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Biomedical subjects

Julie A Ross

Publications and source records attributed to Julie A Ross.

At least 19 recordsLinked to original sources

Genetic susceptibility and body mass in childhood cancer survivors.

Childhood cancer survivors are at increased risk of many long-term treatment-related sequel such as second cancers, cardiovascular disease, and pulmonary complications. Certain treatments seem to influence the risk of becoming overweight, obese, or underweight, and abnormal body mass index (BMI) is associated with increased morbidity and mortality. Because BMI is modifiable, it is important to identify treatment and patient-related factors contributing to altered BMI. New research areas include exploring how genetic susceptibility through population polymorphism may contribute to BMI. Illuminating potential gene-environment interactions that influence obesity and underweight might be more readily accomplished in a study of high-risk individuals (i.e., childhood cancer survivors) with well-characterized exposures. The new Childhood Cancer Research Network in the Children's Oncology Group, when fully implemented, should make it less difficult in the future to recruit the large numbers of patients needed for such studies.

Adult↗

Birth characteristics, maternal reproductive history, and the risk of infant leukemia: a report from the Children's Oncology Group.

Leukemias with MLL gene rearrangements predominate in infants (<1 year of age), but not in older children, and may have a distinct etiology. High birth weight, higher birth order, and prior fetal loss have, with varying consistency, been associated with infant leukemia, but no studies have reported results with respect to MLL status. Here, we report for the first time such an analysis. During 1999 to 2003, mothers of 240 incident cases (113 MLL(+), 80 MLL(-), and 47 indeterminate) and 255 random digit dialed controls completed a telephone interview. Odds ratios and 95% confidence intervals for quartile of birth weight, birth order, gestational age, maternal age at delivery, prior fetal loss, pre-pregnancy body mass index, and weight gain during pregnancy were obtained using unconditional logistic regression; P for linear trend was obtained by modeling continuous variables. There was a borderline significant linear trend of increasing birth weight with MLL(+) (P = 0.06), but not MLL(-) (P = 0.93), infant leukemia. Increasing birth order showed a significant inverse linear trend, independent of birth weight, with MLL(+) (P = 0.01), but not MLL(-) (P = 0.18), infant leukemia. Other variables of interest were not notably associated with infant leukemia regardless of MLL status. This investigation further supports the contention that molecularly defined subtypes of infant leukemia have separate etiologies.

Adult↗

Intake of the major carotenoids and the risk of epithelial ovarian cancer in a pooled analysis of 10 cohort studies.

Carotenoids, found in fruits and vegetables, have the potential to protect against cancer because of their properties, including their functions as precursors to vitamin A and as antioxidants. We examined the associations between intakes of alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein/zeaxanthin and lycopene and the risk of invasive epithelial ovarian cancer. The primary data from 10 prospective cohort studies in North America and Europe were analyzed and then pooled. Carotenoid intakes were estimated from a validated food frequency questionnaire administered at baseline in each study. Study-specific relative risks (RR) were estimated using the Cox proportional hazards model and then combined using a random-effects model. Among 521,911 women, 2,012 cases of ovarian cancer occurred during a follow-up of 7-22 years across studies. The major carotenoids were not significantly associated with the risk of ovarian cancer. The pooled multivariate RRs (95% confidence intervals) were 1.00 (0.95-1.05) for a 600 microg/day increase in alpha-carotene intake, 0.96 (0.93-1.03) for a 2,500 microg/day increase in beta-carotene intake, 0.99 (0.97-1.02) for a 100 microg/day increase in beta-cryptoxanthin intake, 0.98 (0.94-1.03) for a 2,500 microg/day increase in lutein/zeaxanthin intake and 1.01 (0.97-1.05) for a 4,000 microg/day increase in lycopene intake. These associations did not appreciably differ by study (p-values, tests for between-studies heterogeneity >0.17). Also, the observed associations did not vary substantially by subgroups of the population or by histological type of ovarian cancer. These results suggest that consumption of the major carotenoids during adulthood does not play a major role in the incidence of ovarian cancer.

Breast Neoplasms↗

Exposure to medical test irradiation and acute leukemia among children with Down syndrome: a report from the Children's Oncology Group.

OBJECTIVE: The etiology of acute childhood leukemia is not well understood, particularly among children with Down syndrome, in whom a 10- to 20-fold increased risk of leukemogenesis has been reported compared with children without Down syndrome. We explored the association between medical test irradiation, a postulated leukemogenic agent, and acute leukemia among children with Down syndrome. PATIENTS AND METHODS: Children with Down syndrome (controls) were frequency matched on age to children with Down syndrome and leukemia (cases) diagnosed at ages 0 to 19 years during the period 1997-2002 at participating Children's Oncology Group institutions in North America. Telephone interviews were completed with mothers of 158 cases (n = 97 acute lymphoblastic leukemia and n = 61 acute myeloid leukemia) and 173 controls. Paternal interviews were completed with 275 fathers and 40 mothers serving as surrogates. Three irradiation exposure periods were examined: preconception, in utero, and postnatal. Multivariate unconditional logistic regression models were constructed to evaluate the associations of interest, resulting in odds ratios and 95% confidence intervals. RESULTS: There was little evidence that maternal or paternal preconception irradiation exposure, intrauterine exposure, or postnatal exposure contributes to leukemogenesis in children with Down syndrome. Overall, no evidence for an effect of any periconceptional exposure was observed. Similar results were observed among acute lymphoblastic leukemia and acute myeloid leukemia cases analyzed separately. CONCLUSIONS: This was the first study, to our knowledge, to examine such an association among this unique patient population. The results do not provide evidence of a positive association between ionizing radiation exposure and acute leukemia among children with Down syndrome. The absence of an association should be encouraging for concerned parents of children with Down syndrome who undergo a series of diagnostic radiographs in the course of their standard care.

Adolescent↗

Child and maternal household chemical exposure and the risk of acute leukemia in children with Down's syndrome: a report from the Children's Oncology Group.

Compared with the general pediatric population, children with Down's syndrome have a much higher risk of acute leukemia. This case-control study was designed to explore potential risk factors for acute lymphoblastic leukemia and acute myeloid leukemia in children with Down's syndrome living in the United States or Canada. Mothers of 158 children with Down's syndrome and acute leukemia (97 acute lymphoblastic leukemia, 61 acute myeloid leukemia) diagnosed between January 1997 and October 2002 and mothers of 173 children with Down's syndrome but without leukemia were interviewed by telephone. Positive associations were found between acute lymphoblastic leukemia and maternal exposure to professional pest exterminations (odds ratio = 2.25, 95% confidence interval: 1.13, 4.49), to any pesticide (odds ratio = 2.18, 95% confidence interval: 1.08, 4.39), and to any chemical (odds ratio = 2.72, 95% confidence interval: 1.17, 6.35). Most of the associations with acute myeloid leukemia were nonsignificant, and odds ratios were generally near or below 1.0. This exploratory study suggests that household chemical exposure may play a role in the development of acute lymphoblastic leukemia in children with Down's syndrome.

Adult↗

Ethnicity and survival in childhood acute myeloid leukemia: a report from the Children's Oncology Group.

We evaluated differences in outcome by ethnicity among children with acute myeloid leukemia (AML). We analyzed 791 children in the CCG 2891 trial and confirmed positive findings in 850 children in the CCG 2961 trial. Hispanic and black children treated with chemotherapy in CCG 2891 had significantly inferior overall survival (OS) from study entry compared with white children (37%+/- 9% vs 48%+/- 4% [P = .016] and 34% +/- 10% vs 48% +/- 4%, [P = .007], respectively). Significantly fewer black children had related donors. Analyses of CCG 2961 confirmed that black children had significantly decreased OS rates compared with white children (45% +/- 12% vs 60% +/- 4%; P = .007) The difference in OS rates between Hispanic and white children approached statistical significance (51% +/- 8% vs 60% +/- 4%; P = .065) Only 7.5% of black children on CCG 2961 had an available family donor. In conclusion, Hispanic and black children with AML have worse survival than white children. Access to chemotherapy, differences in supportive care or leukemia phenotype, and reduced compliance are unlikely explanations for this difference because therapy was given intravenously according to CCG protocols. Fewer black children than expected had an available family marrow donor.

Acute Disease↗

A pooled analysis of 12 cohort studies of dietary fat, cholesterol and egg intake and ovarian cancer.

Fat and cholesterol are theorized to promote ovarian carcinogenesis by increasing circulating estrogen levels. Although case-control studies have reported positive associations between total and saturated fat intake and ovarian cancer risk, two cohort studies have observed null associations. Dietary cholesterol and eggs have been positively associated with ovarian cancer risk. A pooled analysis was conducted on 12 cohort studies. Among 523,217 women, 2,132 incident epithelial ovarian cancer cases were identified. Study-specific relative risks (RR) and 95% confidence intervals (CI) were calculated by Cox proportional hazards models, and then pooled using a random effects model. Total fat intake was not associated with ovarian cancer risk (pooled multivariate RR = 1.08, 95% CI 0.86-1.34 comparing > or =45 to 30-<35% of calories). No association was observed for monounsaturated, polyunsaturated, trans-unsaturated, animal and vegetable fat, cholesterol and egg intakes with ovarian cancer risk. A weakly positive, but non-linear association, was observed for saturated fat intake (pooled multivariate RR = 1.29, 95% CI: 1.01-1.66 comparing highest versus lowest decile). Results for histologic subtypes were similar. Overall, fat, cholesterol and egg intakes were not associated with ovarian cancer risk. The positive association for saturated fat intake at very high intakes merits further investigation.

Cholesterol↗

Breast-feeding and Wilms tumor: a report from the Children's Oncology Group.

OBJECTIVE: Previous research has shown that breast-feeding offers many nutritional benefits to children including protection against infection and possibly a decreased risk of childhood cancer. We investigated the association between breast-feeding and Wilms tumor, a childhood kidney tumor. METHODS: We used data from a large case-control study in the United States and Canada. Cases were children under age 16 years who were diagnosed with Wilms tumor from 1999 to 2002 and were participating in the National Wilms Tumor Study. Controls were identified by random-digit dialing and were age and region matched to cases. Mothers of 501 cases and 480 controls provided information on breast-feeding by telephone interviews. RESULTS: Breast-feeding was associated with a reduced risk of Wilms tumor [adjusted odds ratio (OR) = 0.7; 95% confidence interval (CI) = 0.5-0.9]. Longer duration did not provide any additional reduction in risk. When stratified by maternal education, breast-feeding lowered risk among children whose mothers had less than a college education (OR = 0.6; 95% CI = 0.4-0.8) but not for mothers who had a college degree or more (OR = 1.1; 95% CI = 0.6-1.9). CONCLUSIONS: The results of this study are suggestive of an association between breast-feeding and Wilms tumor, but further research is needed to confirm this relationship.

Adolescent↗

Parental marijuana use and risk of childhood acute myeloid leukaemia: a report from the Children's Cancer Group (United States and Canada).

The aetiology of childhood acute myeloid leukaemia (AML) is largely unknown. Maternal marijuana use just before, or during pregnancy has been previously associated with childhood AML. This case-control investigation formally tested the hypothesis that parental marijuana use increases the risk of childhood AML in offspring. Incident cases of AML <18 years of age, diagnosed between 1989 and 1993, and registered with the Children's Cancer Group (a paediatric clinical co-operative group), were eligible for inclusion. Control children were selected via random digit dialling and individually matched 1:1 to cases on age, race and residential location, except for rare morphological subtypes that were matched 1:2. Parental telephone interviews were conducted to determine exposure and covariate information. Conditional logistic regression was used to estimate matched odds ratios (OR) and 95% confidence intervals [CI] adjusted for household income, parental education and parental age. The analysis included 517 cases and 610 matched controls. A series of sensitivity analyses examined the potential for recall bias. Ever lifetime use of marijuana by mothers was not associated with childhood AML [OR = 0.89; 95% CI = 0.66, 1.19]. Maternal marijuana use any time during the 3 months before, or during pregnancy was inversely associated with childhood AML [OR = 0.43; 95% CI = 0.23, 0.80]. Paternal use during the same time period was not associated with risk. Assuming a large degree of differential exposure misclassification was present, the corrected ORs ranged between 0.82 and 1.40. The previously reported positive association between maternal marijuana use before or during pregnancy and childhood AML was not confirmed. The decreased ORs observed in this study may be due to recall bias assuming plausibly low values of sensitivity.

Acute Disease↗

XPD Lys751Gln polymorphism in the etiology and outcome of childhood acute myeloid leukemia: a Children's Oncology Group report.

Genetic polymorphisms result in interindividual variation in DNA repair capacity and may, in part, account for susceptibility of a cell to genotoxic agents and to malignancy. Polymorphisms in XPD, a member of the nucleotide excision repair pathway, have been associated with development of treatment-related acute myeloid leukemia (AML) and with poor outcome of AML in elderly patients. We hypothesized that XPD Lys751Gln polymorphism may play a role in causation of AML in children and, as shown in adults, may affect the outcome of childhood AML therapy. Genotyping of 456 children treated for de novo AML was performed at XPD exon 23. Genotype frequencies in patients were compared with healthy control subject frequencies, and patient outcomes were analyzed according to genotype. Gene frequencies in AML patients and healthy controls were similar. There were no significant differences in overall survival (P = .82), event-free survival (P = .78), treatment-related mortality (P = .43), or relapse rate (RR) (P = .92) between patients with XPD751AA versus 751AC versus 751CC genotypes, in contrast to reports in adult AML. These data, representing the only data in pediatric AML, suggest that XPD genotype does not affect the etiology or outcome of childhood AML.

Acute Disease↗

Periconceptional vitamin useand leukemia risk in children with Down syndrome: a Children's Oncology Group study.

BACKGROUND: Periconceptional vitamin supplementation reduces the risk of neural tube defects, and possibly may reduce the risk of certain childhood malignancies, including acute lymphoblastic leukemia (ALL). Because children with Down syndrome (DS) experience a 20-fold higher risk of leukemia than the general population, the authors evaluated whether periconceptional vitamin supplementation reduced the risk of leukemia in children with DS. METHODS: From 1997 to 2002, 158 children ages birth-18 years with DS and acute leukemia (n = 61 children with acute myeloid leukemia [AML] and n = 97 children with ALL) were enrolled through the Children's Oncology Group in North America. Children with DS alone (n = 173) were identified through the cases' pediatric clinics and frequency matched to cases on age. Mothers of cases and controls completed a telephone interview that included questions regarding vitamin supplement use in the periconceptional period and after knowledge of pregnancy. RESULTS: A decreased risk of leukemia was observed with vitamin supplementation in the periconceptional period (odds ratio [OR] = 0.63; 95% confidence interval [95% CI], 0.39-1.00). When stratified by leukemia type, the reduced risk was observed for ALL (OR = 0.51; 95% CI, 0.30-0.89), but not for AML (OR = 0.92; 95% CI, 0.48-1.76). Compared with vitamin use in the periconceptional period, use only after knowledge of pregnancy was associated with an increased risk of leukemia (OR = 1.61; 95% CI, 1.00-2.58). This was observed for both ALL and AML. CONCLUSIONS: These data added to a growing body of evidence that suggests that periconceptional vitamin use may be protective in the development of certain childhood cancers.

Adolescent↗

Epidemiology of leukemia in children with Down syndrome.

Studies suggest nearly a 20-fold increased risk of leukemia in individuals with Down syndrome. Most of this increased risk appears in the first few decades of life, with the highest incidence in children less than 5 years of age. It is unknown why children with Down syndrome are at such an increased risk of leukemia. With respect to environmental exposures, it will be important to investigate risk factors associated with childhood leukemia in general (including diagnostic x-rays, pesticides, and other occupational exposures) as well as experiences common to children with Down syndrome (including routine medical screening tests, increased susceptibility to infections, and increased vitamin deficiencies).

Adolescent↗

Hormone replacement therapy is not associated with an increased risk of leukemia (United States).

OBJECTIVE: Recent studies have reported an increased risk of certain cancers associated with hormone replacement therapy (HRT), possibly due to stimulation of estrogen receptors. Since estrogen receptors are expressed on certain hematopoietic cells, it is possible that HRT use may also increase the risk of leukemia. METHODS: A cohort of 37,172 post-menopausal Iowa women ages 55-69 years with no history of prior cancer was linked annually to the population-based state cancer registry through 2001. In addition to other self-reported cancer risk factors, participants were asked about current and former use of HRT in 1986 and on four subsequent follow-up questionnaires. A total of 201 cases of leukemia were identified over 16 years of follow-up including 74 acute myeloid leukemias (AMLs) and 87 chronic lymphocytic leukemias (CLLs). RESULTS: Compared to never users of HRT at study baseline, current [multivariate relative risk (RR), 1.09; 95% confidence interval (CI) 0.70-1.71)] and former users (RR=0.82, 95% CI=0.59-1.15) were at no increased risk of developing leukemia. For AML, current users also had no increased risk (RR=0.83, 95% CI=0.37-1.84) and there was a suggestion that former users had a slightly decreased risk (RR=0.66, 95% CI=0.37-1.17). For CLL, all RRs were around unity. CONCLUSION: We conclude that HRT is unlikely to be an appreciable risk factor for leukemia.

Age Factors↗

Childhood cancer following neonatal oxygen supplementation.

OBJECTIVE: To evaluate the relationship between neonatal oxygen supplementation (O2) and childhood cancer in the Collaborative Perinatal Project (CPP). STUDY DESIGN: The CPP consisted of 54,795 children born between 1959 and 1966 and followed to age 8 years. We used Cox proportional hazards modeling to examine the association between history of neonatal O2 and cancer (n = 48). RESULTS: The hazard ratio (HR) for any O2 was 1.77 (95% confidence interval [CI] = 0.94 to 3.35). The HR for continuous duration of O2 was near 1 and not significant. However, the HRs were 0.69 (95% CI = 0.17 to 2.88) and 2.87 (95% CI = 1.46 to 5.66) when comparing 0 to 2 and 3 or more minutes of O2, respectively, to no O2. The latter association was weaker (HR = 2.00; 95% CI = 0.88 to 4.54) and not significant ( P = .10) when analysis was restricted to cancers diagnosed after age 1 year (n = 41). CONCLUSIONS: These findings are consistent with an association between O 2 for 3 minutes or longer and cancer in childhood, and should serve as a basis for further study.

Child↗