Multi-Niche Human Bone Marrow On-A-Chip for Studying the Interactions of Adoptive CAR-T Cell Therapies with Multiple Myeloma

Multiple myeloma (MM), a cancer of bone marrow plasma cells, is the second-most common hematological malignancy. However, despite immunotherapies like chimeric antigen receptor (CAR)-T cells, relapse is nearly universal. The bone marrow (BM) microenvironment influences how MM cells survive, proliferate, and resist treatment. Yet, it is unclear which BM niches give rise to MM pathophysiology. Here, we present a 3D microvascularized culture system, which models the endosteal and perivascular bone marrow niches, allowing us to study MM-stroma interactions in the BM niche and model responses to therapeutic CAR-T cells. We demonstrated the prolonged survival of cell line-based and patient-derived multiple myeloma cells within our in vitro system and successfully flowed in donor-matched CAR-T cells. We then measured T cell survival, differentiation, and cytotoxicity against MM cells using a variety of analysis techniques. Our MM-on-a-chip system could elucidate the role of the BM microenvironment in MM survival and therapeutic evasion and inform the rational design of next-generation therapeutics.

TEASER

A multiple myeloma model can study why the disease is still challenging to treat despite options that work well in other cancers.

Generation of LexA enhancer-trap lines in Drosophila by an international scholastic network

Conditional gene regulation in Drosophila through binary expression systems like the LexA-LexAop system provides a superb tool for investigating gene and tissue function. To increase the availability of defined LexA enhancer trap insertions, we present molecular, genetic, and tissue expression studies of 301 novel Stan-X LexA enhancer traps derived from mobilization of the index SX4 line. This includes insertions into distinct loci on the X, II, and III chromosomes that were not previously associated with enhancer traps or targeted LexA constructs, an insertion into ptc, and seventeen insertions into natural transposons. A subset of enhancer traps was expressed in CNS neurons known to produce and secrete insulin, an essential regulator of growth, development, and metabolism. Fly lines described here were generated and characterized through studies by students and teachers in an international network of genetics classes at public, independent high schools, and universities serving a diversity of students, including those underrepresented in science. Thus, a unique partnership between secondary schools and university-based programs has produced and characterized novel resources in Drosophila, establishing instructional paradigms devoted to unscripted experimental science.

O30: EVALUATION OF AXILLARY LYMPH NODE METASTATIC BURDEN BY PREOPERATIVE ULTRASOUND

Introduction

Sentinel lymph node biopsy (SLNB) is the gold standard for determining axillary nodal status. There is growing interest in using preoperative axillary ultrasound (AUS) as a non-invasive means of assessing the axilla. However, AUS has limited sensitivity and is subject to operator dependency. This study aimed to quantify axillary nodal burden in preoperative AUS.

Method

This retrospective study used an institutional database of all primary invasive breast carcinomas from 2006–2019. Those with pathologically proven axillary metastatic disease were included. Patients were considered in two groups, low nodal burden/LNB(1-2LN) and high nodal burden/HNB(≥3LN) based on total positive lymph node count(SLNB+ALND). Preoperative AUS reports were assessed to determine those suspicious for axillary metastasis.

Result

Of the 347 patients (n=349 axillae), 77.9% had LNB and 22.1% had HNB. In patients with LNB, 228(83.8%) had a normal AUS versus 44(16.2%) suspicious AUS. In those with HNB 60(77.9%) had normal AUS findings versus 17(22.1%) suspicious findings. On multivariate analysis Nottingham Grade-3 was associated with suspicious AUS findings (p=0.02). However, receptor status, SLN macro-metastasis and extra-nodal extension were not associated with abnormal AUS.

Conclusion

As the surgical approach to the axilla becomes increasingly conservative, detection of axillary involvement by non-invasive means is an area of increasing research. In this cohort, AUS did not reliably identify patients with axillary metastasis. These results highlight the challenges in accurately assessing the axilla using preoperative AUS, which may result in axillary undertreatment if used as an alternative to surgical staging.

Take-home message

As the surgical approach to the axilla becomes increasingly conservative, detection of axillary involvement by non-invasive means is an area of increasing research. This study highlights the challenges in accurately assessing the axilla using preoperative AUS, which may result in axillary undertreatment if used as an alternative to surgical staging.

O61: TEXTBOOK SURGICAL OUTCOMES IN OESOPHAGO-GASTRIC CANCER: THE INFLUENCE OF NATIONAL KEY PERFORMANCE INDICATORS

Introduction

High quality surgery remains the cornerstone of treating oesophago-gastric malignancy. Recent work from the Dutch Upper-gastrointestinal Cancer Audit (DUCA) have defined ten surgical and perioperative ‘textbook’ parameters that correlate with improved overall survival. The aim of this project was to examine the proportion of patients attaining ‘textbook’ outcomes for oesophagectomy and gastrectomy in our unit before and after the introduction of national key performance indicators (KPIs).

Method

A retrospective review of all oesophagectomies and gastrectomies from January 2010 until June 2019 was performed. Clinical, pathological, perioperative, morbidity and mortality outcomes were recorded. 10 ‘textbook’ parameters were studied pre- and post-KPI introduction.

Result

269 and 284 patients underwent oesophagectomy and gastrectomy respectively, 167 pre-KPI and 386 post-KPI. There were no significant differences in age (67.6 vs 66.4 years, p=0.6), gender (71% male, 29% female vs 68% male, 22% female, p=0.48), ASA grade (p=0.6) or tumour stage (p=0.37) pre- and post-KPI. In the pre-KPI era, 28/167 (17%) patients achieved all ten textbook parameters, compared with 157/386, (41%, p=0.001) post-KPI. This compares favourably to DUCA ‘textbook’ data. There was an improvement in adequate lymphadenectomy (56% vs 83%, p=0.002), a reduction in margin positivity (21% vs 7%, p= 0.001) and peri-operative mortality (6% vs 2%, p=0.03) post-KPI.

Conclusion

There has been a significant improvement in perioperative outcomes in esophagectomy following the introduction of national KPIs in our unit. The number of patients achieving ‘textbook’ outcomes is comparable with international standards. The identification of textbook parameters allows further focus for future quality improvement initiatives.

Take-home message

National KPIs improve peri-operative outcomes in oesophago-gastric cancer.

Breast clinic referrals: can mastalgia be managed in primary care?

BACKGROUND

Centralisation of breast cancer services in Ireland has resulted in a significant increase in the number of patients attending symptomatic breast units (SBU). A considerable proportion of patients referred to SBU present with non-suspicious symptoms and fall into a "low-risk" category for breast cancer. It has been proposed that consideration be given to a primary care-delivered service for these patients.

AIM

To evaluate SBU attendances and correlate with diagnosis to identify a cohort of patients who may be suitable for management in the primary care setting.

METHODS

Data were collected from a prospectively maintained database on patients attending SBU at two tertiary referral centres (Beaumont Hospital and University College Hospital Galway) from January 2011 to 2012. Reasons for attendance, outcome of triple-assessment and incidence of malignancy were analysed.

RESULTS

14,325 patients underwent triple assessment at the SBU in this time period. 5,841 patients were referred with mastalgia, of whom 3,331 (57 %) reported mastalgia as the only symptom. The incidence of breast cancer in patients presenting with mastalgia alone was 1.2 %. All patients diagnosed with breast cancer in this cohort were over 35 years of age.

CONCLUSION

The incidence of breast cancer in patients referred to SBU with mastalgia as an isolated symptom is extremely low. Patients under 35 years of age, with mastalgia as an isolated symptom do not require breast imaging and have a sufficiently low risk of breast cancer that they may be suitable for management in the primary care setting.

Nurses' clinical decision-making regarding the management of pain

Effective pain management remains an elusive goal within the profession of nursing. While considerable improvement has occurred, patients continue to experience inappropriate levels of pain. To date, research has focused on objective factors that influence pain management. Few studies have examined attitudinal factors that may influence nurses' decision-making. This quasi-experiment was based on preliminary data showing that nurses' preconceived notions regarding certain patient groups influenced their management of pain. An intervention was tested for its' effect on nurses' preconceived notions regarding specific patient groups. A significant difference in a positive direction was found. Nurses were more willing to spend time and energy managing pain across all patient groups following the intervention.

Nurses’ clinical decision-making regarding the management of pain

Effective pain management remains an elusive goal within the profession of nursing. While considerable improvement has occurred, patients continue to experience inappropriate levels of pain. To date, research has focused on objective factors that influence pain management. Few studies have examined attitudinal factors that may influence nurses' decision-making. This quasi-experiment was based on preliminary data showing that nurses' preconceived notions regarding certain patient groups influenced their management of pain. An intervention was tested for its' effect on nurses' preconceived notions regarding specific patient groups. A significant difference in a positive direction was found. Nurses were more willing to spend time and energy managing pain across all patient groups following the intervention.

Identity of bovine growth hormone and peptidylglycine monooxygenase

The C-terminal alpha-amidation of peptides is one of the most important events in prohormone and neuropeptide processing. Peptide amidation is a two-step process catalyzed by peptidylglycine (hydroxylating) monooxygenase (B. A. Eipper et al., 1983, Proc. Natl. Acad. Sci. USA 80, 5144-5148) followed by dismutation of the resultant hydroxylated peptide to peptide amide and glyoxylate, stimulated by alpha-hydroxyglycine amidating dealkylase (K. Takahashi et al., 1990, Arch. Biochem. Biophys. 169, 524-530). Previous reports on peptidylglycine monooxygenase from bovine pituitary have generated substantial disagreement as to its molecular size. We have reinvestigated the purification of this enzyme and we find that peptidylglycine monooxygenase activity from fresh bovine pituitary is entirely due to a previously unrecognized catalytic function of growth hormone (somatotropin).

Exogenous interferon administration in experimental leishmaniasis: in vivo and in vitro studies

The potential feasibility of using exogenously administered human interferon for the treatment of selected cases of leishmaniasis prompted us to study the effects of murine interferon on the course of Leishmania tropica infection in C57Bl/6 mice. L cell-derived mouse interferon was administered daily by intraperitoneal (1,000 and 10,000 U) or intralesional (100 U) injection in mice inoculated into footpads with L. tropica amastigotes. Footpad swelling and tissue parasite density were assessed over the course of infection. Interferon treatment did not significantly affect these clinical and parasitological parameters. Furthermore, addition of interferon (100--100,000 U) to cultures of amastigote-infected mouse peritoneal macrophages or to axenic cultures of promastigotes did not affect replication. We conclude that interferon lacks intrinsic antileishmanial activity and does not significantly enhance host defense against Leishmania.

Serum chemistry templates of disease in liver, pancreas, and gallbladder

On routine hospital admission, 23,714 patients received a 28-test serum metabolic profile. The 33 most common diseases (4,132 patients) of liver, pancreas, and gallbladder (LPG) had unique chemical templates averaging 15 significant serum deviations. Each LPG disease differed from all others by elevations of both leucine-aminopeptidase (LAP) and alkaline phosphatase (AP) levels. LAP level was low or normal and serum glutamic oxaloacetic transaminase (SGOT) and AP levels were elevated in 43 non-LPG diseases. Patients with acute and chronic pancreatitis had elevated amylase levels. The four nonmalignant diseases of the gallbladder were associated with normal levels of amylase and lactic dehydrogenase (LDH); except for silent cholelithiasis, each showed elevated total bilirubin (BIL) levels. Patients with solitary or scattered lesions of the liver had normal bilirubin levels (2,115 patients), and those with diffuse interstitial or parencymal disease had elevated BIL levels. Cancer patients had elevated LDH and alpha1 globulin (A1G) levels, but low albumin levels. The importance of comprehensive liver profiles in the treatment of psychoses is emphasized by significant liver damage in a number of these patients. A1G was normal and LDH was elevated in patients having mononucleosis, hepatitis, lupus erythematosus, alcoholism, and alcoholic cirrhosis.