Pyruvate carboxylase deficiency type C; variable presentation and beneficial effect of triheptanoin

Pyruvate carboxylase is a mitochondrial enzyme essential for the tricarboxylic acid cycle (TCA), gluconeogenesis and fatty-acid synthesis. Pyruvate carboxylase deficiency (PCD) mostly presents with life-limiting encephalopathy (types A/B). A milder type C presentation is rare, with a comparatively favourable prognosis. Therapies remain essentially supportive. Triheptanoin is an odd-chain triglyceride, with the potential to replenish TCA intermediates (anaplerosis), and its metabolites cross the blood-brain-barrier. Outcomes of triheptanoin treatment in PCD types A/B have been disappointing, but have not been reported in type C. Here, we present two new patients with PCD type C, and report the response to treatment with triheptanoin in one. Patient 1 (P1) presented with neonatal-onset lactic acidosis and recurrent symptomatic lactic acidosis following exercise and during illnesses, with frequent hospitalisations. Speech development was delayed. MRI-brain showed delayed cerebral myelination. Patient 2 (P2) presented with episodic ketoacidosis, hyperlactataemia and hypoglycaemia at 2 years of age, with gross motor delay and mild global volume loss on MRI brain. Treatment with triheptanoin was commenced in P1 at 3 years of age with up-titration to 35 mL/day (25% of daily energy intake) over 6 months, due to transient diarrhoea. Dietary long-chain triglycerides were restricted, with fat-soluble vitamin supplementation. Subsequently, hospitalisations during intercurrent illnesses decreased, post-exertional hyperlactataemia resolved and exercise tolerance improved. Continued developmental progress was observed, and repeat MRI 18 months after initiation showed improved myelination. Triheptanoin was well-tolerated and appeared efficacious during 2 years' follow-up, and has potential to restore energy homeostasis and myelin synthesis in PCD type C.

Improving oncology first-in-human and Window of opportunity informed consent forms through participant feedback

BACKGROUND

Although patient advocates have developed templates for standard consent forms, evaluating patient preferences for first in human (FIH) and window of opportunity (Window) trial consent forms is critical due to their unique risks. FIH trials are the initial use of a novel compound in study participants. In contrast, Window trials give an investigational agent over a fixed duration to treatment naïve patients in the time between diagnosis and standard of care (SOC) surgery. Our goal was to determine the patient-preferred presentation of important information in consent forms for these trials.

METHODS

The study consisted of two phases: (1) analyses of oncology FIH and Window consents; (2) interviews of trial participants. FIH consent forms were analyzed for the location(s) of information stating that the study drug has not been tested in humans (FIH information); Window consents were analyzed for the location(s) of information stating the trial may delay SOC surgery (delay information). Participants were asked about their preferred placement of the information in their own trial's consent form. The location of information in the consent forms was compared to the participants' suggestions for placement.

RESULTS

34 [17 FIH; 17 Window] of 42(81%) cancer patients approached participated. 25 consents [20 FIH; 5 Window] were analyzed. 19/20 FIH consent forms included FIH information, and 4/5 Window consent forms included delay information. 19/20(95%) FIH consent forms contained FIH information in the risks section 12/17(71%) patients preferred the same. Fourteen (82%) patients wanted FIH information in the purpose, but only 5(25%) consents mentioned it there. 9/17(53%) Window patients preferred delay information to be located early in the consent, before the "Risks" section.  3/5(60%) consents did this.

CONCLUSIONS

Designing consents that reflect patient preferences more accurately is essential for ethical informed consent; however, a one-size fits all approach will not accurately capture patient preferences. We found that preferences differed for FIH and Window trial consents, though for both, patients preferred key risk information early in the consent. Next steps include determining if FIH and Window consent templates improve understanding.

Heterogeneity of management practices surrounding operable gallbladder cancer - results of the OMEGA-S international HPB surgical survey

BACKGROUND

Gallbladder cancer (GBC) is an aggressive, uncommon malignancy, with variation in operative approaches adopted across centres and few large-scale studies to guide practice. We aimed to identify the extent of heterogeneity in GBC internationally to better inform the need for future multicentre studies.

METHODS

A 34-question online survey was disseminated to members of the European-African Hepatopancreatobiliary Association (EAHPBA), American Hepatopancreatobiliary Association (AHPBA) and Asia-Pacific Hepatopancreatobiliary Association (A-PHPBA) regarding practices around diagnostic workup, operative approach, utilization of neoadjuvant and adjuvant therapies and surveillance strategies.

RESULTS

Two hundred and three surgeons responded from 51 countries. High liver resection volume units (>50 resections/year) organised HPB multidisciplinary team discussion of GBCs more commonly than those with low volumes (p < 0.0001). Management practices exhibited areas of heterogeneity, particularly around operative extent. Contrary to consensus guidelines, anatomical liver resections were favoured over non-anatomical resections for T3 tumours and above, lymphadenectomy extent was lower than recommended, and a minority of respondents still routinely excised the common bile duct or port sites.

CONCLUSION

Our findings suggest some similarities in the management of GBC internationally, but also specific areas of practice which differed from published guidelines. Transcontinental collaborative studies on GBC are necessary to establish evidence-based practice to minimise variation and optimise outcomes.

Evaluation of Standard-of-Care Practices Among Physicians Who Treat Other Physicians: A Qualitative Study

IMPORTANCE

Ethical discussions have suggested that physicians who treat other physicians may put their physician-patients at risk of receiving non-standard-of-care treatment, which may result in worse outcomes. This phenomenon occurs when a physician treats a fellow physician as a VIP (very important person), and is therefore known as VIP syndrome. It is important to assess physicians' perceptions when treating physician-patients.

OBJECTIVE

To determine whether the physicians treating other physicians have attitudes toward or act in ways that could place physician-patients at risk for VIP syndrome.

DESIGN, SETTING, AND PARTICIPANTS

This 2-part qualitative study was conducted from December 1, 2021, to February 28, 2022. Physicians who worked at a single comprehensive cancer center with experience treating other physicians were eligible to participate. Convenience sampling was used. Emails and flyers were sent out with study information, and if interested, physicians were able to schedule an interview. Of 24 physicians responding, 3 did not have experience treating other physicians, yielding a sample of 21 (88%), which was sufficient to reach a saturation of themes. After the initial structured interview of physicians, follow-up key informant interviews were performed.

EXPOSURES

The structured interview was developed on the basis of a literature review and focused on factors that may contribute to VIP syndrome.

MAIN OUTCOMES AND MEASURES

Participant responses to open-ended questions were qualitatively coded using standard multilevel semantic analysis to assess physician perceptions of treating fellow physicians. A series of Likert-scaled questions were used to identify potential contributing factors to VIP syndrome.

RESULTS

Twenty-one physicians (11 men [52%], 11 White [52%], and 15 [71%] younger than 49 years) participated. Although no physician interviewed stated that they altered their usual treatment plans, 11 (52%) agreed that their physician-patients tried to dictate their own care, and 17 (81%) believed that their physician-patients obtained privileges, such as use of medical knowledge to participate in in-depth discussions of care, ability to obtain and use the treating physicians personal contact information, and receiving faster access to care. Eleven respondents (52%) reported increased stress, and 12 (57%) experienced more pressure not to disappoint their physician-patients.

CONCLUSIONS AND RELEVANCE

The findings of this qualitative study suggest that when physicians treat other physicians, the physician-patients may obtain privileges unavailable to patients who are not physicians. Therefore, guidelines to help physicians navigate the complex relationships between themselves and their physician-patients are needed to ensure equitable outcomes between physician and nonphysician patients.

Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Effect of reduced atmospheric pressure on growth and quality of two lettuce cultivars

Future space missions will likely include plants to provide fresh foods and bioregenerative life support capabilities. Current spacecraft such as the International Space Station (ISS) operate at 1 atm (101 kPa) pressure, but future missions will likely use reduced pressures to minimize gas leakage and facilitate rapid egress (space walks). Plants for these missions must be able to tolerate and grow reliably at these reduced pressures. We grew two lettuce cultivars, 'Flandria' a green bibb-type and 'Outredgeous,' a red, loose-leaf type, under three pressures: 96 kPa (ambient control), 67 kPa (2/3 atm), and 33 kPa (1/3 atm) for 21 days in rockwool using recirculating nutrient film technique hydroponics. Each treatment was repeated three times using a different hypobaric chamber each time. A daily light integral of 17.2 Moles Photosynthetically Active Radiation per day was provided with metal halide lamps set to deliver 300 µmol m-2s -1 photosynthetic photon flux (PPF) for a 16 h photoperiod at 22 °C. Oxygen was maintained at 21 kPa (equal to 21% at 1 atm) and CO2 at 0.12 kPa (equal to 1200 ppm at 1 atm). Leaf area for 'Outredgeous' was reduced 20% and 38% at 67 kPa and 33 kPa respectively; shoot fresh mass was reduced 22% and 41% at 67 kPa and 33 kPa respectively when compared to control plants at 96 kPa. These trends were not statistically significant at P ≥ 0.05. Leaf area for 'Flandria' showed no difference between 96 and 67 kPa but was reduced 31% at 33 kPa; shoot fresh mass was reduced 6% and 27% at 66 kPa and 33 kPa respectively compared to 96 kPa. There were 10% and 25% increases in anthocyanin concentration at 66 kPa and 33 kPa compared to 96 kPa, potentially increasing the bioprotective capacity of the plant. Previous studies with other cultivars of lettuce showed slight change in growth across this range of pressures, suggesting responses may vary among genotypes, hypobaric exposure treatments, and / or environmental conditions. Collectively, the findings suggest further testing is needed to understand the effects of atmospheric pressure on plant growth.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Understanding Immunotherapy Terminology: An Analysis of Provider-Patient Conversations

BACKGROUND

Immunotherapy terminology is complex and can be difficult for patients to understand, threatening informed consent. The aims of this exploratory study are to determine whether patients understand immunotherapy terminology and if the provider defining the term improves patient understanding.

METHODS

Conversations between oncology providers and patients discussing immunotherapy were observed(n=39), and technical terms used were noted. With consent, patients were interviewed post-conversation to assess their understanding of these terms(n=39). Comparisons of the terms were conducted using chi-square tests, Fisher's exact tests, or ANOVA where appropriate.

RESULTS

'Immunotherapy' was the most difficult for participants to understand with 48.7% (19/39) correctly defining immunotherapy. 'Immunotherapy agents' was understood 53.8% (14/26) of the time. 'Immune system' was well understood (88.5%;23/26). Providers defined immunotherapy in 97.4% of conversations. There was no correlation between having immunotherapy defined in the conversation, and the likelihood of a correct definition (p=0.487). 'Immune system' was defined in 92.3% of conversations (n=26), and defining it in the conversation was correlated with increased patient understanding (p=0.009).

CONCLUSION

Our results indicate that patients have difficulty understanding some immunotherapy terminology. Since patient understanding of key terminology is crucial for informed consent and patient care, it is essential to implement interventions to improve understanding.

Physician Communication and Patient Understanding of Molecular Testing Terminology

BACKGROUND

The use of molecular testing in oncology is rapidly expanding. The aim of this study was to determine how oncologists describe molecular testing and whether patients understand the terminology being used.

MATERIALS AND METHODS

Sixty conversations between oncologists and patients about molecular testing were observed, and the used technical terms were noted by the researcher. Patients were interviewed post-conversation to assess their understanding of the noted technical terms. A patient understanding score was calculated for each participant. Comparisons of the terms were conducted using χ² tests, Fisher's exact tests, or ANOVA when appropriate.

RESULTS

Sixty-one unique technical terms were used by oncologists, to describe seven topics. "Mutation" was a challenging term for patients to understand with 48.8% (21/43 mentions) of participants correctly defining the term. "Genetic testing" and "Gene" were understood a little more than half the time (53.3%; 8/15 and 56.4%; 22/39 respectively). "DNA" was well understood (80%; 12/15). There was no correlation between the terms being defined by the oncologist in the conversation, and the likelihood of the patient providing a correct definition. White participants were significantly more likely to understand both "mutation" and "genetic testing" than non-White participants. Forty-two percent (n = 25) of participants had an understanding score below 50%, and a higher family income was significantly correlated with a higher score.

CONCLUSION

Our results show that oncologists use variable terminology to describe molecular testing, which is often not understood. Because oncologists defining the terms did not correlate with understanding, it is imperative to develop new, improved methods to explain molecular testing.

IMPLICATIONS FOR PRACTICE

The use of molecular testing is expanding in oncology, yet little is known about how effectively clinicians are communicating information about molecular testing and whether patients understand the terminology used. The results of this study indicate that patients do not understand some of the terminology used by their clinicians and that clinicians tend to use highly variable terminology to describe molecular testing. These results highlight the need to develop and implement effective methods to explain molecular testing terminology to patients to ensure that patients have the tools to make autonomous and informed decisions about their treatment.

Ex vivo synergistic effects of apixaban with dual anti-platelet therapy (DAPT) in lowering platelet reactivity and thrombin generation (SEARCH)

 

Direct oral anticoagulants such as apixaban are increasingly being evaluated clinically for the secondary prevention of cardiovascular events; however, their effects on platelet function in combination with dual anti-platelet therapy (DAPT) have not been fully investigated. The purpose of this translational, in vitro study was to determine if apixaban via inhibition of thrombin generation exhibits synergistic activity with DAPT to reduce platelet reactivity. Consented subjects with a prior history (&lt;12 mo) of ACS on DAPT regime with aspirin and clopidogrel (n=15; DAPT-C) or aspirin and ticagrelor (n=15; DAPT-T) were recruited, along with the age-matched healthy subjects as controls. Enrolled DAPT subjects had taken their prescribed regimen &gt;7 days prior to blood collection. Platelet-rich plasma from TSC anticoagulated blood was prepared and treated in vitro with nothing, a carrier control or apixaban (40, 90 and 220 ng/mL). The range of 40 to 220 ng/mL brackets the expected apixaban exposure at steady state with all three approved regimens with the 40 ng/mL treatment corresponding to &lt;5th percentile for the 2.5 mg bid dose, the 90 ng/mL corresponding to Cmax after the 2.5 mg bid or to Cmin after the 5 mg bid dose, and the 220 ng/mL corresponding to the Cmax after 10 mg bid dose. Platelet aggregation was measured by light transmission aggregometry (LTA) with tissue factor (TF) as agonist. Platelet p-selectin expression was measured by flow cytometry and thrombin generation was quantified. TF agonist was chosen to evaluate endogenous thrombin effects via Factor Xa activation (fXa). The CaCl2 concentration in the TF was titrated in the presence of peptide GPRP which minimized fibrin generation. The baseline maximal aggregation (MA) response was similar for both DAPT-T and DAPT-C (64%). Compared to DAPT alone, 90 and 220 ng/mL apixaban treatments decreased MA from 64% to 36% and 17% in the DAPT-T group and from 64% to 28% and 9% in the DAPT-C group (p&lt;0.009), respectively. Platelet P-selectin expression decreased by 53% in the DAPT-T group with 220 ng/mL apixaban treatment (p&lt;0.02) and in the DAPT-C group by 70% and 76% with 90 and 220 ng/mL apixaban treatment (p&lt;0.004), respectively, compared to DAPT alone. Apixaban treatment (90 and 220 ng/mL) significantly increased thrombin generation lag time and time-to-peak results and significantly decreased peak thrombin in both DAPT groups (p&lt;0.05). ACS patients on a DAPT regimen were susceptible to thrombin-mediated platelet activation via fXa. Apixaban treatment in vitro caused a larger reduction in thrombin-mediated platelet activation in the clopidogrel group compared to the ticagrelor group, consistent with ticagrelor having a more potent anti-platelet effect compared to clopidogrel. The in vitro addition of apixaban that corresponded to currently approved dosing regimens and at plasma drug levels routinely achieved demonstrated synergy with DAPT to reduce platelet reactivity and thrombin generation.

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): Bristol-Myers Squibb

Abstract P5-04-17: Local network topology differences between early and late recurrence in ER+ breast cancers

Background: Late recurrence is characteristic of ER+ breast cancers. Despite an apparently effective adjuvant endocrine therapy, many breast cancers recur years after their initial endocrine treatment. Why some tumors recur early (&lt;3 years) and some recur later (&gt;5 years) is poorly understood. If systemic endocrine therapies killed all cells, recurrence would reflect only the appearance of new disease. Thus, we hypothesized that cells that survive and lie dormant may be driven, in part, by altered wiring of their cell death signaling. We, therefore, studied how cell death signaling is differentially wired in primary tumors that will recur early versus those that will recur later.

Method: Genes involved in apoptosis, autophagy, ferroptosis, necrosis, and pyroptosis were identified from KEGG to initiate network feature analysis of gene expression data from public and our first in-house gene expression dataset. Data were collected from ER+ breast cancer pre-endocrine treatment samples with up to 20 years follow-up. Publicly available datasets used were GSE6532, GSE2034, GSE7390, GSE17705, GSE12093, and TCGA. We applied our Knowledge-fused Differential Dependency Network (KDDN) analysis tool to the public datasets; KDDN has provided powerful new insights into signaling in breast and other cancers. Common gene-gene interactions (edges) predicted in at least two different datasets were extracted from all KDDN analyses results. To strengthen the relevance of these features, predicted network edges that represent known protein-protein interactions (PPI) were identified from the STRING database, and these edges were noted in the signaling graphs. Final network graphs were constructed using the common edges from all overlaid networks. We conducted IPA analysis on all nodes in the final network and selected those incorporating network hubs. We took a similar approach to our second in-house dataset, which we used for independent testing. Here, patients were included if their tumor exhibited an initial reduction in volume of at least 40% by four months in response to neo-adjuvant Letrozole. Patients were then classified into two groups during follow-up of up to 3.7 years: i) initial tumor size reduction followed by continued response (expected to recur late); ii) initial reduction followed by tumor regrowth (expected to recur early). KDDN analysis was performed on pretreatment samples from these two groups and a network created annotated with PPI information.

Results: MAPK8 and CYCS (Molecular Mechanisms of Cancer, p=1.58E-52), TNFRSF1A Neuroinflammation Signaling Pathway, p=1.26E-54), RELA, and NFKB1 (Colorectal Cancer Metastasis Signaling, p=7.94E-35), were identified as hubs. Hubs may be critical signaling components driving the differences between tumors that will become dormant and recur late. Connections between SLC25A6 and SQSTM1 (p = 0.008), BIRC2 and GABARAP (p = 0.021) in the early group, and AKT3 and IRS2 (p = 0.014) in the late group, were shared between the two final networks. With longer follow-up time on the second in-house dataset, we will better define the two groups and identify additional common phenotype specific gene-gene interactions.

Citation Format: Clarke R, Dixon M, Jin L, Pearce D, Turnbull A, Selli C, Hu R, Zwart A, Wang Y, Xuan J, Sengupta S, Sims A, Liu MC. Local network topology differences between early and late recurrence in ER+ breast cancers [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 P5-04-17.

Geographic variation in surgical practice patterns and outcomes for resected nonmetastatic gastric cancer in Ontario

Background

Gastrectomy with negative resection margins and adequate lymph node dissection is the cornerstone of curative treatment for gastric cancer (gc). However, gastrectomy is a complex and invasive operation with significant morbidity and mortality. Little is known about surgical practice patterns or short- and long-term outcomes in early-stage gc in Canada.

Methods

We undertook a population-based retrospective cohort study of patients with gc diagnosed between 1 April 2005 and 31 March 2008. Chart review provided clinical and operative details such as disease stage, primary tumour location, surgical approach, operation, lymph nodes, and resection margins. Administrative data provided patient demographics, geography, and vital status. Variations in treatment and outcomes were compared for 14 local health integration networks. Descriptive statistics and log-rank tests were used to examine geographic variation.

Results

We identified 722 patients with nonmetastatic resected gc. We documented significant provincial variation in case mix, including primary tumour location, stage at diagnosis, and tumour grade. Short-term surgical outcomes varied across the province. The percentage of patients with 15 or fewer lymph nodes removed and examined varied from 41.8% to 73.8% (p = 0.02), and the rate of positive surgical margins ranged from 15.2% to 50.0% (p = 0.002). The 30-day surgical mortality rates did not vary statistically significantly across the province (p = 0.13); however, rates ranged from 0% to 16.7%. Overall 5-year survival was 44% and ranged from 31% to 55% across the province.

Conclusions

This cohort of patients with resected stages i-iii gc is the largest analyzed in Canada, providing important historical information about treatment outcomes. Understanding the causes of regional variation will support interventions aiming to improve gc operative outcomes in the cancer system.

Potential Benefits to Families, Children, and Adolescents Enrolled in Longitudinal Qualitative Research

Previous research has focused on the risks of research participation but has rarely considered possible benefits. For a study of family decision-making during pediatric bone marrow transplant, we conducted qualitative interviews with 132 family members across 36 families up to three times over the course of a year, before and after transplant. We concluded the study with qualitative interviews of 70 family members from 21 of the original families one year after the transplants, focusing on benefits and concerns regarding their research participation. Participants, including children and adolescents, reported benefits including the opportunity to talk, be altruistic, reflect, have a safe space, gain understanding or perspective, and express emotions. Sixteen percent expressed concerns, mostly finding aspects of the methodology annoying. We encourage institutional review boards to understand that sensitive conversations with adults, children or adolescents may not always increase the risk of the study and may offer benefits to those who agree to be interviewed. We therefore suggest that language describing potential benefits could be included in consent and assent forms for qualitative studies.

Abstract P4-13-01: Oncoplastic breast conservations – The Scottish Audit: Surgical techniques, oncological outcomes, complication rates and variations in practice across the country based on the analysis of 589 patients

Introduction: current evidence for oncoplastic breast conservation (OBC) is based on single institutional series. We studied the outcomes of OBC practice in Scotland and compare individual breast units.

Methods: a predefined database of patients treated with OBC was completed retrospectively in 11 breast units in Scotland. Patients were treated with OBC from 2005 onwards were included. For statistical calculations Chi-test, ANOVA and Pearson correlation analysis were used.

Results: Altogether 589 patients were included. Median age was 56 years [21-86]. Patients were diagnosed between September 2005 and March 2017. Number of patients treated with OBC per unit ranged between 4 and 145. High volume units were doing a mean of 19.3 OBCs per year [17.3 – 26.5] vs. low volume units doing 11.1 OBCs per year [7 .7– 14.4] (p=0.012).

23 different oncoplastic surgical techniques were applied. Range of oncoplastic techniques used was associated with case-loads: high volume units used a wider range (8 – 14 different techniques) compared to low volume units (3 – 6) (p=0.004). Volume displacement was done in 515 patients (91.3%), volume replacement in 49 patients (8.7%). OBC was carried out as a joint operation between a breast and a plastic surgeon in 66.3% (389 patients). Immediate contralateral symmetrisation rate was significantly higher when the procedure was carried out as a joint operation (70.7% vs. not joint operations: 29.8%; p&lt;0.001).

Incomplete excision rate was 10.4% (60 of 578). Incomplete excision was significantly higher after invasive lobular carcinoma (18.9%; 10 of 43; p=0.0292). After neoadjuvant chemotherapy incomplete excision rate was significantly lower (3%; 2 of 66 vs. no neoadjuvant chemotherapy: 11%; 35 of 319; p=0.031).

Neodjuvant systemic treatment rate was 28.6% (142 of 496 patients). Of those 68 patients received neoadjuvant chemotherapy (13.7%) and 74 patients had neoadjuvant hormonal treatment (14.9%). Neoadjuvant systemic treatment rate varied amongst the units from 9.7% to 57.2% for patients with invasive carcinoma.

259 patients diagnosed with (non)invasive carcinoma had a median follow-up time of 5 years [35-124]. Of these 7 patients (2.7%) developed isolated local recurrence. 5-year local recurrence rate after DCIS was higher than after pure invasive ductal carcinoma (DCIS: 8.3%; 3 of 36 vs. ductal: 1.6%; 3 of 181; p=0.02567). 5-year disease-free survival of these patients was 91.7%, overall survival was 93.8%, and cancer-specific survival was 96.1%.

145 of 510 patients developed complications, which is 28.4% overall complication rate. 71 patients had major complications (13.9%) and 74 patients had minor complications (14.5%). Overall complication rate was significantly lower after neoadjuvant chemotherapy (15.9%; 11 of 69) compared to patients who did not receive neoadjuvant chemotherapy (27.9%; 127 of 455 patients) (p=0.035).

Conclusion: this national audit demonstrated similar outcomes overall compared to relevant published data. Units should be urged to build stronger collaboration in order to reduce variability in OBC practices.

None of the authors have conflict of interest to declare.

Citation Format: Romics L, Macaskill J, Fernandez T, Morrow E, Simpson L, Pitsinis V, Barber M, Tovey S, Masannat Y, Young O, Mansell J, Stallard S, Doughty J, Dixon M. Oncoplastic breast conservations – The Scottish Audit: Surgical techniques, oncological outcomes, complication rates and variations in practice across the country based on the analysis of 589 patients [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-13-01.

Dietary practices in propionic acidemia: A European survey

Background

The definitive dietary management of propionic acidaemia (PA) is unknown although natural protein restriction with adequate energy provision is of key importance.

Aim

To describe European dietary practices in the management of patients with PA prior to the publication of the European PA guidelines.

Methods

This was a cross-sectional survey consisting of 27 questions about the dietary practices in PA patients circulated to European IMD dietitians and health professionals in 2014.

Results

Information on protein restricted diets of 186 PA patients from 47 centres, representing 14 European countries was collected. Total protein intake [PA precursor-free L-amino acid supplements (PFAA) and natural protein] met WHO/FAO/UNU (2007) safe protein requirements for age in 36 centres (77%). PFAA were used to supplement natural protein intake in 81% (n = 38) of centres, providing a median of 44% (14–83%) of total protein requirement. Seventy-four per cent of patients were prescribed natural protein intakes below WHO/FAO/UNU (2007) safe levels in one or more of the following age groups: 0–6 m, 7–12 m, 1–10 y, 11–16 y and > 16 y. Sixty-three per cent (n = 117) of patients were tube fed (74% gastrostomy), but only 22% received nocturnal feeds.

Conclusions

There was high use of PFAA with intakes of natural protein commonly below WHO/FAO/UNU (2007) safe levels. Optimal dietary management can only be determined by longitudinal, multi-centre, prospective case controlled studies. The metabolic instability of PA and small patient cohorts in each centre ensure that this is a challenging undertaking.

Dietary practices in isovaleric acidemia: A European survey

Background

In Europe, dietary management of isovaleric acidemia (IVA) may vary widely. There is limited collective information about dietetic management.

Aim

To describe European practice regarding the dietary management of IVA, prior to the availability of the E-IMD IVA guidelines (E-IMD 2014).

Methods

A cross-sectional questionnaire was sent to all European dietitians who were either members of the Society for the Study of Inborn Errors of Metabolism Dietitians Group (SSIEM-DG) or whom had responded to previous questionnaires on dietetic practice (n = 53). The questionnaire comprised 27 questions about the dietary management of IVA.

Results

Information on 140 patients with IVA from 39 centres was reported. 133 patients (38 centres) were given a protein restricted diet. Leucine-free amino acid supplements (LFAA) were routinely used to supplement protein intake in 58% of centres. The median total protein intake prescribed achieved the WHO/FAO/UNU [2007] safe levels of protein intake in all age groups. Centres that prescribed LFAA had lower natural protein intakes in most age groups except 1 to 10 y. In contrast, when centres were not using LFAA, the median natural protein intake met WHO/FAO/UNU [2007] safe levels of protein intake in all age groups. Enteral tube feeding was rarely prescribed.

Conclusions

This survey demonstrates wide differences in dietary practice in the management of IVA across European centres. It provides unique dietary data collectively representing European practices in IVA which can be used as a foundation to compare dietary management changes as a consequence of the first E-IMD IVA guidelines availability.

Microbial Community Dynamics and Response to Plant Growth-Promoting Microorganisms in the Rhizosphere of Four Common Food Crops Cultivated in Hydroponics

Plant growth promoting microorganisms (PGPMs) of the plant root zone microbiome have received limited attention in hydroponic cultivation systems. In the framework of a project aimed at the development of a biological life support system for manned missions in space, we investigated the effects of PGPMs on four common food crops (durum and bread wheat, potato and soybean) cultivated in recirculating hydroponic systems for a whole life cycle. Each crop was inoculated with a commercial PGPM mixture and the composition of the microbial communities associated with their root rhizosphere, rhizoplane/endosphere and with the recirculating nutrient solution was characterised through 16S- and ITS-targeted Illumina MiSeq sequencing. PGPM addition was shown to induce changes in the composition of these communities, though these changes varied both between crops and over time. Microbial communities of PGPM-treated plants were shown to be more stable over time. Though additional development is required, this study highlights the potential benefits that PGPMs may confer to plants grown in hydroponic systems, particularly when cultivated in extreme environments such as space.

Increase in hospital mortality from non-communicable disease and HIV-related conditions in Bulawayo, Zimbabwe, between 1992 and 2000

The HIV/AIDS pandemic is creating a strain on health care services in the developing world, with knock-on consequences for HIV negative patients. We looked for possible changes over time in the patterns of illness and outcomes of admission to an adult medical unit in Zimbabwe.

We performed a prospective descriptive study of discharge diagnoses and causes of in-hospital ;mortality for all medical patients under the care of one consultant at Mpilo Central Hospital, Bulawayo, Zimbabwe. Two similar 7-month periods were compared in 1992 and 2000. Data recorded included: initials, sex, alive or dead status, diagnosis and HIV/AIDS status.

Similar numbers of patients were admitted in 1992 and 2000 (1305 and 1369), but in-hospital mortality increased from 13.3% to 28.6% ( P<0.001), especially in male patients (13.1% to 33.9% P<0.001). Mortality rates increased for both infectious and non-communicable diseases such as cardiac failure, stroke and diabetes. The 10 most common diagnoses were similar, apart from Pneumocystis carinii pneumonia (PCP) cases, which increased from 18 to 90. The proportion of patients clinically or serologically positive for HIV/AIDS rose from 13.9% to 51.1% ( P<0.001), but the number of cases of the HIV wasting syndrome (SLIM)/chronic gastroenteritis did not change significantly. In 1992 there happened to be a large number of cases of malaria transmission.

Mortality related to both communicable and non-communicable diseases increased, confirming that HIV negative patients are also being affected by the strain on health services. Although based on clinical and radiological diagnosis, PCP pneumonia appears to be increasingly common in this area.

Embryo Development and Morphology of the Rocky Mountain Wood Tick (Acari: Ixodidae)

Dermacentor andersoni Stiles embryogenesis was observed using fluorescent and scanning electron microscopy for eggs held under laboratory conditions (25°C and at 93% relative humidity). Early embryonic cell divisions appeared to be synchronous and holoblastic, giving rise to a uniform blastoderm surrounding the yolk. The cells of the blastoderm became concentrated on one side of the embryo, forming the segmented germ band. Distinct opisthosomal and prosomal segment morphologies, which are characteristic of chelicerate embryos, were observed during germ band elongation. Mouth and leg appendages grew from the prosomal segments. As development progressed, the segments were fused into the idiosoma and capitulum of the free-living larval form. An embryo staging system was established based on embryo developmental morphology and the timing of morphogenetic events. The staging system will serve as a basis for future studies directed at understanding morphogenetic mechanisms or for observing the impact of abiotic factors, such as temperature or humidity, on tick development.

Abstract P5-04-05: Targeting the pH regulatory mechanisms of breast cancer cells

Background:

The abnormal regulation of H+ ions, leading to a reversed pH gradient in tumor cells in comparison to normal cells, is considered to be one of the hallmarks of cancer. This feature, however, has yet to be exploited as a therapeutic target. The aim of this study was to assess whether targeting proteins (CAIX, NHE1 and V-ATPase) that permit hypoxic cancer cell adaptation to acidosis in the tumor microenvironment can produce an effective therapeutic response in breast cancer, using 2D and 3D models.

Method:

Western blotting and gene expression analysis were performed on MCF-7, MDA-MB-231 and HBL-100 cancer cells to assess target protein expression in differing O2 conditions in 2D, while IHC was used to measure protein levels in 3D using multicellular tumor spheroids. Sulforhodamine B assays were executed to analyze the effects of inhibitors targeting CAIX, NHE1 and V-ATPase on breast cancer cell proliferation in 2D. 3D invasion assays were performed with MDA-MB-231 spheroids and explant tissue derived from human patients to see if CAIX inhibition had any effect on cancer cell invasion. An MDA-MB-231 xenograft model was used to investigate the effects of CAIX inhibition in vivo. Clonogenic assays were performed with MDA-MB-231 spheroids to evaluate whether any of the drugs combined effectively with irradiation.

Results:

2D and 3D expression analysis showed that CAIX levels were extremely responsive to changes in O2 conditions in each of the cell lines, with HBL100 cells exhibiting the largest changes in both mRNA (42-fold increase) and protein (78-fold increase) levels at low (0.5%) O2 concentrations. NHE1 and V-ATPase mRNA/protein levels were, however, much more consistently expressed across the cell lines in different O2 conditions. Drugs targeting CAIX, NHE1 and V-ATPase had anti-proliferative effects on the breast cancer cells in 2D. Normoxic cancer cells were the most sensitive to drug treatment, acute hypoxic cancer cells showed increased resistance to the anti-proliferative effects of these drugs, while chronic hypoxic cells had IC50 values more similar to the normoxic cells. The results for the CAIX inhibitor were unexpected, as we had predicted that the increased levels of CAIX in the acute hypoxic cells would make them more sensitive to treatment. CAIX inhibition did, however, significantly reduce the invasion of cancer cells from both MDA-MB-231 spheroids (p≤0.01) and explant tissue (p≤0.001). Targeting pH regulation was also shown to have an effect in vivo on MDA-MB-231 xenografts, with CAIX inhibition significantly reducing the growth (p≤0.05) and proliferation (p≤0.05) of tumors within mice. Finally, clonogenic assays showed that drugs targeting both CAIX and NHE1 led to a significant reduction in colony number when combined with radiation (p≤0.05), compared to either drug individually or radiation treatment alone.

Conclusions:

This study shows that drugs targeting pH regulation molecules have potential in the treatment of breast cancer. This is highlighted by their ability to affect the proliferation and invasion of breast cancer cells, along with their ability to be combined with radiation. Of the 3 pH regulatory molecules, CAIX represents the target with the most promise.

Citation Format: Meehan J, Ward C, Jarman E, Xintaropoulou C, Martinez-Perez C, Turnbull A, Supuran C, Dixon M, Kunkler I, Langdon SP. Targeting the pH regulatory mechanisms of breast cancer cells. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-04-05.

Cardiovascular safety of the glucagon-like peptide-1 receptor agonist taspoglutide in people with type 2 diabetes: an individual participant data meta-analysis of randomized controlled trials

AIMS

To study the short-term cardiovascular effects of the once-weekly glucagon-like peptide-1 receptor agonist taspoglutide.

METHODS

We conducted a meta-analysis of individual-participant data from nine randomized controlled trials in the T-Emerge programme, which assessed the efficacy and safety of taspoglutide in type 2 diabetes. Our primary outcome was a composite of death from cardiovascular disease (CVD) and acute myocardial infarction, stroke and hospitalization for unstable angina.

RESULTS

Overall, 7056 individuals were included in the analysis, and there were 67 primary endpoint events during 7478 person-years of follow-up (40 vs 27 events in the intervention vs control groups, respectively). The odds ratio for the composite endpoint among people randomized to taspoglutide was 0.94 (95% confidence interval 0.57-1.56), which was robust across multiple subgroups. Longer-term data were not available as the development of taspoglutide was stopped because of gastrointestinal intolerance and serious hypersensitivity reactions.

CONCLUSIONS

The available data suggest that short-term, once-weekly administration of taspoglutide was not associated with an excess risk of CVD, and provide insights relevant to the development of other novel once-weekly incretin mimetics.

The function of Drosophila p53 isoforms in apoptosis

The p53 protein is a major mediator of the cellular response to genotoxic stress and is a crucial suppressor of tumor formation. In a variety of organisms, p53 and its paralogs, p63 and p73, each encode multiple protein isoforms through alternative splicing, promoters, and translation start sites. The function of these isoforms in development and disease are still being defined. Here, we evaluate the apoptotic potential of multiple isoforms of the single p53 gene in the genetic model Drosophila melanogaster. Most previous studies have focused on the p53A isoform, but it has been recently shown that a larger p53B isoform can induce apoptosis when overexpressed. It has remained unclear, however, whether one or both isoforms are required for the apoptotic response to genotoxic stress. We show that p53B is a much more potent inducer of apoptosis than p53A when overexpressed. Overexpression of two newly identified short isoforms perturbed development and inhibited the apoptotic response to ionizing radiation. Analysis of physiological protein expression indicated that p53A is the most abundant isoform, and that both p53A and p53B can form a complex and co-localize to sub-nuclear compartments. In contrast to the overexpression results, new isoform-specific loss-of-function mutants indicated that it is the shorter p53A isoform, not full-length p53B, that is the primary mediator of pro-apoptotic gene transcription and apoptosis after ionizing radiation. Together, our data show that it is the shorter p53A isoform that mediates the apoptotic response to DNA damage, and further suggest that p53B and shorter isoforms have specialized functions.

Mandibular incisal edge demineralization and caries associated with Twin Block appliance design

Demineralization and caries are well documented and unwanted complications of orthodontic therapy. These are most commonly reported in relation to fixed appliance therapy. Five cases are presented of patients undergoing Twin Block appliance therapy with the appliances incorporating lower labial segment capping, illustrating a pattern of demineralization and caries of the incisal tips of the mandibular labial segment, influenced by the incisal capping and the frequent intake of carbonated soft drinks.

Unmet needs of siblings of pediatric stem cell transplant recipients

BACKGROUND AND OBJECTIVES

In 2010, the Bioethics Committee of the American Academy of Pediatrics issued recommendations that pediatric hematopoietic stem cell donors should have an independent advocate. Formulating appropriate guidelines is hindered by the lack of prospective empirical evidence from families about the experience of siblings during typing and donation. Our aim was to provide these data.

METHODS

Families with a child scheduled to undergo hematopoietic stem cell transplant were recruited. All family members, including children aged 9 to 22 years, were eligible. Qualitative interviews were conducted within 3 time periods: pretransplant, 6 to 8, and 9 to 11 months posttransplant. Quantitative scales assessing decision satisfaction and regret were administered at time 2.

RESULTS

Thirty-three families were interviewed. Of the 119 family members, 76% perceived there was no choice in the decision to HLA-type siblings; 77% perceived no choice in sibling donation; 86% had no concerns about typing other than needle sticks; and 64% had no concerns about donation. Common concerns raised were dislike of needle sticks (19%), stress before typing results (14%), and fear of donation (15%). Posttransplantation, 33% of donors wished they had been given more information; 56% of donors stated they benefited from donation. Only 1 donor expressed regret posttransplant.

CONCLUSIONS

Most family members did not view sibling typing and donation as a choice, were positive about the experience, and did not express regrets. We recommend education for all siblings before typing, comprehensive education for the donor by a health care provider pretransplant, and systematic donor follow-up after transplantation.

Dietary management of urea cycle disorders: European practice

BACKGROUND

There is no published data comparing dietary management of urea cycle disorders (UCD) in different countries.

METHODS

Cross-sectional data from 41 European Inherited Metabolic Disorder (IMD) centres (17 UK, 6 France, 5 Germany, 4 Belgium, 4 Portugal, 2 Netherlands, 1 Denmark, 1 Italy, 1 Sweden) was collected by questionnaire describing management of patients with UCD on prescribed protein restricted diets.

RESULTS

Data for 464 patients: N-acetylglutamate synthase (NAGS) deficiency, n=10; carbamoyl phosphate synthetase (CPS1) deficiency, n=29; ornithine transcarbamoylase (OTC) deficiency, n=214; citrullinaemia, n=108; argininosuccinic aciduria (ASA), n=80; arginase deficiency, n=23 was reported. The majority of patients (70%; n=327) were aged 0-16y and 30% (n=137) >16y. Prescribed median protein intake/kg body weight decreased with age with little variation between disorders. The UK tended to give more total protein than other European countries particularly in infancy. Supplements of essential amino acids (EAA) were prescribed for 38% [n=174] of the patients overall, but were given more commonly in arginase deficiency (74%), CPS (48%) and citrullinaemia (46%). Patients in Germany (64%), Portugal (67%) and Sweden (100%) were the most frequent users of EAA. Only 18% [n=84] of patients were prescribed tube feeds, most commonly for CPS (41%); and 21% [n=97] were prescribed oral energy supplements.

CONCLUSIONS

Dietary treatment for UCD varies significantly between different conditions, and between and within European IMD centres. Further studies examining the outcome of treatment compared with the type of dietary therapy and nutritional support received are required.