Early detection: the impact of genomics

The field of genomics has shifted our view on disease development by providing insights in the molecular and functional processes encoded in the genome. In the case of cancer, many alterations in the DNA accumulate that enable tumor growth or even metastatic dissemination. Identification of molecular signatures that define different stages of progression towards cancer can enable early tumor detection. In this review, the impact of genomics will be addressed using early detection of colorectal cancer (CRC) as an example. Increased understanding of the adenoma-to-carcinoma progression has led to the discovery of several diagnostic biomarkers. This combined with technical advancements, has facilitated the development of molecular tests for non-invasive early CRC detection in stool and blood samples. Even though several tests have already made it to clinical practice, sensitivity and specificity for the detection of precancerous lesions still need improvement. Besides the diagnostic qualities, also the accuracy of the intermediate endpoint is an important issue on how the effectiveness of a novel test is perceived. Here, progression biomarkers may provide a more precise measure than the currently used morphologically based features. Similar developments in biomarker use for early detection have taken place in other cancer types.

Clinical and microbiological features of maternal sepsis: a retrospective study

BACKGROUND

Identifying pregnant women with sepsis is challenging because diagnostic clinical and laboratory criteria overlap with normal pregnant physiologic indices. Our primary study aim was to describe clinical and laboratory characteristics of women diagnosed with sepsis, severe sepsis and septic shock. Our secondary aim was to determine positive predictive values for International Classification of Disease (ICD)-9 billing codes for sepsis, severe sepsis, and septic shock.

METHODS

After gaining Institutional Review Board approval, we identified women with ICD-9 codes for sepsis, severe sepsis and septic shock who were admitted to a single tertiary obstetric center from 2007-2013. Diagnoses were confirmed using criteria from the International Sepsis Definitions Conference report. Demographic, obstetric, vital signs and laboratory data were abstracted by medical chart review.

RESULTS

We identified 190 women with sepsis-related ICD-9 codes: of these, 35 (18%) women met the criteria for a clinical diagnosis of sepsis, severe sepsis or septic shock. Twenty (57%) women had a sepsis-related diagnosis after cesarean delivery. Twenty-one (60%) women had one or more pre-existing medical conditions and 19 (54%) women had one or more obstetric-related conditions. The genital tract was the most common site of infection. We observed considerable heterogeneity in maternal vital signs and laboratory indices for women with ICD-9 codes for sepsis, severe sepsis, and septic shock. The positive predictive value for each sepsis-related ICD-9 code was low: 16% (95% CI 10 to 24%) for sepsis, 10% (95% CI 3 to 25%) for severe sepsis and 24% (95% CI 10 to 46%) for septic shock.

CONCLUSION

We identified marked heterogeneity in patient characteristics, clinical features, laboratory indices and microbiological findings among cohorts of women diagnosed with maternal sepsis, severe sepsis or septic shock. Based on our findings, the incidence of maternal sepsis using ICD-9 codes may be significantly overestimated.

Checklists and multidisciplinary team performance during simulated obstetric hemorrhage

BACKGROUND

Checklists can optimize team performance during medical crises. However, there has been limited examination of checklist use during obstetric crises. In this simulation study we exposed multidisciplinary teams to checklist training to evaluate checklist use and team performance during a severe postpartum hemorrhage.

METHODS

Fourteen multidisciplinary teams participated in a postpartum hemorrhage simulation occurring after vaginal delivery. Before participating, each team received checklist training. The primary study outcome was whether each team used the checklist during the simulation. Secondary outcomes were the times taken to activate our institution-specific massive transfusion protocol and commence red blood cell transfusion, and whether a designated checklist reader was used.

RESULTS

The majority of teams (12/14 (86%)) used the checklist. Red blood cell transfusion was administered by all teams. The median [IQR] times taken to activate the massive transfusion protocol and transfuse red blood cells were 5min 14s [3:23-6:43] and 14min 40s [12:56-17:28], respectively. A designated checklist reader was used by 7/12 (58%) teams that used the checklist. Among teams that used a checklist with versus without a designated reader, we observed no differences in the times to activate the massive transfusion protocol or to commence red blood cell transfusion (P>0.05).

CONCLUSIONS

Although checklist training was effective in promoting checklist use, multidisciplinary teams varied in their scope of checklist use during a postpartum hemorrhage simulation. Future studies are required to determine whether structured checklist training can result in more standardized checklist use during a postpartum hemorrhage.

The Effect of patient warming during Caesarean delivery on maternal and neonatal outcomes: a meta-analysis

BACKGROUND

Perioperative warming is recommended for surgery under anaesthesia, however its role during Caesarean delivery remains unclear. This meta-analysis aimed to determine the efficacy of active warming on outcomes after elective Caesarean delivery.

METHODS

We searched databases for randomized controlled trials utilizing forced air warming or warmed fluid within 30 min of neuraxial anaesthesia placement. Primary outcome was maximum temperature change. Secondary outcomes included maternal (end of surgery temperature, shivering, thermal comfort, hypothermia) and neonatal (temperature, umbilical cord pH and Apgar scores) outcomes. Standardized mean difference/mean difference/risk ratio (SMD/MD/RR) and 95% confidence interval (CI) were calculated using random effects modelling (CMA, version 2, 2005).

RESULTS

13 studies met our criteria and 789 patients (416 warmed and 373 controls) were analysed for the primary outcome. Warming reduced temperature change (SMD -1.27°C [-1.86, -0.69]; P=0.00002); resulted in higher end of surgery temperatures (MD 0.43 °C [0.27, 0.59]; P<0.00001); was associated with less shivering (RR 0.58 [0.43, 0.79]; P=0.0004); improved thermal comfort (SMD 0.90 [0.36, 1.45]; P=0.001), and decreased hypothermia (RR 0.66 [0.50, 0.87]; P=0.003). Umbilical artery pH was higher in the warmed group (MD 0.02 [0, 0.05]; P=0.04). Egger's test (P=0.001) and contour-enhanced funnel plot suggest a risk of publication bias for the primary outcome of temperature change.

CONCLUSIONS

Active warming for elective Caesarean delivery decreases perioperative temperature reduction and the incidence of hypothermia and shivering. These findings suggest that forced air warming or warmed fluid should be used for elective Caesarean delivery.

Programmed intermittent epidural boluses for maintenance of labor analgesia: an impact study

INTRODUCTION

The aim of this impact study was to compare the analgesic efficacy and side effect profile of programmed intermittent epidural boluses (PIEB)+patient-controlled epidural analgesia (PCEA) to continuous epidural infusion (CEI)+PCEA for maintenance labor analgesia after the introduction of PIEB at our institution.

METHODS

We conducted a retrospective analysis after replacing the background CEI with PIEB for our labor PCEA. Pre-change pump settings were CEI 12mL/h with PCEA (12mL bolus, lockout 15min); PIEB settings were a 9mL bolus every 45min with PCEA (10mL bolus, lockout 10min). We compared medical records of all women receiving epidural or combined spinal-epidural labor analgesia for vaginal delivery for two months before PIEB implementation to a two-month period of PIEB utilization following a five-month introductory familiarization period. The primary outcome was the proportion of women requiring rescue clinician boluses.

RESULTS

Fewer patients in the PIEB group required rescue clinician boluses compared to the CEI group (12% vs. 19%, P=0.012). Time to first rescue bolus request and total bolus dose were not different. Peak (median [IQR]) pain scores were 2[0-5] with CEI and 0[0-4] with PIEB. There was no difference in instrumental delivery rates.

CONCLUSIONS

Using PIEB compared to CEI as the background maintenance epidural analgesia method in conjunction with PCEA reduced the number of women requiring clinician rescue boluses while providing comparable labor analgesia. The findings of this clinical care impact study confirm the results of randomized controlled studies and suggest PIEB may be a preferable technique to CEI for the maintenance of labor analgesia.

Prognostic value of BRAF and KRAS mutation status in stage II and III microsatellite instable colon cancers

Microsatellite instability (MSI) has been associated with favourable survival in early stage colorectal cancer (CRC) compared to microsatellite stable (MSS) CRC. The BRAF V600E mutation has been associated with worse survival in MSS CRC. This mutation occurs in 40% of MSI CRC and it is unclear whether it confers worse survival in this setting. The prognostic value of KRAS mutations in both MSS and MSI CRC remains unclear. We examined the effect of BRAF and KRAS mutations on survival in stage II and III MSI colon cancer patients. BRAF exon 15 and KRAS exon 2-3 mutation status was assessed in 143 stage II (n = 85) and III (n = 58) MSI colon cancers by high resolution melting analysis and sequencing. The relation between mutation status and cancer-specific (CSS) and overall survival (OS) was analyzed using Kaplan-Meier and Cox regression analysis. BRAF V600E mutations were observed in 51% (n = 73) and KRAS mutations in 16% of cases (n = 23). Patients with double wild-type cancers (dWT; i.e., BRAF and KRAS wild-type) had a highly favourable survival with 5-year CSS of 93% (95% CI 84-100%), while patients with cancers harbouring mutations in either BRAF or KRAS, had 5-year CSS of 76% (95% CI 67-85%). In the subgroup of stage II patients with dWT cancers no cancer-specific deaths were observed. On multivariate analysis, mutation in either BRAF or KRAS vs. dWT remained significantly prognostic. Mutations in BRAF as well as KRAS should be analyzed when considering these genes as prognostic markers in MSI colon cancers.

Magnesium sulfate exposure and neonatal intensive care unit admission at term

OBJECTIVE

The aim of this study was to investigate the effect of maternal magnesium sulfate (MgSO4) exposure for eclampsia prophylaxis on neonatal intensive care unit (NICU) admission rates for term newborns.

STUDY DESIGN

A secondary analysis of the Maternal-Fetal Medicine Unit Network Cesarean Registry, including primary and repeat cesarean deliveries, and failed and successful trials of labor after cesarean was conducted. Singleton pregnancies among women with preeclampsia and >37 weeks of gestation were included. Pregnancies with uterine rupture, chorioamnionitis and congenital malformations were excluded. Logistic regression analysis was used to determine associations between MgSO4 exposure and NICU admission. P<0.05 was considered statistically significant.

RESULT

Two thousand one hundred and sixty-six term pregnancies of women with preeclampsia were included, of whom 1747 (81%) received MgSO4 for eclampsia prophylaxis and 419 (19%) did not. NICU admission rates were higher among newborns exposed to MgSO4 vs unexposed (22% vs 12%, P<0.001). After controlling for neonatal birth weight, gestational age and maternal demographic and obstetric factors, NICU admission remained significantly associated with antenatal MgSO4 exposure (adjusted odds ratio 1.9, 95% confidence interval 1.3 to 2.6, P<0.001). Newborns exposed to MgSO4 were more likely to have Apgar scores <7 at 1 and 5 min (15% vs 11% unexposed, P=0.01 and 3% vs 0.7% unexposed, P=0.008). There were no significant differences in NICU length of stay (median 5 (range 2 to 91) vs 6 (3 to 15), P=0.5).

CONCLUSION

Antenatal maternal MgSO4 treatment was associated with increased NICU admission rates among exposed term newborns of mothers with preeclampsia. This study highlights the need for studies of maternal MgSO4 administration protocols that optimize maternal and fetal benefits and minimize risks.

Ondansetron pharmacokinetics in pregnant women and neonates: towards a new treatment for neonatal abstinence syndrome

Ondansetron is the drug of choice to prevent nausea in women undergoing cesarean surgery and can be used to prevent neonatal abstinence syndrome (NAS). The pharmacokinetics of ondansetron have not been characterized in pregnant women or in newborns. A nonlinear mixed-effects modeling approach was used to analyze plasma samples obtained from 20 nonpregnant and 40 pregnant women following a single administration of 4 or 8 mg ondansetron, from umbilical cord blood at delivery, and from neonates after birth. The analysis indicates that: ondansetron disposition is not affected by pregnancy (P > 0.05), but influenced by dose (P < 0.05), and is characterized by rapid transplacental transfer and longer elimination half-life in neonates compared to their mother. A dosing regimen for prevention of NAS was designed based on the model. The regimen involves IV administration of 4 mg to the mothers shortly before cord clamping, or oral administration of 0.07 mg/kg (or equivalently 0.04 mg/kg IV) to neonates.

Abstract 4285: Structural variant breakpoint detection in advanced colorectal cancer

Introduction

Development of colorectal cancer (CRC) is accompanied by genomic alterations that drive tumor initiation and progression. Gains and losses of large chromosome segments result in DNA copy number alterations and subsequently quantitative changes in mRNA and protein expression levels. Interestingly, the accompanying chromosome breakpoints represent structural variants (SV) that may affect gene architecture and thereby normal gene function.

Aim

The aim of this study was to identify recurrent SV breakpoints in advanced CRC.

Methods

Previously a series of 352 advanced CRC samples from CAIRO and CAIRO2 clinical studies [Koopman et al. Lancet 2007; Tol et al. N Engl J Med 2009] was characterized for genome-wide DNA copy number alterations. DNA from formalin-fixed paraffin-embedded (FFPE) tumor and patient-matched normal tissue was subjected to high-resolution array-Comparative Genomic Hybridization (Agilent 180K arrays). Using these data, we now determined the prevalence of recurrent breakpoints in genes in CRC by computational analysis. In addition, multiplexed amplicon analysis involving 48 cancer-related genes (Illumina TruSeq Amplicon Cancer Panel) was applied to determine mutation frequencies. Multi-Dendrix was used to identify modules of (mutually exclusively mutated) cancer driver genes.

Results

We identified 748 recurrent SV breakpoints in genes (FDR&lt;0.1). The highest frequency of recurrent breakpoints was detected in MACROD2, in up to ∼40% of CRC samples. Most recurrent breakpoints occurred in less than 5% of all tumors, and have not been reported before in CRC. Mutation frequencies in APC, TP53 and KRAS were conform expectations (60%, 58%, and 48%, respectively). Multi-Dendrix analysis revealed modules of cancer driver genes that included both the commonly mutated CRC cancer genes as well as genes with recurrent breakpoints, suggesting that several of the SV breakpoint genes are candidate drivers of the carcinogenic process.

Conclusions

We were able to pinpoint the prevalence of 748 recurrent SV breakpoint regions in genes using array-CGH data from 352 CRC samples. Moreover, our studies revealed several breakpoints in genes that are mutually exclusive with the commonly mutated APC, KRAS, and TP53 genes, and therefore represent novel candidate cancer driver genes. Further studies are required to investigate their functional and clinical significance.

Citation Format: E van den Broek, O Krijgsman, D Sie, JC Haan, M Komor, J Traets, DAM Heideman, MA van de Wiel, ID Nagtegaal, CJA Punt, B Carvalho, B Ylstra, GA Meijer, RJA Fijneman. Structural variant breakpoint detection in advanced colorectal cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4285. doi:10.1158/1538-7445.AM2014-4285