Frecuencia de la leucemia felina (vilef): refugio municipal Rionegro, Colombia 2020

La leucemia viral felina (ViLeF) es una enfermedad retroviral letal, de una elevada prevalencia en Colombia, que afecta a felinos de diferentes edades y sexos. El objetivo de esta investigación fue determinar la frecuencia por serodiagnóstico de ViLeF en felinos del centro integral de bienestar animal Ceiba, ubicado en Rionegro, Antioquia (Colombia), en 2020. Para ello, se realizó un estudio descriptivo longitudinal de serofrecuencia de ViLeF desde enero hasta diciembre de 2020. Fueron muestreados 92 gatos, a los cuales se les efectuó una prueba p27 por inmunoensayo comercial Elisa (Idexx©, Snap Combo Plus®, Maine, EE. UU.). La frecuencia de felinos positivos fue 30/92 (32,60%) y el mes de mayo fue el de mayor frecuencia (9,78%). Los machos positivos fueron 17/92 (18,47%) y las hembras 13/92 (14,13%). La edad promedio de seropositividad fue 2,14 años. La frecuencia de ViLeF en 2020 para Ceiba, Rionegro (Colombia) es de 32,60%, un valor elevado con respecto a descripciones en otros albergues para felinos. ViLeF es una enfermedad que está siendo reportada con mayor frecuencia en Colombia, debido a que las medidas de prevención no se están adoptando rutinariamente.

How trauma related to sex trafficking challenges parenting: Insights from Mexican and Central American survivors in the US

Sex trafficking, a form of human trafficking for the purpose of commercial sexual exploitation, with a global prevalence of 4.5 million, has pervasive effects in the mental and physical health of survivors. However, little is known about the experiences and needs of Latinx migrants (the majority of sex trafficking victims in the US) after trafficking, particularly regarding parenting. This QUAL-quant study examines how 14 survivors of sex trafficking (mean age = 30) from Mexico and Central America encounter and respond to parenting experiences after escaping sexual exploitation. Combining a bio-ecological model of parenting with Zimmerman's framework on human trafficking we identified how trauma related to sex trafficking can challenge parenting and how relational and contextual pre and post trafficking factors (dis)enable women to respond to such challenges. Psychological consequences of daily victimization primarily manifested in three ways: overprotective parenting in a world perceived to be unsafe, emotional withdraw when struggling with stress and mental health symptoms, and challenges building confidence as mothers. These experiences were accentuated by pre-trafficking experiences of neglect and abuse, forced separation from their older children, poverty post-trafficking, and migration-related stressors. Yet, finding meaning in the birth of their child, having social support, and faith, also enable mothers to cope with such challenges. We conclude that motherhood after surviving sex trafficking presents new challenges and opportunities in the path to recovery from trauma. Interventions at the policy, community and individual level are needed to support survivors of sex trafficking as they enter motherhood.

Discovery of a transcriptomic core of genes shared in 8 primary retinoblastoma with a novel detection score analysis

PURPOSE

Expression microarrays are powerful technology that allows large-scale analysis of RNA profiles in a tissue; these platforms include underexploited detection scores outputs. We developed an algorithm using the detection score, to generate a detection profile of shared elements in retinoblastoma as well as to determine its transcriptomic size and structure.

METHODS

We analyzed eight briefly cultured primary retinoblastomas with the Human transcriptome array 2.0 (HTA2.0). Transcripts and genes detection scores were determined using the Detection Above Background algorithm (DABG). We used unsupervised and supervised computational tools to analyze detected and undetected elements; WebGestalt was used to explore functions encoded by genes in relevant clusters and performed experimental validation.

RESULTS

We found a core cluster with 7,513 genes detected and shared by all samples, 4,321 genes in a cluster that was commonly absent, and 7,681 genes variably detected across the samples accounting for tumor heterogeneity. Relevant pathways identified in the core cluster relate to cell cycle, RNA transport, and DNA replication. We performed a kinome analysis of the core cluster and found 4 potential therapeutic kinase targets. Through analysis of the variably detected genes, we discovered 123 differentially expressed transcripts between bilateral and unilateral cases.

CONCLUSIONS

This novel analytical approach allowed determining the retinoblastoma transcriptomic size, a shared active transcriptomic core among the samples, potential therapeutic target kinases shared by all samples, transcripts related to inter tumor heterogeneity, and to determine transcriptomic profiles without the need of control tissues. This approach is useful to analyze other cancer or tissue types.

Protective Effects of Dietary Intake of Antioxidants and Treatment-Related Toxicity in Childhood Leukemia: A Report From the DALLT Cohort

PURPOSE

The benefits and risks of supplementation with antioxidants during cancer therapy have been a controversial area. Few studies have systematically evaluated dietary intake of antioxidants with toxicity and survival in childhood cancer. We sought to determine the role of dietary intake of antioxidants on rates of infections, mucositis, relapse, and disease-free survival during induction and postinduction phases of therapy among children and adolescents with acute lymphoblastic leukemia (ALL).

PATIENTS AND METHODS

We enrolled 794 children in a prospective clinical trial for treatment of ALL. Dietary intake was prospectively evaluated by a food frequency questionnaire. The association between dietary intake of antioxidants and treatment-related toxicities and survival were evaluated with the Benjamini-Hochberg false discovery rate (q) and logistic regression and the Kaplan-Meier method, respectively.

RESULTS

Dietary surveys were available for analysis from 614 (77%), and 561 (71%) participants at diagnosis and at end of induction, respectively. Of 513 participants who completed the dietary surveys at both time points, 120 (23%) and 87 (16%) experienced a bacterial infection and 22 (4%) and 55 (10%) experienced mucositis during the induction or postinduction phases of treatment, respectively. Increased intake of dietary antioxidants was associated with significantly lower rates of infection and mucositis. No association with relapse or disease-free survival was observed. Supplementation was not associated with toxicity, relapse, or survival.

CONCLUSION

Consumption of antioxidants through dietary intake was associated with reduced rates of infection or mucositis, with no increased risk of relapse or reduced survival. Dietary counseling on a well-balanced diet that includes an array of antioxidants from food sources alone may confer a benefit from infections and mucositis during treatment of childhood ALL.

Circulating miRNome detection analysis reveals 537 miRNAS in plasma, 625 in extracellular vesicles and a discriminant plasma signature of 19 miRNAs in children with retinoblastoma from which 14 are also detected in corresponding primary tumors

miRNAs regulate post-transcriptional gene expression in metazoans, and thus are involved in many fundamental cellular biological processes. Extracellular miRNAs are also found in most human biofluids including plasma. These circulating miRNAs constitute a long distance inter cellular communication system and are potentially useful biomarkers. High throughput technologies like microarrays are able to scan a complete miRNome providing useful detection scores that are underexplored. We proposed to answer how many and which miRNAs are detectable in plasma or extracellular vesicles as these questions have not yet been answered. We set out to address this knowledge gap by analyzing the mirRNome in plasma and corresponding extracellular vesicles (EVs) from 12 children affected by retinoblastoma (Rb) a childhood intraocular malignant tumor, as well as from 12 healthy similarly aged controls. We calculated an average of 537 detectable miRNAs in plasma and 625 in EVs. The most miRNA enriched compartment were EVs from Rb cases with an average of 656 detectable elements. Using hierarchical clustering with the detection scores, we generated broad detection mirnome maps and identified a plasma signature of 19 miRNAs present in all Rb cases that is able to discriminate cases from controls. An additional 9 miRNAs were detected in all the samples; within this group, miRNA-5787 and miRNA-6732-5p were highly abundant and displayed very low variance across all the samples, suggesting both are good candidates to serve as plasma references or normalizers. Further exploration considering participant’s sex, allowed discovering 5 miRNAs which corresponded only to females and 4 miRNAs corresponding only to males. Target and pathway analysis of these miRNAs revealed hormonal function including estrogen, thyroid signaling pathways and testosterone biosynthesis. This approach allows a comprehensive unbiased survey of a circulating miRNome landscape, creating the possibility to define normality in mirnomic profiles, and to locate where in these miRNome profiles promising and potentially useful circulating miRNA signatures can be found.

Abstract 5143: Transcriptomic analysis of primary retinoblastoma with affymetrix HTA2 chip using a detection score reveals a central core of mRNA shared by all the samples

Introduction: Retinoblastoma (Rb) is an intraocular malignant tumour of early childhood, considered the most robust clinical model of genetic predisposition to develop cancer. Previous transcriptomic studies in Rb are based on differential analysis of expression data, ignoring the detection scores that can be obtained from high throughput technologies. The detection score allows to obtain profiles of present/absent mRNAs across samples without the need of a control sample. In this study, 8 primary cultured tumors and Rb cell line Y79 were analyzed using the detection scores, with the aim to discover what is similar and what is different among them in terms of mRNA detection.

Methodology: Tumors were obtained from enucleated eyes of Rb patients treated at Hospital de Pediatría, CMN SXXI, Instituto Mexicano Del Seguro Social (IMSS) and Hospital Infantil de México Federico Gómez, Secretaría de Salud in Mexico City. Tumor tissues were cultured for a week and total RNA extracted. We used Affymetrix Human Transcriptome Array 2.0 able to detect many isoforms. Pre-processing included normalization with RMA (Average Robust Multiarray) and DABG (Detection Above Background) to calculate the detection score for each exon as present or absent. We carried out subsequent analysis to determine the detection score of each transcript and each gene in two corresponding datasets. For each of these detection datasets, hierarchical clustering (HC) was performed producing two color detection maps for present and absent elements.

Results: We obtained detection scores for 21,986 genes and 59,629 annotated transcripts (isoforms). In the detection map of genes obtained with HC, we discovered a central core of 3,391 mRNAs cluster shared by all the samples, while in the detection map of transcripts we discovered a 12,799 mRNAs cluster shared by all the samples. Absent mRNAs cluster were also shared across the samples with 9,005 in the genes and 18,651 in the transcripts detection maps. Notably, variability accounted for a cluster of 9,590 and 28,179 across the genes and transcripts detection maps, respectively. Furthermore, we determined the Rb transcriptomic size by counting the mRNAs in each sample and calculating the average across the datasets with 8,238 and 28,396 mRNA detected, 13,747 and 31,232 not detected corresponding to gene or transcript detection maps. When Y79 was introduced in the datasets, these numbers change considerably, and the corresponding detection maps show mRNA clusters specific for the cell line, but not present in the primary tissues.

Conclusion: Rb samples shared a central mRNA cluster of detected elements and a cluster of not detected elements, despite tumor heterogeneity. This systems level analysis brings a coherent and easy way for biological interpretation of high throughput data.

Note: This abstract was not presented at the meeting.

Citation Format: Diana E. Alvarez Suarez, Hugo Tovar, Enrique Hernández, Manuela Orjuela, Lourdes Cabrera, Claudia Hernández, Daphne García, Adriana Hernández, Verónica Ponce. Transcriptomic analysis of primary retinoblastoma with affymetrix HTA2 chip using a detection score reveals a central core of mRNA shared by all the samples [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 5143.

Fluctuations in dietary intake during treatment for childhood leukemia: A report from the DALLT cohort

BACKGROUND

Acute lymphoblastic leukemia (ALL) is the most common pediatric malignancy. Nutritional morbidities are a persistent problem facing pediatric patients during and after treatment and age-gender groups that are at risk for nutritional conditions have not been clearly identified. Therapy is a contributing factor; however, the role of dietary intake remains largely unknown. Prior to conduct of interventional trials, an understanding of the effects of treatment on fluctuations in dietary intake is necessary.

METHODS

We enrolled 794 children with ALL in a prospective clinical trial. Dietary intake was collected with a food frequency questionnaire at diagnosis and throughout the course of treatment for pediatric ALL. Reported values were compared to the Dietary Recommended Intake (DRI), and normative values (NHANES). Hierarchical linear models and multilevel mixed-effects ordered logistic regression models were used to evaluate longitudinal changes in dietary intake; independent samples t-test with Bonferroni correction was performed to compare to NHANES.

RESULTS

Of the evaluable participants at each timepoint, dietary intake was obtained on 81% (n = 640), 74% (n = 580) and 74% (n = 558) at diagnosis, end of induction phase of treatment, and continuation, respectively. Despite exposure to corticosteroids, caloric intake decreased over therapy for most age-gender groups. Predictive models of excess intake found reduced odds of over-consuming calories (OR 0.738, P < 0.05); however, increased odds of over-consuming fat (OR 6.971, P < 0.001). When compared to NHANES, we consistently found that ≥1/3 of children were consuming calories in excess of normative values. For select micronutrients, a small proportion of participants were above or below the DRI at each time evaluated.

CONCLUSIONS

Our study suggests that dietary intake fluctuates during treatment for ALL as compared to age-gender recommended and normative values. Improving our understanding of nutrient fluctuations and dietary quality will facilitate subsequent analyses addressing relationships of dietary intake, toxicity, and survival.

miRNome landscape analysis reveals a 30 miRNA core in retinoblastoma

Background

miRNAs exert their effect through a negative regulatory mechanism silencing expression upon hybridizing to their target mRNA, and have a prominent position in the control of many cellular processes including carcinogenesis. Previous miRNA studies on retinoblastoma (Rb) have been limited to specific miRNAs reported in other tumors or to medium density arrays. Here we report expression analysis of the whole miRNome on 12 retinoblastoma tumor samples using a high throughput microarray platform including 2578 mature miRNAs.

Methods

Twelve retinoblastoma tumor samples were analyzed using an Affymetrix platform including 2578 mature miRNAs. We applied RMA analysis to normalize raw data, obtained categorical data from detection call values, and also used signal intensity derived expression data. We used Diana-Tools-microT-CDS to find miRNA targets and ChromDraw to map miRNAs in chromosomes.

Results

We discovered a core-cluster of 30 miRNAs that were highly expressed in all the cases and a cluster of 993 miRNAs that were uniformly absent in all cases. Another 1022 miRNA were variably present in the samples reflecting heterogeneity between tumors. We explored mRNA targets, pathways and biological processes affected by some of these miRNAs. We propose that the core-cluster of 30 miRs represent miRNA machinery common to all Rb, and affecting most pathways considered hallmarks of cancer. In this core, we identified miR-3613 as a potential and critical down regulatory hub, because it is highly expressed in all the samples and its potential mRNA targets include at least 36 tumor suppressor genes, including RB1. In the variably expressed miRNA, 36 were differentially expressed between males and females. Some of the potential pathways targeted by these 36 miRNAs were associated with hormonal production.

Conclusion

These findings indicate that Rb tumor samples share a common miRNA expression profile regardless of tumor heterogeneity, and shed light on potential novel therapeutic targets such as mir-3613 This is the first work to delineate the miRNA landscape in retinoblastoma tumor samples using an unbiased approach.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3421-3) contains supplementary material, which is available to authorized users.

Illumina next generation sequencing data and expression microarrays data from retinoblastoma and medulloblastoma tissues

Retinoblastoma (Rb) is a pediatric intraocular malignancy and probably the most robust clinical model on which genetic predisposition to develop cancer has been demonstrated. Since deletions in chromosome 13 have been described in this tumor, we performed next generation sequencing to test whether recurrent losses could be detected in low coverage data. We used Illumina platform for 13 tumor tissue samples: two pools of 4 retinoblastoma cases each and one pool of 5 medulloblastoma cases (raw data can be found at http://www.ebi.ac.uk/ena/data/view/PRJEB6630).

We first created an in silico reference profile generated from a human sequenced genome (GRCh37p5). From this data we calculated an integrity score to get an overview of gains and losses in all chromosomes; we next analyzed each chromosome in windows of 40 kb length, calculating for each window the log₂ ratio between reads from tumor pool and in silico reference. Finally we generated panoramic maps with all the windows whether lost or gained along each chromosome associated to its cytogenetic bands to facilitate interpretation. Expression microarrays was done for the same samples and a list of over and under expressed genes is presented here. For this detection a significance analysis was done and a log₂ fold change was chosen as significant (raw data can be found at http://www.ncbi.nlm.nih.gov/geo/accession number GSE11488). The complete research article can be found at Cancer Genetics journal (Garcia-Chequer et al., in press) [1]. In summary here we provide an overview with visual graphics of gains and losses chromosome by chromosome in retinoblastoma and medulloblastoma, also the integrity score analysis and a list of genes with relevant expression associated. This material can be useful to researchers that may want to explore gains and losses in other malignant tumors with this approach or compare their data with retinoblastoma.

Abstract A26: Analysis of ABCB1, ABCC1 and ABCG2 expression and clinical parameters in 40 primary retinoblastoma cases

Multidrug resistance (MDR) is one of the most important mechanisms involved in chemotherapy failure in cancer. ABC transporters constitute a superfamily of pumps that efflux metabolites, xenobiotics and drugs outside the cell. In many types of malignant tumors some of these transporters are overexpressed causing MDR and consequently tumor progression. ABCB1, ABCC1 and ABCG2 are the ABC transporters whose overexpressions are most frequently involved in chemotherapy failure. Eventhough expression of these transporters has been well studied in many types of adult tumors, expression of ABC transporters and correlation with clinical features have been scarcely reported in retinoblastoma, and intraocular malignant tumor occurring in early infancy. Therefore our objective in this work was to determine ABCB1, ABCC1 and ABCG2 expression by qPCR in untreated primary retinoblastoma cases and to explore whether or not correlations with relevant clinical features do exist. Our results on RNA from 40 retinoblastoma cases naive to chemotherapy treatment, show high mRNA expression of ABCC1 followed by ABCB1 and marginal expression of ABCG2, these results are consistent with immunohistochemistry results from others. ABCC1 was found significantly more expressed in bilateral than unilateral cases.

Citation Format: Blanca Elena Castro, Eunice Aguilar, Lourdes Cabrera, Javier Camacho, Adriana Hernandez, Guillermo Ramón, Stanislaw Sadowinski, Manuela Orjuela, Veronica Ponce. Analysis of ABCB1, ABCC1 and ABCG2 expression and clinical parameters in 40 primary retinoblastoma cases. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Drug Sensitivity and Resistance: Improving Cancer Therapy; Jun 18-21, 2014; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(4 Suppl): Abstract nr A26.

Blood lead levels in Mexico and pediatric burden of disease implications

BACKGROUND

Although there has been success in reducing lead exposure with the phase-out of leaded gasoline, exposure to lead in Mexico continues to threaten the health of millions, much of which is from lead-based glazes used in pottery that leaches into food.

OBJECTIVES

An extensive historical review and analysis of available data on blood lead levels in Mexican populations was conducted. We used a calculated geometric mean to evaluate the effect of lead on the pediatric burden of disease.

METHODS

An extensive bibliographic search identified 83 published articles from 1978 to 2010 with blood lead level (BLL) data in Mexican populations representing 150 data points from more than 50,000 study participants. Values from these publications were categorized into various groupings. We then calculated the incidence of disease and disability-adjusted life-years resulting from these BLLs using the World Health Organization's burden of disease spreadsheets for mild mental retardation.

RESULTS

Reviewing all relevant studies, the geometric means of Mexican BLLs in urban and rural areas were found to be 8.85 and 22.24 ug/dL, respectively. Since the phase-out of leaded gasoline, the mean in urban areas was found to be 5.36 ug/dL and the average in rural areas is expected to be much higher. The U.S. Centers for Disease Control and Prevention's (CDC) upper limit of blood lead in children under the age of 6 years is 5 ug/dL and the current U.S. average is 1.2 ug/dL. Our results indicate that more than 15% of the population will experience a decrement of more than 5 IQ points from lead exposure. The analysis also leads us to believe that lead is responsible for 820,000 disability-adjusted life-years for lead-induced mild mental retardation for children aged 0 to 4 years.

CONCLUSION

Lead continues to threaten the health of millions and remains a significant cause of disability in Mexico. Additional interventions in reducing or managing lead-based ceramic glazes are necessary to protect the public health.

Intensive multimodality therapy for patients with stage 4a metastatic retinoblastoma

BACKGROUND

We previously reported promising pilot results treating patients with stage 4a metastatic retinoblastoma with combined intensive conventional chemotherapy, high-dose chemotherapy with autologous hematopoietic stem cell rescue, and radiation therapy and now present an expanded and updated series.

PROCEDURE

Fifteen patients with bone marrow (n = 14), bone (n = 10), orbit (n = 9), and/or liver (n = 4) disease were treated. Induction chemotherapy usually consisted of vincristine, cyclophosphamide, cisplatin, and etoposide. The high-dose chemotherapy regimen included carboplatin and thiotepa alone (n = 1) or with etoposide (n = 5) or topotecan (n = 7).

RESULTS

Bone marrow cleared at first post-initiation of chemotherapy examination in all patients and stem cells were harvested after a median of 3.5 cycles of chemotherapy (range 3-6 cycles). Two patients progressed prior to high-dose chemotherapy and died. Thirteen received high-dose chemotherapy at a median of 6 months post-diagnosis of metastases (range 4-8 months). Ten are retinoblastoma-free in first remission at a median follow-up of 103 months (range 34-202 months) while three recurred (two in the CNS, one in the mandible) 14-20 months post-diagnosis of metastases. Retinoblastoma-free and event-free survival at 5 years are 67% (95% confidence interval 38-85%) and 59% (95% confidence interval 31-79%). Six of the 10 survivors received radiation therapy. Three patients developed secondary osteosarcoma 14, 4, and 9 years after diagnosis of metastatic disease.

CONCLUSIONS

Intensive multimodality therapy including high-dose chemotherapy with autologous hematopoietic stem cell rescue was curative for the majority of patients with stage 4a metastatic retinoblastoma treated. The contribution of external beam radiation therapy is unclear.

Trilateral retinoblastoma: potentially curable with intensive chemotherapy

BACKGROUND

Trilateral retinoblastoma has been lethal in virtually all cases previously reported. We describe a series of 13 patients treated with intensive chemotherapy, defined as the intention to include high-dose chemotherapy with autologous hematopoietic stem cell rescue.

PROCEDURE

Induction chemotherapy generally included vincristine, cisplatin or carboplatin, cyclophosphamide, and etoposide. Hematopoietic stem cells typically were harvested after the first or second cycle of induction chemotherapy, usually from peripheral blood. High-dose chemotherapy regimens were thiotepa-based (n = 7) or melphalan and cyclophosphamide (n = 3).

RESULTS

Trilateral sites were pineal (n = 11) and suprasellar (n = 2); 7 patients had localized (M-0) disease and six had leptomeningeal dissemination (M-1+). Five patients had trilateral retinoblastoma at original diagnosis of intra-ocular retinoblastoma; eight later developed trilateral disease at a median of 35 months (range 3-60 months) following diagnosis of intra-ocular retinoblastoma. One patient died of toxicity (septicemia and multi-organ system failure) during induction and three developed disease progression prior to high-dose chemotherapy. Nine patients received high-dose chemotherapy at a median of 5 months (range 4-9) post-diagnosis of trilateral disease. Five patients survive event-free at a median of 77 months (range 36-104 months) and never received external beam radiation therapy. Four of seven patients with M-0 disease survive event-free versus only one of six patients with M-1+ disease.

CONCLUSIONS

Intensive chemotherapy is potentially curative for some patients with trilateral retinoblastoma, especially those with M-0 disease.

Preliminary studies on the effect of moderate physical activity on blood levels of glutathione

Molecular epidemiological approaches are being used to study how physical activity may protect against cancer. Prior epidemiological data suggest that physical activity protects against lung cancer; however, interpretation of these data is complicated by potential confounding by smoking. Glutathione (GSH) detoxifies cigarette smoke carcinogens and the paper tests whether physical activity levels are associated with blood GSH levels. Study subjects were enrolled in a chemoprevention trial testing whether antioxidant micronutrient supplementation reduces genetic damage from cigarette smoking. Physical activity data were collected by questionnaire from 178 subjects at 12 months of follow-up in the trial. Total GSH (tGSH), which is the sum of free and protein-bound GSH and glutathione disulfide levels, was measured using the 5,5'-dithiobis-(2-nitrobenzenoic acid) colormetric assay with red blood cell samples collected at the 12-month time point. In multivariate linear regression analyses that controlled for gender and cigarettes smoked per day, tGSH was positively associated with hours per week of moderate intensity activity (beta=0.005, p=0.02). Hours per week of vigorous intensity activity were unassociated with tGSH and the effect of moderate activity remained after control for vigorous activity. The results are consistent with prior research showing differential effects of moderate and vigorous activity and suggest a mechanism through which physical activity may influence lung cancer risk.

World disparities in risk definition and management of retinoblastoma: a report from the International Retinoblastoma Staging Working Group

Following from the publication of the International Retinoblastoma Staging System, an open internet discussion group was created at the www.cure4kids.org resource. The results of a survey distributed among participants are discussed. Although most patients with retinoblastoma were treated under prospective protocols, there was a wide variation in the definition of risk criteria and in the criteria for giving adjuvant chemotherapy following enucleation. Definition of high-risk histological features and the criteria for use of adjuvant therapy will be standardized in future studies. Internet meetings are a valuable mechanism for enabling participation from under-resourced countries in the development of cooperative studies.

Traditional physical activity indexes derived from the Harvard alumni activity survey have low construct validity in a lower income, urban population

The purpose of this study is to investigate the construct validity of the Harvard Alumni Activity Survey (HAAS) in an urban, lower income population. Data were collected from 192 smokers enrolled in an antioxidant micronutrient trial. Activity data were compared to body mass index (BMI), diastolic, and systolic blood pressure. The traditional physical activity index (PAI), using data on stair climbing, walking, and sports, was calculated including and excluding body mass. A new scale, the total weekly activity (TWA) scale, was derived from other questions on the HAAS. The PAI scale calculated with body mass was unassociated with BMI and blood pressure. The PAI scale calculated without body mass was unassociated with BMI and systolic blood pressure but was associated with diastolic blood pressure (Beta = -0.001, p = 0.03). The TWA scale was associated with BMI (Beta = -0.01, p = 0.01), diastolic (Beta = -0.03, p = 0.01), and systolic blood pressure (Beta = -0.04, p = 0.01). A one standard deviation change in the TWA scale is predicted to be equivalent to a change of 0.99 BMI units, 2.97 mmHg of diastolic blood pressure, and 3.96 mmHg of systolic blood pressure. This work suggests that the TWA scale has greater construct validity than the traditional PAI scale in this population.

The association between benzo[a]pyrene-DNA adducts and body mass index, calorie intake and physical activity

Prior work suggests that body size and fat content may influence carcinogen-DNA adduct levels measured in white blood cells. Here we consider energy balance more broadly by assessing the impact of body mass index (BMI), physical activity and calorie intake on the presence of benzo[a]pyrene-DNA (BP-DNA) adducts in white blood cell DNA. Our cross-sectional study employed subjects from a separately conducted intervention trial. Physical activity and food intake data were collected at 12 and 15 months of follow-up, respectively. BP-DNA adducts were measured by high-performance liquid chromatography (HPLC) in white blood cell samples collected at 12 months of follow-up. Complete data on all variables were available from 143 subjects. Logistic regression showed that BMI was inversely associated with the presence of detectable adducts (OR = 0.90, p = 0.02), and that hours of moderate-intensity physical activity were positively associated with the presence of detectable adducts (OR = 1.04, p = 0.04). These results provide further evidence that body fat content influences carcinogen-DNA adduct levels, probably by altering the distribution of the lipophilic parent compound.

Association of CD20 positivity (+) with event free survival (EFS) in children with post-transplant lymphoproliferative disease (PTLD) following solid organ transplantation (SOT)

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Background: The roles of CD20 and EBV as prognostic features for development and survival of pediatric PTLD after SOT are poorly understood. We previously demonstrated the safety and efficacy of cyclophosphamide, prednisone and rituximab (CPR) in CD20+ PTLD (Orjuela/Cairo, CCR 2005) Methods: All patients (pts), =25 yrs with PTLD in the past 15 yrs were analyzed and classified according to presence of detectable EBV or CD20 by IHC or ISH. Overall survival (OS) and EFS were estimated using Kaplan-Meier, significance was assessed by t-test comparison and Mantel-Cox. Results: 41 SOT pts (28 heart, 8 liver, 4 kidney) had PTLD (53.6% female) at a median of 38.8 months (mo) post SOT (4–43); Age 14–263 mo. Of 35 evaluable tumors, 29 (82.9%) had detectable EBV, while 22 (62.9%) expressed CD20 antigen. All pts had immunosuppression reduced, followed by chemo- and immunotherapy as needed. In pts with =9 mo follow-up after PTLD (n = 38) (median 49 mo, 10–184) OS is 73.2% and PTLD related EFS is 63%. Pts with EBV+ tumors had a shorter time to onset than those with EBV- tumors (median 18 vs 44 mo, p = 0.002). Pts with CD20+ PTLD were diagnosed earlier than those with CD20- PTLD (median 19 vs 62 mo, p= 0.006). PTLD-related 5 yr EFS showed significantly increased survival for CD20+ over CD20- pts (90 ± 6.5% vs 25 ± 11.2%, respectively [95% CI], p = 0.001). EBV status did not have a significant effect on OS (p=0.7) or EFS (p=0.7). Conclusions: CD20 and EBV are important predictors of time to PTLD development and presence of CD20 predicts for significantly improved EFS for SOT PTLD. CD20- PTLD pts appear to have lower EFS suggesting a need for alternative treatment strategies.

No significant financial relationships to disclose.

Androgen and c-Kit receptors in desmoplastic small round cell tumors resistant to chemotherapy: novel targets for therapy

PURPOSE

Desmoplastic small round cell tumor (DSRCT) is a highly fatal, mainly peritoneal cell origin cancer which predominantly affects young adult males. This predilection in young males led us to examine the role of androgen receptors (AR), testosterone, and growth factors in the biology of DSRCT.

METHODS

Slides were prepared from 27 multi-institutional patients all with end-stage DSRCT. Slides were stained for AR, c-Kit, various growth factors, and drug resistance-associated proteins. Immunohistochemical (IHC) expression was scored semi-quantitatively. Western blot and MTT studies were performed to validate the IHC findings of over-expression of the AR and its functional status by stimulation of growth by dihydrotestosterone, respectively. Six patients with positive AR status were treated solely with combined androgen blockade (CAB) as used for prostate cancer.

RESULTS

Twenty-two patients were male (81%) and five were female (19%) with a median age at diagnosis of 23. All patients had failed at least two prior multi-agent chemotherapy regimens and 44% had progressed after autologous stem cell transplant. DSRCT samples from 10 of 27 patients were >or=2+ IHC positive for AR (37%,P=0.0045) and 7 of 20 patients were >or=2+ IHC positive for c-Kit (35%, P=0.018). We found elevated IHC expression of GST-pi, MRP and thymidylate synthase in smaller subsets of patients. In vitro studies for AR by Western blot and stimulation of growth by dihydrotestosterone in MTT assays suggest that the AR in DSRCT cells is functional. Six patients with positive AR status were treated with CAB alone and three of six attained clinical benefit (1-PR, 1-MR, 1-SD) in a range of 3-4 months. The three patients who responded to CAB had normal testosterone levels before CAB, while the three who did not respond to CAB had baseline castrate levels of testosterone.

CONCLUSIONS

DSRCT has significant IHC expression of AR and c-Kit in heavily pre-treated patients. The presence of significant AR expression in 37% suggests that these patients could possibly respond to CAB. The significance of c-Kit expression in 35% of DSRCT patients is unknown and warrants further investigation.

A pilot study of chemoimmunotherapy (cyclophosphamide, prednisone, and rituximab) in patients with post-transplant lymphoproliferative disorder following solid organ transplantation

PURPOSE

We have previously demonstrated a >80% complete response (CR) rate with cyclophosphamide/prednisone (Cy/Pred) chemotherapy alone in patients with post-transplant lymphoproliferative disease (PTLD) after solid organ transplantation (SOT), but only a 58% 2-year event-free survival. The response rate to immunotherapy (rituximab) is only about 46% with a 54% relapse/progression rate. In this study, we investigated the use of a combination of Cy/Pred with rituximab as treatment for this disease.

EXPERIMENTAL DESIGN

Patients received two to six courses of cyclophosphamide (600 mg/m(2), on day 1 of each course) and prednisone (1 mg/kg, every 12 h x 10 doses), given every 3 weeks. The first two courses were given in combination with 4-6 weekly doses of rituximab (375 mg/m(2), i.v.). Imaging studies were done every 2 months to document response.

RESULTS

There were six PTLD patients (two fulminant); age, 4-23 year; sex, male:female (3:3); status post SOT (two cardiac, two liver, two renal); median onset, 39 months (10-144 months). Fifty percent were polyclonal, 100% were CD20+, and 83% were EBV+. The overall response rate was 100% (five CRs and one PR). All five CRs showed no evidence of disease, and one PR eventually progressed and died of fulminant disease. All allografts in surviving patients were functional. There was no grade III/IV toxicity and/or no infectious complications related to the combination of Cy/Pred with rituximab. Median follow-up was 12.5 months (range, 4-29 months).

CONCLUSIONS

These preliminary results suggest that the combination of Cy/Pred and targeted immunotherapy (rituximab) is well tolerated and may be more efficacious in patients with PTLD after SOT. Future prospective larger trials with longer follow-up investigating this combination will be required to confirm these preliminary results.

Alterations of cell cycle regulators affecting the RB pathway in nonfamilial retinoblastoma

We undertook the present study to examine alterations affecting the RB pathway in the G1 checkpoint and to determine their potential clinical significance in children affected with nonfamilial retinoblastoma. Using immunohistochemistry, patterns of expression of pRB, p16/INK4A, and E2F1 were analyzed in tissue from a cohort of 86 well-characterized patients with nonfamilial retinoblastoma diagnosed at the "Instituto Nacional de Pediatria" in Mexico City. The relationship of these phenotypes to proliferative index was assessed by analysis of Ki67 antigen expression. pRB expression was found in 11 (13%) cases. Using a hypophosphorylated specific pRB antibody, we observed low levels of underphosphorylated pRB expression in only 1 of 9 evaluable positive cases. These data suggest that the detected pRB products were hyperphosphorylated and thus had decreased functional activity. Increased p16 nuclear expression was found in only 6 tumors. No tumors showed deletions or mobility shifts of the INK4A gene. Undetectable pRB levels were significantly associated with undetectable p16 expression (odds ratio, 10.8; 95% confidence interval, 1.4-81.3; P =.03). All tumors showed nuclear immunoreactivities for E2F1 and Ki67. Increased Ki67 proliferative index was associated with increased staining for E2F1 (r =.44; P =.008) and increasing clinical stage (P =.03). Among children with unilateral disease, the mean Ki67 proliferative index was significantly higher in children with advanced clinical disease (stages 3 and 4) (mean 81.25; SD 6.78) than in those with earlier stage disease (mean 69.50; SD 9.45) (P = 0.001). Among children with bilateral disease, however, the mean proliferative index was not significantly higher for children with advanced clinical stage. When examining all cases together, there was a significant trend toward increasing proliferative index with increasing clinical stage (P =.03). In unilateral tumors, we also found that presence of detectable pRB was associated with a lower percentage of cells expressing E2F1 (46.7% v 70.8%) (P = 0.05), whereas there was no association between presence of pRB and E2F1 among bilateral tumors. We have found that expression of some of the cell cycle markers examined varies according to laterality, suggesting underlying differences in the capacity for cell cycle regulation between these 2 forms of the disease. Differences in capacities for cell cycle regulation may account for some differences in clinical behavior. Thus, the inclusion of molecular markers may become useful adjuncts to clinicopathological staging and subsequent determination of therapy.

Presence of human papilloma virus in tumor tissue from children with retinoblastoma: an alternative mechanism for tumor development

Epidemiological studies have shown that the use of barrier methods of contraception is associated with a decreased incidence of papilloma virus infection and reduced risk of having a child with retinoblastoma. Thirty-nine primary retinoblastomas were analyzed for the presence of papilloma virus sequences. Tumor tissue sections were also used to assess the expression of the retinoblastoma protein and proliferative index. Papilloma sequences were detected in 14 of 39 (36%) tumors. Tumors in which viral sequences were detected were associated with a lower proliferative index (68% versus 78%; P = 0.015). Children with tumors containing viral sequences had a lower risk of extraocular disease (odds ratio, 9.0; 95% confidence interval, 1.6-49; P = 0.008) and a lower birth weight (2.9 versus 3.5 kg; P = 0.030). Based on these data, it is our hypothesis that papilloma viruses may play a role in the development of sporadic retinoblastoma. Detection of papilloma virus sequences and retinoblastoma protein in certain primary lesions suggests an alternative mechanism of tumor development for sporadic retinoblastoma.