International Retrospective Cohort Study Research Articles

B.1 CT Or MRI protocol for acute stroke reperfusion with EVT (COMPARE): an international retrospective cohort study

Background: Patients with an acute ischemic stroke (AIS) are selected to receive reperfusion therapy using either computed tomography (CT-CTA) or magnetic brain imaging (MRI). The aim of this study was to compare CT and MRI as the primary imaging modality for AIS patients undergoing EVT. Methods: Data for AIS patients between January 2018 and January 2021 were extracted from two prospective multicenter EVT cohorts: the ETIS registry in France (MRI) and the OPTIMISE registry in Canada (CT). Demographics, procedural data and outcomes were collected. We assessed the association of qualifying imaging (CT vs. MRI) with time metrics and functional outcome. Results: From January 2018 to January 2021, 4059 patients selected by MRI and 1324 patients selected by CT were included in the study. Demographics were similar between the two groups. The median imaging-to-arterial puncture time was 37 minutes longer in the MRI group. Patients selected by CT had more favorable 90-day functional outcomes (mRS 0-2) as compared to patients selected by MRI (48.5% vs 44.4%; adjusted OR (aOR), 1.54, 95%CI 1.31 to 1.80, p<0.001). Conclusions: Patients with AIS undergoing EVT who were selected with MRI as opposed to CT had longer imaging-to-arterial-puncture delays and worse functional outcomes at 90 days.

Characterization of HER2-low breast cancer in young women with germline BRCA1/2 pathogenetic variants: Results of a large international retrospective cohort study.

Breast cancer (BC) in women aged ≤40 years carrying germline pathogenetic variants (PVs) in BRCA1/2 genes is infrequent but often associated with aggressive features. Human epidermal growth factor receptor 2 (HER2)-low-expressing BC has recently emerged as a novel therapeutic target but has not been characterized in this rare patient subset. Women aged ≤40 years with newly diagnosed early-stage HER2-negative BC (HER2-0 and HER2-low) and germline BRCA1/2 PVs from 78 health care centers worldwide were retrospectively included. Chi-square test and Student t-test were used to describe variable distribution between HER2-0 and HER2-low. Associations with HER2-low status were assessed with logistic regression. Kaplan-Meier method and Cox regression analysis were used to assess disease-free survival (DFS) and overall survival. Statistical significance was considered for p≤.05. Of 3547 included patients, 32.3% had HER2-low BC, representing 46.3% of hormone receptor-positive and 21.3% of triple-negative (TN) tumors. HER2-low vs. HER2-0 BC were more often of grade 1/2 (p<.001), hormone receptor-positive (p<.001), and node-positive (p=.003). BRCA2 PVs were more often associated with HER2-low than BRCA1 PVs (p<.001). HER2-low versus HER2-0 showed better DFS (hazard ratio [HR], 0.86; 95% CI, 0.76-0.97) in the overall population and more favorable DFS (HR, 0.78; 95% CI, 0.64-0.95) and overall survival (HR, 0.65; 95% CI, 0.46-0.93) in the TN subgroup. Luminal A-like tumors in HER2-low (p=.014) and TN and luminal A-like in HER2-0 (p=.019) showed the worst DFS. In young patients with HER2-negative BC and germline BRCA1/2 PVs, HER2-low disease was less frequent than expected and more frequently linked to BRCA2 PVs and associated with luminal-like disease. HER2-low status was associated with a modestly improved prognosis.

Defining Benchmarks for Pelvic Exenteration Surgery: A Multicentre Analysis of Patients with Locally Advanced and Recurrent Rectal Cancer.

To establish globally applicable benchmark outcomes for pelvic exenteration (PE) in patients with locally advanced primary (LARC) and recurrent rectal cancer (LRRC), using outcomes achieved at highly specialised centres. PE is established as the standard of care for selected patients with LARC and LRRC. There are currently no available benchmarks against which surgical performance in PE can be compared for audit and quality improvement. This international multicentre retrospective cohort study included patients undergoing PE for LARC or LRRC at 16 highly experienced centres between 2018 and 2023. Ten outcome benchmarks were established in a lower-risk subgroup. Benchmarks were defined by the 75th percentile of the results achieved at the individual centres. 763 patients underwent PE, of which 464 patients (61%) had LARC and 299 (39%) had LRRC. 544 patients (71%) who met predefined lower risk criteria formed the benchmark cohort. For LARC patients, the calculated benchmark threshold for major complication rate was ≤44%; comprehensive complication index (CCI): ≤30.2; 30-day mortality rate: 0%; 90-day mortality rate: ≤4.3%; R0 resection rate: ≥79%. For LRRC patients, the calculated benchmark threshold for major complication rate was ≤53%; CCI: ≤34.1; 30-day mortality rate: 0%; 90-day mortality rate: ≤6%; R0 resection rate: ≥77%. The reported benchmarks for PE in patients with LARC and LRRC represent the best available care for this patient group globally and can be used for rigorous assessment of surgical quality and to facilitate quality improvement initiatives at international exenteration centres.

Vena cava replacement and major hepatectomy for liver tumors: international multicenter retrospective cohort study.

Involvement of the inferior vena cava (IVC) and hepatic veins (HV) has been considered a relative contraindication to hepatic resection for primary and metastatic liver tumors. However, patients affected by tumors extending to the IVC have limited therapeutic options and suffer worsening of quality of life due to IVC compression. Cases of primary and metastatic liver tumors with vena cava infiltration from 10 international centers were collected (7 European, 1 US, 2 Brazilian, 1 Indian) were collected. Inclusion criteria for the study were major liver resection with concomitant vena cava replacement. Clinical data and short-term outcomes were analyzed. 36 cases were finally included in the study. Median tumor max size was 98mm (range: 25-250). A biliary reconstruction was necessary in 28% of cases, while a vascular reconstruction other than vena cava in 34% of cases. Median operative time was 462 min (range: 230-750), with 750 median ml of estimated blood loss and a median of one pRBC transfused intraoperatively (range: 0-27). Median ICU stay was 4 days (range: 1-30) with overall in-hospital stay of 15 days (range: 3-46), post-operative CCI score of 20.9 (range: 0-100), 12% incidence of PHLF grade B-C. Five patients died in a 90-days interval from surgery, 1 due to heart failure, 1 due to septic shock and 3 due to multiorgan failure. With a median follow-up of 17 months (interquartile range: 11-37), the estimated five-years overall survival was 48% (95% CI: 27%-66%), and five-year cumulative incidence of tumor recurrence was 55% (95% CI: 33%-73%). Major liver resections with vena cava replacement can be performed with satisfactory results in expert HPB centers. This surgical strategy represents a feasible alternative for otherwise unresectable lesions and is associated with favorable prognosis compared to non-operative management, especially in patients affected by intrahepatic cholangiocarcinoma.

Real-world effectiveness and safety of risankizumab in adult patients with plaque psoriasis: A 1-year international multicenter retrospective cohort study

Real-world effectiveness and safety of risankizumab in adult patients with plaque psoriasis: A 1-year international multicenter retrospective cohort study

Robotic versus Laparoscopic Liver Resection in Various Settings: An International Multicenter Propensity Score Matched Study of 10.075 Patients.

The aim of this study was to compare the perioperative outcomes of robotic liver surgery (RLS) and laparoscopic liver surgery (LLS) in various settings. Clear advantages of RLS over LLS have rarely been demonstrated, and the associated costs of robotic surgery are generally higher than those of laparoscopic surgery. Therefore, the exact role of the robotic approach in minimally invasive liver surgery remains to be defined. In this international retrospective cohort study, the outcomes of patients who underwent RLS and LLS for all indications between 2009 and 2021 in 34 hepatobiliary referral centers were compared. Subgroup analyses were performed to compare both approaches across several types of procedures: minor resections in the anterolateral (2, 3, 4b, 5, and 6) or posterosuperior segments (1, 4a, 7, 8), and major resections (≥3 contiguous segments). Propensity score matching (PSM) was used to mitigate the influence of selection bias. The primary outcome was textbook outcome in liver surgery (TOLS), previously defined as the absence of intraoperative incidents ≥grade 2, postoperative bile leak ≥grade B, severe morbidity, readmission, and 90-day or in-hospital mortality with the presence of an R0 resection margin in case of malignancy. The absence of a prolonged length of stay was added to define TOLS+. Among the 10.075 included patients, 1.507 underwent RLS and 8.568 LLS. After PSM, both groups constituted 1.505 patients. RLS was associated with higher rates of TOLS (78.3% vs. 71.8%, P<0.001) and TOLS+ (55% vs. 50.4%, P=0.026), less Pringle usage (39.1% vs. 47.1%, P<0.001), blood loss (100 vs. 200 milliliters, P<0.001), transfusions (4.9% vs. 7.9%, P=0.003), conversions (2.7% vs 8.8%, P<0.001), overall morbidity (19.3% vs. 25.7%, P<0.001) and R0 resection margins (89.8% vs. 86%, P=0.015), but longer operative times (190 vs. 210min, P=0.015). In the subgroups, RLS tended to have higher TOLS rates, compared to LLS, for minor resections in the posterosuperior segments (n=431 per group, 75.9% vs. 71.2%, P=0.184) and major resections (n=321 per group, 72.9% vs. 67.5%, P=0.086), although these differences did not reach statistical significance. While both producing excellent outcomes, RLS might facilitate slightly higher TOLS rates than LLS.

Concurrent progestogen and cerclage to reduce preterm birth: a multicenter international retrospective cohort

Objective: We aimed to evaluate whether cerclage with progestogen therapy was superior to cerclage alone in the prevention of spontaneous preterm birth (sPTB) in singleton pregnancies Methods: This is an international retrospective cohort study of singleton pregnancies, without major anomaly or aneuploidy, and with cerclage placed at 10 different institutions in the United States and Colombia from June 2016-June 2020. Exclusion criteria were: lack of documentation regarding whether progestogen was or was not prescribed, delivery outcome unavailable, and pregnancy termination (spontaneous or induced) prior to 16 weeks’ gestation. Exposure of interest was progestogen use with cerclage placement, which included those who were continued on progestogen or who started progestogen after cerclage. Comparator was those without progestogen use after cerclage placement, which included those who had no progestogen use the whole pregnancy, or who initiated progestogen and then stopped it after cerclage placement. Progestogen type, cerclage indication, maternal baseline characteristics, and maternal/neonatal outcomes were collected. Primary outcome was sPTB <37 weeks. Secondary outcomes were sPTB <34 weeks, gestational age at delivery, composite neonatal outcome including ≥1 of the following: perinatal mortality, confirmed sepsis, Grade III or IV intraventricular hemorrhage, retinopathy of prematurity, respiratory distress syndrome, bronchopulmonary dysplasia. There was planned subgroup analyses by cerclage indication, progestogen type (vaginal progesterone vs 17-hydroxyprogesterone caproate (17-OHPC)), preterm birth history, and site.Continuous variables compared in adjusted analyses with ANCOVA and categorical variables compared with multivariable logistic regression adjusting for potential confounders with adjusted odds ratio (aOR). Cox regression survival curve was generated to compare latency to spontaneous delivery, censored after 37 weeks. Results: During the study period, a total of 699 singletons met inclusion, N=561 in the progestogen with cerclage group, and N=138 with cerclage alone. Baseline characteristics were similar, except those in the progestogen group were more likely to have had a prior sPTB (61% vs 41%, p<0.001). Within the progestogen group, 52% were on 17-OHPC weekly, 44% on vaginal progesterone daily, and 3% on oral progesterone daily. Progestogen with cerclage was associated with a significantly lower frequency of sPTB<37 (31% vs 39% aOR 0.59 (0.39 - 0.89), p=0.01) and <34 weeks (19% vs 27%, aOR 0.55 (0.35 - 0.87), p=0.01), increased latency to spontaneous delivery (Hazard ratio to sPTB <37wk, 0.66 (0.49-0.90), p=0.009), and lower frequency of perinatal death (7% vs 16%, aOR 0.37 (0.20-0.67), p=0.001). In planned subgroup analyses, association with reduced odds of preterm birth <37 weeks persisted in those on vaginal progesterone, those without a prior preterm birth, those with ultrasound or exam-indicated cerclage, those that started progestogen therapy prior to cerclage, and in sites restricted to the United States. Conclusion: Use of progestogen with cerclage was associated with reduced rates of sPTB and early sPTB compared to cerclage alone. Although not powered for subgroups, the strength of evidence for benefit appeared greatest for those with ultrasound or exam-indicated cerclage, and with vaginal progesterone.

Evaluation of predictive factors for i-CLARAS (intraoperative complications in laparoscopic renal and adrenal surgery): a multicentre international retrospective cohort study

The laparoscopic approach represents the standard of treatment for renal and adrenal diseases, and its use is increasing even outside referral centres. Although most procedures are routinely performed, intraoperative complications do not occur, and the rate and predictive factors of these complications have not been established. The aim of this study was to evaluate the incidence and type of intraoperative complications and to identify predictive factors in patients undergoing laparoscopic renal and adrenal surgery. This was a cohort, multicentre, international retrospective study. Patients who underwent laparoscopic renal and adrenal surgeries between April 2017 and March 2022 were included in the study. Bivariate analysis was performed using contingency tables and the χ2 test for independent samples to compare qualitative variables and the T test and Mood test for continuous variables. Multivariate analysis was performed using a logistic regression model to obtain adjusted odds ratios. A total of 2374 patients were included in the study. Intraoperative complications were reported for 8.09% of patients who underwent renal surgery, with the most common complications reported being hollow viscus and vascular complications, and for 6.75% of patients who underwent adrenal surgery, with the most common complication reported being parenchymatous viscous complications. Multivariate analysis revealed that both adrenal and renal surgery radiological preoperative factors, such as invasive features during adrenalectomy and the RENAL score during nephrectomy, are predictive factors of intraoperative complications. In contrast to existing data, surgeon experience was not associated with a reduction in the incidence of perioperative complications.

Multifocal, Asymmetric Bilateral Primary Aldosteronism Cannot be Excluded by Strong Adrenal Vein Sampling Lateralization: An International Retrospective Cohort Study.

Primary aldosteronism (PA) has been broadly dichotomized into unilateral and bilateral forms. Adrenal vein sampling (AVS) lateralization indices (LI) ≥2 to 4 are the standard-of-care to recommend unilateral adrenalectomy for presumed unilateral PA. We aimed to assess the rates and characteristics of residual PA after AVS-guided adrenalectomy. We conducted an international, retrospective, cohort study of patients with PA from 7 referral centers who underwent unilateral adrenalectomy based on LI≥4 on baseline and/or cosyntropin-stimulated AVS. Aldosterone synthase (CYP11B2) immunohistochemistry and next generation sequencing were performed on available formalin-fixed paraffin-embedded adrenal tissue. The cohort included 283 patients who underwent AVS-guided adrenalectomy, followed for a median of 326 days postoperatively. Lack of PA cure was observed in 16% of consecutive patients, and in 22 patients with lateralized PA on both baseline and cosyntropin-stimulated AVS. Among patients with residual PA postoperatively, 73% had multiple CYP11B2 positive areas within the resected adrenal tissue (versus 23% in those cured), wherein CACNA1D mutations were most prevalent (63% versus 33% in those cured). In adjusted regression models, independent predictors of postoperative residual PA included Black versus White race (odds ratio, 5.10 [95% CI, 1.45-17.86]), AVS lateralization only at baseline (odds ratio, 8.93 [95% CI 3.00-26.32] versus both at baseline and after cosyntropin stimulation), and CT-AVS disagreement (odds ratio, 2.75 [95% CI, 1.20-6.31]). Multifocal, asymmetrical bilateral PA is relatively common, and it cannot be excluded by robust AVS lateralization. Long-term postoperative monitoring should be routinely pursued, to identify residual PA and afford timely initiation of targeted medical therapy.

As simple as it sounds? The treatment of simple bone cysts in the proximal femur in children and adolescents: Retrospective multicenter EPOS study of 74 patients.

Simple bone cysts are among the most prevalent benign cystic tumor-like lesions in children. Proximal femoral simple bone cysts may require specific treatment because of increased fracture risk. With limited literature available on this specific localization, consensus regarding optimal treatment is lacking. We present a large international multicenter retrospective cohort study on proximal femoral simple bone cysts. All consecutive pediatric patients with proximal femoral simple bone cyst from 10 tertiary referral centers for musculoskeletal oncology were included (2000-2021). Demographics, primary treatment, complications, and re-operations were evaluated. Primary outcomes were time until full weight-bearing and failure-free survival. Overall, 74 simple bone cyst patients were included (median age 9 years (range = 2-16), 56 (76%) male). Median follow-up was 2.9 years (range = 0.5-21). Index procedure was watchful waiting (n = 6), percutaneous procedure (n = 12), open procedure (n = 50), or osteosynthesis alone (n = 6). Median time until full weight-bearing was 8 weeks (95% confidence interval = 0.1-15.9) for watchful waiting, 9.5 (95% confidence interval = 3.7-15.3) for percutaneous procedure, 11 (95% confidence interval = -0.7 to 13.7) for open procedure, and 6.5 (95% confidence interval = 5.9-16.1) for osteosynthesis alone (p = 0.58). Failure rates were 33%, 58%, 29%, and 0%, respectively (p = 0.069). Overall failure-free survival at 1, 2, and 5 years was 77.8% (95% confidence interval = 68.2-87.4), 69.5% (95% confidence interval = 58.5-80.5), and 62.0% (95% confidence interval = 47.9-76.1), respectively. A preferred treatment for proximal femoral simple bone cysts remains unclear, with comparable failure rates and times until full weight-bearing. Watchful waiting may be successful in certain cases. If not feasible, osteosynthesis alone can be considered. Treatment goals should be cyst control, minimizing complications and swift return to normal activities. Therefore, an individualized balance should be made between undertreatment, with potentially higher complication risks versus overtreatment, resulting in possible larger interventions and accompanying complications. Level IV, retrospective multicentre study.

The differences in lymph node metastases patterns among non-pancreatic periampullary cancers and histological subtypes: an international multicenter retrospective cohort study and systematic review

The differences in lymph node metastases patterns among non-pancreatic periampullary cancers and histological subtypes: an international multicenter retrospective cohort study and systematic review

OGC O07 The prognostic role of positive peritoneal cytology in gastric cancer

Abstract Background Locally advanced non-metastatic gastric cancer is primarily managed with surgical resection and peri-operative oncological therapies. Positive peritoneal cytology is often considered to be indicative of disseminated malignancy. We have previously shown that conversion from positive (Cy+) to negative (Cy0) cytology with systemic therapy, and absence of macroscopic disease, improves survival. With the advent of novel chemo- and radiotherapy regimes as well as immunotherapy, we recognise a lack of current understanding of the role of peritoneal cytology as a prognostic factor. Our study aims to determine the role of positive peritoneal cytology as a prognostic factor in gastric cancer. Methods This is an international multi-centre retrospective cohort study including high-volume, gastric cancer tertiary referral centres. Adult patients without macroscopic metastatic disease who underwent peritoneal cytology, and subsequently multi-modality treatment including surgical resection between 2011 and 2021 were included. The primary outcome measure is overall survival at 1, 3 and 5 years. Secondary outcome measures include recurrence-free survival at 1, 3 and 5 years; 30-day and 90-day major postoperative morbidity; and subset survival analyses were performed in patients who converted to Cy0 in restaging laparoscopy after neoadjuvant therapy. Statistical analysis was performed using R software. Results This is an interim analysis of the data of 280 patients with a mean age of 64.9 (0.72). 231 patients received pre-operative chemotherapy. 51.0% underwent open gastrectomy (41.2% laparoscopic and 4.64% robotic). 55% of patients underwent a total gastrectomy. 25.9% patients had positive cytology on laparoscopy, while 9.71% had indeterminate cytology. There was significant variation in the sites of peritoneal washings (Figure 1). So far, only 1 patient has shown conversion from positive to negative cytology after oncological therapy. At 1 year, the mortality rate was 41.5% (figure 2), while the recurrence rate was 41.4%. Conclusions In this interim report, we demonstrate significant heterogeneity in the way peritoneal cytology is performed, and the peri-operative management of this cohort. The POPEC study closes to patient recruitment at the end of August 2023, and thus at AUGIS we plan to report on the final findings of this study with an anticipated sample size of over 1000 patients.

EPID-10. CNSONTRK STUDY: CLINICAL CHARACTERISTICS AND OUTCOME OF CENTRAL NERVOUS SYSTEM TUMORS HARBORING NTRK GENE FUSIONS

Abstract BACKGROUND TRK fusions are detected in less than 2% of central nervous system (CNS) tumors. There are limited data on the clinical course of affected patients. METHODS We conducted an international retrospective cohort study of patients with TRK fusion-driven CNS tumors. Data extracted included demographics, histopathology, TRK gene fusion, treatment modalities and outcomes. The growth modulation index (GMI) was calculated as a ratio of time to progression with TRK inhibitors to time to progression with the prior line of therapy. RESULTS 119 patients with TRK fusion-driven primary CNS tumors were identified. Median age at diagnosis was 4.5 years (range 0.0–78.3); 101 (85.6%) were &amp;lt; 18 and 45.3% were &amp;lt; 3 years of age. The most frequent tumor location was hemispheric (63.8%). Tumor types included 68 high-grade gliomas (HGG; 57.1%), 33 low-grade gliomas (LGG; 27.7%), 5 embryonal tumors (4.2%) and 13 others (10.9%). Median follow-up was 38.5 months (range 0.03–229.3). Pediatric patients had a better prognosis with a median OS of 185.5 months compared to 24.8 months in adults (p&amp;lt; .0001). Patients with LGG also had a better outcome with median OS that was not reached for LGG compared to 99.5 months for HGG and 38.5 months for embryonal tumors (p=0.0012). Out of 16 evaluable treatment regimens with larotrectinib an objective response was reported in 11 (11/16 (68.8%)-4 CR, 5 PR and 2 MR) compared to 38.1% for non-targeted treatment regimens (24/63 (38.1%)-10 CR, 13 PR and 1 MR). The GMI was 2.11 for pediatric patients treated with larotrectinib. CONCLUSIONS We report a large cohort of patients with TRK fusion-driven primary CNS tumors. Children with LGG glioma had a favorable outcome compared to adult and HGG. Larotrectinib appears to be associated with a better response rate and longer duration of response compared to non-targeted therapy.

Trends in the characteristics and perioperative outcomes of patients undergoing laparoscopic and open resections for benign liver lesions: An international multicenter retrospective cohort study of 845 patients

BackgroundSolid benign liver lesions (BLL) are increasingly discovered, but clear indications for surgical treatment are often lacking. Concomitantly, laparoscopic liver surgery is increasingly performed. The aim of this study was to assess if the availability of laparoscopic surgery has had an impact on the characteristics and perioperative outcomes of patients with BLL. MethodsThis is a retrospective international multicenter cohort study, including patients undergoing a laparoscopic or open liver resection for BLL from 19 centers in eight countries. Patients were divided according to the time period in which they underwent surgery (2008–2013, 2014–2016, and 2017–2019). Unadjusted and risk-adjusted (using logistic regression) time-trend analyses were performed. The primary outcome was textbook outcome (TOLS), defined as the absence of intraoperative incidents ≥ grade 2, bile leak ≥ grade B, severe complications, readmission and 90-day or in-hospital mortality, with the absence of a prolonged length of stay added to define TOLS+. ResultsIn the complete dataset comprised of patients that underwent liver surgery for all indications, the proportion of patients undergoing liver surgery for benign disease remained stable (12.6% in the first time period, 11.9% in the second time period and 12.1% in the last time period, p = 0.454). Overall, 845 patients undergoing a liver resection for BLL in the first (n = 374), second (n = 258) or third time period (n = 213) were included. The rates of ASA-scores≥3 (9.9%–16%,p < 0.001), laparoscopic surgery (57.8%–77%,p < 0.001), and Pringle maneuver use (33.2%–47.2%,p = 0.001) increased, whereas the length of stay decreased (5 to 4 days,p < 0.001). There were no significant changes in the TOLS rate (86.6%–81.3%,p = 0.151), while the TOLS + rate increased from 41.7% to 58.7% (p < 0.001). The latter result was confirmed in the risk-adjusted analyses (aOR 1.849,p = 0.004). ConclusionThe surgical treatment of BLL has evolved with an increased implementation of the laparoscopic approach and a decreased length of stay. This evolution was paralleled by stable TOLS rates above 80% and an increase in the TOLS + rate.

Editor's Choice – External Validation of a Prognostic Model for Survival of Patients With Abdominal Aortic Aneurysms Treated by Endovascular Aneurysm Repair

Current guidelines recommend diameter monitoring of small and asymptomatic abdominal aortic aneurysms (AAAs) due to the low risk of rupture. Elective AAA repair is recommended for diameters ≥ 5.5 cm in men and ≥ 5.0 cm in women. However, data supporting the efficacy of elective treatment for all patients above these thresholds are diverging. For a subgroup of patients, life expectancy might be very short, and elective AAA repair at the current threshold may not be justified. This study aimed to externally validate a predictive model for survival of patients with asymptomatic AAA treated with endovascular aneurysm repair (EVAR). This was a multicentre international retrospective observational cohort study. Data were collected from four European aortic centres treating patients between 2001 and 2021. The initial model included age, estimated glomerular filtration rate (eGFR), and chronic obstructive pulmonary disease (COPD) as independent predictors for survival. Model performance was measured by discrimination and calibration. The validation cohort included 1 500 patients with a median follow up of 65 months, during which 54.6% of the patients died. The external validation showed slightly decreased discrimination ability and signs of overfitting in model calibration. However, a high risk subgroup of patients with impaired survival rates was identified: octogenarians with eGFR < 60 OR COPD, septuagenarians with eGFR < 30, and septuagenarians with eGFR < 60 and COPD having survival rates of only 55.2% and 15.5% at five and 10 years, respectively. EVAR is a valuable treatment option for AAA, especially for patients unsuitable for open repair. Nonetheless, not all these patients will benefit from EVAR, and an individualised treatment recommendation should include considerations on life expectancy. This study provides a risk stratification to identify patients who may not benefit from EVAR under the present diameter threshold.

Hepatocellular carcinoma risk in sub-Saharan African and Afro-Surinamese individuals with chronic hepatitis B living in Europe

Sub-Saharan African (SSA) ethnicity has been associated with a higher risk of hepatocellular carcinoma (HCC) among individuals with chronic hepatitis B in cross-sectional studies. However, the incidence of HCC and performance of HCC risk scores in this population are unknown. We conducted an international multicenter retrospective cohort study of all consecutive HBV-monoinfected individuals of SSA or Afro-Surinamese (AS) ethnicity managed at sites in the Netherlands, the United Kingdom and Spain. We assessed the 5- and 10-year cumulative incidences of HCC in the overall study population, among different clinically relevant subgroups and across (m)PAGE-B subgroups. Next, we explored the different risk factors for HCC. During a median follow-up of 8 years, we analyzed 1,473 individuals of whom 34 developed HCC. The 5- and 10-year cumulative incidences of HCC were 1% and 2.4%. The 10-year cumulative incidence of HCC was 0.7% among individuals without advanced fibrosis at baseline, compared to 12.1% among individuals with advanced fibrosis (p <0.001). Higher age (adjusted hazard ratio [aHR] 1.05), lower platelet count (aHR 0.98), lower albumin level (aHR 0.90) and higher HBV DNA log10 (aHR 1.21) were significantly associated with HCC development. The 10-year cumulative incidence of HCC was 0.5% among individuals with a low PAGE-B score, compared to 2.9% in the intermediate- and 15.9% in the high-risk groups (p <0.001). In this unique international multicenter cohort of SSA and AS individuals with chronic hepatitis B, we observed 5- and 10-year cumulative HCC risks of 1% and 2.4%, respectively. The risk of HCC was negligible for individuals without advanced fibrosis at baseline, and among individuals with low baseline (m)PAGE-B scores. These findings can be used to guide HCC surveillance strategies. Sub-Saharan African ethnicity has been associated with a higher risk of hepatocellular carcinoma among individuals with chronic hepatitis B. In this international multicenter cohort study of sub-Saharan African and Afro-Surinamese individuals living with chronic hepatitis B in Europe, we observed 5- and 10-year cumulative incidences of hepatocellular carcinoma of 1% and 2.4%, respectively. The risk was negligible among individuals without advanced fibrosis and a low baseline (m)PAGE-B score. These findings can be used to guide HCC surveillance strategies in this population.

FTP7.4 Variations in the type of nutritional support provided after pancreatoduodenectomy: results from an international multicentre retrospective cohort study

Abstract Aims An early oral diet is recommended after pancreatoduodenectomy (PD), however, the nutritional management of PD patients is known to be highly variable, and some centres still provide postoperative parenteral nutrition (PN) routinely. A proportion of patients who receive PN experience clinically significant complications underscoring its judicious use. Using a multicentre cohort, this study aimed to determine the proportion of PD patients that received postoperative nutritional support (NS), describe the variations in this support, and investigate whether receiving PN correlated with morbidity. Methods Data was extracted from the Recurrence After Whipple’s (RAW) study database, a retrospective study of patients undergoing PD for histologically confirmed pancreatic, ampullary or distal bile duct malignancy. Results 1323 patients (89.2%) had data on their postoperative NS status available. Of these, 45.4% received postoperative NS. This was “enteral only”, “parenteral only”, and “enteral and parenteral” in 44.3%, 35.2% and 20.5% of cases, respectively. Body mass index &amp;lt;18.5 kg/m2 (p=0.03), an absence of preoperative biliary stenting (p=0.009) and preoperative serum albumin &amp;lt;36 g/L (p=0.009) all correlated with receiving postoperative NS. Among those who did not develop a serious postoperative complication (Clavien-Dindo grade ≥IIIa), one-fifth received PN. Conclusions Being underweight, not undergoing preoperative biliary stenting and having a low preoperative serum albumin all correlated with receiving postoperative NS. A considerable number of patients who had an uneventful recovery received PN; this should be reserved for those who are unable to take an oral diet or those in whom an oral diet is contraindicated.

Stoma-free Survival After Rectal Cancer Resection With Anastomotic Leakage: Development and Validation of a Prediction Model in a Large International Cohort.

To develop and validate a prediction model (STOMA score) for 1-year stoma-free survival in patients with rectal cancer (RC) with anastomotic leakage (AL). AL after RC resection often results in a permanent stoma. This international retrospective cohort study (TENTACLE-Rectum) encompassed 216 participating centres and included patients who developed AL after RC surgery between 2014 and 2018. Clinically relevant predictors for 1-year stoma-free survival were included in uni and multivariable logistic regression models. The STOMA score was developed and internally validated in a cohort of patients operated between 2014 and 2017, with subsequent temporal validation in a 2018 cohort. The discriminative power and calibration of the models' performance were evaluated. This study included 2499 patients with AL, 1954 in the development cohort and 545 in the validation cohort. Baseline characteristics were comparable. One-year stoma-free survival was 45.0% in the development cohort and 43.7% in the validation cohort. The following predictors were included in the STOMA score: sex, age, American Society of Anestesiologist classification, body mass index, clinical M-disease, neoadjuvant therapy, abdominal and transanal approach, primary defunctioning stoma, multivisceral resection, clinical setting in which AL was diagnosed, postoperative day of AL diagnosis, abdominal contamination, anastomotic defect circumference, bowel wall ischemia, anastomotic fistula, retraction, and reactivation leakage. The STOMA score showed good discrimination and calibration (c-index: 0.71, 95% CI: 0.66-0.76). The STOMA score consists of 18 clinically relevant factors and estimates the individual risk for 1-year stoma-free survival in patients with AL after RC surgery, which may improve patient counseling and give guidance when analyzing the efficacy of different treatment strategies in future studies.

Detailed Clinical, Ophthalmic, and Genetic Characterization of ADGRV1-Associated Usher Syndrome

To present the clinical characteristics, retinal features, natural history, and genetics of ADGRV1-Usher syndrome (USH). Multicenter international retrospective cohort study. Clinical notes, hearing loss history, multimodal retinal imaging, and molecular diagnosis were reviewed. Thirty patients (28 families) with USH type 2 and disease-causing variants in ADGRV1 were identified. Visual function, retinal imaging, and genetics were evaluated and correlated, with retinal features also compared with those of the commonest cause of USH type 2, USH2A-USH. The mean age at the first visit was 38.6 ± 12.0 years (range: 19-74 years), and the mean follow-up time was 9.0 ± 7.7 years. Hearing loss was reported in the first decade of life by all patients, 3 (10%) described progressive loss, and 93% had moderate-severe impairment. Visual symptom onset was at 17.0 ± 7.7 years of age (range: 6-32 years), with 13 patients noticing problems before the age of 16. At baseline, 90% of patients had no or mild visual impairment. The most frequent retinal features were a hyperautofluorescent ring at the posterior pole (70%), perimacular patches of decreased autofluorescence (59%), and mild-moderate peripheral bone-spicule-like deposits (63%). Twenty-six (53%) variants were previously unreported, 19 families (68%) had double-null genotypes, and 9 were not-double-null. Longitudinal analysis showed significant differences between baseline and follow-up central macular thickness (-1.25 µm/y), outer nuclear layer thickness (-1.19 µm/y), and ellipsoid zone width (-40.9 µm/y). The rate of visual acuity decline was 0.02 LogMAR (1 letter)/y, and the rate of constriction of the hyperautofluorescent ring was 0.23 mm2/y. ADGRV1-USH is characterized by early-onset, usually non-progressive, mild-to-severe hearing loss and generally good central vision until late adulthood. Perimacular atrophic patches and relatively retained ellipsoid zone and central macular thickness in later adulthood are more often seen in ADGRV1-USH than in USH2A-USH.

Metastatic renal cell carcinoma to the pancreas and other sites-a multicenter retrospective study.

Metastatic renal cell carcinoma (mRCC) is a heterogenous disease with poor 5-year overall survival (OS) at 14%. Patients with mRCC to endocrine organs historically have prolonged OS. Pancreatic metastases are uncommon overall, with mRCC being the most common etiology of pancreatic metastases. In this study, we report the long-term outcomes of patients with mRCC to the pancreas in two separate cohorts. We performed a multicenter, international retrospective cohort study of patients with mRCC to the pancreas at 15 academic centers. Cohort 1 included 91 patients with oligometastatic disease to the pancreas. Cohort 2 included 229 patients with multiples organ sites of metastases including the pancreas. The primary endpoint for Cohorts 1 and 2 was median OS from time of metastatic disease in the pancreas until death or last follow up. In Cohort 1, the median OS (mOS) was 121 months with a median follow up time of 42 months. Patients who underwent surgical resection of oligometastatic disease had mOS of 100 months with a median follow-up time of 52.5 months. The mOS for patients treated with systemic therapy was not reached. In Cohort 2, the mOS was 90.77 months. Patients treated with first-line (1L) VEGFR therapy had mOS of 90.77 months; patients treated with IL immunotherapy (IO) had mOS of 92 months; patients on 1L combination VEGFR/IO had mOS of 74.9 months. This is the largest retrospective cohort of mRCC involving the pancreas. We confirmed the previously reported long-term outcomes in patients with oligometastatic pancreas disease and demonstrated prolonged survival in patients with multiple RCC metastases that included the pancreas. In this retrospective study with heterogeneous population treated over 2 decades, mOS was similar when stratified by first-line therapy. Future research will be needed to determine whether mRCC patients with pancreatic metastases require a different initial treatment strategy. Statistical analyses for this study were supported in part by the University of Colorado Cancer Center Support Grant from the NIH/NCI, P30CA046934-30.