in an Australasian population.

BACKGROUND: Use of neoadjuvant (NA) chemotherapy is recommended when pancreatic ductal adenocarcinoma (PDAC) is borderline resectable METHOD: A retrospective analysis of consecutive patients with localized PDAC between January 2016 and March 2019 within the Australasian Pancreatic Cancer Registry (PURPLE, Pancreatic cancer: Understanding Routine Practice and Lifting End results) was performed. Clinicopathological characteristics, treatment, and outcome were analyzed. Overall survival (OS) comparison was performed using log-rank model and Kaplan-Meier analysis. RESULTS: The PURPLE database included 754 cases with localised PDAC, including 148 (20%) cases with borderline resectable pancreatic cancer (BRPC). Of the 148 BRPC patients, 44 (30%) underwent immediate surgery, 80 (54%) received NA chemotherapy, and 24 (16%) were inoperable. The median age of NA therapy patients was 63 years and FOLFIRINOX (53%) was more often used as NA therapy than gemcitabine/nab-paclitaxel (31%). Patients who received FOLFIRINOX were younger than those who received gemcitabine/nab-paclitaxel (60 years vs. 67 years, p = .01). Surgery was performed in 54% (43 of 80) of BRPC patients receiving NA chemotherapy, with 53% (16 of 30) achieving R0 resections. BRPC patients undergoing surgery had a median OS of 30 months, and 38% (9 of 24) achieved R0 resection. NA chemotherapy patients had a median OS of 20 months, improving to 24 months versus 10 months for patients receiving FOLFIRINOX compared to gemcitabine/nab-paclitaxel (Hazard Ratio (HR) .3, p < .0001). CONCLUSIONS: NA chemotherapy use in BRPC is increasing in Australia. One half of patients receiving NA chemotherapy proceed to curative resection, with 53% achieving R0 resections. Patients receiving Infusional 5-flurouracil, Irinotecan and Oxaliplatin (FOLIRINOX) had increased survival than gemcitabine/nab-paclitaxel. Treatment strategies are being explored in the MASTERPLAN and DYNAMIC-Pancreas trials.

Angiopoietin-1 Is Required for Vortex Vein and Choriocapillaris Development in Mice.

BACKGROUND: The choroidal vasculature, including the choriocapillaris and vortex veins, is essential for providing nutrients to the metabolically demanding photoreceptors and retinal pigment epithelium. Choroidal vascular dysfunction leads to vision loss and is associated with age-related macular degeneration and the poorly understood pachychoroid diseases including central serous chorioretinopathy and polypoidal choroidal vasculopathy that are characterized by formation of dilated pachyvessels throughout the choroid. METHODS: Using neural crest-specific Angpt1 knockout mice, we show that Angiopoietin 1, a ligand of the endothelial receptor TEK (also known as Tie2) is essential for choriocapillaris development and vortex vein patterning. RESULTS: Lacking choroidal ANGPT1, neural crest-specific Angpt1 knockout eyes exhibited marked choriocapillaris attenuation and 50% reduction in number of vortex veins, with only 2 vortex veins present in the majority of eyes. Shortly after birth, dilated choroidal vessels resembling human pachyvessels were observed extending from the remaining vortex veins and displacing the choriocapillaris, leading to retinal pigment epithelium dysfunction and subretinal neovascularization similar to that seen in pachychoroid disease. CONCLUSIONS: Together, these findings identify a new role for ANGPT1 in ocular vascular development and demonstrate a clear link between vortex vein dysfunction, pachyvessel formation, and disease.

Impact of first-line FOLFIRINOX versus Gemcitabine/Nab-Paclitaxel chemotherapy on survival in advanced pancreatic cancer: Evidence from the prospective international multicentre PURPLE pancreatic cancer registry.

BACKGROUND: First-line palliative chemotherapy regimens in advanced pancreatic ductal adenocarcinoma (PDAC) have not been compared in head-to-head phase III randomised controlled trials (RCT). Data on optimum first-line treatment and subsequent sequencing is lacking. OBJECTIVE: To compare overall survival (OS) between first-line treatment regimens in a real-world population to determine if an optimal therapeutic sequence is associated with survival benefit. METHODS: A retrospective analysis of prospectively collated data from the Australasian PURPLE pancreatic cancer registry was undertaken. FINDINGS: From 2016 to 2020, of 1551 pancreatic cancer patients, 615 received palliative-intent chemotherapy. Patients with early-stage resected disease without recurrence (n = 369), radiotherapy alone (n = 43), received supportive care alone (n = 458) or had less than 3 months follow-up (n = 66) were excluded. Median OS was comparable between patients receiving first-line Gemcitabine/Nab-Paclitaxel (n = 376) and those receiving FOLFIRINOX (n = 73) (11.3 versus 12.3 months, P = 0.37), with 38% proceeding to second-line chemotherapy which was associated with longer mOS compared to first-line treatment alone (17.4 versus 8.2 months, P < 0.001). With second-line treatment following prior FOLFIRINOX (n = 29) or Gemcitabine/Nab-Paclitaxel (n = 101), mOS did not differ significantly (17.3 versus 15.9 months, P = 0.92), respectively, whilst median progression-free survival was longer with prior FOLFIRINOX (5.2 versus 2.9 months, P = 0.03). CONCLUSION: There was no significant difference in overall survival between either first-line chemotherapy choice, despite patients receiving FOLFIRINOX being younger, fitter, and more likely to have localised disease. However, FOLFIRINOX was associated with delayed progression. In the absence of phase III RCT data, clinicians should be comfortable using either Gemcitabine/Nab-Paclitaxel or FOLFIRINOX as first-line therapy in advanced PDAC.

Real-world staging computed tomography scanning technique and important reporting discrepancies in pancreatic ductal adenocarcinoma.

BACKGROUND: Computed tomography (CT) is the first-line staging imaging modality for pancreatic ductal adenocarcinoma (PDAC) which determines resectability and treatment pathways. METHODS: Between January 2016 and December 2019, prospectively collated data from two Australian cancer centres was extracted from the PURPLE Pancreatic Cancer registry. Real-world staging CTs and corresponding reports were blindly reviewed by a sub-specialist radiologist and compared to initial reports. RESULTS: Of 131 patients assessed, 117 (89.3%) presented with symptoms, 74 (56.5%) CTs included slices ≤3 mm thickness and CT pancreas protocol was applied in 69 (52.7%) patients. Initial reports lacked synoptic reporting in 131 (100%), tumour identification in 2 (1.6%) and tumour measurement in 13 (9.9%) cases. Tumour-vascular relationship reporting was missing in 69-109 (52.7-83.2%) for regarding the key arterial and venous structures that is required to assess resectability. Initial reports had no comment on venous thrombus or venous collaterals in 80 (61.1%) and 109 (83.2%) and lacked locoregional lymphadenopathy interpretation in 13 (9.9%) cases. Complete initial staging report was present in 72 (55.0%) patients. Sub-specialist radiological review resulted in down-staging in 16 (22.2%) and up-staging in 1 (1.4%) patient. Staging discrepancies were mainly regarding metastatic disease (12, 70.6%) and tumour-vascular relationship (5, 29.4%). CONCLUSION: Real-world staging imaging in PDAC patients show low proportion of dedicated CT pancreas protocol, high proportion of incomplete staging reports and no synoptic reporting. The most common discrepancy between initial and sub-specialist reporting was regarding metastases and tumour-vascular relationship assessment resulting in sub-specialist down-staging in almost every fifth case.

Comparison of risk adjusted excess post-operative pancreatic fistula rates after pancreaticoduodenectomy using cumulative sum analysis.

BACKGROUND: Post-operative pancreatic fistula (POPF) is a key outcome post pancreaticoduodenectomy. There are numerous POPF risk calculators but no agreed benchmark, a key component of meaningful audit. We compared observed versus predicted POPF for six risk adjusted POPF calculators, to ascertain how they differ and thus contribute to discussion around benchmarking. METHODS: This was a retrospective single-arm cohort study at the Royal Melbourne Hospital of patients who underwent pancreaticoduodenectomy 1 November 2015 to 31 December 2021 with a primary outcome of a clinically relevant POPF. Cumulative sum (CUSUM) plots of observed versus predicted rate of POPF for sequential patients were constructed for six risk adjusted POPF calculators - Birmingham, updated Birmingham, fistula risk score (FRS), modified FRS (m-FRS), alternative FRS (a-FRS), and updated alternative FRS (ua-FRS). RESULTS: The study included 77 patients. The actual rate of clinically relevant POPF was 14.3%. FRS calculated an excess of 1.3 POPF per 100 cases. All other calculators demonstrated prevention of POPF per 100 cases: Birmingham 3.4, updated Birmingham 14.0, m-FRS 0.3, a-FRS 1.2, ua-FRS 19.7. CONCLUSION: The observed versus predicted rate of POPF was near zero for all risk calculators except ua-FRS and updated Birmingham, which predicted a higher POPF than observed (19.7, 14.0, respectively). These results indicate that, excepting ua-FRS and updated Birmingham, these calculators yield comparable results. Benchmarks for POPF should prescribe which risk calculators are used, and ideally a unified standard between centres should be the goal to provide consistency in outcome reporting and robust audit processes.

Longitudinal Monitoring of Intra-Tumoural Heterogeneity Using Optical Barcoding of Patient-Derived Colorectal Tumour Models.

Geno- and phenotypic heterogeneity amongst cancer cell subpopulations are established drivers of treatment resistance and tumour recurrence. However, due to the technical difficulty associated with studying such intra-tumoural heterogeneity, this phenomenon is seldom interrogated in conventional cell culture models. Here, we employ a fluorescent lineage technique termed "optical barcoding" (OBC) to perform simultaneous longitudinal tracking of spatio-temporal fate in 64 patient-derived colorectal cancer subclones. To do so, patient-derived cancer cell lines and organoids were labelled with discrete combinations of reporter constructs, stably integrated into the genome and thus passed on from the founder cell to all its clonal descendants. This strategy enables the longitudinal monitoring of individual cell lineages based upon their unique optical barcodes. By designing a novel panel of six fluorescent proteins, the maximum theoretical subpopulation resolution of 64 discriminable subpopulations was achieved, greatly improving throughput compared with previous studies. We demonstrate that all subpopulations can be purified from complex clonal mixtures via flow cytometry, permitting the downstream isolation and analysis of any lineages of interest. Moreover, we outline an optimized imaging protocol that can be used to image optical barcodes in real-time, allowing for clonal dynamics to be resolved in live cells. In contrast with the limited intra-tumour heterogeneity observed in conventional 2D cell lines, the OBC technique was successfully used to quantify dynamic clonal expansions and contractions in 3D patient-derived organoids, which were previously demonstrated to better recapitulate the heterogeneity of their parental tumour material. In summary, we present OBC as a user-friendly, inexpensive, and high-throughput technique for monitoring intra-tumoural heterogeneity in in vitro cell culture models.

Epidemiology of pregnant patients with major trauma in Victoria.

OBJECTIVE: Trauma is one of the most common contributors to maternal and foetal morbidity and mortality. The aim of the present study was to describe the characteristics and outcomes of major trauma in pregnant patients using a population-based registry. METHODS: Registry-based study using data from the Victorian State Trauma Registry (VSTR), a population-based database of all hospitalised major trauma (death due to injury, Injury Severity Score [ISS] ≥12, admission to an intensive care unit [ICU] for more than 24 h and requiring mechanical ventilation for at least part of their ICU stay or urgent surgery) in Victoria, Australia, from 1 July 2007 to 30 June 2019. Pregnant patients with major trauma were identified on the VSTR. We summarised patient data using descriptive statistics. RESULTS: Over the 12-year study period, there were 63 pregnant major trauma patients. Fifty-two (82.5%) patients sustained injuries resulting from road transport collisions. The maternal survival rate was 98.4% and the foetal survival rate was 88.9%. Thoracic injury was the most common injury (25/63), followed by abdominal injury (23/63). Eighty-six percent of the third trimester patients (19/22) were transported directly to a major trauma service with capacity for definitive care of the pregnancy. CONCLUSION: The present study demonstrated road transport injury was the most common mechanism of injury and both maternal survival rates and foetal survival rates were high. This information is essential for trauma care system planning and public health initiatives to improve the clinical management and outcomes of pregnant women with major trauma.

Treatment and outcomes of unresectable and metastatic pancreatic cancer treated in public and private Australian hospitals.

BACKGROUND: Prior studies have reported for several cancer types that treatment in the private sector is associated with improved survival outcomes. Data for patients with locally advanced unresectable and metastatic pancreatic ductal adenocarcinoma (PDAC) have not previously been reported. METHODS: Analysis of patients from January 2016 to June 2020 registered to a multicentre prospective cancer database. Baseline demographic and clinicopathologic characteristics were compared. The Kaplan-Meier method was used to compare overall survival (OS). Multivariate Cox and logistic regression analyses were used to determine predictors of mortality and first-line chemotherapy treatment, respectively. RESULTS: Of 822 patients, 22.5% received private care. Private patients were older (median 71.5 vs. 68.9 years, p ≤ .05), had better performance status (ECOG 0 to 1: 82.2 vs. 73.5%, p = .05) and more likely to reside in an area with high socioeconomic advantage (67.0 vs. 19.6%, p ≤ .01). Private patients were more likely to receive first-line chemotherapy (69.7 vs. 54.2%, p ≤ .01) with logistic regression demonstrating private care (OR: 1.87, 95% CI: 1.20 to 2.97) as an independent predictor of receiving chemotherapy. Private patients had prolonged survival (median OS: 9.2 vs. 6.9 months, HR 1.2, p = .05). Receiving first-line chemotherapy was an independent predictor of mortality, but private care was not. CONCLUSIONS: Care in the private system is associated with improved OS, with higher uptake of first-line chemotherapy appearing to be the main contributor. Given the discrepancy, further studies are needed to determine what factors are driving this difference.

Circulating tumor DNA dynamics and recurrence risk in patients undergoing curative intent resection of colorectal cancer liver metastases: A prospective cohort study.

BACKGROUND: In patients with resectable colorectal liver metastases (CRLM), the role of pre- and postoperative systemic therapy continues to be debated. Previous studies have shown that circulating tumor DNA (ctDNA) analysis, as a marker of minimal residual disease, is a powerful prognostic factor in patients with nonmetastatic colorectal cancer (CRC). Serial analysis of ctDNA in patients with resectable CRLM could inform the optimal use of perioperative chemotherapy. Here, we performed a validation study to confirm the prognostic impact of postoperative ctDNA in resectable CRLM observed in a previous discovery study. METHODS AND FINDINGS: We prospectively collected plasma samples from patients with resectable CRLM, including presurgical and postsurgical samples, serial samples during any pre- or postoperative chemotherapy, and serial samples in follow-up. Via targeted sequencing of 15 genes commonly mutated in CRC, we identified at least 1 somatic mutation in each patient's tumor. We then designed a personalized assay to assess 1 mutation in plasma samples using the Safe-SeqS assay. A total of 380 plasma samples from 54 patients recruited from July 2011 to Dec 2014 were included in our analysis. Twenty-three (43%) patients received neoadjuvant chemotherapy, and 42 patients (78%) received adjuvant chemotherapy after surgery. Median follow-up was 51 months (interquartile range, 31 to 60 months). At least 1 somatic mutation was identified in all patients' tumor tissue. ctDNA was detectable in 46/54 (85%) patients prior to any treatment and 12/49 (24%) patients after surgery. There was a median 40.93-fold (19.10 to 87.73, P < 0.001) decrease in ctDNA mutant allele fraction with neoadjuvant chemotherapy, but ctDNA clearance during neoadjuvant chemotherapy was not associated with a better recurrence-free survival (RFS). Patients with detectable postoperative ctDNA experienced a significantly lower RFS (HR 6.3; 95% CI 2.58 to 15.2; P < 0.001) and overall survival (HR 4.2; 95% CI 1.5 to 11.8; P < 0.001) compared to patients with undetectable ctDNA. For the 11 patients with detectable postoperative ctDNA who had serial ctDNA sampling during adjuvant chemotherapy, ctDNA clearance was observed in 3 patients, 2 of whom remained disease-free. All 8 patients with persistently detectable ctDNA after adjuvant chemotherapy have recurred. End-of-treatment (surgery +/- adjuvant chemotherapy) ctDNA detection was associated with a 5-year RFS of 0% compared to 75.6% for patients with an undetectable end-of-treatment ctDNA (HR 14.9; 95% CI 4.94 to 44.7; P < 0.001). Key limitations of the study include the small sample size and the potential for false-positive findings with multiple hypothesis testing. CONCLUSIONS: We confirmed the prognostic impact of postsurgery and posttreatment ctDNA in patients with resected CRLM. The potential utility of serial ctDNA analysis during adjuvant chemotherapy as an early marker of treatment efficacy was also demonstrated. Further studies are required to define how to optimally integrate ctDNA analyses into decision-making regarding the use and timing of adjuvant therapy for resectable CRLM. TRIAL REGISTRATION: ACTRN12612000345886.