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J D Buckley

Publications and source records attributed to J D Buckley.

At least 37 records · Page 2Linked to original sources
PubMed1998

Lack of TEL/AML1 fusion in pediatric AML: further evidence for lineage specificity of TEL/AML1.

BACKGROUND: The TEL/AML1 fusion associated with t(12;21)(p13;q22) is the most common gene rearrangement in childhood malignancy, occurring in approximately 25% of pediatric acute lymphoblastic leukemia. The TEL/AML1 rearrangement is cryptic at the cytogenetic level but confers a favorable prognosis. The AML1 gene was first identified by virtue of its involvement in adult and pediatric acute myeloid malignancies associated with t(8;21) and t(3;21)(q26;q22.1). We have therefore determined the frequency of the TEL/AML1 fusion in pediatric myeloid leukemias by RT-PCR analysis. METHODS: Total RNA was isolated from cryopreserved bone marrow samples of 38 pediatric patients with AML. RNA quality was controlled for by amplification of the TEL gene. An RT-PCR assay was then used to test for the presence of the TEL/AML1 fusion. RESULTS: 29 patients had adequate RNA for analysis. Zero out of 29 pediatric AML patients had evidence for the TEL/AML1 fusion by RT-PCR. CONCLUSIONS: The TEL/AML1 fusion does not occur in children with AML and suggests that the TEL/AML1 rearrangement is restricted in pediatric hematologic malignancy to B lineage ALL.

Acute Disease↗
PubMed1997

Reduced performance of male and female athletes at 580 m altitude.

This study examined the effect of mild hypobaria (MH) on the peak oxygen consumption (VO2peak) and performance of ten trained male athletes [x (SEM); VO2peak = 72.4 (2.2) ml x kg(-1) x min(-1)] and ten trained female athletes [VO2peak = 60.8 (2.1) ml x kg(-1) x min(-1)]. Subjects performed 5-min maximal work tests on a cycle ergometer within a hypobaric chamber at both normobaria (N, 99.33 kPa) and at MH (92.66 kPa), using a counter-balanced design. MH was equivalent to 580 m altitude. VO2peak at MH decreased significantly compared with N in both men [-5.9 (0.9)%] and women [-3.7 (1.0)%]. Performance (total kJ) at MH was also reduced significantly in men [-3.6 (0.8)%] and women [-3.8 (1.2)%]. Arterial oxyhaemoglobin saturation (SaO2) at VO2peak was significantly lower at MH compared with N in both men [90.1 (0.6)% versus 92.0 (0.6)%] and women [89.7 (3.1)% versus 92.1 (3.0)%]. While SaO2 at VO2peak was not different between men and women, it was concluded that relative, rather than absolute. VO2peak may be a more appropriate predictor of exercise-induced hypoxaemia. For men and women, it was calculated that 67-76% of the decrease in VO2peak could be accounted for by a decrease in O2 delivery, which indicates that reduced O2 tension at mild altitude (580 m) leads to impairment of exercise performance in a maximal work bout lasting approximately 5 min.

Adult↗
PubMed1997

High birth weight and risk of specific childhood cancers: a report from the Children's Cancer Group.

OBJECTIVES: High birth weight has been associated with a number of childhood cancers. This study was conducted to test the hypothesis that elevated birth weight is associated with an increased risk of diagnosis-specific and age-specific groups of childhood cancers. METHODS: A case-control study, using a large Children's Cancer Group database, examined birth weight as a risk factor for childhood cancer. Birth weight information for the index child was available for 3711 cases and 816 control subjects. RESULTS: There was a statistically significant increased risk of acute lymphoblastic leukemia, Wilms' tumor, and neuroblastoma with increasing birth weight (p, trend = 0.006, 0.003, and 0.001, respectively). A statistically significant decreased risk of cancer was observed for soft tissue sarcoma (p, trend = 0.04). When data were stratified on the basis of age at diagnosis, many of these associations were apparent for children whose disease was diagnosed before the age of 2 years. Moreover, for acute myeloid leukemia, age at diagnosis was an important effect modifier. For children with acute myeloid leukemia whose disease was diagnosed before 2 years of age, there was a statistically significant increased risk with high birth weight (odds ratio = 2.5, 95% confidence interval 1.1 to 5.5); there was no increased risk of acute myeloid leukemia with high birth weight noted for children whose disease was diagnosed after 2 years of age (odds ratio 1.3, 95% confidence interval 0.8 to 2.2). CONCLUSIONS: Biologic studies are needed to address why high birth weight may increase risk (particularly at younger ages) of development of certain cancers.

Birth Weight↗
PubMed1997

Epidemiologic study of Langerhans cell histiocytosis in children.

OBJECTIVE: The etiology and pathogenesis of Langerhans cell histiocytosis (LCH) remain poorly understood. We conducted an exploratory epidemiologic study to investigate potential risk factors associated with LCH. STUDY DESIGN: We used a case-control study design to obtain data from parents of children with LCH (n = 459) who were members of the Histiocytosis Association of America and Canada. The two control groups consisted of 683 community control subjects and 3719 children with childhood cancers treated at participating Children's Cancer Group institutions. RESULTS: The median age at diagnosis of LCH was 1.8 years (range 0.1 to 14.6 years). Cases were categorized as multisystem LCH (MS-LCH) (n = 208) and single-system LCH (SS-LCH) (n = 198). Statistically significant associations included the following: infections in the neonatal period (MS-LCH, odds ratio (OR) = 2.2), solvent exposure (SS-LCH, OR = 54.9), childhood vaccinations (MS-LCH and SS-LCH, OR = 0.4), thyroid disease in the proband (MS-LCH and SS-LCH, OR = 21.6), and family history of thyroid disease (MS-LCH and SS-LCH, OR = 1.4). The association with thyroid disease in the proband was explained partially by the involvement of the pituitary, with the relative risk decreasing when patients with diabetes insipidus and thyroid involvement were excluded from analysis. CONCLUSIONS: This large hypothesis-generating study provides directions for future investigations in well-designed population-based or hospital-based epidemiologic studies.

Adolescent↗
PubMed1997

Timing and magnitude of decline in alpha-fetoprotein levels in treated children with unresectable or metastatic hepatoblastoma are predictors of outcome: a report from the Children's Cancer Group.

PURPOSE: We analyzed data on 31 children with primary unresectable or metastatic hepatoblastoma (HB) to investigate possible prognostic correlations between the serum level of alpha-fetoprotein (AFP), its changes during treatment, and outcome. PATIENTS AND METHODS: Patients were treated according to the Children's Cancer Group (CCG) protocol 823F, which included an initial surgery before eight courses of chemotherapy that consisted of cisplatin immediately followed by a continuous infusion of doxorubicin. Four courses were given before and four after the second surgery. AFP levels were measured before treatment, before and after second surgery, and at the end of treatment. RESULTS: Twenty-four of 31 patients showed a decline of > or = 1 log in AFP levels before second surgery (early responders). By the end of treatment, there were 16 patients, all early responders, without clinical or radiographic evidence of tumor and with normal AFP levels. Fifteen of those 16 had a decline of > or = 2 logs in AFP before second surgery (large early response). Of the 15 patients who failed to respond to treatment, 10 died, among whom only one patient had a large early response. A large early response was the strongest independent predictor of outcome in a univariate and multivariate Cox regression model, and patients with such a response had the best survival (P < .0001). CONCLUSION: For children with unresectable or metastatic HB, early changes in AFP levels are a reliable predictor of outcome and can be used for identification of poor responders to treatment, ie, patients whose AFP level fails to decrease 2 logs before second surgery should be considered for alternative treatment.

Child↗
PubMed1996

Prediction of relapse of pediatric acute myeloid leukemia by use of multidimensional flow cytometry.

BACKGROUND: Most patients receiving therapy for acute myeloid leukemia (AML) enter an interval in which leukemic blast cells cannot be detected by light microscopy (i.e., morphologic remission). However, many of these patients experience a subsequent relapse. Multidimensional flow cytometry, which allows the discrimination of antigens expressed on normal and malignant cells, can detect small numbers of cancer cells in bone marrow or peripheral blood specimens. This technique enables the detection of one leukemic blast cell among 10(3) to 10(2) normal regenerating hematopoietic cells. PURPOSE: We determined whether the presence of residual leukemic blast cells, identified in the bone marrow of pediatric patients with AML by use of multidimensional flow cytometry, would be predictive of subsequent leukemic relapse. METHODS: Multidimensional flow cytometry was performed on 205 marrow specimens collected throughout the course of treatment from 39 patients who had achieved morphologic remission. The analyses employed monoclonal antibodies directed against CD45 in combination with mixed pairs of monoclonal antibodies directed against 10 other antigens. A time-varying Cox regression analysis that controlled for sample time intervals, age, sex, morphologic classification of disease, and white blood cell count at diagnosis was used to relate the multidimensional flow cytometric results to the risk of relapse after achieving remission. Reported P values are two-sided. RESULTS: Thirty-five of the 39 patients had bone marrow specimens available from the time that first morphologic remission was achieved. Leukemic blast cells were detected in the specimens from 19 (54%) of these 35 patients. Twenty-five of the 35 patients did not receive an allogeneic (i.e., from a different genetic background) bone marrow transplant during first morphologic remission, and 13 of 14 with residual leukemic cells experienced a relapse at a median time of 153 days after diagnosis (range, 48-863 days). Nine of the 11 patients who did not receive an allogeneic bone marrow transplant and lacked evidence of leukemic blast cells at first morphologic remission relapsed at a median time of 413 days after diagnosis (range, 321-794 days). Among the 10 individuals who received an allogeneic bone marrow transplant during first morphologic remission, five were positive for leukemic blast cells and five were negative; one of these patients (positive for leukemic blast cells) experienced a relapse 265 days after diagnosis, and three others died of transplant-related complications. The estimated risk of relapse during intervals of multidimensional flow cytometric positivity (i.e., intervals of remission for which the immediately preceding cytometry measurement was positive) was 2.8 times greater than that during negative intervals (95% confidence interval = 1.1-7.0; P = .02). CONCLUSIONS AND IMPLICATIONS: Multidimensional flow cytometry identifies residual leukemia in more than half of the patients with AML who are in morphologic remission. The detection of leukemic blast cells in these patients by multidimensional flow cytometry is predictive of a more rapid relapse.

Acute Disease↗
PubMed1996

Timed-sequential induction therapy improves postremission outcome in acute myeloid leukemia: a report from the Children's Cancer Group.

Timed sequencing of cycles of induction chemotherapy in acute myeloid leukemia (AML) has been proposed as a way to achieve maximal leukemic cell kill through recruitment and synchronization of residual neoplastic cells. Furthermore, whether intensive induction therapy should be continued in the presence of profound myelosuppression is an important question. The Children's Cancer Group (CCG) conducted a prospective randomized trial in which 589 patients with AML were randomized at diagnosis to one of two induction approaches involving a 4-day cycle of five active chemotherapeutic agents, with the second cycle administered either 10 days after the first cycle, despite low or dropping blood counts (intensive timing), or 14 days or later from the beginning of the first cycle, depending on bone marrow status (standard timing). All patients achieving remission received a total of four cycles of induction therapy. They were then allocated to allogeneic bone marrow transplantation (BMT) if a compatible family donor was present or randomized to aggressive nonmyeloablative therapy or to myeloablative therapy with purged autologous BMT rescue. The three postremission arms remain coded. Induction success and median days to complete induction were similar for the 295 patients randomized to the intensive timing arm (75%, 99 days) compared with the 294 patients randomized to the standard timing arm (70%, 105 days; P = .18 for remission). However, a marked improvement in outcome was demonstrated in patients randomized to the intensive timing arm, with an actuarial event-free survival at 3 years of 42% +/- 7% (95% confidence interval [CI]) versus 27% +/- 6% for patients on the standard timing arm (P = .0005). Disease-free survival results at 3 years from the end of induction were superior for patients receiving intensively timed induction therapy (N = 211), 55% +/- 9% versus 37% +/- 9% for standard timing patients (N = 195, P = .0002), with a median follow-up from achieving remission of 28 months. Superior results were documented for patients receiving intensive timing irrespective of the postremission therapy to which they were allocated. Intensively timed induction therapy for patients with AML markedly improves event-free survival, even for patients undergoing myeloablative therapy with BMT rescue. Without controlling for the type of induction therapy received, results of various BMT studies in AML comparing different preparative regimens will be difficult to interpret.

Acute Disease↗
PubMed1996

The rate of CpG mutation in Alu repetitive elements within the p53 tumor suppressor gene in the primate germline.

Cytosine to thymine transition mutations at the CpG dinucleotide are the most common point mutations in cancer and genetic disease. We calculated the in vivo rate of CpG mutation in the primate germline by deriving a primordial consensus sequence for an Alu repetitive element which inserted into intron 6 of the primate p53 gene 35 to 55 million years ago. Comparison of this primordial sequence to the Alu sequence in intron 6 of present-day primates was used to determine the nature and rate of mutations which occurred during evolution. We estimate the half-life of a CpG nucleotide to be 24 to 60 million years, and the rate constant for mutation at this dinucleotide to be 1.2 x 1O(-8) to 2.9 x 1O(-8) years(-1). These results were confirmed by the analysis of a second Alu sequence in intron 10 of the p53 gene. The in vivo mutation rate is at least 1250-fold slower than the in vitro chemical rate of 5-methylcytosine deamination in double-stranded DNA, showing that current estimates of CpG mutation repair have been significantly underestimated. Furthermore, the mutability of the CpG dinucleotide has led to the depletion of this dinucleotide from the vertebrate genome, and calculations in this study suggest that current levels of the CpG dinucleotide in the primate genome are very close to a steady state equilibrium in which the rate of CpG mutation is equal to the rate of CpG formation by random mutation.

Animals↗
PubMed1996

The human homologue of rat NG2, a chondroitin sulfate proteoglycan, is not expressed on the cell surface of normal hematopoietic cells but is expressed by acute myeloid leukemia blasts from poor-prognosis patients with abnormalities of chromosome band 11q23.

In our efforts to produce monoclonal antibodies that recognize cell-surface antigens expressed by hematopoietic precursor and stromal cells, we generated a monoclonal antibody, 7.1, which recognizes a 220- to 240-kD cell-surface protein whose N-terminal amino acid sequence is identical to the rat NG2 chondroitin sulfate proteoglycan molecule. This chondroitin sulfate proteoglycan, previously reported to be expressed by human melanoma cells, was not found to be expressed by normal hematopoietic cells, nor was it expressed on the cell surface of cell lines of hematopoietic origin including cell lines with 11q23 abnormalities. It was found on the cell surface of acute myeloid leukemia (AML) blasts and cell lines derived from nonhematopoietic tissues. Samples of leukemic marrow from 166 children with AML enrolled on Childrens Cancer Group protocol 213 were evaluated for cell-surface expression of this proteoglycan molecule. In 18 of 166 (11%) patient samples, greater than 25% of leukemic blasts expressed the NG2 molecule. These 18 patients had a poorer outcome with respect to survival (P = .002) and event-free survival (P = .035) with an actuarial survival at 4 years of 16.7%. Blast cell expression of the NG2 molecule was strongly associated with French-American-British M5 morphology (P < .0001) and abnormalities in chromosome band 11q23, site of the MLL gene. These results show that the NG2 molecule is expressed by malignant hematopoietic cells that have abnormalities in chromosome band 11q23, suggesting that antibody 7.1 may be useful in the rapid identification of this group of poor-prognosis patients.

Actuarial Analysis↗
PubMed1996

Concordance for childhood cancer in twins.

The causes of most childhood cancer remain elusive; some children clearly have a genetic predisposition, but in the majority the relative contributions of environmental and host factors are not established. One approach to this question is through twin concordance studies, but only the most common malignancy, acute leukemia, has been studied to date, owing to the rarity of other forms of childhood cancer. The aim of the study was to determine the concordance rates for childhood cancer in twins, in order to clarify the importance of constitutional predisposition for a range of tumor types. Twins with cancer were ascertained through three cooperative clinical trials groups, a cancer-twin registry, and a large pediatric hospital. Subjects were sent a postal questionnaire requesting information on cancer concordance and zygosity. Data were obtained on 556 twins with cancer. Three twin pairs, out of 197 twin pairs (76 monozygous, MZ, twin pairs), were concordant for leukemia, giving an MZ case-wise concordance rate (5%) that is substantially lower than previously reported. The case-wise concordance for non-retinoblastoma solid tumors was 2.2%: Two twin pairs were concordant for CNS tumors, one was concordant for neuroblastoma, and two twin pairs were concordant for cancer but not for the type of cancer. The results of the present study, together with previous data from population studies of siblings and offspring, suggest that there is not in general a strong constitutional genetic component for childhood cancers other than retinoblastoma.

Adolescent↗
PubMed1996

Morphologic, immunologic, and cytogenetic classification of acute myeloid leukemia and myelodysplastic syndrome in childhood: a report from the Childrens Cancer Group.

The purposes of this report are to reaffirm concordance difficulties with the acute myeloid leukemia (AML) French-American-British (FAB) classification, to present the frequency of previously delineated AML syndromes in pediatric patients and to describe additional characteristic AML profiles utilizing composite morphologic, cytogenetic and immunophenotypic data. Profiles of 124 children with acute myeloid leukemia (AML) and 13 children with myelodysplastic syndrome entered on the Childrens Cancer Group (CCG) pilot study CCG-2861 were examined. Concordance between institutions and reviewers for FAB designation was 65%. Discordance was found principally between M1 and M2, M2 and M4, and M4 and M5. In 49% of marrow specimens, leukemic blasts expressed at least one T lineage-related antigen; 24% expressed the B lineage-related antigen CD19. CDw14 correlated with FAB M4 or M5 morphology and was the only surface antigen associated with a specific FAB subtype. Normal karyotypes were found for 15% of the 75 children with satisfactory karyotype preparations. Recurring aberrations, found in 76% of children, included t(15;17)(q22;q11), t(8;21)(q22;q22), inv(16)(p13q22), rearrangements of band 11q23, t(6;9) (p23;q34), trisomy 8 and monosomy 7. Results from this pilot study and from the current CCG randomized trial correlating morphology, immunophenotyping and cytogenetics, will help to classify AML into unique subgroups with differing clinical consequences or therapy requirements.

Adolescent↗
PubMed1995

History of maternal fetal loss and increased risk of childhood acute leukemia at an early age. A report from the Childrens Cancer Group.

BACKGROUND: Maternal reproductive history of fetal loss previously has been reported to be associated with an increased risk of leukemia in subsequent offspring. Data from a Childrens Cancer Group (CCG) case-control study were analyzed to test the hypothesis that this association was dependent on the number of previous fetal losses and age at leukemia diagnosis. METHODS: A case-control study using a large Childrens Cancer Group database examined maternal history of fetal loss as a risk factor for childhood leukemia in subsequent offspring. One thousand seven hundred fifty-three patients with childhood acute leukemia were compared with 839 community control subjects s and 2081 nonleukemia cancer control subjects. RESULTS: A modest increase in risk was found to be associated with a history of fetal loss. Stratification by age at diagnosis of leukemia showed that this association was significant only for those patients diagnosed before 4 years of age and most significant in those patients diagnosed before 2 years of age. When comparing community controls with patients acute lymphocytic leukemia diagnosed before 2 years of age, one previous fetal loss was associated with a five-fold increased risk (P < 0.001) whereas two or more fetal losses were associated with a relative risk of 24.8 (P < 0.001). Similarly, patients with acute myelocytic leukemia diagnosed before 2 years of age demonstrated 5-fold and 12-fold increased risks associated with the previous fetal loss and 2 or more previous fetal losses, respectively. CONCLUSIONS: Childhood acute leukemia occurring at younger ages may be associated with an underlying genetic abnormality or chronic environmental exposure, which can be either lethal to the developing fetus or mutagenic and result in the development of acute leukemia.

Abortion, Spontaneous↗
PubMed1995

An exploratory analysis of risk factors for childhood malignant germ-cell tumors: report from the Childrens Cancer Group (Canada, United States).

A study of 105 patients with childhood malignant germ-cell tumors (MGCT) and 639 community controls was conducted utilizing a large epidemiologic database collected by the Childrens Cancer Group from 25 member institutions in the United States and Canada. This study was designed to explore the risk factors of this malignancy whose etiology remains poorly understood. A structured, self-administered questionnaire was used to collect exposure information, and data were analyzed using an unconditional logistic regression model with adjustment for relevant confounders. Consistent with the findings from studies of adult MGCT, gestational age was associated inversely with risk of MGCT, with a 70 to 75 percent reduction in risk for children born at term compared with those born pre-term. Parental, particularly maternal, self-reported exposure to chemicals or solvents (odds ratio [OR] = 4.6, 95 percent confidence interval [CI] = 1.9-11.3) and OR = 2.2, CI = 1.1-4.7 for maternal and paternal exposure, respectively) and plastic or resin fumes (OR = 12.0, CI = 1.9-75.0 [maternal] and OR = 2.5, CI = 1.0-6.5 [paternal]) were associated with elevated risk of MGCT. New findings, not reported previously, include a positive relationship of MGCT risk with birthweight and prolonged breastfeeding, an inverse association between MGCT risk and number of cigarettes smoked by the mother during pregnancy, and a 3.1-fold increased risk (CI = 1.5-6.6) associated with maternal urinary infections during index pregnancy. Although these findings need confirmation from future studies, they suggest a potential influence of in utero exposure to maternal endogenous hormones, parental environmental exposures, and maternal diseases during pregnancy in the development of childhood MGCT.

Adolescent↗
PubMed1995

Mosaicism in human epithelium: macroscopic monoclonal patches cover the urothelium.

Previous studies of chimeric animals and human tissues have shown the clonal nature of organ development, giving clues as to the normal development of organs and also to abnormal developments, such as atheromatous plaques. The clonal nature of bladder cancer in female patients has been demonstrated, but little has been known of the clonal development of the normal urothelium. Using an X chromosome inactivation analysis of cells microdissected from histologic slides from the female human bladder, macroscopic urothelial patches of monoclonality were detected. These patches are about 120 mm.2 in size, contain about 2 x 10(6) cells each and reflect the presence of coherent cellular families composed of stem cells and their differentiated derivatives. The large size of these patches was surprising when compared with previously reported patch sizes in other organ systems. The patches most probably are composed of the descendants of the original founder cells, which would suggest that only 200 to 300 cells participated in the formation of the urothelium. The limited number of stem cells, each giving rise to millions of cells may provide an explanation for the "field defect" that is often referred to in the pathogenesis of bladder cancer, as different cell patches may possess different predispositions to tumorigenesis.

Dosage Compensation, Genetic↗
PubMed1995

Assessment of environmental and genetic factors in the etiology of childhood cancers: the Childrens Cancer Group epidemiology program.

The occurrence of cancer during childhood represents one of the leading causes of death within the pediatric and adolescent age group. It is estimated that approximately 8000 children will be diagnosed annually with cancer in the United States. Epidemiologic research addressing the etiology of childhood cancer has been limited because of the difficulties in identifying a sufficiently large study population. Moreover, the use of retrospectively ascertained childhood cancer cases in epidemiologic investigations has restricted the incorporation of biological and clinical parameters. The Childrens Cancer Group has developed an active program in epidemiologic research, with over a decade of experience demonstrating the feasibility and strengths of conducting analytic epidemiologic studies within a cooperative clinical trials network. The availability of detailed clinical and biologic data on cases diagnosed within the cooperative group facilitates the transfer of state-of-the-art technology to epidemiologic research.

Acute Disease↗
PubMed1994

Cell surface expression of c-kit receptors by childhood acute myeloid leukemia blasts is not of prognostic value: a report from the Childrens Cancer Group.

The prognostic significance of c-kit receptor expression on leukemic blast cells was determined in 122 children with acute myeloid leukemia (AML) entered onto Childrens Cancer Group protocol 213. Clinical and laboratory characteristics as well as outcome were analyzed according to the percentage of blast cells expressing c-kit receptors and the relative number of c-kit receptors per cell as determined by indirect immunofluorescence. c-kit receptor expression was strongly associated with the expression of the CD34 antigen. However, contrary to findings in adult patients with AML, c-kit receptor expression by childhood AML blast cells was not predictive of a poor response to therapy.

Acute Disease↗
PubMed1994

Maternal diet and risk of astrocytic glioma in children: a report from the Childrens Cancer Group (United States and Canada)

N-nitroso compounds and their precursors, nitrites and nitrates, have been hypothesized as risk factors, and vitamins C and E, which inhibit N-nitroso formation, as protective factors for brain tumors. A case-control study of maternal diet during pregnancy and risk of astrocytoma, the most common childhood brain tumor, was conducted by the Childrens Cancer Group. The study included 155 cases under age six at diagnosis and the same number of matched controls selected by random-digit dialing. A trend was observed for consumption of cured meats, which contain preformed nitrosamines (a class of N-nitroso compounds) and their precursors (adjusted odds ratio [OR] for highest quartile of intake relative to lowest = 1.7, P trend = 0.10). However, no strong trends were observed for nitrosamine (OR = 0.8, P = 0.60); nitrite (OR = 1.3, P = 0.54); nitrate (OR = 0.7, P = 0.43); vitamin C (OR = 0.7, P = 0.37); or vitamin E (OR = 0.7, P = 0.48). Iron supplements were associated with a significant decrease in risk (OR = 0.5, 95 percent confidence interval = 0.3-0.8). The effect of several dietary factors differed by income level, making interpretation of the results difficult. Future research should investigate the effect of dietary components not assessed in this study, as these may explain the disparate effects by income level. The results of this study provide limited support for the nitrosamine hypothesis.

Astrocytoma↗
PubMed1994

Processed meats and risk of childhood leukemia (California, USA).

The relation between the intake of certain food items thought to be precursors or inhibitors of N-nitroso compounds (NOC) and risk of leukemia was investigated in a case-control study among children from birth to age 10 years in Los Angeles County, California (United States). Cases were ascertained through a population-based tumor registry from 1980 to 1987. Controls were drawn from friends and by random-digit dialing. Interviews were obtained from 232 cases and 232 controls. Food items of principal interest were: breakfast meats (bacon, sausage, ham); luncheon meats (salami, pastrami, lunch meat, corned beef, bologna); hot dogs; oranges and orange juice; and grapefruit and grapefruit juice. We also asked about intake of apples and apple juice, regular and charcoal broiled meats, milk, coffee, and coke or cola drinks. Usual consumption frequencies were determined for both parents and the child. When the risks were adjusted for each other and other risk factors, the only persistent significant associations were for children's intake of hot dogs (odds ratio [OR] = 9.5, 95 percent confidence interval [CI] = 1.6-57.6 for 12 or more hot dogs per month, trend P = 0.01), and fathers' intake of hot dogs (OR = 11.0, CI = 1.2-98.7 for highest intake category, trend P = 0.01). There was no evidence that fruit intake provided protection. While these results are compatible with the experimental animal literature and the hypothesis that human NOC intake is associated with leukemia risk, given potential biases in the data, further study of this hypothesis with more focused and comprehensive epidemiologic studies is warranted.

Animals↗