Abstract P4-06-02: Germline analysis of breast cancer patients with abnormal somatic results: Ancillary assessment or critical co-diagnostic?

Background: Tumor genetic testing (TGT) is increasingly used for planning cancer treatment and identifying appropriate clinical trials. Emerging literature shows that 4–12% of genetic variants identified on TGT are also present in the germline, conferring hereditary cancer risk. Germline genetic testing (GGT) guidelines were recently expanded to include the identification of a BRCA1/BRCA2 variant on TGT as an indication for germline analysis. We evaluated the diagnostic yield of current GGT guidelines by assessing the rate of pathogenic and likely pathogenic (P/LP) germline findings in a series of patients who had a variant identified on TGT and underwent GGT. Methods: We analyzed de-identified data from 185 sequential patients with various tumor types who had TGT and GGT. Personal and family histories were compared to all available NCCN guidelines for GGT. Results: Sixty-four of 185 patients (34.6%) had at least one P/LP germline variant, and among these patients, 42% (27/64) had variants in BRCA1/BRCA2. Variants in all but one patient (26/27) were also found on TGT. Fourteen of 27 (52%) patients had a personal diagnosis of cancer not typically associated with BRCA1/BRCA2, including colorectal (5), lung (3), and one each of cervical, cholangiocarcinoma, gastric, thymus, thyroid, and uterine. Furthermore, prior TGT results were the only reason GGT guidelines were met in 12 of 27 (44%) patients with germline BRCA1/BRCA2 variants. Among 34 patients with a personal history of breast or ovarian cancer, a P/LP germline variant was identified in nine (26%); the majority (5 of 9) were in non-BRCA1/BRCA2 genes including CDKN2A (1), FANCA (1), MUTYH (1), and PALB2 (2). Notably, the patient with the CDKN2A variant did not meet current breast cancer guidelines for GGT, and one patient with breast cancer and a germline BRCA2 mutation only met GGT guidelines due to prior TGT results. Discussion: Genetic testing guidelines have begun to reflect the opportunity for TGT to identify families at risk for hereditary cancer. Expanding GGT criteria to include TGT results is critical for capturing patients who may not otherwise receive GGT. Our data showed a substantial diagnostic yield in patients—including those with breast or ovarian cancer—who completed GGT after variant identification on TGT. Although current genetic testing guidelines capture the portion of these patients with a BRCA1/BRCA2 mutation identified with TGT, our data suggest that P/LP variants in other genes should also be considered during the evaluation of TGT results for subsequent GTG. Finally, the broad spectrum of tumor types with BRCA1/BRCA2 P/LP variants emphasizes the need for all clinicians, regardless of subspecialty, to be aware of current GTG recommendations when TGT identifies a BRCA1/BRCA2 variant and the potential implications of GTG, including targeted therapy, screening, prevention, and family testing.

Citation Format: Blanco AM, Yang S, Michalski ST, Ouyang K, Hamlington B, Fulbright J, Erhard K, Kang HC, Jacobs M, Koptiuch C, Vig H, Silver E, Benson C, Massingham L, Lincoln SE, Nussbaum RL, Hampel H, Esplin ED. Germline analysis of breast cancer patients with abnormal somatic results: Ancillary assessment or critical co-diagnostic? [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 P4-06-02.

Minimal modulation of the host immune response to SIS matrix implants by mesenchymal stem cells from the amniotic fluid

PURPOSE

Surgical restoration of soft tissue defects often requires implantable devices. The clinical outcome of the surgery is determined by the properties inherent to the used matrix. Mesenchymal stem cells (MSC) modulate the immune processes after in vivo transplantation and their addition to matrices is associated with constructive remodeling. Herein we evaluate the potential of MSC derived from the amniotic fluid (AF-MSC), an interesting MSC source for cell therapeutic applications in the perinatal period, for immune modulation when added to a biomaterial.

METHODS

We implant cell free small intestinal submucosa (SIS) or SIS seeded with AF-MSC at a density of 1 × 10⁵/cm² subcutaneously at the abdominal wall in immune competent rats. The host immune response is evaluated at 3, 7 and 14 days postoperatively.

RESULTS

The matrix-specific or cellular characteristics are not altered after 24 h of in vitro co-culture of SIS with AF-MSC. The host immune response was not different between animals implanted with cell free or AF-MSC-seeded SIS in terms of cellular infiltration, vascularity, macrophage polarization or scaffold replacement. Profiling the mRNA expression level of inflammatory cytokines at the matrix interface shows a significant reduction in the expression of the pro-inflammatory marker Tnf-α and a trend towards lower iNos expression upon AF-MSC-seeding of the SIS matrix. Anti-inflammatory marker expression does not alter upon cell seeding of matrix implants.

CONCLUSION

We conclude that SIS is a suitable substrate for in vitro culture of AF-MSC and fibroblasts. AF-MSC addition to SIS does not significantly modulate the host immune response after subcutaneous implantation in rats.

Openspritzer: an open hardware pressure ejection system for reliably delivering picolitre volumes

The ability to reliably and precisely deliver picolitre volumes is an important component of biological research. Here we describe a high-performance, low-cost, open hardware pressure ejection system (Openspritzer), which can be constructed from off the shelf components. The device is capable of delivering minute doses of reagents to a wide range of biological and chemical systems. In this work, we characterise the performance of the device and compare it to a popular commercial system using two-photon fluorescence microscopy. We found that Openspritzer provides the same level of control over delivered reagent dose as the commercial system. Next, we demonstrate the utility of Openspritzer in a series of standard neurobiological applications. First, we used Openspritzer to deliver precise amounts of reagents to hippocampal neurons to elicit time- and dose-precise responses on neuronal voltage. Second, we used Openspritzer to deliver infectious viral and bacterial agents to living tissue. This included viral transfection of hippocampal interneurons with channelrhodopsin for the optogenetic manipulation of hippocampal circuitry with light. We anticipate that due to its high performance and low cost Openspritzer will be of interest to a broad range of researchers working in the life and physical sciences.

Surgical sutures: coincidence or experience?

BACKGROUND

Knotting sutures by hand is still important in daily surgical routine, especially laparotomy closure. The expectation is that hand suturing relies on the experience and subjective estimation of the surgeon. The aim of this study was to investigate whether hand suturing tension is reproducible and if surgical experience influences reproducibility.

METHODS

At the annual Congress of the German Association of Surgery, 118 surgeons performed repetitive sutures on a standardized and certified measuring device simulating the final knot of a fascial closure. Each surgeon was asked to perform five identical single knots in a row using the suture tension that each considered ideal. Tension during knotting was measured in Newtons. The surgeons were divided into five subgroups based on surgical experience: group 1, <1 year; group 2, 2-5 years; group 3, 6-10 years; group 4, 11-20 years; and group 5, >30 years.

RESULTS

The tension measured at the end of knotting ranged from 0.19 to 10 N. The mean suture tension at endpoint was 3.88 N for group 1 and slightly higher in the other groups, but not significantly different. The overall mean suture tension was 5.43 N and did not correlate with surgical experience. Suture tension was not reproducible.

CONCLUSION

Sequential suture tension varied, even among experienced surgeons. The ideal tissue-dependent suture tension has not been defined. Measured values appear to be intuitive, relying on individual feeling rather than the level of experience.

[Driving with Alzheimer's disease]

OBJECTIVE

To summarise the available literature on driving with Alzheimer's disease (AD) and to investigate the relationship between driving and cognitive functioning.

DESIGN

Literature review.

METHOD

A systematic search of the electronic databases PubMed/MEDLINE was conducted to select the relevant literature on the driving competence of patients with Alzheimer's disease.

RESULTS

A total of 31 studies were selected that investigated driving competence in AD using either an on-road driving assessment or a driving simulator. The driving competence of patients with AD was less accurate compared with controls. The most commonly made errors included errors in staying in lane, lane changing, slower reaction times, and more fluctuations in speed. Cognitive functioning was more predictive of driving competence than a diagnosis of AD alone.

CONCLUSION

Based on the available literature it is difficult to determine when patients with AD should be restricted in their driving. In addition, there is currently no consensus on which neuropsychological tests are useful in clinical practice to predict driving competence. Specific practical guidelines that can be implemented in daily practice are still lacking.

Development and feasibility of a web-based question prompt sheet to support information provision of health-related quality of life topics after oesophageal cancer surgery

We developed a web-based question prompt sheet (QPS) to support information provision of health-related quality of life (HRQL) topics after oesophageal cancer surgery. The QPS was evaluated and updated in three consecutive studies. In Study 1, eight patients were guided in using the QPS. Feasibility was assessed by cognitive walkthrough, questionnaire and interview. We obtained 430 notes (217 negative, 213 positive) of patients' actions and or remarks, and 91 suggestions. With minor support, most patients were able to use the QPS. In Study 2, forty patients independently used and appraised a modified version of the QPS by questionnaire. All patients deemed the QPS to be usable and useful. In Study 3, 21 patients and three surgeons used the QPS in clinical practice. Clinical feasibility was assessed by the number of QPS sent to the researcher/surgeon. Patients and surgeons were surveyed and the follow-up consultation was audio-recorded. Surgeons were additionally interviewed. Twenty/fourteen patients sent their QPS to the researcher/surgeon. Five QPSs were read by the consultation surgeon. Patients considered the QPS usable and useful. Surgeons considered the QPS of added value and helpful in informing patients, but currently not clinically feasible due to increased consultation time.

Scientific principles for the identification of endocrine-disrupting chemicals: a consensus statement

Endocrine disruption is a specific form of toxicity, where natural and/or anthropogenic chemicals, known as "endocrine disruptors" (EDs), trigger adverse health effects by disrupting the endogenous hormone system. There is need to harmonize guidance on the regulation of EDs, but this has been hampered by what appeared as a lack of consensus among scientists. This publication provides summary information about a consensus reached by a group of world-leading scientists that can serve as the basis for the development of ED criteria in relevant EU legislation. Twenty-three international scientists from different disciplines discussed principles and open questions on ED identification as outlined in a draft consensus paper at an expert meeting hosted by the German Federal Institute for Risk Assessment (BfR) in Berlin, Germany on 11-12 April 2016. Participants reached a consensus regarding scientific principles for the identification of EDs. The paper discusses the consensus reached on background, definition of an ED and related concepts, sources of uncertainty, scientific principles important for ED identification, and research needs. It highlights the difficulty in retrospectively reconstructing ED exposure, insufficient range of validated test systems for EDs, and some issues impacting on the evaluation of the risk from EDs, such as non-monotonic dose-response and thresholds, modes of action, and exposure assessment. This report provides the consensus statement on EDs agreed among all participating scientists. The meeting facilitated a productive debate and reduced a number of differences in views. It is expected that the consensus reached will serve as an important basis for the development of regulatory ED criteria.

Global minimally invasive pyeloplasty study in children: Results from the Pediatric Urology Expert Group of the European Association of Urology Young Academic Urologists working party

INTRODUCTION

Minimally invasive pyeloplasty (MIP) for ureteropelvic junction (UPJ) obstruction in children has gained popularity over the past decade as an alternative to open surgery. The present study aimed to identify the factors affecting complication rates of MIP in children, and to compare the outcomes of laparoscopic (LP) and robotic-assisted laparoscopic pyeloplasty (RALP).

MATERIALS AND METHODS

The perioperative data of 783 pediatric patients (<18 years old) from 15 academic centers who underwent either LP or RALP with an Anderson Hynes dismembered pyeloplasty technique were retrospectively evaluated. Redo cases and patients with anatomic renal abnormalities were excluded. Demographics and operative data, including procedural factors, were collected. Complications were classified according to the Satava and modified Clavien systems. Failure was defined as any of the following: obstructive parameters on diuretic renal scintigraphy, decline in renal function, progressive hydronephrosis, or symptom relapse. Univariate and multivariate analysis were applied to identify factors affecting the complication rates. All parameters were compared between LP and RALP.

RESULTS

A total of 575 children met the inclusion criteria. Laparoscopy, increased operative time, prolonged hospital stay, ureteral stenting technique, and time required for stenting were factors influencing complication rates on univariate analysis. None of those factors remained significant on multivariate analysis. Mean follow-up was 12.8 ± 9.8 months for RALP and 45.2 ± 33.8 months for LP (P = 0.001). Hospital stay and time for stenting were shorter for robotic pyeloplasty (P < 0.05 for both). Success rates were similar between RALP and LP (99.5% vs 97.3%, P = 0.11). The intraoperative complication rate was comparable between RALP and LP (3.8% vs 7.4%, P = 0.06). However, the postoperative complication rate was significantly higher in the LP group (3.2% for RALP and 7.7% for LP, P = 0.02). All complications were of no greater severity than Satava Grade IIa and Clavien Grade IIIb.

DISCUSSION

This was the largest multicenter series of LP and RALP in the pediatric population. Limitations of the study included the retrospective design and lack of surgical experience as a confounder.

CONCLUSIONS

Both minimally invasive approaches that were studied were safe and highly effective in treating UPJ obstruction in children in many centers globally. However, shorter hospitalization time and lower postoperative complication rates with RALP were noted. The aims of the study were met.

Progression of motor subtypes in Huntington's disease: a 6-year follow-up study

The objective of this study is to investigate the progression of predominantly choreatic and hypokinetic-rigid signs in Huntington’s disease (HD) and their relationship with cognitive and general functioning over time. The motor signs in HD can be divided into predominantly choreatic and hypokinetic-rigid subtypes. It has been reported in cross-sectional studies that predominantly choreatic HD patients perform better on functional and cognitive assessments compared to predominantly hypokinetic-rigid HD patients. The course of these motor subtypes and their clinical profiles has not been investigated longitudinally. A total of 4135 subjects who participated in the European HD Network REGISTRY study were included and classified at baseline as either predominantly choreatic (n = 891), hypokinetic-rigid (n = 916), or mixed-motor (n = 2328), based on a previously used method. The maximum follow-up period was 6 years. The mixed-motor group was not included in the analyses. Linear mixed models were constructed to investigate changes in motor subtypes over time and their relationship with cognitive and functional decline. Over the 6-year follow-up period, the predominantly choreatic group showed a significant decrease in chorea, while hypokinetic-rigid symptoms slightly increased in the hypokinetic-rigid group. On the Total Functional Capacity, Stroop test, and Verbal fluency task the rate of change over time was significantly faster in the predominantly choreatic group, while on all other clinical assessments the decline was comparable for both groups. Our results suggest that choreatic symptoms decrease over time, whereas hypokinetic-rigid symptoms slightly increase in a large cohort of HD patients. Moreover, different motor subtypes can be related to different clinical profiles.

Patients with oesophageal cancer report elevated distress and problems yet do not have an explicit wish for referral prior to receiving their medical treatment plan

OBJECTIVE

This study aims to identify patients with oesophageal cancer's level of distress, type of problems, and wish for referral prior to treatment. To identify the clinical relevance of patients with oesophageal cancer's level of distress and type of problems, we build models to predict elevated distress, wish for referral, and overall survival.

METHODS

We implemented the Distress Thermometer and Problem List in daily clinical practice. A score of ≥5 on the Distress Thermometer reflected elevated distress. We first created an initial model including predictors based on the literature. We then added predictors to the initial model to create an extended model based on the sample data. We used the 'least absolute shrinkage and selection operator' to define our final model.

RESULTS

We obtained data from 187 patients (47.9%, of 390 eligible patients with oesophageal cancer) which were similar to non-respondents in their demographic and clinical characteristics. One-hundred thirteen (60%) patients reported elevated distress. The five most frequently reported problems were as follows: eating, tension, weight change, fatigue, and pain. Most patients did not have a wish for referral. Predictors for elevated distress were as follows: being female, total number of practical, emotional, and physical problems, pain, and fatigue. For referral, we identified age, the total number of emotional problems, the level of distress, and fear. The level of distress added prognostic information in a model to predict overall survival.

CONCLUSIONS

Patients with oesophageal cancer report elevated distress and a myriad of problems yet do not have an explicit wish for referral prior to receiving their medical treatment plan. Copyright © 2016 John Wiley & Sons, Ltd.

Binding of the substrate UDP-glucuronic acid induces conformational changes in the xanthan gum glucuronosyltransferase

GumK is a membrane-associated glucuronosyltransferase of Xanthomonas campestris that is involved in xanthan gum biosynthesis. GumK belongs to the inverting GT-B superfamily and catalyzes the transfer of a glucuronic acid (GlcA) residue from uridine diphosphate (UDP)-GlcA (UDP-GlcA) to a lipid-PP-trisaccharide embedded in the membrane of the bacteria. The structure of GumK was previously described in its apo- and UDP-bound forms, with no significant conformational differences being observed. Here, we study the behavior of GumK toward its donor substrate UDP-GlcA. Turbidity measurements revealed that the interaction of GumK with UDP-GlcA produces aggregation of protein molecules under specific conditions. Moreover, limited proteolysis assays demonstrated protection of enzymatic digestion when UDP-GlcA is present, and this protection is promoted by substrate binding. Circular dichroism spectroscopy also revealed changes in the GumK tertiary structure after UDP-GlcA addition. According to the obtained emission fluorescence results, we suggest the possibility of exposure of hydrophobic residues upon UDP-GlcA binding. We present in silico-built models of GumK complexed with UDP-GlcA as well as its analogs UDP-glucose and UDP-galacturonic acid. Through molecular dynamics simulations, we also show that a relative movement between the domains appears to be specific and to be triggered by UDP-GlcA. The results presented here strongly suggest that GumK undergoes a conformational change upon donor substrate binding, likely bringing the two Rossmann fold domains closer together and triggering a change in the N-terminal domain, with consequent generation of the acceptor substrate binding site.