Hsa_circ_0101050 accelerates the progression of Colon cancer by targeting the miR-140-3 p/MELK axis

BACKGROUND

Circular RNAs (circRNAs) are involved in the progression of colon cancer (CC). This study aimed to examine the role of a new circRNA circ_0101050 in CC.

METHODS

Dual-luciferase reporter and RNA immunoprecipitation analyses were performed to validate the target relationships among maternal embryonic leucine zipper kinase (MELK), microRNA (miR)-140-3 p, and circ_0101050. Expression levels were calculated using western blotting and/or quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Western blotting was performed to evaluate the relative expression of Bcl-2 and Bax proteins to determine cell death. Cell Counting Kit-8 (CCK-8) and colony formation assays were performed to determine the proliferative potential of CC cells. The migration rate of CC cells was evaluated using wound healing assays. Tumor formation tests were performed to determine the effect of circ_0101050 on tumor development in vivo.

RESULTS

Elevated levels of circ_0101050 and MELK were observed in CC. By inhibiting circ 0,101,050 or MELK, CC cell proliferation and migration were inhibited, but CC cell apoptosis was promoted. Silencing circ_0101050 also inhibited CC growth in vivo. We also found that miR-140-3 p was downregulated, which alleviated the repressive effects of circ_0101050 knockdown on proliferating and migrating CC cells, as well as the stimulating effect on apoptosis. In addition, the absence of MELK alleviated the effects of miR-140-3 p downregulation, which enhanced CC cell malignancy.

CONCLUSIONS

Circ_0101050 exacerbates malignant phenotypes in CC by targeting the miR-140-3 p/MELK axis. These findings suggested that the circ_0101050/miR-140-3 p/MELK network may be a prospective target for CC treatment.

[A rational analysis of the commonly used renal tumor scoring systems in predicting surgical outcomes of cystic renal masses]

Objective: To explore the predictive effect of the renal tumor scoring system on the surgical outcomes of cystic renal masses (CRM). Methods: A retrospective analysis was performed on the data of 234 patients who received robotic-assisted partial nephrectomy (RAPN) treatment in the First Affiliated Hospital of Xi'an Jiaotong University from January 2018 to June 2020. And 31 cases had CRM and 203 cases had solid renal masses (SRM). The propensity score of patients was calculated by logistic regression model, and 1∶2 matching was performed by the nearest neighbor method. The changes in perioperative indexes and long-term estimated glomerular filtration rate (eGFR) in CRM group and SRM group were compared. The CRM group and SRM group were stratified according to the complexity grading of R.E.N.A.L. score and PADUA score, respectively, to compare the difference in the achievement rate of ideal surgical outcome between the two groups, and analyze the predictive factors affected. The CRM diameter was stratified with 4 cm as the cut-off value (CRM1 group with a diameter<4 cm, CRM2 group with a diameter≥4 cm), and the surgical results were compared with the matched SRM1 group and SRM2 group. Results: In the matching cohort, the CRM group comprised 29 patients with a mean age of (48.7±10.8) years, of which 22 (75.9%) were males. The SRM group included 58 patients with a mean age of (50.4±10.2) years, of which 41 (70.7%) were males, with no statistically significant difference (all P>0.05). The warm ischemia time (WIT) [M (Q1,Q3)] in the CRM group was longer than that in the SRM group [23(18, 25) vs 19(17, 25) min, P=0.040]. The operation time (OT) [M (Q1,Q3)] in the CRM group was also longer than that of the SRM group [130(100, 150) vs 108(86, 120) min, P=0.006]. The change in serum creatinine before and after the operation [M (Q1,Q3)] was higher in the CRM group than in the SRM group [15(10, 23) vs 12(6, 17) μmol/L, P=0.030]. The ideal surgical outcomes were achieved in 7 patients (24.1%) in the CRM group and 36 patients (62.1%) in the SRM group. The number of patients achieving ideal surgical outcomes in R.E.N.A.L. intermediate complex surgery and PADUA advanced complex surgery in the SRM group were 24 (58.5%) and 15 (51.7%), respectively, which were higher than those in the CRM group 6 (27.3%) and 1 (5.9%) respectively (P<0.05). Preoperative eGFR (OR=0.758, 95%CI: 0.719-0.799) and the nature of the tumor (CRM as reference, OR=4.883, 95%CI: 1.550-15.378) were influencing factors for achieving the ideal surgical outcome. Subgroup analysis showed that eGFR changes before and after surgery and the estimated blood loss (EBL) in the CRM2 group were higher than those in the SRM2 group, and WIT and OT were longer than those in the SRM2 group (all P<0.05). The EBL and WIT of the CRM1 group were shorter than those of the CRM2 group (P<0.05). Conclusion: The surgical risk of RAPN in complex CRMs with a maximum diameter of≥4 cm is higher than the risk of RAPN in SRM with equivalent R.E.N.A.L. and PADUA scores.

Radiation Therapy Knowledge and Health Literacy among Culturally Diverse Patients with Prostate Cancer Treated at a Safety-Net Hospital

PURPOSE/OBJECTIVE(S)

Shared decision making is integral to the physician-patient relationship for radiotherapy (RT) patients. It is implicit that patients both comprehend and retain information explained during consultation. However, quality and quantity of patient knowledge following this visit is unknown. The purpose of this study was to evaluate post-consultation RT knowledge and health literacy among a diverse group of patients.

MATERIALS/METHODS

Participants were patients ≥18 years old who received consultation for definitive or salvage RT to the prostate gland/fossa between April 2021 and January 2023 at an urban safety-net hospital. Following consultation, patients completed the Radiation Oncology Knowledge Assessment Survey (ROKAS), designed to measure patient understanding of proposed RT treatment (e.g., treatment frequency, length, safety) and possible short- and long-term side effects (SE). Additional measures included patients' health literacy, health numeracy (numerical medical concepts), acculturation (assimilation to the dominant culture), and socioeconomic factors. ROKAS was administered in both English and Spanish with Spanish-speaking patients offered medical translation if desired. Bivariate Pearson correlations were conducted to examine the relationships between independent variables and post-consultation RT knowledge. Two-sided t-tests were conducted to examine differences in patients' knowledge by language.

RESULTS

Overall, 39 ROKAS were completed by 24 English-speaking and 15 Spanish-speaking patients (mean age 64.4 [SD 6.8], range 52-79). The majority (93%) of patients 'agreed' or 'strongly agreed' that they understood all the RT information presented. However, only 70% of the RT questions were answered correctly with 26% of patients answering all RT questions correctly. Similarly, 95% of patients 'agreed' or 'strongly agreed' with knowing the side effects of their proposed treatment, but only 71% and 74% of short- and long-term SE questions, respectively, were answered correctly. Higher health literacy (p = 0.04) and health numeracy (p = 0.001) were significantly correlated with better understanding of short-term SE, but not with RT knowledge or long-term SE. Spanish-speaking patients had significantly lower scores of health literacy (p = 0.001) and understanding of long-term (p = 0.01), but not short-term SE.

CONCLUSION

There is a significant gap between perceived and measured knowledge of RT treatment and SE in patients who receive consultation for RT to the prostate gland/fossa. Health literacy was significantly associated with improved knowledge of RT and short-term SE. Spanish-speaking patients had poorer understanding of long-term SE than English-speaking patients. Efforts to identify gaps in patient health literacy are needed to target those at risk and ensure that culturally diverse patient populations can engage in shared decision making with their providers.

Contouring Analysis on Synthetic Contrast-Enhanced MR from GRMM-GAN and Implications on MR-Guide Radiation Therapy

PURPOSE/OBJECTIVE(S)

MR-guided linear accelerators have been commercialized making MR-only planning and adaptation an appealing alternative circumventing MR-CT registration. However, obtaining daily contrast-enhanced MR images can be prohibitive due to the increased risk of side effects from repeated contrast injections. In this work, we evaluate the quality of contrast-enhanced multi-modal MR image synthesis network GRMM-GAN (gradient regularized multi-modal multi-discrimination sparse-attention fusion generative adversarial network) for MR-guided radiation therapy.

MATERIALS/METHODS

With IRB approval, we trained the GRMM-GAN based on 165 abdominal MR studies from 65 patients. Each study included T2, T1 pre-contrast (T1pre), and T1 contrast enhanced (T1ce) images. The two pre-contrast MR modalities, T2 and T1pre images were adopted as inputs for GRMM-GAN, and the T1ce image at the portal venous phase was used as an output. Ten MR scans containing 21 liver tumors were selected for contouring analysis. A Turing test was first given to six radiation oncologists, in which 100 real T1ce and synthetic T1ce image slices are randomly given to the radiation oncologists to determine the authenticity of the synthesis. We then invited two radiation oncologists (RadOnc 1 and RadOnc2) to manually contour the 21 liver tumors independently on the real T1ce images. RadOnc2 then performed contouring on the respective synthetic T1ce MRs. DICE coefficient (defined as the intersection over the average of two volumes) and Hausdorff distance (HD, measuring how far two volumes are from each other) were used as analysis metrics. The DICE coefficients were calculated from the two radiation oncologists' contours on the real T1ce MR for each tumor. The DICE coefficients were also calculated from RadOnc 2's contours on real and synthetic MRs. Besides, tumor center shifts were extracted. The tumor center of mass coordinates was extracted from real and synthetic volumes. The difference in the coordinates indicated the shifts in the superior-inferior (SI), right-left (RL), and anterior-posterior (AP) directions between real and synthetic tumor volumes.

RESULTS

An average of 52.3% test score was achieved from the six radiation oncologists, which is close to random guessing. RadOnc 1 and RadOnc 2, who had participated in the contouring analysis, achieved an average DICE of 0.91±0.02 from tumor volumes drawn on the real T1ce MRs. This result sets the inter-operator uncertainty baseline in the real clinical setting. RadOnc 2 achieved an average DICE (real vs. synth) of 0.90±0.04 and HD of 4.76±1.82 mm. Only sub-millimeter (SI: 0.67 mm, RL: 0.41 mm, AP: 0.39 mm) tumor center shifts were observed in all three directions.

CONCLUSION

The GRMM-GAN method has the potential for MR-guided liver radiation when contrast agents cannot be administered daily and provide synthetic contrast-enhanced MR for better tumor targeting. The network can produce synthetic MR images with satisfactory contour agreement and geometric integrity.

Automation of Dosimetric Data Collection Using C# ESAPI for Intracavitary and Hybrid Intracavitary/Interstitial Brachytherapy Plans

PURPOSE/OBJECTIVE(S)

Dosimetric data extraction for complex brachytherapy plans can be a time-consuming and error-prone process. The Eclipse Scripting API (ESAPI) Microsoft .NET framework and its ability to access the ARIA treatment planning database makes it a powerful tool for researchers to incorporate automation into data collection. This automation allows for more efficient and error-free collection of dosimetric data, and the program can be iterated over multiple patients at one time. The main objectives of this study were (i) to develop a C# ESAPI script capable of automated data collection for multiple brachytherapy plans and (ii) to apply the script and examine dosimetric characteristics of a patient cohort with locally advanced cervical cancer treated using tandem and ovoid (T/O) applicators or hybrid tandem and ovoid applicators with needles (T/O + N).

MATERIALS/METHODS

We developed a ESAPI script capable of receiving a list of patient IDs and creating a CSV dataset of dosimetric data of the requested patients. Eclipse commands were accessed to create a CSV dataset consisting of baseline demographic data, average V100, V125, D100, D90 as well as D0.1cc, D1cc, D2cc of organs at risk (bladder, rectum, sigmoid colon, small bowel) per fraction. We applied the ESAPI script to our single-institution retrospective cohort which included patients who underwent brachytherapy as part of definitive radiation treatment for cervical cancer between May 2017 and November 2022. Patients either received T/O or T/O + N brachytherapy boost. Statistical analysis was performed using two-sided t-tests to examine differences in descriptive dose metrics between the two techniques.

RESULTS

The developed ESAPI script automatically generated a CSV file of baseline demographic data as well as dosimetric data for patients who underwent T/O or T/O + N brachytherapy boost. We demonstrated that the ESAPI script could acquire and analyze the data quickly (<5 s per test case) compared to time required to generate data via manual review (5 min per test case). This is a 98% reduction in time required to review and collect data per patient. The analyzed cohort included 72 patients with cervical cancer: 40 with T/O technique and 32 with T/O + N technique. Larger clinical target volumes (CTV) were seen in the group that received treatment with T/O + N technique versus T/O alone (37.4 cc vs 25.2 cc, p < 0.0007). Dose metrics including V100, V125, D100, D90 of the high-risk CTV as well as D0.1cc, D1cc, D2cc of the bladder, rectum, small bowel were not significantly different between techniques. However, the D0.1cc, D1cc, D2cc of the sigmoid colon were higher for patients who received T/O + N technique by 95, 74, and 64 cGy respectively (p < 0.005, p < 0.003 and p < 0.007).

CONCLUSION

This study highlights the use of a newly developed ESAPI script specific to brachytherapy plans which allows for iteration over multiple patients at one time. We were able to quickly compare multiple dose metrics for two patient groups treated at our institution.

Impact of FAPI-PET/CT on Target Volume Definition in Radiation Therapy of Locally Advanced Biliary Tract Cancer: Compared with MRI/CT

PURPOSE/OBJECTIVE(S)

A new radioactive positron emission tomography (PET) tracer uses inhibitors of fibroblast activation protein (FAPI) to visualize FAP-expressing cancer associated fibroblasts. Significant FAPI-uptake has recently been demonstrated in biliary tract cancer (BTC) patients. Target volume delineation for radiation therapy still relies on often less precise conventional magnetic resonance imaging (MRI) registered with computed tomography (CT) imaging, especially in locally advanced BTC patients. The need for improvement in precise tumor detection and delineation led us to innovatively use the novel FAPI-PET/CT for radiation treatment planning.

MATERIALS/METHODS

Gross tumor volumes (GTVs) of five locally advanced BTC cases were contoured under FAPI-PET/CT method. MRI/CT was used to delineate tumors additionally. The differentiation in target definition was analyzed between FAPI-PET/CT-based GTVs and the manually MRI/CT-based GTVs.

RESULTS

Target definition differed significantly between different imaging methods with mean dice similarity coefficients of 0.5527, mean Jaccard similarity coefficients of 0.4296 and mean volumetric overlap difference of 0.5704, while the mean volumes and standard deviations of GTVs were 18.12±15.10 cm3 and 38.44±24.72 cm3, based on FAPI-PET/CT and MRI/CT respectively (P = 0.102). There was a discordance and difference between the volumes of FAPI-GTVs-based GTVs and the manually contoured GTVs based on MRI/CT.

CONCLUSION

Due to its high tumor to background contrast, FAPI-PET/CT seems to be a superior imaging modality compared to the current gold standard MRI/CT in BTC. For the first time, we demonstrate how FAPI-PET/CT could facilitate target definition and increases accuracy in radiation oncology in BTC. Limited to the sample size, we still need more large-scale data to support this view.

Universal DNA methylation age across mammalian tissues

Aging, often considered a result of random cellular damage, can be accurately estimated using DNA methylation profiles, the foundation of pan-tissue epigenetic clocks. Here, we demonstrate the development of universal pan-mammalian clocks, using 11,754 methylation arrays from our Mammalian Methylation Consortium, which encompass 59 tissue types across 185 mammalian species. These predictive models estimate mammalian tissue age with high accuracy (r > 0.96). Age deviations correlate with human mortality risk, mouse somatotropic axis mutations and caloric restriction. We identified specific cytosines with methylation levels that change with age across numerous species. These sites, highly enriched in polycomb repressive complex 2-binding locations, are near genes implicated in mammalian development, cancer, obesity and longevity. Our findings offer new evidence suggesting that aging is evolutionarily conserved and intertwined with developmental processes across all mammals.

[Safety and efficacy of the early administration of levosimendan in patients with acute non-ST-segment elevation myocardial infarction and elevated NT-proBNP levels: An Early Management Strategy of Acute Heart Failure (EMS-AHF)]

Objectives: To investigated the safety and efficacy of treating patients with acute non-ST-segment elevation myocardial infarction (NSTEMI) and elevated levels of N-terminal pro-hormone B-type natriuretic peptide (NT-proBNP) with levosimendan within 24 hours of first medical contact (FMC). Methods: This multicenter, open-label, block-randomized controlled trial (NCT03189901) investigated the safety and efficacy of levosimendan as an early management strategy of acute heart failure (EMS-AHF) for patients with NSTEMI and high NT-proBNP levels. This study included 255 patients with NSTEMI and elevated NT-proBNP levels, including 142 males and 113 females with a median age of 65 (58-70) years, and were admitted in the emergency or outpatient departments at 14 medical centers in China between October 2017 and October 2021. The patients were randomly divided into a levosimendan group (n=129) and a control group (n=126). The primary outcome measure was NT-proBNP levels on day 3 of treatment and changes in the NT-proBNP levels from baseline on day 5 after randomization. The secondary outcome measures included the proportion of patients with more than 30% reduction in NT-proBNP levels from baseline, major adverse cardiovascular events (MACE) during hospitalization and at 6 months after hospitalization, safety during the treatment, and health economics indices. The measurement data parameters between groups were compared using the t-test or the non-parametric test. The count data parameters were compared between groups using the χ² test. Results: On day 3, the NT-proBNP levels in the levosimendan group were lower than the control group but were statistically insignificant [866 (455, 1 960) vs. 1 118 (459, 2 417) ng/L, Z=-1.25,P=0.21]. However, on day 5, changes in the NT-proBNP levels from baseline in the levosimendan group were significantly higher than the control group [67.6% (33.8%,82.5%)vs.54.8% (7.3%,77.9%), Z=-2.14, P=0.03]. There were no significant differences in the proportion of patients with more than 30% reduction in the NT-proBNP levels on day 5 between the levosimendan and the control groups [77.5% (100/129) vs. 69.0% (87/126), χ²=2.34, P=0.13]. Furthermore, incidences of MACE did not show any significant differences between the two groups during hospitalization [4.7% (6/129) vs. 7.1% (9/126), χ²=0.72, P=0.40] and at 6 months [14.7% (19/129) vs. 12.7% (16/126), χ²=0.22, P=0.64]. Four cardiac deaths were reported in the control group during hospitalization [0 (0/129) vs. 3.2% (4/126), P=0.06]. However, 6-month survival rates were comparable between the two groups (log-rank test, P=0.18). Moreover, adverse events or serious adverse events such as shock, ventricular fibrillation, and ventricular tachycardia were not reported in both the groups during levosimendan treatment (days 0-1). The total cost of hospitalization [34 591.00(15 527.46,59 324.80) vs. 37 144.65(16 066.90,63 919.00)yuan, Z=-0.26, P=0.80] and the total length of hospitalization [9 (8, 12) vs. 10 (7, 13) days, Z=0.72, P=0.72] were lower for patients in the levosimendan group compared to those in the control group, but did not show statistically significant differences. Conclusions: Early administration of levosimendan reduced NT-proBNP levels in NSTEMI patients with elevated NT-proBNP and did not increase the total cost and length of hospitalization, but did not significantly improve MACE during hospitalization or at 6 months.

Can a simple echocardiographic Doppler VTI based flow comparison between the RVOT and LVOT assist in identifying patients with a significant atrial septal defect?

Background

Detection of haemodynamically significant shunting from atrial septal defect (ASD) can be identified by using the pulmonary-systemic flow ratio (Qp/Qs). However, calculation of Qp/Qs by echocardiography relies on geometric assumptions that outflow tracts are circular, suffers from squared linear measures, and accurate measurement of right ventricular outflow tract (RVOT) diameter is challenging. Whilst adults with ASD should have overt right ventricular dilatation, RV sizing on echocardiography is often subjective and underappreciated. We evaluated whether a dimensionless index of flow (VTI) differences between the RVOT and left ventricular outflow tract (LVOT) could assist in identifying patients with ASD, and compared it with relative atrial index (RAI), a parameter previously assessed in identifying atrial shunting.

Methods

Data from 64 consecutive patients who underwent ASD closure and had no concomitant lesions, were compared with 63 normal controls. RVOT VTI, LVOT VTI, LVOT diameter, and atrial areas were measured.

Results

Between controls and ASD patients, there was no difference in LVOT VTI or forward stroke volume, but ASD patients had significantly higher RVOT VTI. The RVOT-LVOT VTI ratio was 1:1 in controls and 1.5:1 in ASD patients. Area under the ROC curve analysis of RVOT-LVOT VTI ratio was 0.83, and a ratio of 1.1:1 predicted patients with ASD with 86% sensitivity and 73% specificity. In comparison, the area under the ROC curve analysis of RAI was 0.70, and an RAI of 1.05:1 predicted patients with ASD with 77% sensitivity and 44% specificity.

Conclusion

Calculation of the dimensionless RVOT-LVOT VTI ratio is simple, and may be a useful additional semi-quantitative tool to assist cardiologists and sonographers in detecting atrial shunting, particularly in patients with borderline or overt right heart dilatation, and identify who patients should undergo further evaluation.

Funding Acknowledgement

Type of funding sources: None.

[Expression and diagnostic value of NKX3.1 and NKX2.2 in mesenchymal chondrosarcoma]

Objective: To investigate the immunohistochemical expression of NKX3.1 and NKX2.2 in mesenchymal chondrosarcoma (MC), and to explore the differential diagnostic value of NKX3.1 and NKX2.2 in MC and other types of small round cell malignant tumors. Methods: A total of 12 cases of MC and 97 other small round cell malignant tumors diagnosed in Jinling Hospital, Nanjing University School of Medicine from 2001 to 2020 were collected for NKX3.1 and NKX2.2 immunohistochemical detection. Among them, two kinds of NKX3.1 antibodies [rabbit polyclonal antibody and rabbit monoclonal antibody (EP356)] were used for detection in 12 cases of MC, and one NKX3.1 antibody (rabbit polyclonal antibody) was detected in 97 cases of other small round cell malignant tumors, and the relevant literature was reviewed. Results: The 12 MC patients included 7 females and 5 males, with a mean age of 33 years (14-54 years). Nine cases were from bone and three from soft tissue. Among the 12 MC patients, 8 patients had postoperative recurrence or metastasis, and 3 of them died of tumor recurrence or metastasis. Histologically, 12 cases of MC showed typical bidirectional differentiation.The positive rate of both NKX3.1 antibodies in MC was 12/12, NKX3.1 was focal weakly positive in only one of 12 chondrosarcomas (grade 3), 5 alveolar rhabdomyosarcomas, 5 embryonal rhabdomyosarcomas, and 5 solitary fibrous tumors, respectively. The remaining 70 cases of other small round cell malignant tumors were negative. The positive rates of NKX2.2 in MC, Ewing sarcoma and olfactory neuroblastoma were 12/12, 15/15 and 4/5, respectively. In 12 cases of chondrosarcoma (grade 3), 5 cases of poorly differentiated synovial sarcoma, 5 cases of alveolar rhabdomyosarcoma, and 5 cases of solitary fibrous tumor, NKX2.2 was focally and weakly positive in only one case, respectively, and all the remaining 50 cases of other small round cell malignant tumors were negative. Conclusions: The expression of NKX3.1 and NKX2.2 proteins are significant indicators in the diagnosis of MC, and the combined detection of NKX3.1 and NKX2.2 can help distinguish MC from most other small round cell malignant tumors.

[Succinate dehydrogenase-deficient renal cell carcinoma:a clinicopathological, ultrastructural and molecular analysis]

Objective: To investigate the clinicopathological features, immunophenotype, ultrastructure, genetic alterations and prognosis of succinate dehydrogenase-deficient renal cell carcinoma (SDH RCC). Methods: A total of 11 SDH RCCs, diagnosed from 2010 to 2019, were selected from the Department of Pathology of Nanjing Jingling Hospital, Nanjing University School of Medicine for clinicopathologic, immunohistochemical (IHC), ultrastructural investigation and follow-up. The molecular features of seven cases were analyzed by the panel-targeted DNA next generation sequencing (NGS). Results: There were seven males and four females, with ages ranging from 24 to 62 years (mean 41.4 years, median 41 years). Microscopically, SDH RCC was mainly composed of solid and tubular structures with local cystic change. Four cases showed nested or trabecular structure distributed in a loose hypocellular connective tissue or around scar, similar to oncocytoma. The neoplastic cells demonstrated flocculent eosinophilic cytoplasm with typical intracytoplasmic vacuoles. Immunohistochemically, eight cases were negative for SDHB; three cases showed focal and weak expression, whereas normal renal tubular and vascular endothelial cells demonstrated strong cytoplasmic staining. NGS of DNA targeted-panel detected pathogenic mutations of SDHB gene in seven cases (including three cases with equivocal IHC expression of SDHB), without any mutations in other SDH related genes. There were four cases of SDHB missense mutation, one case of frameshift mutation, one case of splicing mutation, and one case of acquired stop codon mutation. Conclusions: SDH RCC is a distinct variant of RCCs with genetic tendency or with hereditary cancer syndrome. NGS is recommended to detect the related gene mutations for a definitive diagnosis. The patients should be closely followed up.

Long term prognostic utility of exercise capacity in renal transplant candidates

Background

Pharmacological stress testing is commonly performed for cardiovascular risk stratification in potential renal transplant candidates due to a perceived inability for these patients to exercise. We have previously reported that exercise stress testing is feasible in renal transplant candidates but the prognostic utility of exercise capacity in this patient group is not known.

Purpose

This study prospectively evaluated the effect of exercise capacity on the risk of major adverse cardiovascular events (MACE), defined as a composite of cardiac death, non-fatal myocardial infarction, and stroke, in renal transplant candidates undergoing exercise stress echocardiography (ESE) for pre-transplant cardiovascular assessment.

Methods

We evaluated 898 consecutive patients with chronic kidney disease stage 4/5 who underwent symptom-limited treadmill ESE over 5-year mean follow-up. Exercise capacity was measured by age and sex predicted metabolic equivalents (METs). The primary outcome was achievement of predicted METs with first MACE. Cox proportional hazard multivariable modelling was used to determine MACE predictors with transplantation treated as a time-varying covariate. We also performed secondary analysis using a 7 MET threshold.

Results

There were 106 MACE with an annual cumulative risk of 2.4%. During follow-up, 525 (58%) received transplantation. Achievement of predicted METs (48%) (hazard ratio (HR) 0.49, 95% confidence interval (CI) 0.29–0.82, p=0.007) and transplantation (HR 0.52, 95% CI 0.30–0.91, p=0.02) were independently associated with reduced MACE. Similar results were observed using a 7 MET threshold achieved by 734 (82%) patients. Patients achieving predicted METs had no difference in MACE regardless of subsequent transplantation (HR 0.78, 95% CI 0.32–1.92, p=0.59). Patients who achieved predicted METs and did not receive transplantation had similar outcomes to those that did not achieve predicted METs and received transplantation (HR 0.97, 95% CI 0.42–2.25, p=0.95).

Conclusions

Exercise capacity is associated with reduced long-term MACE in renal transplant candidates undergoing ESE for pre-transplant cardiovascular assessment. Achievement of age and sex predicted METs confers excellent prognosis independent of subsequent transplantation.

Funding Acknowledgement

Type of funding sources: None.

[Hypoxia Accelerate β-Actin Expression through Transcriptional Activation of ACTB by Nuclear Respiratory Factor-1]

Cytoskeletal protein β-actin is abundant both in the cytoplasm and the nucleus, its mRNA is commonly utilized an internal control for gene expression analysis. Recent reports demostrated that hypoxia influences the levels of β-actin in a variety of cells. The mechanism underlying this change are not yet elucidated. In this work, we show that the changes in the levels of hypoxia-induced Nuclear respiratory factor-1 (NRF-1) lead to the change in expression of β-actin. We compared the protein levels of NRF-1 and β-actin in gastric cancer and adjacent tissues and found their significantly upregulation in cancer (33% patitents). When gastric cancer cells and normal gastric cells were treated with 1% O2 for 48 h, the trends in expression levels of NRF-1 and β-actin were similar. When NRF-1 expression was modified by its overexpressing or silencing, the levels of β-actin changed accordingly. In β-actin gene (ACTB), three binding sites for NRF-1 were found. These sites are conserved in human, mouse and rat genomes. In ChIP experiments, we showed that NRF-1 directly binds to human ACTB and mouse Actb coding regions. Its seems that the transcription of β-actin encoding gene is NRF-1 dependent.

11-year follow-up outcomes of catheter ablation of para-hisian accessory pathways

Funding Acknowledgements

Type of funding sources: None.

Background

Ablation of para-hisian accessory pathways (APs) remains challenging due to anatomic characteristics and few studies have focused on the causes for recurrence of radiofrequency ablation of para-hisian APs.

Objective

This retrospective single center study was aimed to explore the risk factors for recurrence of para-hisian APs.

Methods

113 patients who had a para-hisian AP with an acute success were enrolled in the study. In the 11-year follow-up, 15 cases had a recurrent para-hisian AP. Therefore 98 patients were classified into success group while 15 patients were classified into recurrence group. Demographic and ablation characteristics were analyzed.

Results

Gender difference was similar in two groups. The median age was 36.2 years old and was younger in recurrence group. Maximum ablation power was significantly higher in success group (29 ± 7.5 vs 22.9 ± 7.8, p &lt; 0.01). Ablation time of final target sites was found to be markedly higher in success group (123.4 ± 53.1 vs 86.7 ± 58.3, p &lt; 0.05). Ablation time less than 60 seconds was detected in 12 (12.2%) cases in success group and 7 (46.7%) cases in recurrence group (p &lt; 0.01). Occurrence of junctional rhythm was significantly higher in recurrence group (25.5% vs 53.3%, p &lt; 0.05). No severe conduction block, no pacemaker implantation and no stroke were reported. Junctional rhythm during ablation (OR = 3.833, 95%CI 1.083-13.572, p = 0.037) and ablation time &lt;60s (OR = 5.487, 95%CI 1.411-21.340, p = 0.014) were independent risk factors for the recurrence of para-hisian AP.

Conclusions

Considering the long-term safety of ablation of para-hisian AP, proper extension of ablation time and increase of ablation power could be applied during operation.

The tissue transglutaminase: a potential target regulating MDR in breast cancer

OBJECTIVE

Multi-drug resistance (MDR) is the main obstacle influencing the anti-tumor effect in breast cancer. To date, no proper potential targets are found to overcome MDR. Here, tTG was explored to show whether it is a potential target to regulate MDR in breast cancer.

MATERIALS AND METHODS

tTG was silenced by small interfere siRNA. After that, the mRNA level of CD44, CD24, LRP, MRP and MDR1 were detected by RT-PCR. The Western blot analysis was used to detect the expression of LRP, P-gp and MRP. In addition, the impact of tTG on cell apoptosis, as well as cell proliferation were observed. Finally, to evaluate the role of tTG in BALB/c nude mice, the growth of tumor was performed, and the immunohistochemistry analysis was used to observe the expression of LRP, P-gp and MRP in vivo.

RESULTS

In MCF-7/ADR, Compared to MCF-7, tTG expression was highly increased. After silencing tTG, the mRNA level and the protein level of P-gp, MRP, LRP were both differently decreased. The mRNA level of CD44 and CD24 was also down-regulated after silencing tTG. In addition, the cell proliferation was significantly inhibited in the ADR + tTG siRNA+Adriamycin group (p<0.05), and the tumor growth was prevented in a time-dependent situation. Cell apoptosis was significantly strengthened in the ADR+tTG siRNA+Adriamycin group (p<0.05). In vivo, the growth of tumors was reduced after silencing tTG, and the LRP, P-gp and MRP expression were significantly down-regulated in ADR + tTG SiRNA +adriamycin group (p<0.05).

CONCLUSIONS

It is concluded that the tTG may be a potential target regulating the MDR by regulating LRP, P-gp and MRP expression as well as the expression of CD44CD24 to improve the MDR in breast cancer.

[Clinicopathological and molecular features of biphenotypic sinonasal sarcoma]

Objective: To study the clinicopathologic features, immunophenotype, molecular genetics and differential diagnosis of biphenotypic sinonasal sarcoma (BSNS), and to evaluate the role of PAX3 and PAX8 immunohistochemical (IHC) antibodies in the diagnosis of BSNS. Methods: Nasal sinus spindle cell tumors surgically treated at the Jinling Hospital from 2000 to 2019 were collected, including three cases of BSNS, 10 cases of acinar rhabdomyosarcoma, eight cases of schwannoma, five cases of hemangiopericytoma, three cases of fibrosarcoma, and one case of triton tumor. The cases were evaluated by histology, IHC by EnVision for PAX3 and PAX 8 (including PAX8 murine monoclonal antibody, clone number OTI6H8, hereinafter referred to as PAX8-OTI6H8 antibody; PAX8 rabbit monoclonal antibody, clone number EP298, hereinafter referred to as PAX8-EP298 antibody) molecular genetic tests. Results: All three BSNS patients were elderly women with clinical manifestations of nasal congestion and bleeding. Imaging showed a soft tissue density shadow of the nasal cavity and sinuses with bone destruction. The boundaries of tumors which were covered with ciliated columnar epithelium were unclear, and mucosal invasion and squamous metaplasia could be seen. Tumor cells were spindle-shaped, arranged in a bundle-like, braided arrangement, with little cellular atypia and occasional atypical mitotic figures. The tumoral interstitial vessels were mostly thin-walled, some showing staghorn-like changes. There was focal striated muscle differentiation in two cases, and bone invasion was seen in two cases. IHC staining showed that all three cases of BSNS expressed PAX3 and PAX8-OTI6H8, but not PAX8-EP298. All eight cases of schwannoma, five cases of hemangiopericytoma, and one case of triton tumor did not express PAX3, PAX8-OTI6H8 or PAX8-EP298. Eight of the ten cases of alveolar rhabdomyosarcoma expressed PAX3 and PAX8-OTI6H8, but not PAX8-EP298. Three cases of fibrosarcoma showed weak PAX3 and PAX8-OTI6H8 expression, but there was no PAX8-EP298 expression. FISH detection showed that PAX3 break apart in the tumor cells from all three patients (four specimens). Conclusions: BSNS is a distinct sinonasal low grade malignancy with dual differentiation which could be readily confused with a variety of spindle cell tumors encountered in the sinonasal cavity. The molecular genetics of PAX3 gene break is the gold standard for diagnosis of this tumor. IHC marker monoclonal PAX3 is 100% expressed in BSNS, while the specificity is limited. PAX8-OTI6H8 is also expressed in BSNS due to the cross reaction with PAX3 antibody, while PAX8-EP298 is all negative for these tumors.

Clinicopathologic characteristics, survival, and treatments for gastric adenosquamous carcinoma: a population-based study

Background

Gastric adenosquamous carcinoma (gasc) is a rare entity with distinctive characteristics that are not fully understood. In the present study, we evaluated the characteristics of this rare disease.

Methods

The U.S. Surveillance, Epidemiology, and End Results program database was searched to determine the clinicopathologic features, prognostic factors, and treatments for 246 patients with gasc and 42,735 patients with gastric adenocarcinoma (gac).

Results

Relative to gac, gasc is associated with higher proportions of cardia involvement, high-grade tumours, deep tumour invasion, metastatic lymph nodes, and chemotherapy treatment. In patients who underwent potentially curative surgery (pcs), gasc was associated with a higher proportion of radiotherapy use and poorer overall survival (p < 0.001), although no significant difference (p = 0.802) was observed after propensity score matching (psm). Multivariate analysis after psm revealed that the independent prognostic factors for gasc were TNM stage [hazard ratio (hr): 1.512; p = 0.021] and regional nodes examined (hr: 0.588; p = 0.02). In patients with advanced disease, no significant difference in survival between gasc and gac was observed (p = 0.212), although survival was significantly poorer for gasc after psm (p = 0.019). Multivariate analysis after psm revealed that the independent prognostic factors for gasc were invasion depth (hr: 1.303; p = 0.036) and chemotherapy (hr: 0.444; p < 0.001).

Conclusions

Relative to gac, gasc was associated with more aggressive features, although survival outcomes were similar after pcs. Chemotherapy remains a mainstay of treatment for patients with advanced gasc, but its role remains unclear for patients who are undergoing pcs.

Stress perfusion cardiac magnetic resonance imaging to identify coronary aneurysms, ischaemia and fibrosis in adult patients with convalescent Kawasaki disease

Background

Kawasaki disease is a common cause of coronary aneurysms in early adulthood. Non-invasive imaging plays a crucial role in the diagnosis and surveillance of these patients who are known to develop ischaemia, premature coronary artery disease and have poorer long-term health outcomes. Stress perfusion cardiac MRI (CMR) is considered the “gold standard” for the assessment of ischaemia and risk stratification of major adverse cardiovascular events in patients with coronary artery disease. Its use in the long-term follow-up of patients with Kawasaki disease is particularly attractive as it avoids the use of ionising radiation. However, data on its utility, together with magnetic resonance angiography (MRA) and late gadolinium enhancement (LGE) to identify ischaemia, coronary aneurysms, and fibrosis, over long-term follow-up in this population remains limited.

Purpose

To evaluate the diagnostic utility of comprehensive non-invasive stress perfusion CMR to identify inducible ischaemia, coronary aneurysms and myocardial fibrosis in adult patients with convalescent Kawasaki disease.

Methods

We performed a retrospective review of all adult patients in our Kawasaki service who underwent stress perfusion CMR with MRA and LGE as part of routine clinical care. Data collected included the presence of inducible perfusion defects, coronary anatomy and LGE. Data was compared to contemporary CT coronary angiography (CTCA). In patients who had repeated stress perfusion CMR, changes in perfusion over time were investigated.

Results

Seventeen patients underwent stress perfusion CMR (total 30 scans). Seven patients underwent ≥2 scans. Median age was 21 years; 14 patients were male. Five patients (30%) had areas of inducible hypoperfusion of which 3 also had LGE. A further 2 patients had LGE with no ischaemia. Coronary MRA was performed in 12 patients (71%) and identified 14 aneurysms. In 8 patients with both MRA and CTCA, detection of aneurysms was significantly correlated (Pearson's coefficient 0.776; P value 0.024). Of the 5 patients with ischaemia, 4 patients had previous CABG. All areas of ischaemia corresponded to persistent calcified aneurysms in the responsible artery. In the 7 patients with multiple perfusion CMR scans (median follow-up 47 months), 3 patients developed new ischaemia.

Conclusions

Long-term surveillance of coronary arteries in adult patients with a childhood history of Kawasaki disease is crucial in the early identification and management of complications. We show that stress perfusion CMR is a useful radiation-free technique for the long-term follow-up of these young patients and is able to identify the development of new ischaemia. Coronary MRA has good agreement in the identification of aneurysms when compared to CTCA. Little is reported in the literature regarding the use of a comprehensive CMR assessment in the follow-up of adult patients with Kawasaki disease and further studies are needed to validate this approach.

Funding Acknowledgement

Type of funding source: None

Effects of diets with different energy and bile acids levels on growth performance and lipid metabolism in broilers

This experiment was conducted to evaluate the effects of bile acids (BAs) on the growth performance and lipid metabolism of broilers fed with different energy level diets. 480 one-day-old Arbor Acres broilers (45.01 ± 0.26 g) were allotted to a 2 × 2 factorial design with 2 levels of energy (basal or high-energy level) and 2 levels of BAs (with or without BAs supplementation), resulting in 4 groups of 8 replicates; the experiment lasted 42 d. High-energy diets decreased the feed/gain ratio (F/G) from 1 to 21 d (P < 0.05), and increased the liver index and abdominal fat percentage at 42 d (P < 0.05). The serum total triglyceride (TG) and high-density lipoprotein cholesterol at 42 d were increased by high-energy diets (P < 0.05), while the hepatic lipoprotein lipase (LPL) activity at 21 and 42 d was decreased (P < 0.05). BAs supplementation increased the body weight at 21 d and decreased the F/G during entire period (P < 0.05), as well as improved the carcass quality reflected by decreased abdominal fat percentage at 42 d and increased breast muscle percentage at 21 and 42 d (P < 0.05). The serum TG at 21 and 42 d were decreased by BAs (P < 0.05), and the hepatic LPL activity at 42 d was increased (P < 0.05). In addition, high-energy diets increased the expression of sterol regulatory element binding transcription factor 1, acetyl-CoA carboxylase, and fatty acid synthase (P < 0.05), while BAs diets decreased these genes expression (P < 0.05). Moreover, BAs supplementation also increased the expression of carnitine palmitoyltransferase 1 (P < 0.05), which was increased in high-energy groups (P < 0.05). In conclusion, BAs supplementation could increase growth performance, elevate carcass quality, and improve lipid metabolism in broilers.

Alterations in Blood-Brain Barrier Permeability in Patients with Systemic Lupus Erythematosus

BACKGROUND AND PURPOSE

Neuropsychiatric systemic lupus erythematosus refers to central and peripheral nervous system involvement, which may occur secondary to antineuronal antibodies crossing the blood-brain barrier that preferentially target cells in the hippocampus leading to abnormal hypermetabolism and atrophy. Thus, we hypothesized that alterations in BBB permeability, detected on dynamic contrast-enhanced MR imaging, occur in the hippocampus in patients with systemic lupus erythematosus before development of neuropsychiatric systemic lupus erythematosus.

MATERIALS AND METHODS

Six patients with systemic lupus erythematosus without neuropsychiatric systemic lupus erythematosus and 5 healthy controls underwent dynamic contrast-enhanced MR imaging with postprocessing into BBB permeability parameters (K ^trans and Ve) and CBF. Standardized methods selected ROI sampling of the abnormal brain regions detected on FDG-PET. The mean and SD of K ^trans, Ve, and CBF were calculated. Linear regression and nonparametric Spearman rank correlation analyses of K ^trans and Ve with CBF were performed. Dynamic contrast-enhanced curves and the area under the curve were generated for each brain region. Student t test comparisons were performed.

RESULTS

Quantitative data revealed that patients with systemic lupus erythematosus have statistically increased K ^trans (P < .001) and Ve (P < .001) compared with controls. In patients with systemic lupus erythematosus, statistically significant positive correlations were seen between K ^trans (P < .001) and Ve (P < .001) with CBF. Furthermore, the mean area under the curve revealed statistically increased BBB permeability in the hippocampus (P = .02) compared with other brain regions in patients with systemic lupus erythematosus compared with controls.

CONCLUSIONS

These initial findings are proof-of-concept to support the hypothesis that patients with systemic lupus erythematosus have increased BBB permeability, specifically in the hippocampus, compared with other brain regions. These findings may advance our understanding of the underlying pathophysiology affecting the brain in autoimmune diseases.

Abstract P3-12-25: Dosimetric impact of patient rotation during prone breast radiotherapy

Purpose

Prone positioning has been used as a viable alternative to conventional supine position for patients receiving breast radiation therapy. However, little research has been done exploring the axial rotation of patients toward the treated breast when “sinking” into the opening of the breast board and its potentially negative effects on dosimetric outcomes, which may include increased heart and lung dose. The physician may need to move the posterior border away from the chest wall to reduce heart and lung dose.

Methodology

49 consecutive female patients with left sided early stage breast cancer treated at University of California Davis Medical Center were assessed from 2015 to 2018 (age range: 42-84 years, median age: 62 years). All patients underwent prone whole breast therapy with conventional external beam radiation therapy (EBRT) at doses of 50 Gy (n = 12) or hypofractionated at 42.56 Gy (n = 37). Treatment plans and dose volumes were retrospectively analyzed for each patient. Standard tangents were designed for each patient using clinical landmarks of the midaxillary line and midsternal line, which were then compared to the delivered tangent beams. The angle created between a vertical line centered on center sternum and a line drawn from center sternum to center spinal cord served to define degree of axial rotation. Breast depth was defined by the longest horizontal length from outer rib to edge of breast on sagittal view. Patients were divided into subgroups by degree of rotation and absolute breast depth. A two tailed paired Student's t-test was used for analysis.

Results

Overall mean heart and lung dose were 82.2 cGy and 50.43 cGy for the entire cohort, respectively. For standard tangents, patients with degree of rotation &lt; 5 degrees in the prone position (n = 23) had significant lung sparing as compared to patients with degree of rotation &gt; 5 cm (n = 26) (mean lung dose: 61.8 cGy vs 129.6 cGy, p = 0.00329). This was also seen for cardiac sparing (mean heart dose: 105.9 cGy vs 183.9 cGy, p = 0.000235). Even with reduction of posterior border for treatment delivery, there remained a significant increase in mean heart and lung dose with increased rotation (p = 0.038, p = 0.046). Although not statistically significant, for patients with &gt; 5 degrees of rotation there was a trend toward increased reduction of the posterior border of the tangent (13 mm vs. 7.5 mm, p = 0.13). A significant predictor of increased rotation was breast depth &gt; 10 cm (p = 0.01). Patients with absolute breast depth &gt; 10 cm (n = 23) in the prone position had significant lung sparing as compared to patients with absolute breast depth &lt; 10 cm (n = 26) (mean lung dose: 58.6 cGy vs 40.8 cGy, p = 0.042).

Conclusion

To our knowledge, this is the first dosimetric comparison of prone breast therapy exploring the degree of patient roll into the prone-breast setup cavity. This study demonstrates a significant increase in mean lung and heart dose when patient rotation is greater than 5 degrees. Given this, the posterior border may have to be reduced to prevent a higher than intended dose to the heart and lung. Proper attention during simulation is important to allow for optimal dose distribution and special attention should be paid to women with smaller breast size.

Citation Format: Cheng K, Hoopingarner S, Wright C, Daly M, Fragoso R, Zhao X. Dosimetric impact of patient rotation during prone breast radiotherapy [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-12-25.

Dynamic Contrast-Enhanced MRI Reveals Unique Blood-Brain Barrier Permeability Characteristics in the Hippocampus in the Normal Brain

We report a prospective dynamic contrast-enhanced MR imaging analysis of region-specific blood-brain barrier permeability in 5 healthy subjects. By means of standardized postprocessing and ROI sampling methods, the hippocampi revealed significantly elevated area under the dynamic contrast-enhanced curve and significantly increased blood-brain barrier permeability metrics (volume transfer constant and volume in the extravascular extracellular space) from model-based quantitation. These findings suggest unique blood-brain barrier permeability characteristics in the hippocampus, which are concordant with previous animal studies, potentially laying the groundwork for future studies assessing patient populations in which hippocampal pathology plays a role.

200 Developing exosomes as a mediator for CRISPR/Cas-9 delivery

CRISPR/Cas systems present a powerful gene-editing tool with the potential for widespread therapeutic use; however, current methods of in vivo delivery such as adeno-associated viruses (AAV) may stimulate an immune response, creating the need for an alternative for delivery of CRISPR/Cas9. Exosomes are small vesicles that are released by cells and serve as a delivery system for RNA, proteins, and various molecules to other cells. The focus of this project was to use exosomes as a delivery system for Cas9, exploiting their high uptake by target cells and their ability to avoid the immune system in vivo. Porcine fetal fibroblasts (PFF) were grown to 80% confluency; after 48h, exosomes were isolated and concentrated from conditioned media by filtration with a 0.22-μm filter followed by 100-kDa molecular weight cutoff filter. Transmission electron microscopy, Western blotting for presence of CD81, and an uptake assay for exosomes stained with the lipophilic dye DiI (Invitrogen/Thermo Fisher Scientific, Waltham, MA, USA) were used to characterise isolated exosomes, and average particle size was evaluated by NanoSight (Salisbury, United Kingdom). After characterisation, exosomes were loaded with Cas9 (PNA Bio, Newbury Park, CA, USA) using sonication, incubation with saponin, or extrusion. For each method of loading, 1.0×1011 exosomes and 500ng of Cas9 were used. For sonication, exosomes and Cas9 were sonicated 4 times: 4s on/2s off, left on ice for 2min, and then repeated for 4 more cycles. Loaded exosomes were then incubated at 37°C for 20min. For incubation with saponin, 100μL of 0.6% saponin solution was made in PBS, mixed with exosomes and Cas9, and then incubated on a shaker at 800 rpm for 20min. For extrusion, exosomes and Cas9 were extruded (Avanti Polar Lipids, Alabaster, AL, USA) 10, 15, or 20 times through a 0.22-μm filter. To evaluate efficiency of Cas9 loading into exosomes, loaded exosome samples were split in half, with one-half receiving a proteinase K digest (100μg mL−1) to remove free Cas9 and the other receiving no treatment. Proteinase K-treated and untreated samples were then compared side by side on Western blot staining for Cas9. ImageJ software (National Institutes for Health, Bethesda, MD, USA) was used to quantify band intensity and loading efficiency. With optimal conditions, our preliminary results show loading efficiency for sonication and saponin to be 16.7 and 19.2%, respectively, whereas loading by extrusion was undetectable. For CRISPR/Cas targeting, transgenic PFF carrying one copy of H2B-GFP were used to test delivery of ribonucleotide protein complex (RNP). To verify efficiency of the guide (g)RNA targeting green fluorescent protein (GFP), cells were nucleofected with Cas9 and gRNA. The DNA was extracted, PCR amplified, and sequenced (Eton Bioscience, San Diego, CA, USA) and then evaluated for indels with TIDE, resulting in a 53.2% cleavage efficiency. Next, exosomes will be loaded with RNP to knockout GFP in H2B-GFP cells, and targeting efficiency will be evaluated by flow cytometry and TIDE. We hypothesise that based on loading efficiency and target cell uptake, exosomes will present a safe and efficient method for in vitro and in vivo delivery of Cas9. The financial support of the Comparative Medicine Institute is gratefully acknowledged.

Critical care usage after major gastrointestinal and liver surgery: a prospective, multicentre observational study

BACKGROUND

Patient selection for critical care admission must balance patient safety with optimal resource allocation. This study aimed to determine the relationship between critical care admission, and postoperative mortality after abdominal surgery.

METHODS

This prespecified secondary analysis of a multicentre, prospective, observational study included consecutive patients enrolled in the DISCOVER study from UK and Republic of Ireland undergoing major gastrointestinal and liver surgery between October and December 2014. The primary outcome was 30-day mortality. Multivariate logistic regression was used to explore associations between critical care admission (planned and unplanned) and mortality, and inter-centre variation in critical care admission after emergency laparotomy.

RESULTS

Of 4529 patients included, 37.8% (n=1713) underwent planned critical care admissions from theatre. Some 3.1% (n=86/2816) admitted to ward-level care subsequently underwent unplanned critical care admission. Overall 30-day mortality was 2.9% (n=133/4519), and the risk-adjusted association between 30-day mortality and critical care admission was higher in unplanned [odds ratio (OR): 8.65, 95% confidence interval (CI): 3.51-19.97) than planned admissions (OR: 2.32, 95% CI: 1.43-3.85). Some 26.7% of patients (n=1210/4529) underwent emergency laparotomies. After adjustment, 49.3% (95% CI: 46.8-51.9%, P<0.001) were predicted to have planned critical care admissions, with 7% (n=10/145) of centres outside the 95% CI.

CONCLUSIONS

After risk adjustment, no 30-day survival benefit was identified for either planned or unplanned postoperative admissions to critical care within this cohort. This likely represents appropriate admission of the highest-risk patients. Planned admissions in selected, intermediate-risk patients may present a strategy to mitigate the risk of unplanned admission. Substantial inter-centre variation exists in planned critical care admissions after emergency laparotomies.