Role of non-chromosomal birth defects on the risk of developing childhood Hodgkin lymphoma: A Children's Oncology Group study.

BACKGROUND: Non-chromosomal birth defects are an important risk factor for several childhood cancers. However, these associations are less clear for Hodgkin lymphoma (HL). Therefore, we sought to more fully elucidate the association between non-chromosomal birth defects and HL risk. PROCEDURE: Information on cases (n = 517) diagnosed with HL (ages of 0-14) at Children's Oncology Group Institutions for the period of 1989-2003 was obtained. Control children without a history of cancer (n = 784) were identified using random digit dialing and individually matched to cases on sex, race/ethnicity, age, and geographic location. Parents completed comprehensive interviews and answered questions including whether their child had been born with a non-chromosomal birth defect. To test the association between birth defects and HL risk, conditional logistic regression was applied to generate adjusted odds ratios (aORs) and 95% confidence intervals (CIs). RESULTS: Children born with any non-chromosomal birth defect were not more likely to be diagnosed with HL at 0-14 years of age (aOR: 0.91; 95% CI: 0.69-1.21). No associations were detected between major or minor birth defects and HL (aOR: 1.34; 95% CI: 0.67-2.67 and aOR: 0.88; 95% CI: 0.57-1.34, respectively). Similarly, no association was observed for children born with any birth defect and EBV-positive HL (aOR: 0.57; 95% CI: 0.25-1.26). CONCLUSIONS: Previous assessments of HL in children with non-chromosomal birth defects have been limited. Using data from the largest case-control study of HL in those <15 years of age, we did not observe strong associations between being born with a birth defect and HL risk.

Histiocytic disorders.

The historic term 'histiocytosis' meaning 'tissue cell' is used as a unifying concept for diseases characterized by pathogenic myeloid cells that share histological features with macrophages or dendritic cells. These cells may arise from the embryonic yolk sac, fetal liver or postnatal bone marrow. Prior classification schemes align disease designation with terminal phenotype: for example, Langerhans cell histiocytosis (LCH) shares CD207+ antigen with physiological epidermal Langerhans cells. LCH, Erdheim-Chester disease (ECD), juvenile xanthogranuloma (JXG) and Rosai-Dorfman disease (RDD) are all characterized by pathological ERK activation driven by activating somatic mutations in MAPK pathway genes. The title of this Primer (Histiocytic disorders) was chosen to differentiate the above diseases from Langerhans cell sarcoma and malignant histiocytosis, which are hyperproliferative lesions typical of cancer. By comparison LCH, ECD, RDD and JXG share some features of malignant cells including activating MAPK pathway mutations, but are not hyperproliferative. 'Inflammatory myeloproliferative neoplasm' may be a more precise nomenclature. By contrast, haemophagocytic lymphohistiocytosis is associated with macrophage activation and extreme inflammation, and represents a syndrome of immune dysregulation. These diseases affect children and adults in varying proportions depending on which of the entities is involved.

International trends in incidence of osteosarcoma (1988-2012).

Osteosarcoma (OS) is the most common primary bone tumor in children and adolescents. The etiology of OS is largely unknown but may be informed by comparisons of incidence and trends between geographic regions. Using the Cancer Incidence in Five Continents (CI5) data from 1988 to 2012, we present OS age-standardized incidence rates (ASRs; cases/million) and average annual percent change (AAPC) and 95% confidence interval (CI) by geographic region among the age groups 0-9, 10-19, 20-29, 30-59, 60-79, 0-79. Among the 10-19 age group, we also used the most recent data (2008-2012) to present the ASRs for each country. We observed little variation in OS incidence between geographic regions in 2008-2012 across all age groups. Overall, the ASR for 0-79 ranged from 2 cases per million in Southern Asia to 4.2 in Sub-Saharan Africa. A bimodal distribution in incidence was observed with peaks in the 10-19 and 60-79 age groups across all regions over time. Overall, OS incidence was relatively stable across 1988-2012 with the only statistically significant increases in the 0-79 age group observed in Eastern Asia (AAPC: 1.8; 95% CI: 0.6, 1.9) and Sub-Saharan Africa (AAPC: 3.1; 95% CI: 0.5, 5.8). The small variation in incidence between regions and the stability in incidence over time suggests that OS carcinogenesis is not influenced by environmental or time-varying exposures.

Socioeconomic disparities in survival after high-risk neuroblastoma treatment with modern therapy.

BACKGROUND: Modern therapeutic advances in high-risk neuroblastoma have improved overall survival (OS), but it is unclear whether these survival gains have been equitable. This study examined the relationship between socioeconomic status (SES) and overall survival (OS) in children with high-risk neuroblastoma and whether SES-associated disparities have changed over time. PROCEDURE: In this population-based cohort study, children <18 years diagnosed with high-risk neuroblastoma (diagnosis at age ≥12 months with metastatic disease) from 1991 to 2015 were identified through the National Cancer Institute's Surveillance, Epidemiology, and End Results database. Associations of county-level SES variables and OS were tested with univariate Cox proportional hazards regression. For a subcohort diagnosed after 2007, insurance status was examined as an individual-level SES variable. Multivariable regression analyses with treatment era and interaction terms were performed when SES variables reached near-significance (p ≤ .1) in univariate and bivariate modeling with treatment era. RESULTS: Among 1217 children, 2-year OS improved from 53.0 ± 3.4% in 1991-1998 to 76.9 ± 2.9% in 2011-2015 (p < .001). In univariate analyses, children in high-poverty counties (hazard ratio [HR] = 1.74, 95% confidence interval [CI] = 1.17-2.60, p = .007), and those with Medicaid (HR = 1.40, 95% CI = 1.05-1.86, p = .02) experienced an increased hazard of death. No interactions between treatment era and SES variables were statistically significant in multivariable analyses, indicating that differences in the OS between SES groups did not change over time. CONCLUSIONS: Survival disparities among children with high-risk neuroblastoma have not widened over time, suggesting equitable access to and benefit from therapeutic advances. However, children of low SES experience persistently inferior survival. Interventions to narrow this disparity are paramount.

Handovers Among Staff Intensivists: A Study of Information Loss and Clinical Accuracy to Anticipate Events.

OBJECTIVES: Handovers are associated with medical errors, and our primary objective is to identify missed diagnosis and goals immediately after a shift handover. Our secondary objective is to assess clinicians' diagnostic accuracy in anticipating clinical events during the night shift. DESIGN: Single-center prospective observational cohort study. SETTING: Thirty-bed tertiary ICU in Sao Paulo, Brazil. PATIENTS: Three-hundred fifty-two patient encounters over 44 day-to-night handovers. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We used a multimethods approach to measure transmission of information among staff physicians on diagnoses and goals for the night shift. We surveyed clinicians immediately after a handover and identified clinical events through chart abstractions and interviews with clinicians the next morning. Nighttime clinicians correctly identified 454 of 857 diagnoses (53%; 95% CI 50-56) and 123 of 304 goals (40%; 95% CI, 35-46). Daytime clinicians were more sensitive (65% vs 46%; p < 0.01) but less specific (82% vs 91%; p < 0.01) than nighttime clinicians in anticipating clinical events at night, resulting in similar accuracy (area under the receiver operating characteristic curve, 0.74 [95% CI, 0.68-0.79] vs 0.68 [95% CI 0.63-0.74]; p = 0.09). The positive predictive value of both daytime and nighttime clinicians was low (13% vs 17%; p = 0.2). Gaps in diagnosis and anticipation of events were more pronounced in neurologic diagnoses. CONCLUSIONS: Among staff intensivists, diagnoses and goals of treatment are either not conveyed or retained 50-60% of the cases immediately after a handover. Clinicians have limited ability to anticipate events, and the expectation that anticipatory guidance can inform handovers needs to be balanced against information overload. Handovers among staff intensivists showed more gaps in the identification of diagnostic uncertainty and for neurologic diagnoses, which could benefit from communication strategies such as cognitive checklists, prioritizing discussion of neurologic patients, and brief combined clinical examination at handover.

Ethnic, Racial, and Socioeconomic Disparities in Retinoblastoma.

IMPORTANCE: Most children with retinoblastoma in the United States are diagnosed as having a large intraocular tumor burden that requires intensive ocular-salvage treatment or enucleation. OBJECTIVE: To investigate the effect of socioeconomic status, race, and ethnicity on the extent of disease and the outcomes of retinoblastoma. DESIGN, SETTING, AND PARTICIPANTS: A population-based review of 18 Surveillance, Epidemiology, and End Results (SEER) registries. From January 1, 2000, through December 31, 2010, 830 cases of retinoblastoma were recorded for children aged 0 to 9 years. Data were collected and analyzed from January 1, 2000, through December 31, 2010, with the last follow-up on December 31, 2010. EXPOSURES: County-based socioeconomic variables analyzed included poverty level, educational attainment, language isolation, crowding, unemployment, and percentage of immigrants. MAIN OUTCOMES AND MEASURES: Extent of disease, ocular outcome, and children's survival. RESULTS: Of the 830 individuals included, Hispanic children had a higher percentage of extraocular disease (86 of 261 [33.0%] vs. 102 of 510 non-Hispanic children [20.0%]; odds ratio [OR], 1.97 [95% CI, 1.38-2.79]). The percentage of extraocular cases was also higher in counties with the following low socioeconomic status indicators: higher vs. lower poverty status (115 of 413 [27.8%] vs. 73 of 358 [20.4%]; OR, 1.51; 95% CI, 1.06-2.14); lower vs. higher educational attainment (115 of 400 [28.7%] vs. 73 of 371 [19.7%]; OR, 1.65; 95% CI, 1.16-2.34); higher vs. lower levels of crowding (124 of 398 [31.2%] vs. 64 of 373 [17.2%]; OR, 2.18; 95% CI, 1.53-3.13); higher vs. lower unemployment (119 of 411 [28.9%] vs. 69 of 360 [19.2%]; OR, 1.72; 95% CI, 1.21-2.45); higher vs. lower language isolation (117 of 388 [30.2%] vs. 71 of 383 [18.5%]; OR, 1.89; 95% CI, 1.34-2.70); and higher vs. lower percentage of immigrants (109 of 386 [28.2%] vs. 79 of 385 [20.5%]; OR, 1.52; 95% CI, 1.08-2.16). Higher rates of enucleation were associated with low educational attainment (265 of 401 [66.1%] vs 309 of 421 [73.4%]; OR, 1.42; 95% CI, 1.04-1.93), a higher level of crowding (316 of 416 [76.0%] vs. 258 of 406 [63.5%]; OR, 1.81; 95% CI, 1.32-2.48), and Hispanic origin (202 of 271 [74.5%]; OR, 1.41; 95% CI, 1.01-1.98). Relative survival at 5 years was lower among black compared with non-Hispanic white children (92.7% vs. 99.2%; P < .001). CONCLUSIONS AND RELEVANCE: Significant disparities exist in the care and outcomes of children with retinoblastoma. A low socioeconomic status negatively affects disease extent and ocular outcomes, presumably by limiting access to primary and cancer-directed care. Hispanic children in particular have more advanced disease and higher rates of enucleation.

Trends in incidence of primary cutaneous malignancies in children, adolescents, and young adults: a population-based study.

BACKGROUND: Skin cancer incidence among young adults is rising; however, the epidemiological characteristics of primary cutaneous lymphomas and cutaneous soft tissue sarcomas (CSTS) in individuals <30 years old has not been investigated. We analyzed the incidence and time-trends of primary cutaneous malignancies in children and adolescents/young adults (AYA). PROCEDURE: SEER-17 and -13 data were used to assess the descriptive epidemiology and time-trends in incidence of primary cutaneous malignancies in children and AYA. SEERStat and Joinpoint softwares were utilized to estimate annual percent changes (APC) in incidence. RESULTS: In total, 7,814 cases (ASR = 25.66/1,000,000 habitants) of primary skin cancers in <30 years old were diagnosed in 2000-2008. Females had a higher incidence of melanoma (risk ratio (RR) = 1.95; P < 0.001) and a lower risk of developing CSTS (RR = 0.64, P < 0.001). Compared to whites, blacks have a lower incidence of melanoma (RR = 0.03, P < 0.001), and higher risk of CSTS (RR = 2.28, P < 0.001). Melanoma increased in females over a 15-year period (1992-2006) (APC = 2.5, 95%CI = 1.8; 3.2), and the incidence of cutaneous T-cell lymphomas increased over the period 1992-2008 (APC = 9.5, 95% CI = 6.7; 12.4). CSTS incidence decreased among males over the period 1992-1999 (APC = -21.4, 95% CI -27.2; -15.1), particularly due to a decrease in Kaposi sarcoma incidence (AAPC 1992-2008 = -13.6, 95% CI = -22.4;-3.8), although with a notable racial disparity (whites, AAPC = -15.2, 95% CI = -23.2;-6.4; blacks, AAPC = -10.6, 95% CI = -13.2;-7.9). CONCLUSIONS: Non-melanoma skin cancer is very rare in children and AYA. We have shown variation in time-trends in incidence as well as in incidence patterns by race, sex, age, and histologic type, highlighting the importance of descriptive epidemiology to better understand the characteristics of these malignancies.

Linfoma de Hodgkin clássico na infância. Experiência de tratamento e fatores prognósticos / Classical Hodgkin?s lymphoma in childhood. Therapeutic experience and prognostic factors

Objetivos: Estimar as taxas de sobrevida global e livre de eventos em portadores de linfoma de Hodgkin (LH), bem como identificar fatores prognósticos. Métodos: Estudo de coorte retrospectivo, incluindo variáveis demográficas, laboratoriais, tipo histológico, estadiamento e tratamento de 107 pacientes menores de 18 anos de idade admitidos no Departamento de Pediatria do Centro de Tratamento e Pesquisa Hospital do Câncer, no período entre 1985 e 1995. Resultados: Dos pacientes, 81 (76%) eram do sexo masculino e 80% da raça branca. A média de idade foi 10 anos (2 a 18 anos). Adenomegalia cervical foi a principal queixa referida (68% dos pacientes) e 55% apresentavam tempo de queixa menor que seis meses. Os subtipos EN e CM foram encontrados em 43% e 41% dos casos, respectivamente. Os estádios clínicos II e III foram os mais frequentes (33% cada um). Os sítios metastáticos mais frequentes nos EC IV foram fígado (42%) e pulmão (38%). As taxas de SG e SLE em 10 anos foram de 82,4% e 82,5%, respectivamente. O estádio clínico se mostrou como fator prognóstico significativo para as SG e SLE. A análise univariada revelou a presença de sintomas B, nível de Hb £ 9,3 g/dl, leucócitos £ 6.100 mm3, plaquetas £ 274.000/mm3 e ocorrência de recaída como fatores de mau prognóstico, enquanto a análise múltipla mostrou como fatores prognósticos independentes a presença de sintomas B e contagem de plaquetas. Conclusões: A identificação de fatores prognósticos é valiosa para a adequada estratificação dos pacientes em grupos de risco, adequando-os a esquemas de tratamento que maximizem as taxas de cura e minimizem os efeitos colaterais tardios.

Low prevalence of HPV in Brazilian children with retinoblastoma.

Retinoblastoma is the most frequent intra-ocular malignant tumor of the childhood, occurring in 1 of 18,000-30,000 live births. Little is known about the causes of sporadic retinoblastoma and only a few authors have investigated the etiologic role of human papillomavirus (HPV), with controversial results. Formalin-fixed, paraffin-embedded tissue blocks containing retinoblastoma were retrieved from the archives of the Department of Pathology at Hospital A C Camargo, São Paulo, Brazil. All patients were treated with enucleation (21 children had both eyes enucleated). Retinoblastoma and, when possible, normal retina of each specimen, were micro-dissected under direct light microscopic visualization by using a PixCell II Laser Capture Micro-dissection System. The DNA quality was evaluated by polymerase chain reaction (PCR) amplification of 110 base pairs fragment of the human ß-globin gene using primers PCO3+/PCO4+. All globin positive specimens were analyzed by PCR for the presence of HPV DNA using consensus primers GP5+/GP6+. A total of 154 specimens were evaluated. Forty-four patients also had normal retinal specimens available for analysis of DNA HPV. The DNA HPV prevalence among all tumor specimens was 4.6% (95% CI 2.0; 8.8) (7 positive specimens/153 adequate specimens). Among normal retinal specimens, the DNA HPV prevalence was 9.1% (95% CI 2.9; 20.5) (4 positive specimens/44 specimens). There was no statistically significant difference between these rates (P = 0.318). Excluding any experimental failure, our results indicate a low prevalence of HPV DNA in retinoblastomas. We were therefore unable to conclude about the association between these oncogenic viruses and this rare pediatric neoplasm.

ADAM23 negatively modulates alpha(v)beta(3) integrin activation during metastasis.

The ADAM23 gene is frequently silenced in different types of tumors, and, in breast tumors, silencing is correlated with tumor progression, suggesting that it might be associated with the acquisition of a metastatic phenotype. ADAM23 exerts its function mainly through the disintegrin domain, because its metalloprotease domain is inactive. Analysis of ADAM23 binding to integrins has revealed a specific interaction with alpha(v)beta(3) integrin mediated by the disintegrin domain. Altered expression of alpha(v)beta(3) integrin has been observed in different types of tumors, and expression of this integrin in the activated form has been shown to promote metastasis formation. Here, we investigated the possibility that interaction between ADAM23 and alpha(v)beta(3) integrin might negatively modulate alpha(v)beta(3) activation during metastatic progression. ADAM23 expression was knocked down using short hairpin RNA in the MDA-MB-435 cell line, which has been extensively used as a model for alpha(v)beta(3) integrin activation. Ablation of ADAM23 enhanced alpha(v)beta(3) integrin activation by at least 2- to 4-fold and ADAM23 knockdown cells showed enhanced migration and adhesion to classic alpha(v)beta(3) integrin ligands. Ablation of ADAM23 expression also enhanced pulmonary tumor cell arrest in immunodeficient mice. To complement our findings with clinical evidence, we showed that silencing of ADAM23 gene by DNA promoter hypermethylation in a collection of 94 primary breast tumors was significantly associated with lower distant metastases-free and disease-specific survivals and was an independent prognostic factor for poor disease outcome. Our results strongly support a functional role of ADAM23 during metastatic progression by negatively modulating alpha(v)beta(3) integrin activation.

Prion protein ablation increases cellular aggregation and embolization contributing to mechanisms of metastasis.

Cellular Prion Protein (PrP(C)) is a cell surface protein highly expressed in the nervous system, and to a lesser extent in other tissues. PrP(C) binds to the extracellular matrix laminin and vitronectin, to mediate cell adhesion and differentiation. Herein, we investigate how PrP(C) expression modulates the aggressiveness of transformed cells. Mesenchymal embryonic cells (MEC) from wild-type (Prnp(+/+)) and PrP(C)-null (Prnp(0/0)) mice were immortalized and transformed by co-expression of ras and myc. These cells presented similar growth rates and tumor formation in vivo. When injected in the tail vein, Prnp(0/0)ras/myc cells exhibited increased lung colonization compared with Prnp(+/+)ras/myc cells. Additionally, Prnp(0/0)ras/myc cells form more aggregates with blood components than Prnp(+/+)ras/myc cells, facilitating the arrest of Prnp(0/0)ras/myc cells in the lung vasculature. Integrin alpha(v)beta(3) is more expressed and activated in MEC and in transformed Prnp(0/0) cells than in the respective Prnp(+/+) cells. The blocking of integrin alpha(v)beta(3) by RGD peptide reduces lung colonization in transformed Prnp(0/0) cells to similar levels of those presented by transformed Prnp(+/+) cells. Our data indicate that PrP(C) negatively modulates the expression and activation of integrin alpha(v)beta(3) resulting in a more aggressive phenotype. These results indicate that PrP(C) may have main implications in modulating metastasis formation.

Cisplatin and etoposide in childhood germ cell tumor: brazilian pediatric oncology society protocol GCT-91.

PURPOSE: In 1988, we formed a consortium of Brazilian institutions to develop uniform standards for the diagnostic assessment and multidisciplinary treatment of children and adolescents with germ cell tumors. We also implemented the first childhood Brazilian germ cell tumor protocol, GCT-91, evaluating two-agent chemotherapy with cisplatin and etoposide (PE). We now report on the clinical characteristics and survival of children and adolescents with germ cell tumors treated on this protocol. PATIENTS AND METHODS: From May 1991 to April 2000, 115 patients (106 assessable patients) were enrolled onto the Brazilian protocol with a diagnosis of germ cell tumor. RESULTS: Patients were treated with surgery only (n = 35) and chemotherapy (n = 71). Important prognostic factors included stage (P = .025), surgical procedure at diagnosis according to resectability (P < .032), and abnormal lactate dehydrogenase value at diagnosis (P < .001). CONCLUSION: The improvement in survival by the introduction of a standard protocol is an important achievement. This is of particular importance for smaller institutions with previous limited experience in the treatment of childhood germ cell tumors. In addition, the results of a two-agent regimen with PE were favorable (5-year overall survival rate is 83.3% for patients in the high-risk group [n = 36] who received PE v 58.8% for patients in the high-risk patients group who received PE plus ifosfamide, vinblastine, and bleomycin [n = 17; P = .017]). Thus for selected patients, complex three-agent regimens may not be necessary to achieve long-term survival, even for some patients with advanced disease.

Interaction between polymorphisms of the human leukocyte antigen and HPV-16 variants on the risk of invasive cervical cancer.

BACKGROUND: Persistent infection with oncogenic types of human papillomavirus (HPV) is the major risk factor for invasive cervical cancer (ICC), and non-European variants of HPV-16 are associated with an increased risk of persistence and ICC. HLA class II polymorphisms are also associated with genetic susceptibility to ICC. Our aim is to verify if these associations are influenced by HPV-16 variability. METHODS: We characterized HPV-16 variants by PCR in 107 ICC cases, which were typed for HLA-DQA1, DRB1 and DQB1 genes and compared to 257 controls. We measured the magnitude of associations by logistic regression analysis. RESULTS: European (E), Asian-American (AA) and African (Af) variants were identified. Here we show that inverse association between DQB1*05 (adjusted odds ratio [OR] = 0.66; 95% confidence interval [CI]: 0.39-1.12]) and HPV-16 positive ICC in our previous report was mostly attributable to AA variant carriers (OR = 0.27; 95%CI: 0.10-0.75). We observed similar proportions of HLA DRB1*1302 carriers in E-P positive cases and controls, but interestingly, this allele was not found in AA cases (p = 0.03, Fisher exact test). A positive association with DRB1*15 was observed in both groups of women harboring either E (OR = 2.99; 95% CI: 1.13-7.86) or AA variants (OR = 2.34; 95% CI: 1.00-5.46). There was an inverse association between DRB1*04 and ICC among women with HPV-16 carrying the 350T [83L] single nucleotide polymorphism in the E6 gene (OR = 0.27; 95% CI: 0.08-0.96). An inverse association between DQB1*05 and cases carrying 350G (83V) variants was also found (OR = 0.37; 95% CI: 0.15-0.89). CONCLUSION: Our results suggest that the association between HLA polymorphism and risk of ICC might be influenced by the distribution of HPV-16 variants.

The addition of ifosfamide/etoposide to cisplatin/teniposide improves the survival of children with retinoblastoma and orbital involvement.

This study aimed to determine the impact of the addition of ifosfamide/etoposide to a regimen containing cisplatin/teniposide on the survival of patients with retinoblastoma with orbital involvement. Thirty patients were treated at the A. C. Camargo Hospital, Brazil, from 1986 to 2002. From 1986 to April 1992 (period I, n=12), treatment consisted of 3 cycles of induction chemotherapy with cisplatin and teniposide, followed by maintenance with same drugs alternating with cyclophosphamide, vincristine, and doxorubicin every 21 days for 60 weeks. Since April 1992 (period II, n=18), the treatment consisted of 3 cycles of ifosfamide and etoposide followed by maintenance with same drugs, alternating with cisplatin and teniposide every 21 days for 36 weeks. In both periods, children were submitted to exenteration with eyelid preservation and orbital radiation therapy with 45 cGy, and also received intrathecal therapy with methotrexate plus dexamethasone and cytarabine. Kaplan-Meier method was used for survival analysis. The median age was 31 months. Most patients (86.7%) presented unilateral tumors. The 3-year overall survival was 34.4% and 72.2%, respectively, for patients treated during periods I and II (P=0.061). The addition of ifosfamide/etoposide to chemotherapy with cisplatin/teniposide improves survival in these patients, but further studies are still necessary.

Trends in childhood leukemia mortality in Brazil and correlation with social inequalities.

BACKGROUND: Mortality from childhood leukemia has declined substantially in developed countries but less markedly in the developing world. This study was designed to describe mortality trends in childhood leukemia and the impact of social inequalities on these trends in Brazil from 1980 to 2002. METHODS: Cancer mortality data by cause and estimates of resident population stratified by age and sex were obtained from the Brazilian Mortality Information System (SIM) for the years 1980 to 2002. Age-standardized (ages 0-19 years) mortality rates were calculated by the direct method using the 1960 world standard population. Trends were modeled using linear regression with 3-year moving average rates as the dependent variable and with the midpoint of the calendar year interval (1991) as the independent variable. The Index of Social Exclusion was used to classify the 27 Brazilian states. Pearson correlation was used to describe the correlation between social exclusion and variations in mortality in each state. RESULTS: Age-standardized mortality rates for boys decreased from 2.05 per 100,000 habitants in 1984 to 1.44 100,000 habitants in 1995, whereas the observed corresponding decline among girls was from 1.60 per 100,000 habitants in 1986 to 1.14 per 100,000 habitants in 1995. Statistically significant declining trends in mortality rates were observed for boys (adjusted correlation coefficient [r(2)] = 0.68; P < .001) and girls (adjusted r(2) = 0.62; P < .001). Significant negative correlations between social inequality and changes in mortality were noted for boys (r = -0.66; P = .001) and for girls (r = -0.78; P < .001). CONCLUSIONS: A consistent decrease in mortality rates from childhood leukemia was noted in Brazil. Higher decreases in mortality were observed in more developed states, possibly reflecting better health care.

SATR-1 hypomethylation is a common and early event in breast cancer.

Genome stability and normal gene expression are maintained by a fixed and predetermined DNA methylation pattern, which becomes abnormal in malignant cells. Hypomethylation of satellite DNA sequences is frequently found in tumors and has been associated with an increased frequency of DNA rearrangements and chromosome instability. In this work, we used methylation-sensitive arbitrarily primed polymerase chain reaction (MSAP-PCR) to identify differentially methylated DNA fragments in normal and tumor breast samples. We identified a novel differentially methylated fragment located on chromosome 5 with high similarity to a SATR-1 satellite sequence. This fragment was found to be hypomethylated in 63% of breast tumor cell lines and in 86% of breast tumors relative to normal breast tissue. We found that normal tissue adjacent to breast tumors displayed a variable decrease in methylation and that the decrease observed for most of these adjacent samples was higher than observed for normal breast tissue derived from reduction mammoplasty. The methylation decrease was, however, significantly higher in tumor samples than in adjacent tissue (chi2= 154, 1 df, P < 10(-4)), suggesting that SATR-1 hypomethylation frequently occurs in the early stages of tumor development. Our results highlight the importance of global DNA hypomethylation as a contributing factor in breast tumorigenesis.