Qualitative Ampule and Multitest for Beta-Lactam Residues in Fluid Milk Products: Collaborative Study

A collaborative study was performed on a rapid Bacillus stearothermophilus agar diffusion ampule method to detect low levels of penicillin G in 7 types of fluid milk products. A multitest technique for processing a large number of samples simultaneously was also studied. Slight modifications were made in the original method to establish more uniformity and to eliminate doubtful responses by specifying a confirmation procedure. Twenty samples spiked with penicillin G (0.000 to 0.008 IU/mL) and tetracycline hydrochloride were frozen and sent to 20 laboratories in the ampule test, and 16 laboratories in the multitest. Each analyst was asked to do a screening run and a confirmation run. Results were reported by color reaction and also as positive or negative for β-lactam inhibitors. The concentrations (penicillin G) where percent positive results equal 100 or not significantly less than 100 (α = 0.05) ranged from 0.005 to 0.007 IU/mi in the ampule test and from 0.004 to 0.007 IU/mL in the multitest. Both techniques have been adopted official first action.

Pharmacokinetics and pharmacodynamics of the novel monobactam LYS228 in a neutropenic murine thigh model of infection

Objectives

The neutropenic murine thigh infection model and a dose-fractionation approach were used to determine the pharmacokinetic/pharmacodynamic (PK/PD) relationship of LYS228, a novel monobactam antibiotic with activity against Enterobacteriaceae including carbapenem-resistant strains.

Methods

Mice (n = 4 per group) were inoculated with Enterobacteriaceae strains via intramuscular injection. Two hours post-bacterial inoculation, treatment with LYS228 was initiated. Animals were euthanized with CO2 24 h after the start of therapy and bacterial counts (log10 cfu) per thigh were determined. PK parameters were calculated using free (f) plasma drug levels.

Results

Following a dose-fractionation study, non-linear regression analysis determined that the predominant PK/PD parameter associated with antibacterial efficacy of LYS228 was the percentage of the dosing interval that free drug concentrations remained above the MIC (%fT>MIC). In a dose-dependent manner, LYS228 reduced the thigh bacterial burden in models established with Enterobacteriaceae producing β-lactamase enzymes of all classes (e.g. ESBLs, NDM-1, KPC, CMY-2 and OXA-48). The range of the calculated static dose was 86-649 mg/kg/day for the isolates tested, and the magnitude of the driver of efficacy was 37-83 %fT>MIC. %fT>MIC was confirmed as the parameter predominantly driving efficacy as evidenced by a strong coefficient of determination (r2 = 0.68). Neutrophils had minimal impact on the effect of LYS228 in the murine thigh infection model.

Conclusions

LYS228 is efficacious in murine thigh infection models using β-lactamase-producing strains of Enterobacteriaceae, including those expressing metallo-β-lactamases, ESBLs and serine carbapenemases, with the PK/PD driver of efficacy identified as %T>MIC.

The immune microenvironment and expression of PD-L1, PD-1, PRAME and MHC I in salivary duct carcinoma

AIMS

Salivary duct carcinoma (SDC) is an aggressive salivary malignancy that results in high mortality rates and is often resistant to chemotherapy. Anti-programmed death-1 (PD-1)/programmed death ligand-1 (PD-L1) checkpoint inhibitors have led to dramatic improvements in patients with various cancers. Other immunotherapeutic approaches, e.g. cancer vaccines, have shown promising results. Cancer testis antigens, e.g. preferentially expressed antigen in melanoma (PRAME), are regarded as promising vaccine targets because of their tumour-specific expression pattern.

METHODS AND RESULTS

We analysed the immunoexpression of PD-L1, PD-1, major histocompatibility complex class I (MHC I) and PRAME in 53 SDCs. The immunoexpression levels of PD-L1 in tumour cells (TCs) and immune cells (ICs), PD-1 in ICs, PRAME in TCs and MHC I in TCs were analysed, and were correlated with outcome. PRAME expression was seen in 83% of SDCs. No PRAME staining was present in normal salivary gland tissue. With the three established diagnostic algorithms proposed for head and neck squamous cell carcinoma, the criteria being a combined positive score of ≥1, TC% ≥1%, and TC% ≥25%, 35 (66%), 17 (32%) and three cases (6%), respectively, were deemed to be positive for PD-L1. PD-1-positive ICs were seen in 35 (66%) cases. MHC I down-regulation was seen in 82% of SDCs. There was a significant correlation among PD-L1 expression in ICs, PD-1 expression in ICs, and PRAME expression in TCs. PD-L1 expression in TCs and lack of PD-1 expression in ICs were associated with decreased disease-specific survival in SDC patients.

CONCLUSIONS

Alterations of the tumour immune microenvironment are common in SDCs, including expression of PD-1/PD-L1 and PRAME, which opens the way to potential novel immune therapies, such as cancer vaccination and PD-1/PD-L1 blockade, in these tumours.

P3512Sex differences in rats with heart failure with preserved ejection fraction and the effect of autonomic modulation

Background

Heart failure (HF) with preserved ejection fraction (HFpEF) accounts for 50% of HF and sudden death is the leading cause of mortality. There are considerable sex differences in cardiac structure and function, which may be related to outcomes in HFpEF. Transcutaneous vagus nerve stimulation (tVNS) is antiarrhythmic.

Purpose

To describe sex differences in mortality, autonomic tone and ECG parameters in rats with HFpEF and examine the effect of tVNS on these outcomes.

Methods

Dahl salt sensitive (DS) rats of either sex were randomized into high salt (HS, 8% NaCl) or low salt (LS) diet (0.3% NaCl) at 7 weeks of age. After 6 weeks of LS or HS diets, HS rats were randomized to receive active or sham tVNS, 30min daily (20Hz, 3mA) for 4 weeks. The rats were monitored daily for 4 weeks for the development of HFpEF. ECG and echocardiogram were performed at 13 weeks (baseline) and 17 weeks (endpoint). Heart rate variability (HRV) was calculated at the respective time points. ECG and HRV parameters were analyzed in a blinded fashion. Logistic regression analysis was performed to identify independent predictors of mortality.

Results

A total of 58 rats were included (5 male LS, 6 female LS, 22 male HS and 25 female HS). HS rats developed significant hypertension and signs of HFpEF, while 24% of females and 53% of males died (P=0.004). There were 4 sudden cardiac deaths in males (with ventricular tachycardia documented in 1 rat), whereas all the females died of HF or stroke. Corrected QT (QTc) at baseline significantly prolonged in HS compared to LS rats (250.5±14.4ms vs. 226.8±13.9ms, respectively, p=0.0007), while all other ECG parameters did not differ significantly between groups. In HS rats, QTc prolongation was significantly more pronounced in males compared to females (259.4±20.6ms vs. 243.8±14.5ms, respectively, P=0.002). In univariate analysis, prolonged baseline QTc (OR=1.04; 95% CI 1.01–1.06, p=0.003) and male sex (OR=3.21, 95% CI 1.19–8.66, p=0.016) predicted mortality. However, in multivariate analysis, QTc was the only significant predictor of mortality (OR=1.04; 95% CI 1.01–1.06, p=0.003). After 4 weeks of treatment, active tVNS significantly decreased QTc compared to sham (244.6±13.8ms vs. 255.8±14.0ms, respectively, p=0.017) in both male and female rats in a similar manner. The low frequency to high frequency ratio (LF/HF) of HRV, which reflects sympathovagal balance, was significantly decreased in active tVNS rats compared to sham (0.21±0.13 vs. 0.54±0.14, respectively; p=0.001) in both male and female rats in a similar manner.

Conclusions

Male rats with HFpEF exhibit worse survival compared to females and are at higher risk for sudden death. QTc prolongation accounts for the increased risk of sudden death in males compared to females. Autonomic modulation with tVNS attenuates the unfavorable changes in QTc and HRV induced by HS diet and may be used to prevent ventricular arrhythmias in patients with HFpEF.

Successful implementation of bedaquiline for multidrug-resistant TB treatment in remote Papua New Guinea

SETTING

Bedaquiline (BDQ) was introduced in the multi-drug-resistant tuberculosis (MDR-TB) programme in Daru in remote Papua New Guinea in 2015, along with a core package of active drug-safety monitoring (aDSM).

OBJECTIVE

To assess interim results and safety of BDQ for the treatment of MDR-TB from 1 July 2015 to 31 December 2017.

DESIGN

A retrospective cohort analysis of routine programme data.

RESULTS

Of 277 MDR-TB patients, 77 (39%) received BDQ with a total of 8 serious adverse events including 5 (6.5%) deaths, of which 1 (1.3% QTcF prolongation, grade 3) was attributable to BDQ. Of 200 (61%) patients who did not receive BDQ, there were 17 (9%) deaths. Completeness of monitoring for the BDQ group was 90% for >5 electrocardiograms and 79% for ⩾2 cultures. In the interim result indicator analysis at month 6 in the BDQ and non-BDQ groups, there were respectively 0% and 1% lost to follow-up; 6.5% and 8.5% who died; 94% and 91% in care; and 92% and 96% with negative culture among those monitored.

CONCLUSION

Early experience in Daru shows BDQ is safe and feasible to implement with aDSM with good interim effectiveness supporting the rapid adoption and scale-up of the 2019 WHO MDR-TB treatment guidelines in the programme and in similar remote settings.

A pilot model of patient education and counselling for drug-resistant tuberculosis in Daru, Papua New Guinea

Education and counselling for people with drug-resistant tuberculosis (DR-TB) is recommended by the World Health Organization, given the arduous treatment journey. A model of education and counselling involving counsellors and peer counsellors, standard sessions and novel education tools was piloted in the high DR-TB burden context of Daru, Papua New Guinea. The pilot contributed to high retention in care, highlighting the need for investment in scalable models. Future models will need to be adapted as better tolerated regimens are introduced. A focus on patient-centred care requires prioritisation in order to meet the End TB Strategy targets.

The emergency response to multidrug-resistant tuberculosis in Daru, Western Province, Papua New Guinea, 2014-2017

SETTING

A response to an outbreak of multidrug-resistant tuberculosis (MDR-TB) on Daru Island, South Fly District (SFD), Western Province, Papua New Guinea (PNG) was implemented by a national emergency response taskforce.

OBJECTIVE

To describe programmatic interventions for TB in SFD and evaluate characteristics of TB case notifications, drug resistance and treatment outcomes.

DESIGN

This was a retrospective cohort study based on routine programmatic data for all patients enrolled on TB treatment at Daru General Hospital from 2014 to 2017.

RESULTS

The response involved high-level political commitment, joint planning, resource mobilisation, community engagement and strengthening TB case detection and treatment. Of 1548 people enrolled on TB treatment, 1208 (78%) had drug-susceptible TB (DS-TB) and 333 (21.5%) had MDR-TB. There was an increase in MDR-TB as a proportion of all TB. Treatment success rates increased over the study period from 55% to 86% for DS-TB, and from 70% to 81% for MDR-TB from 2014 to 2015. The 2014 case notification rate for TB in SFD was 1031/100 000, decreasing to 736/100 000 in 2017.

CONCLUSION

The outbreak was stabilised through the response from the national and provincial governments and international partners. Additional interventions are needed to decrease the TB burden in Daru.

Tuberculosis treatment unmasking leprosy: management of drug-resistant tuberculosis and leprosy co-infection

Co-infection with tuberculosis (TB) and leprosy is thought to occur infrequently, but has been reported in settings highly endemic for both infectious diseases. We report for the first time a case where treatment for multidrug-resistant TB (MDR-TB) led to the 'unmasking' of clinically silent leprosy through the precipitation of a type-1 immunological reaction. Current treatment regimens for MDR-TB may contain a number of drugs, such as levo-floxacin and clofazimine, which also have activity against M. leprae. A treatment regimen containing drugs active against both mycobacterial species may be used to achieve cure. Individual considerations on drug-drug interactions, potential additive toxicities and other comorbidities should be taken into account.

A1 The role of virus-antibody co-evolution in the development of a V3-glycan-directed HIV-1 broadly neutralizing antibody lineage

Broadly neutralizing antibodies (bNAbs) are essential for a preventative HIV-1 vaccine but have not been elicited through vaccination. bNAbs develop in 20–30 per cent of HIV-1 infections and often target the V3-glycan epitope of the HIV envelope protein (Env). In these individuals, virus-antibody co-evolution is thought to drive the maturation of antibody lineages to neutralization breadth. We used deep sequencing of env genes and antibody transcripts from fourteen time points spanning the first 3 years of infection to characterize the virus-antibody co-evolution in donor CAP255 who developed V3-glycan-specific bNAbs. Sequencing and cloning of env genes, followed by neutralization assays, were used to identify Env mutations associated with neutralization escape from two bNAbs (CAP255.G3 and CAP255.C5) isolated at 149 weeks post-infection (wpi). Sequencing data indicated that CAP255 was co-infected by three related viral variants, all of which had an intact N332 glycan, which persisted in > 90 per cent of later viruses. A recombinant V3-region became fixed from 8 wpi, conferring slight neutralization resistance to CAP255.G3/C5 and other V3-glycan bNAbs. Later, T415R/K substitutions in V4 emerged by 51 wpi and were associated with complete viral escape from CAP255.G3/C5, though not from the polyclonal plasma response. All 93-week and later Envs were resistant to CAP255.G3/C5 and V3-glycan bNAb PGT135. Viral escape by 51 wpi suggested that the CAP255 bNAbs arose earlier, driving escape, but persisted to 149 weeks. This was supported by preliminary deep sequencing of the antibody repertoire that indicated bNAb lineage members were already present in the plasma at 39 wpi. Escape from V3-glycan bNAbs via T415R/K mutations have not previously been shown, suggesting a novel mode of recognition within the V3-glycan supersite. Further work will focus on identifying the bNAb-initiating Env and intermediate bNAb lineage members that were capable of engaging contemporaneous Env neutralization escape mutants. Characterization of Envs that engaged bNAb precursors, as well as those that selected for broader members of the bNAb lineage, will inform the design of immunogens capable of eliciting V3-glycan bNAbs in a novel HIV-1 vaccine regimen.

Embolus Analog Trajectory Paths Under Physiological Flowrates Through Patient-Specific Aortic Arch Models

Atrial fibrillation (AF) is the most common irregular heartbeat among the world's population and is a major contributor to cardiogenic embolisms and acute ischemic stroke (AIS). However, the role AF flow plays in the trajectory paths of cardiogenic emboli has not been experimentally investigated. A physiological simulation system was designed to analyze the trajectory patterns of bovine embolus analogs (EAs) (n = 720) through four patient-specific models, under three flow conditions: steady flow, normal pulsatile flow, and AF pulsatile flow. It was seen that EA trajectory paths were proportional to the percentage flowrate split of 25–31% along the branching vessels. Overall, AF flow conditions increased trajectories through the left- (LCCA) and right (RCCA)-common carotid artery by 25% with respect to normal pulsatile flow. There was no statistical difference in the distribution of clot trajectories when the clot was released from the right, left, or anterior positions. Significantly, more EAs traveled through the brachiocephalic trunk (BCT) than through the LCCA or the left subclavian. Yet of the EAs that traveled through the common carotid arteries, there was a greater affiliation toward the LCCA compared to the RCCA (p < 0.05).

A phase II trial cohort of nivolumab plus ipilimumab in patients (Pts) with recurrent/metastatic adenoid cystic carcinoma (R/M ACC)

6084

Background: R/M ACC is a malignant neoplasm most commonly of salivary gland origin with no standard treatment. The impact of combined PD-1/CTLA-4 checkpoint blockade in R/M ACC is unknown. Methods: In a two-stage minimax phase II trial, pts with progressive R/M ACC (non-salivary primaries allowed) were enrolled and treated with nivolumab 3 mg/kg every 2 weeks plus ipilimumab 1 mg/kg every 6 weeks (1 cycle = 6 weeks). Imaging, using RECIST v1.1 response assessment, was scheduled to be performed approximately every 12 weeks. The primary endpoint was overall response rate (ORR = complete response [CR]+partial response [PR]) per RECIST v1.1. To detect a difference between an unacceptable ORR of 5% and a desirable ORR of 20% (one-sided type I error of 10%, power of 90%), at least 1 in the first 18 pts required an observed response. At least 4 responses of 32 total pts were needed to meet the primary endpoint. Treatment beyond progression of disease (PD) was allowed at the discretion of the investigator. A second cohort of pts with non-ACC salivary cancer is still accruing for separate analysis. Results: From 6/12/2017-6/20/2018, 32 pts were enrolled and evaluable for the primary endpoint. There was 1 confirmed PR in the first 18 pts, therefore enrollment of the second stage continued. ORR was 6% (2/32). One additional pt had an unconfirmed PR (-31% regression before CNS PD). For best overall response, there were 2 PRs, 15 SD, and 11 PD. Four pts never reached a first disease assessment: 3 due to death from clinical PD and 1 was removed for toxicity. Six pts discontinued the trial for toxicities (Grade 4 (G4) neutropenia/sepsis and G3 adrenal insufficiency (1), G2 hypophysitis (2), G3 arthritis > 7 days (1), G3 colitis (1), and G3 hepatitis/G4 creatinine kinase (CK) elevation (1)). The 2 confirmed PRs consisted of -73.1% and -58.4% regressions, with a duration of therapy of 18.4 and 7.8 months, respectively (treatment ongoing for both). Conclusions: The study did not meet its primary endpoint, though the responses observed were dramatic. Paired biopsy and peripheral blood samples will be analyzed to elucidate insights into mechanisms of response and resistance to dual checkpoint blockade. Clinical trial information: NCT03172624.

Abstract P5-18-12: Effectiveness of Oncotype DX DCIS scoring in a community setting

The Oncotype DX DCIS Score was developed to assist in determining a low risk for recurrence subgroup of patients who can avoid radiation therapy following breast conserving surgery. We sought to evaluate our experience using the Oncotype DX DCIS Score and to see if a greater number of patients who did not receive radiation therapy were experiencing a local recurrence than the score predicted.

Between February 23, 2011 and November 29, 2017, 145 women were diagnosed with ductal carcinoma in situ (DCIS) without an invasive component. 126 (87%) underwent breast conserving surgery. Thirty-five underwent Oncotype DX DCIS Score, of whom 26 (74%) were low risk, four were intermediate risk (11%), and five were high risk (14%).

The scores ranged from 0 (7 patients) to 100 (1 patient). Of the 26 patients with low risk scores, one chose to undergo mastectomy, three received radiation therapy, 20 chose observation without radiation therapy, and two patients were unknown because they had no further treatment or follow-up at our facility. Two of the four intermediate risk patients underwent radiation therapy and two did not. Four of the five high risk patients underwent radiation therapy, but one did not.

Twenty-two of the 35 patients who underwent Oncotype DX Score met the criteria for size (based on grade) and margins (at least 3 mm). Ten patients had margins that were less than 3 mm but met the size criteria. Two patients did not meet the size criteria but had at least 3 mm margins. One patient did not meet either the size or margin criteria. None of our 20 patients with low risk Oncotype DX DCIS Score and who met both the size and margin criteria recurred.

With the median follow-up of approximately 2-1/2 years, three of the 21 patients (14%) with low or intermediate risk scores who underwent Oncotype DX DCIS Score and did not receive radiation therapy suffered a local recurrence. The predicted average recurrence risk for these patients based on their Oncotype DX DCIS Score was 12%. Two of these patients who recurred had margins less than 3 mm, and one patient met the size and margin criteria, but had an intermediate risk score.

By comparison, five of 61 (8%) of patients who underwent breast conserving surgery and adjuvant radiation therapy had a local recurrence.

Twenty of the 23 (87%) low risk Oncotype DX DCIS Score patients did not receive radiation therapy and overall 20/35 (57%) of the patients undergoing Oncotype DX DCIS Score did not receive radiation therapy.

Although the follow-up is still relatively short, Oncotype DX DCIS Score allows a considerable number of women to avoid adjuvant radiation therapy.

Citation Format: Wheeler JA, Vaghefi H, Liu F, Owens V, Morris L, Denham F, Coody L. Effectiveness of Oncotype DX DCIS scoring in a community setting [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 P5-18-12.

Loss of the FAT1 Tumor Suppressor Promotes Resistance to CDK4/6 Inhibitors via the Hippo Pathway

Cyclin dependent kinase 4/6 (CDK4/6) inhibitors (CDK4/6i) are effective in breast cancer; however, drug resistance is frequently encountered and poorly understood. We conducted a genomic analysis of 348 estrogen receptor-positive (ER⁺) breast cancers treated with CDK4/6i and identified loss-of-function mutations affecting FAT1 and RB1 linked to drug resistance. FAT1 loss led to marked elevations in CDK6, the suppression of which restored sensitivity to CDK4/6i. The induction of CDK6 was mediated by the Hippo pathway with accumulation of YAP and TAZ transcription factors on the CDK6 promoter. Genomic alterations in other Hippo pathway components were also found to promote CDK4/6i resistance. These findings uncover a tumor suppressor function of Hippo signaling in ER⁺ breast cancer and establish FAT1 loss as a mechanism of resistance to CDK4/6i.

Comparing Kadish, TNM, and the modified Dulguerov staging systems for esthesioneuroblastoma

BACKGROUND

Esthesioneuroblastoma (ENB) is a rare neuroendocrine tumor. The purpose of this study was to compare the Kadish, tumor-node-metastasis (TNM), and Dulguerov's modified TNM staging in order to determine the impact of the stage on primary surgical treatment selection, margin status, and survival.

METHODS

The National Cancer Database (NCDB) was used to identify patients diagnosed with ENB between 2004 to 2015. Patients were excluded based on the ability to properly stage their disease as well as the availability of treatment data.

RESULTS

Eight-hundred eighty-three patients had sufficient data for analysis. On multivariate analysis, age and government insurance were associated with primary surgical treatment, whereas tumor stage, gender, race, hospital type and volume, and comorbidity score were not. Age, charlson-deyo comorbidity (CDCC) score, hospital volume, and nodal status were found to be predictors of survival. Multivariate-analysis controlling for stage failed to demonstrate clear survival differences between staging in both TNM and Kadish systems. T-stage and the presence of regional nodal metastasis were associated with an increased risk of positive margins on multivariate analysis.

CONCLUSION

Although primary surgical management and positive margins can be predicted by certain patient and tumor factors, clinical staging systems for ENB poorly predict prognosis over a 10-year horizon.

A unique schedule of palonosetron, ondansetron, and dexamethasone for the prevention of delayed nausea and vomiting in patients receiving myeloablative chemotherapy

Myeloablative chemotherapy administered prior to autologous stem cell transplantation (auto-SCT) is associated with a significant amount of chemotherapy-induced nausea and vomiting (CINV). We conducted a phase II trial to assess the safety, efficacy, and impact on quality of life when palonosetron (PAL) 0.25 mg combined with dexamethasone were given on the final or only day of myeloablative chemotherapy for auto-SCT. The primary end point of this study was the incidence of achieving a delayed CINV complete response defined as no emetic episode and no use of rescue medications during the 24-120 h period post chemotherapy. Eighty-five patients were enrolled in the study and received PAL. A delayed CINV complete response was achieved in 15% of patients. A multivariate analysis demonstrated no associated differences between age, gender, diagnosis, or regimen. By day 5 after PAL, the mean nausea severity was 0.91 ± 2.45 vs. 0.09 ± 1.58 at baseline (p = 0.012). Quality of life measurements demonstrated similar quality of life between baseline and day 3. By day 6 however, nausea alone had a statistically significant impact on quality of life. In our study, PAL controlled nausea severity and sustained quality of life, but further strategies are needed to control delayed CINV associated with the auto-SCT process.

Communication training interventions for family and professional carers of people living with dementia: a systematic review of effectiveness, acceptability and conceptual basis

OBJECTIVES

To update previous reviews and provide a more detailed overview of the effectiveness, acceptability and conceptual basis of communication training-interventions for carers of people living with dementia.

METHOD

We searched CINAHL Plus, MEDLINE and PsycINFO using a specific search and extraction protocol, and PRISMA guidelines. Two authors conducted searches and extracted studies that reported effectiveness, efficacy or acceptability data regarding a communication training-intervention for carers of people living with dementia. Risk of bias was assessed using the Cochrane Collaboration guidelines. Quality of qualitative studies was also systematically assessed.

RESULTS

Searches identified 450 studies (after de-duplication). Thirty-eight studies were identified for inclusion in the review. Twenty-two studies focused on professional carers; 16 studies focused mainly on family carers. Training-interventions were found to improve communication and knowledge. Overall training-interventions were not found to significantly improve behaviour that challenges and caregiver burden. Acceptability levels were high overall, but satisfaction ratings were found to be higher for family carers than professional carers. Although many interventions were not supported by a clear conceptual framework, person-centred care was the most common framework described.

CONCLUSION

This review indicated that training-interventions were effective in improving carer knowledge and communication skills. Effective interventions involved active participation by carers and were generally skills based (including practicing skills and discussion). However, improvements to quality of life and psychological wellbeing of carers and people living with dementia may require more targeted interventions.

Abstract 4619: Integrated genomic analysis of Hurthle cell carcinoma reveals TMEM233/PRKAB1 fusion as a novel oncogenic driver

Background: Hurthle cell carcinoma (HCC) is an enigmatic malignancy of the thyroid that can behave in an aggressive fashion, sometimes lethal, yet its molecular foundations are poorly understood. Some HCC have a good prognosis (minimally invasive, HMIN) whereas others can be extremely aggressive (widely invasive, HWIDE), leading to metastasis and death. HCCs were not included in the TCGA thyroid cancer study, which focused solely on papillary thyroid carcinomas. To understand the development of HCC and unveil its molecular mechanism, we performed a comprehensive genomic characterization of 56 primary HCCs that span the spectrum of tumor behavior and investigated the role of TMEM233/PRKAB1 fusion as a critical driver of oncogenesis in HCC.

Methods: Tumor and matched normal specimens were obtained from 56 patients with primary HCC. Tumors were classified into minimally invasive ( n=24) or widely invasive subtype (n=32). Whole exome sequencing was used to identify somatic mutations. Copy number changes were identified using FACETS and validated by FISH. RNASeq was used to identify novel fusions genes and to identify differentially expressed genes. Genomic alterations associated with histological phenotype were identified. Genomic changes associated with recurrence and survival were identified by the Kaplan Meier method. Immortalized thyroid epithelial cell line, NTHY-ori 3.1 was used to express control and fusion gene for in vitro and in vivo experiments.

Results: We elucidate the mutational profile and driver mutations in HCC and reveal that they exhibit a diverse spectrum of recurrent mutations, most of which have not been previously associated with this cancer (EIF1AX, MADCAM1). Notably, HCC harbor an extremely high prevalence of disruptive mutations to both protein-coding and tRNA encoding regions of the mitochondrial genome. We reveal unique chromosomal landscapes that involve whole chromosomal duplications of chromosomes 5 and 7 and wide spread major loss of heterozygosity arising from haploidization and copy number neutral uniparental disomy. These chromosomal processes underlie genetic instability and are highly prevalent in aggressive forms of HCC. We also identify novel fusion genes such as TMEM233/PRKAB1 which expression resulted in a transformation, organoids formation and invasion phenotype in vitro and

tumorigenesis in vivo. These data suggested that TMEM233/PRKAB1 fusion plays as a critical driver and may serve as a therapeutic target for HCCs.

Conclusions: We performed integrated genomic analysis of hurthle cell carcinoma revealing novel oncogenic drivers, recurrent mitochondrial mutations and unique chromosomal landscapes, which will help guide development of new treatments for one of the most deadly types of thyroid cancer.

Citation Format: Yiyu Dong, Ian Ganly, Vladimir Makarov, Fengshen Kuo, Shyamprasad Deraje, Ed Reznik, Venkatraman Seshan, Gouri Nanjangud, Luc Morris, Nadeem Riaz, Eric Sherman, Ronald Ghossein, James Fagin, Timothy Chan. Integrated genomic analysis of Hurthle cell carcinoma reveals TMEM233/PRKAB1 fusion as a novel oncogenic driver [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4619.