Micrometer-scale structure in shark vertebral centra

The vertebral centra of sharks consist of cartilage, and many species' centra contain a bioapatite related to that in bone. Centra microarchitectures at the 0.5-50 µm scale do not appear to have been described previously. This study examines centrum microarchitecture in lamniform and carcharhiniform sharks with synchrotron microComputed Tomography (microCT), scanning electron microscopy and spectroscopy and light microscopy. The analysis centers on the blue shark (carcharhiniform) and shortfin mako (lamniform), species studied with all three modalities. Synchrotron microCT results from seven other species complete the report. The main centrum structures, the corpus calcareum and intermedialia, consist of fine, closely-spaced, mineralized trabeculae whose mean thicknesses and spacings range from 4.5 to 11.2 µm and 4.5 to 15.6 µm, respectively. A significant (p = 0.00001) positive linear relationship between and exists for multiple positions within one mako centrum. Carcharhiniform species' and exhibit an inverse linear relationship (p = 0.005) while in lamniforms these variables tend toward a positive relationship which does not reach statistical significance (p = 0.099). In all species, the trabeculae form an uninterrupted, interconnected network, and the unmineralized volumes are similarly interconnected. Small differences in mineralization level are observed in trabeculae. Centrum growth band pairs are found to consist of locally higher /lower mineral volume fraction. Within the intermedialia, radial canals and radial microrods were characterized, and compacted trabeculae are prominent in the mako intermedialia. The centra's mineralized central zones were non-trabecular and are also described. STATEMENT OF SIGNIFICANCE: This study's novel result is the demonstration that the mineralized cartilage of sharks' vertebral bodies (centra) consists of a fine 3D array of interconnected plates (trabeculae) and an interpenetrating network of unmineralized tissue. This microstructure is radically different from that in tesserae or in teeth, the other main mineralized shark tissues. Using volumetric synchrotron microComputed Tomography, numerical values of mean trabecular thickness and spacing and their relationship were measured for nine species. Scanning electron microscopy added a higher resolution view of the microstructures, and histology provided complementary information on cartilage and cells. The present results suggest centra microstructure helps accommodate the very large in vivo strains and may prevent damage accumulation during millions of cycles of swimming-induced loading.

Low Dose Radiotherapy in the Management of COVID-19 Pneumonia (LOWRAD-Cov19): Final Results

Purpose/Objective(s)

To evaluate the results of LD-RT to lungs in the management of patients with COVID-19 pneumonia.

Materials/Methods

We conducted a prospective phase I-II trial enrolling COVID-19 patients ≥50 years-old, with bilateral lung involvement at imaging study and oxygen requirement. Patients received 1 Gy to whole lungs in a single fraction. Primary outcome was radiological response assessed as severity and extension scores at days +3 and +7. Secondary outcomes were toxicity (CTCAE v5.0), days of hospitalization, changes in inflammatory blood parameters (ferritin, lymphocytes, C-reactive protein, d-dimer and LDH) and SatO2/ FiO2 index (SAFI), at day +3 and +7. Descriptive analyses were summarized as means with standard deviation (SD) and/or medians with interquartile ranges (IQR). A Wilcoxon sign rank test for paired data was used to assess the CT scores and Chi Square was used to assess for comparison of categorical variables.

Results

Forty-one patients were included. Median age was 71 (IQR 60-84). Eighteen patients (47%) previously received any antiCOVID treatment (tocilizumab, lopinavir/ritonavir, remdesivir) and thirty-two patients (84%) received steroids during LD-RT. Extension score improved significantly (p=0.02) on day +7 and SAFI on day +3 and + 7 (p<0.01). Median SAFI on day 0 was 147 (IQR 118-264), 230 (IQR 120-343) on day +3 and 293 (IQR 121-353) on day +7. Significant decrease was found in C-reactive protein on day +7 (p=0.02) and in lymphocytes counts on day +3 and +7 (p=0.02). Median number of days in hospital after RT was 11 (range 4-78). With a median follow-up of 60 days after LD-RT, 26 (63%) patients were discharged, 11 (27%) died because of COVID respiratory failure and 4 (10%) died of other causes.

Conclusion

LD-RT is a feasible and well-tolerated treatment that may lead to rapid clinical improvement. Large randomized trials should be done to establish the efficacy of LD-RT to treat COVID-19 pneumonia.

Suicide as a public health concern: Confronting the means, motives, and opportunity

Issue

Suicide continues to present a major public health concern in many societies. Suicide prevention efforts have failed to reduce the rate of suicide in most countries. A change of intervention strategy can help to prevent these deaths from despair.

Description of the problem

Suicide prevention strategies are examined through an integrative review combined with more than 30 years of experience conducting research on suicide attempters and psychological autopsy research on adults who had died by suicide. Journal articles published since 2005 were reviewed for strategies designed to prevent death by suicide.

Results

Suicide risk is examined by confronting the means, motives and opportunities for suicidal behavior. Prevention strategies that limit access to lethal means can have a beneficial impact if the method is easily accessible and not easily replaced. Unfortunately, some individuals merely shift to a different method for their suicidal act. Prevention strategies that restrict the opportunity for self-injury provide time to confront underlying disorders and initiate treatment. Unfortunately, many patients do not continue treatment beyond the acute crisis, and there is often a resurgence of suicidal behavior after discharge from the hospital. Prevention strategies that aim to confront the person’s motivation to die may reduce the underlying cause. It is important to provide interventions to help reduce the desperation and isolation that underlie suicidal urges. These intervention strategies hold potential for making lasting changes that could eliminate, instead of temporarily suppressing, the desire to die.

Lessons

Restricting access to lethal methods and limiting times when a suicidal person is left alone can temporarily block suicidal urges. However, the motive underlying the suicidal urges remains intact. The motivation to die can be addressed through interventions that focuses on helping clients to build a life worth living.

Key messages

• Suicide prevention strategies can confront the desire for death by helping to build a life that is worth living.

• Comprehensive interventions aimed at reducing depression, isolation and addiction hold potential for reducing the rate of suicide.

Evolution and Epidemic Spread of SARS-CoV-2 in Colombia: A Year into the Pandemic

Current efforts to understand the epidemiology, transmission dynamics and emergence of novel SARS-CoV-2 variants worldwide has enabled the scientific community to generate critical information aimed at implementing disease surveillance and control measures, as well as to reduce the social, economic and health impact of the pandemic. Herein, we applied an epidemic model coupled with genomic analysis to assess the SARS-CoV-2 transmission dynamics in Colombia. This epidemic model allowed to identify the geographical distribution, Rt dynamics and predict the course of the pandemic considering current implementation of countermeasures. The analysis of the incidence rate per 100,000 inhabitants carried out across different regions of Colombia allowed visualizing the changes in the geographic distribution of cases. The cumulative incidence during the timeframe March 2020 to March 2021 revealed that Bogotá (8063.0), Quindío (5482.71), Amazonas (5055.68), Antioquia (4922.35) and Tolima (4724.41) were the departments with the highest incidence rate. The highest median Rt during the first period evaluated was 2.13 and 1.09 in the second period; with this model, we identified improving opportunities in health decision making related to controlling the pandemic, diagnostic testing capacity, case registration and reporting, among others. Genomic analysis revealed 52 circulating SARS-CoV-2 lineages in Colombia detected from 774 genomes sequenced throughout the first year of the pandemic. The genomes grouped into four main clusters and exhibited 19 polymorphisms. Our results provide essential information on the spread of the pandemic countrywide despite implementation of early containment measures. In addition, we aim to provide deeper phylogenetic insights to better understand the evolution of SARS-CoV-2 in light of the latent emergence of novel variants and how these may potentially influence transmissibility and infectivity.

SARS-CoV-2 in Transit: Characterization of SARS-CoV-2 Genomes From Venezuelan Migrants in Colombia

OBJECTIVES

To evaluate the genomic epidemiology of SARS-CoV-2 from Venezuelan migrants living in Colombia.

METHODS

This study sequenced SARS-CoV-2 from 30 clinical specimens collected from Venezuelan migrants. Genomes were compared with the Wuhan reference genome to identify polymorphisms, reconstruct phylogenetic relationships and perform comparative genomic analyses. Geographic, sociodemographic and clinical data were also studied across genotypes.

RESULTS

This study demonstrated the presence of six distinct SARS-CoV-2 lineages circulating among Venezuelan migrants, as well as a close relationship between SARS-CoV-2 genomic sequences obtained from individuals living in the Venezuelan-Colombian border regions of La Guajira (Colombia) and Zulia (Venezuela). Three clusters (C-1, C-2 and C-3) were well supported by phylogenomic inference, supporting the hypothesis of three potential transmission routes across the Colombian-Venezuelan border. These genomes included point mutations previously associated with increased infectivity. A mutation (L18F) in the N-terminal domain of the spike protein that has been associated with compromised binding of neutralizing antibodies was found in 2 of 30 (6.6%) genomes. A statistically significant association was identified with symptomatology for cluster C2.

CONCLUSION

The close phylogenetic relationships between SARS-CoV-2 genomes from Venezuelan migrants and from people living at the Venezuela-Colombian border support the importance of human movements for the spread of COVID-19 and for emerging virus variants.

Population health management in France: specifying population groups through the DRG system

Background

Population health management (PHM) by hospital groups is not yet defined nor implemented in France. However, in 2019, the French Hospitals Federation launched a pilot program to experiment PHM in five territories around five Territorial Hospital Groups (GHT’s). In order to implement PHM, it is necessary to firstly define the population which healthcare facilities (hospitals) have responsibility for. In the French healthcare system, mapping of health territories however relies mainly on administrative data criteria which do not fit with the actual implementation of GHT’s. Mapping for the creation of territorial hospital groups (GHTs) also did not include medical criteria nor all healthcare offers particularly in private hospitals and primary care services, who are not legally part of GHT’s but are major healthcare providers. The objective of this study was to define the French population groups for PHM per hospital group.

Methods

A database study based on DRG (acute care, post-acute and rehabilitation, psychiatry and home care) from the French National Hospitals Database was conducted. Data included all hospital stays from 1 January 2016 to 31 December 2017. The main outcome of this study was to create mutually exclusive territories that would reflect an accurate national healthcare service consumption. A six-step method was implemented using automated analysis reviewed manually by national experts.

Results

In total, 2840 healthcare facilities, 5571 geographical zones and 31,441,506 hospital stays were identified and collated from the database. In total, 132 GHTs were included and there were 72 zones (1.3%) allocated to a different GHTs. Furthermore, 200 zones were manually reviewed with 33 zones allocated to another GHT. Only one area did not have a population superior to 50,000 inhabitants. Three were shown to have a population superior to 2 million.

Conclusions

Our study demonstrated a feasible methodology to define the French population under the responsibility of 132 hospital groups validated by a national group of experts.

Evaluation of the diagnostic performance of nine commercial RT-PCR kits for the detection of SARS-CoV-2 in Colombia

The ongoing severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) pandemic has led to the design and development of multiple reverse‐transcription polymerase chain reaction kits aimed to facilitate the rapid scale‐up of molecular testing for massive screening. We evaluated the diagnostic performance of nine commercial kits, which showed optimal performance and high discriminatory power. However, we observed differences in terms of sensitivity, specificity, and E gene Ct Values and discuss these results in light of the influence of SARS‐CoV‐2 genetic variability and its potential impact in current molecular diagnostic assays.

Translating the Symptom Screening in Pediatrics Tool (SSPedi) into Argentinian Spanish for paediatric patients receiving cancer treatments, and evaluating understandability and cultural relevance in a multiple-phase descriptive study

OBJECTIVES

To translate a symptom screening tool developed for paediatric patients receiving cancer therapies called Symptom Screening in Pediatrics Tool (SSPedi) into Argentinian Spanish and to evaluate the understandability and cultural relevance of the translated version of SSPedi among children with cancer and paediatric haematopoietic stem cell transplant (HSCT) recipients.

METHODS

We conducted a multiphase, descriptive study to translate SSPedi into Argentinian Spanish. Using two translators, forward and backward translations were performed. The translated version was evaluated by Spanish-speaking paediatric patients 8-18 years of age receiving cancer treatments in two centres in Argentina and El Salvador.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was patient self-reported difficulty with understanding of the SSPedi instructions and each symptom using a 5-point Likert scale. Secondary outcomes were incorrect understanding of the SSPedi instructions, symptoms and response scale determined by cognitive interviews with the patients and rated using a 4-point Likert scale. Cultural relevance was assessed qualitatively.

RESULTS

There were 30 children enrolled and included in cognitive interviews; 16 lived in Argentina and 14 lived in El Salvador. The most common types of Spanish spoken were Central American (17, 57%) followed by South American (10, 33%) and Castilian (3, 10%). No changes to Argentinian Spanish SSPedi were required based on the outcomes or qualitative comments. No issues with cultural relevance were identified by any of the respondents.

CONCLUSIONS

We translated and finalised Argentinian Spanish SSPedi. Future research will focus on its use to describe bothersome symptoms by Argentinian Spanish-speaking children.

Deciphering the introduction and transmission of SARS-CoV-2 in the Colombian Amazon Basin

BACKGROUND

The SARS-CoV-2 pandemic has forced health authorities across the world to take important decisions to curtail its spread. Genomic epidemiology has emerged as a valuable tool to understand introductions and spread of the virus in a specific geographic location.

METHODOLOGY/PRINCIPAL FINDINGS

Here, we report the sequences of 59 SARS-CoV-2 samples from inhabitants of the Colombian Amazonas department. The viral genomes were distributed in two robust clusters within the distinct GISAID clades GH and G. Spatial-temporal analyses revealed two independent introductions of SARS-CoV-2 in the region, one around April 1, 2020 associated with a local transmission, and one around April 2, 2020 associated with other South American genomes (Uruguay and Brazil). We also identified ten lineages circulating in the Amazonas department including the P.1 variant of concern (VOC).

CONCLUSIONS/SIGNIFICANCE

This study represents the first genomic epidemiology investigation of SARS-CoV-2 in one of the territories with the highest report of indigenous communities of the country. Such findings are essential to decipher viral transmission, inform on global spread and to direct implementation of infection prevention and control measures for these vulnerable populations, especially, due to the recent circulation of one of the variants of concern (P.1) associated with major transmissibility and possible reinfections.

Translating the Symptom Screening in Paediatrics Tool (SSPedi) into North American Spanish and Among Spanish-speaking children receiving cancer treatments: evaluating understandability and cultural relevance in a multiple-phase descriptive study

OBJECTIVES

Symptom screening is important to achieving symptom control. Symptom Screening in Paediatrics Tool (SSPedi) is validated for English-speaking children. Objectives were to translate SSPedi into Spanish, and to evaluate the understandability and cultural relevance of the translated version among Spanish-speaking children with cancer and paediatric haematopoietic stem cell transplant recipients.

METHODS

We conducted a multiphase, descriptive study to translate SSPedi into Spanish. The first step was to determine whether one Spanish version would be appropriate for both North America and Argentina. Once this decision was made, forward and backward translations were performed. The translated version was evaluated by Spanish-speaking children 8-18 years of age receiving cancer treatments.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome was child self-reported difficulty with understanding of the entire instrument and each symptom using a 5-point Likert scale. Secondary outcomes were incorrect understanding of SSPedi items identified by cognitive interviews with the children using a 4-point Likert scale and cultural relevance, which was assessed qualitatively.

RESULTS

This report focuses on North American Spanish as a separate version will be required for Argentinian Spanish SSPedi based on different common vocabulary and grammatical structure. There were 20 children from Toronto and San Antonio included in cognitive interviews. The most common types of Spanish spoken were Mexican (13, 65%), Central American (2, 10%) and South American (2, 10%). No child reported that it was hard or very hard to complete Spanish SSPedi. Changes to the instrument itself were not required based on understanding or cultural relevance.

CONCLUSIONS

We translated and finalised Spanish SSPedi appropriate for use in North America. Future research will translate and evaluate SSPedi for use in Argentina and other Spanish-speaking countries.

SARS-CoV-2 spread across the Colombian-Venezuelan border

INTRODUCTION

Venezuela and Colombia both adopted measures of containment early in response to the COVID-19 pandemic. However, Venezuela's ongoing humanitarian crisis has decimated its health care system, and forced millions of Venezuelans to flee through its porous border with Colombia. The extensive shared border, and illegal cross-border transit through improvised trails between the two countries are major challenges for public health authorities. We report the first SARS-CoV-2 genomes from Venezuela, and present a snapshot of the SARS-CoV-2 epidemiologic landscape in the Colombian-Venezuelan border region.

METHODS

We sequenced and assembled viral genomes from total RNA extracted from nasopharyngeal (NP) clinical specimens using a custom reference-based analysis pipeline. Three assemblies obtained were subjected to typing using the Phylogenetic Assignment of Named Global Outbreak LINeages 'Pangolin' tool. A total of 376 publicly available SARS-CoV-2 genomes from South America were obtained from the GISAID database to perform comparative genomic analyses. Additionally, the Wuhan-1 strain was used as reference.

RESULTS

We found that two of the SARS-CoV-2 genomes from Venezuela belonged to the B1 lineage, and the third to the B.1.13 lineage. We observed a point mutation in the Spike protein gene (D614G substitution), previously reported to be associated with increased infectivity, in all three Venezuelan genomes. Additionally, three mutations (R203K/G204R substitution) were present in the nucleocapsid (N) gene of one Venezuelan genome.

CONCLUSIONS

Genomic sequencing demonstrates similarity between SARS-CoV-2 lineages from Venezuela and viruses collected from patients in bordering areas in Colombia and from Brazil, consistent with cross-border transit despite administrative measures including lockdowns. The presence of mutations associated with increased infectivity in the 3 Venezuelan genomes we report and Colombian SARS-CoV-2 genomes from neighboring borders areas may pose additional challenges for control of SARS-CoV-2 spread in the complex epidemiological landscape in Latin American countries. Public health authorities should carefully follow the progress of the pandemic and its impact on displaced populations within the region.

The arrival and spread of SARS-CoV-2 in Colombia

We performed phylogenomic analysis of severe acute respiratory syndrome coronavirus‐2 from 88 infected individuals across different regions of Colombia. Eleven different lineages were detected, suggesting multiple introduction events. Pangolin lineages B.1 and B.1.5 were the most frequent, with B.1 being associated with prior travel to high‐risk areas.

This is the first genomic epidemiology study of SARS‐CoV2 in Colombia.

Genetic Diversity Among SARS-CoV2 Strains in South America may Impact Performance of Molecular Detection

Since its emergence in Wuhan (China) on December 2019, the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has rapidly spread worldwide. After its arrival in South America in February 2020, the virus has expanded throughout the region, infecting over 900,000 individuals with approximately 41,000 reported deaths to date. In response to the rapidly growing number of cases, a number of different primer-probe sets have been developed. However, despite being highly specific, most of these primer-probe sets are known to exhibit variable sensitivity. Currently, there are more than 300 SARS-CoV2 whole genome sequences deposited in databases from Brazil, Chile, Ecuador, Colombia, Uruguay, Peru, and Argentina. To test how regional viral diversity may impact oligo binding sites and affect test performance, we reviewed all available primer-probe sets targeting the E, N, and RdRp genes against available South American SARS-CoV-2 genomes checking for nucleotide variations in annealing sites. Results from this in silico analysis showed no nucleotide variations on the E-gene target region, in contrast to the N and RdRp genes which showed massive nucleotide variations within oligo binding sites. In lines with previous data, our results suggest that the E-gene stands as the most conserved and reliable target when considering single-gene target testing for molecular diagnosis of SARS-CoV-2 in South America.

High coherence collapse of a hybrid III–V/Si semiconductor laser with a large quality factor

The high-speed dynamics of a hybrid distributed feedback semiconductor laser heterogeneously integrated onto silicon is experimentally investigated in the presence of external optical feedback. The laser fabrication relies on a proper modal engineering in which light is generated in the III–V material and stored in the low-loss silicon region in order to substantially enhance the quality factor of the cavity resonator. In this work, the hybrid laser is found to be insensitive to parasitic reflections leading to a 10 Gbps floor-free transmission with a power penalty no greater than 1.5 dB at room temperature. As a conclusion, owing to the large quality factor, a high coherence collapse level is unveiled in such laser indicating its vast potential to serve as an alternative solution for the development of isolator-free applications in future photonics integrated circuits. A qualitative interpretation is also provided by linking the standard feedback equations to the quality factor of the resonator.

Antlers - Evolution, development, structure, composition, and biomechanics of an outstanding type of bone

Antlers are bony appendages of deer that undergo periodic regeneration from the top of permanent outgrowths (the pedicles) of the frontal bones. Of the "less familiar" bone types whose study was advocated by John Currey to gain a better understanding of structure-function relationships of mineralized tissues and organs, antlers were of special interest to him. The present review summarizes our current knowledge about the evolution, development, structure, mineralization, and biomechanics of antlers and how their formation is affected by environmental factors like nutrition. Furthermore, the potential role of antlers as a model in bone biology and several fields of biomedicine as well as their use as a monitoring tool in environmental studies are discussed.

P6276Impact of the cardiac specific deletion of AMPKalpha2 on the contractile and metabolic phenotype of the heart in male and female mice

Introduction

Mitochondrial dysfunction plays a major role in the Heart Failure (HF) pathophysiology.The AMP activated protein kinase (AMPK) is activated by a high AMP-ADP/ATP ratio and regulates a number of metabolic pathways. Many studies have highlighted a protective role of AMPK in HF, but its relevance to cardiac tissue, its metabolic part and its sex specificity are not well established.

Purpose

Then, the aim of this study is to determine the role of AMPK in the healthy and failing heart in male and female mice.

Methods

We developed and validated a mouse strain with an adult-inducible cardiac-specific deletion of AMPKα2, the major cardiac isoform, using the Cre-Lox system (40mg/kg tamoxifen injection on two consecutive days at adult age). At four months after the deletion, cardiac contractility, morphology and metabolism were studied in control and KO mice from both sexes.

Results

We observed only in male KO mice a decrease of left ventricular ejection fraction (−10%), an increase of the total fibrosis (+64%) and defects in mitochondrial structures. Male KO mice also showed a reduced (−28%) mitochondrial respiration via complex I associated with a different cardiolipin species distribution.

Conclusion

Our results reveal in adult healthy hearts, a sex-specificity in the effects of AMPKα2 deletion, leading to impaired contractile function related to metabolic and non-metabolic alterations only in male mice.

P3510Cardiac function and Ca2+-cycling are different according to the level of cardiac-specific FKBP12.6 overexpression

Cardiac ryanodine receptors (RyR2) have a key role in excitation-contraction coupling by releasing Ca2+ from sarcoplasmic reticulum (SR). In cardiomyocytes, two FK506 binding protein (FKBP) isoforms have been shown to bind and to stabilize RyR2 opening: FKBP12 and FKBP12.6, the later having a stronger affinity for RyR2 despite its lower abundance. Cardiac-specific FKBP12.6 overexpressing mice have fewer arrhythmias induced by β-adrenergic stimulation than wild type (WT) mice, suggesting an implication of FKBP12.6 in an antiarrhythmic mechanism. Heart failure (HF) syndrome has a high incidence of arrhythmias, which may be explained by a decrease of FKBP isoform expression.

The precise mechanism of the antiarrhythmic effect of FKBP12.6 overexpression remains unknown.

To gain insight into this mechanism, we developed 2 transgenic mouse lines with cardiac-specific moderate- (TG1) and high- (TG2) FKBP12.6 overexpression levels. We characterized cardiac function, [Ca2+]i cycling and its response to β-adrenergic stimulation in both mouse lines.

TG1 and TG2 mice developed mild and marked cardiac hypertrophy, respectively, associated with basal cardiac function increase in TG1 mice only. In stimulated cardiomyocytes, [Ca2+]i transient amplitude, measured by confocal microscopy, was higher in TG1 than in WT mice, without a significant difference in their SR Ca2+ content. The effect of β-adrenergic stimulation (50 nM isoproterenol) was attenuated in TG1 mice compared to WT mice, in association with the prevention of pro-arrhythmogenic Ca2+ release events, such as Ca2+ waves. In contrast, TG2 mice showed [Ca2+]i handling characteristics similar to HF, with slower [Ca2+]i transient relaxation. Interestingly, and contrary to HF, pro-arrhythmogenic Ca2+ release events were also reduced in TG2.

These results indicate that the level of FKBP12.6 overexpression has distinct effects on cardiac function and on Ca2+-cycling and its response to β-adrenergic stimulation.

Early bacterial and fungal infection in children receiving allogeneic stem cell transplantation for acute lymphoblastic leukemia in Argentina

Infections are important complications associated with allogeneic HSCT. Describing infection rates in low- and middle-income countries provides data to infer efficacy of supportive care practices in these settings. In this retrospective cohort study, we included patients (age ≤ 18 years) who underwent a first allogeneic HSCT for ALL in a single center in Argentina between 1998 and 2016. The primary outcome was sterile site bacterial infection. Secondary outcomes were proven or probable invasive fungal infection, TRM, and infectious deaths. There were 68 allogeneic HSCT recipients with ALL included in this analysis. Overall, 17 (25.0%) experienced at least one sterile site bacterial infection and 10 (14.7%) experienced at least one proven or probable invasive fungal infection. The TRM rate was 19.1%, and 3 (4.4%) patients died of infection. In a middle-income country center in Argentina, pediatric allogeneic HSCT infection rates, TRM, and infection-related mortality were comparable to high-income countries. These data support continuation of allogeneic HSCT programs in similar resource-limited settings provided that adequate supportive care and monitoring of outcomes can be performed.

Abstract PD8-02: Tumor subtype and survival differences between Hispanic and non-Hispanic white breast cancer patients in the California cancer registry

Background: Prior studies show that Hispanic breast cancer patients are more likely than non-Hispanic white (NHW) women to be diagnosed with triple negative tumors but data on other subtypes are limited. Published data on survival differences between Hispanics and NHW breast cancer patients are inconsistent and vary depending on the covariates included in the multivariate models. We assessed differences in the distribution of the major tumor subtypes of breast cancer, as well as subtype-specific survival, between Hispanic and NHW patients according to nativity, and age and stage at diagnosis.

Methods: We used data from the population-based California Cancer Registry to include female invasive breast cancer cases diagnosed between 2004 and 2013 with follow-up through December 31, 2013, resulting in 90,236 total cases (69,693 NHW and 20,543 Hispanics). Tumor subtypes were classified into four categories: hormone receptor positive and HER2 negative (HR+/HER-), HR+/HER2+, HR-/HER2+, and triple negative (HR-/HER2-). Logistic regression was used to estimate differences in distribution of subtype between Hispanic and NHW women. Cox proportional hazard models were used to estimate differences in survival for Hispanics and NHWs by subtype, adjusting for clinical and sociodemographic characteristics.

Results: Compared to NHW patients, Hispanic women were more likely to be diagnosed with tumors that were HR+/HER2+ (OR=1.22; 95% CI, 1.16-1.29), HR-/HER2+ (OR=1.37; 95% CI, 1.29-1.47), and triple negative (OR=1.27; 95% CI, 1.21-1.34) than HR+/HER2-. Foreign-born Hispanics had a higher odds of having HER2+ than HR+/HER2- tumors compared to NHW women (OR=1.29 for HR+/HER2+ and OR=1.50 for HR-/HER2+); these differences were less pronounced among U.S.-born Hispanics (OR=1.04 for HR+/HER2+ and OR=1.16; 95% CI, 1.06-1.26 for HR-/HER2+). In age-adjusted models, Hispanic women had higher breast cancer mortality than NHW women (HR=1.23; 95% CI, 1.17-1.30), which was consistent across all tumor subtypes. However, the mortality differences disappeared after adjustment for clinical, sociodemographic characteristics, and marital status.

Conclusions: Hispanic women were more likely than NHWs to be diagnosed with triple negative breast cancer as well as tumors overexpressing HER2 than HR+/HER2- tumors. This pattern held true when stratified by nativity, although higher ORs for HER2+ tumors among foreign-born than U.S.-born Hispanic women were observed. Within each subtype, Hispanics had 20%-30% higher mortality than NHW, which appeared to be explained by a combination of sociodemographic and clinical factors.

Citation Format: Martinez ME, Cress R, Gomez S, Rodriguez D, Cook LS, Schwab R, Nodora JN, Porter P, Li C. Tumor subtype and survival differences between Hispanic and non-Hispanic white breast cancer patients in the California cancer registry [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr PD8-02.

Survival of high-risk pediatric neuroblastoma patients in a developing country

Little information is available about survival of high-risk pediatric neuroblastoma patients in developing countries. We aimed to assess survival among high-risk pediatric neuroblastoma patients in La Plata, Argentina. Individuals eligible for our cohort were aged <20 yr when diagnosed with high-risk neuroblastoma and received cancer-directed therapy including stem cell transplantation at Hospital de Niños Sor Maria Ludovica between February 1999 and February 2015. We estimated overall survival probabilities using an extended Kaplan-Meier approach. Our study population comprised 39 high-risk neuroblastoma patients, of whom 39% were aged >4 yr at diagnosis, 54% were male, and 62% had adrenal neuroblastoma. We observed 18 deaths, and the median survival time of our study population was 1.7 yr. The five-yr overall survival probability was 24% (95% CL: 10%, 41%). In contrast, five-yr survival of high-risk neuroblastoma patients ranges between 23% and 76% in developed countries. Survival among high-risk neuroblastoma patients is generally poor regardless of geographic location, but our results illustrate dramatically worse survival for patients in a developing country. We speculate that the observed survival differences could be attenuated or eliminated with improvements in treatment and supportive care, but addressing these issues will require creative solutions because of resource limitations.

Incidence and case-fatality of varicella-zoster virus infection among pediatric cancer patients in developing countries

Limited evidence is available about varicella-zoster virus (VZV) infection among pediatric cancer patients in developing countries, which raises questions about the generalizability of VZV vaccine recommendations for pediatric cancer patients (derived from developed countries) to these settings. We assessed the incidence and case-fatality of VZV infection at three institutions in developing countries (Argentina, Mexico, and Nicaragua). Individuals eligible for our study were aged <20 years and actively receiving cancer-directed therapy. We estimated a summary incidence rate (IR) and case-fatality risk with corresponding 95 % confidence limits (CL) of VZV infection across sites using random-effects models. Our study population comprised 511 pediatric cancer patients, of whom 64 % were aged <10 years, 58 % were male, and 58 % were diagnosed with leukemia. We observed a total of 10 infections during 44,401 person-days of follow-up across the 3 sites (IR = 2.3, 95 % CL 1.2, 4.2). The summary case-fatality risk was 10 % (95 % CL 1.4, 47 %) based on one death.

CONCLUSION

Our results suggest low incidence and case-fatality of VZV infections among pediatric cancer patients in three developing countries. VZV vaccine recommendations for pediatric cancer patients in developed countries may be generalizable to developing countries.

WHAT IS KNOWN

• Current recommendations, based on evidence from pediatric cancer patients in developed countries, contraindicate varicella-zoster virus (VZV) vaccination until completion of cancer-directed therapy and recovery of immune function. • The generalizability of these VZV vaccine recommendations to pediatric cancer patients in developing countries is unknown because of limited information about the incidence and case-fatality of VZV in these settings. What is New: • Our results suggest low incidence and case-fatality of VZV infections among pediatric cancer patients in three developing countries. • VZV vaccine recommendations based on evidence from pediatric cancer patients in developed countries may be generalizable to pediatric cancer patients in developing countries.