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Biomedical subjects

L L Robison

Publications and source records attributed to L L Robison.

At least 19 recordsLinked to original sources
PubMed2000

Extremely low-frequency magnetic fields and childhood acute lymphoblastic leukemia: an exploratory analysis of alternative exposure metrics.

Data collected by the National Cancer Institute-Children's Cancer Group were utilized to explore various metrics of magnetic field levels and risk of acute lymphoblastic leukemia (ALL) in children. Cases were aged 0-14 years, were diagnosed with ALL during 1989-1993, were registered with the Children's Cancer Group, and resided in one home for at least 70 percent of the 5 years immediately prior to diagnosis. Controls were identified by using random digit dialing and met the same residential requirements. With 30-second ("spot") measurements and components of the 24-hour measurement obtained in the subject's bedroom, metrics evaluated included measures of central tendency, peak exposures, threshold values, and measures of short-term temporal variability. Measures of central tendency and the threshold measures showed good-to-high correlation, but these metrics correlated less well with the others. Small increases in risk (ranging from 1.02 to 1.69 for subjects in the highest exposure category) were associated with some measures of central tendency, but peak exposures, threshold values, measures of short-term variability, and spot measurements demonstrated little association with risk of childhood ALL. In general, risk estimates were slightly higher for the nighttime (10 p.m.-6 a.m.) interval than for the corresponding 24-hour period.

Adolescent↗
PubMed2000

Are children living near high-voltage power lines at increased risk of acute lymphoblastic leukemia?

In the National Cancer Institute/Children's Cancer Group case-control study of childhood acute lymphoblastic leukemia (1989-1993), living in a home with a high-voltage wire code was not associated with disease risk. To further investigate risk near power lines, the authors analyzed distance to transmission and three-phase primary distribution lines within 40 m of homes and created an exposure index of distance and strength of multiple power lines (408 case-control pairs). Neither distance nor exposure index was related to risk of childhood acute lymphoblastic leukemia, although both were associated with in-home magnetic field measurements. Residence near high-voltage lines did not increase risk.

Adolescent↗
PubMed2000

Paternal military service and risk for childhood leukemia in offspring.

To assess the association between paternal military service and risk for childhood leukemia, the authors analyzed data from three case-control studies conducted by the Children's Cancer Group from 1983 to 1993. A total of 605 acute myeloid leukemia (AML, age < or = 18 years) cases, 2,117 acute lymphoblastic leukemia (ALL, age < or = 14 years) cases, and 3,155 individually matched controls were included in these studies. Paternal military history and other exposure data were obtained in 2,343 matched case-control sets, including 1,805 ALL and 528 AML cases. Paternal general military service was not associated with the leukemia risk. A small, but significant, increase in the risk for AML was seen, however, among offspring of veterans who had served in Vietnam or Cambodia (odds ratio (OR) = 1.7; 95% confidence interval (CI): 1.0, 2.9), after adjustment for paternal education, race, income, smoking, X-ray exposure, and marijuana use. The risk was predominantly present in children diagnosed before the age of 2 (OR = 4.6; 95% CI: 1.3, 16.1), although there were inconsistencies in the risks associated with length of time served and interval between service and diagnosis of leukemia. Military service in Vietnam or Cambodia was unrelated to the risk for ALL. The etiologic importance, if any, of these observations has yet to be determined.

Adolescent↗
PubMed2000

Changes in body mass index and prevalence of overweight in survivors of childhood acute lymphoblastic leukemia: role of cranial irradiation.

BACKGROUND: The risk factors responsible for an increased prevalence of obesity or overweight in survivors of acute lymphoblastic leukemia (ALL) remain controversial. We evaluated changes in body mass index (BMI) in a cohort of ALL survivors, all of whom have been followed until completion of linear growth. PROCEDURE: BMI (weight/height(2)) was used as an index of adiposity and was calculated at diagnosis, at the end of treatment, and at attainment of final height in a cohort of 126 (59 males) survivors of ALL. BMI was adjusted for age and sex by computing a BMI standard deviation score (SDS) or z score. The spectrum of therapies used included intrathecal chemotherapy given alone (n = 38) or combined with cranial irradiation (CRT; 18 Gy, n = 35; 24 Gy, n = 53) and exposure to prednisone at a low dose (<3.5 gm, n = 49), medium dose (3.5-9.4 gm, n = 46), or high dose (>9.4 gm, n = 30). RESULTS: Overall, mean +/- SEM BMI-SDS increased significantly between diagnosis (-0.18 +/- 0.08) and the end of therapy (0.41 +/- 0.09, P < 0.01), with no significant change thereafter. For patients without CRT, mean BMI-SDS remained unchanged, whereas, for those so treated, mean BMI-SDS increased significantly between diagnosis and the completion of therapy (P < 0.001). The change in mean BMI-SDS was greater in the 24 Gy group vs. the 18 Gy CRT sample (P < 0.005). In a multivariate logistic regression model, CRT was an independent predictor of being overweight (BMI >/=85 percentile) at attainment of final height [odds ratio = 1.6 (95% confidence interval 1.0-23. 1)]. The percentage of subjects who were overweight at attainment of final height was 10.5%, 40%, and 38% for subjects treated with no CRT, 18 Gy CRT, or 24 Gy CRT, respectively (P < 0.01). CONCLUSIONS: Children with ALL given CRT develop increases in their BMI-SDS early on and during treatment and remain at significant risk for becoming overweight as young adults, a development that may increase their already heightened risk for various adverse health outcomes.

Adolescent↗
PubMed2000

Allergic disorders and the risk of childhood acute lymphoblastic leukemia (United States).

OBJECTIVES: To test the hypothesis that childhood acute lymphoblastic leukemia (ALL) is associated with allergic disorders. METHODS: We compared the histories of selected allergic disorders (asthma, hay fever, food or drug allergies, eczema, and hives) of 1842 cases of ALL with those of 1986 individually matched controls. The histories of the allergic disorders among siblings of cases and controls were also compared. RESULTS: The combined history of any one or more of the five allergic disorders evaluated was associated with a significant reduced risk of ALL (adjusted OR = 0.7, 95% CI 0.6-0.8), as were histories of four specific allergic disorders (asthma, hay fever, food or drug allergies, and eczema). The combined history of any one or more of the five allergic disorders among any of the siblings of the study subjects also revealed a significantly inverse association (adjusted OR = 0.9, 95% CI 0.8-1.0). CONCLUSION: The results from this study, in agreement with most previous studies on adult cancer, suggest that allergic disorders may be associated with a reduced risk of childhood ALL.

Adult↗
PubMed2000

Validation of self-reported complications by bone marrow transplantation survivors.

Self-administered questionnaires are commonly used to measure exposures and outcomes in epidemiological research and thus need good validity. With increasing numbers of cancer survivors, there is interest in the ongoing assessment of therapy-related complications. A medical record validation of patient-reported complications following bone marrow transplantation (BMT) was performed using a self-administered questionnaire. The study population consisted of 100 patients who had undergone BMT at the City of Hope. The following self-reported complications were validated using medical records: ocular, endocrine, cardiovascular, musculoskeletal, pulmonary, gastrointestinal, neurological, graft-versus-host disease, and subsequent cancers. Using information from medical records as the standard, sensitivities ranged from 52.9% for subsequent cancers to 100% for avascular necrosis and hypothyroidism. Specificities ranged from 75.4% for ocular complications to 100% for avascular necrosis. There was intermediate to excellent agreement (kappa = 0. 4-1.0) for all complications evaluated. Thus, the agreement between self-reporting and medical records was good for complications with clear diagnostic criteria that are easily communicated to the patient, but was diminished for complications with non-established diagnostic criteria (xerophthalmia) or a fluctuating course (peripheral neuropathies and hypertension). Overall these results suggest that cancer survivors can self-report serious complications with an acceptable level of accuracy in epidemiological research.

Adult↗
PubMed2000

Patterns of infection and day care utilization and risk of childhood acute lymphoblastic leukaemia.

To investigate if decreased exposure to common childhood infections is associated with risk of childhood acute lymphoblastic leukaemia (ALL) we conducted a case-control study of 1842 newly diagnosed and immunophenotypically defined cases of ALL under age 15, and 1986 matched controls in the US. Data regarding day care, sibship size and common childhood infections were obtained through parental interviews. Data were analysed stratified by leukaemia lineage and separately for 'common' childhood ALL (age 2-5 years, CD19, CD10-positive). Neither attendance at day care nor time at day care was associated with risk of ALL overall or 'common' ALL. Ear infections during infancy were less common among cases, with odds ratios of 0.86, 0.83, 0.71 and 0.69 for 1, 2-4, 5+ episodes, and continuous infections respectively (trend P = 0.026). No effect of sibship size or birth interval was seen. With one exception (ear infections), these data do not support the hypothesis that a decrease in the occurrence of common childhood infection increases risk of ALL.

Adolescent↗
PubMed2000

Do confounding or selection factors of residential wiring codes and magnetic fields distort findings of electromagnetic fields studies?

In contrast with several previous studies, our recent large case-control study found little association between childhood acute lymphoblastic leukemia (ALL) and electric-power-line wire codes. Here we examine internal evidence from our study to assess the possibility that selection bias and/or confounding may have affected the findings. We compared the relation between childhood ALL and wire codes and direct measurements of magnetic fields in subjects who participated in all phases of the study with the relation in all subjects, including those who declined to allow access inside the home. We found that the odds ratio for ALL among those living in homes with very high current configurations increased by 23% when 107 "partial participants" were excluded. We found similar, but slightly smaller, increases in the odds ratios when we performed the same comparisons using direct measurements of magnetic fields, excluding subjects who allowed only a measurement outside the front door. "Partial participants" tended to be characterized by lower socioeconomic status than subjects who participated fully, suggesting possible selection bias. We also examined the relation between a large number of potential confounding variables and both proxy and direct measurements of magnetic fields. Univariate adjustment for individual variables changed the odds ratio for ALL by less than 8%, while simultaneous adjustment for several factors reduced the estimate by a maximum of 15%. We conclude that while confounding alone is unlikely to be an important source of bias in our own and previous studies of magnetic fields, selection bias may be more of a concern, particularly in light of the generally low response rates among controls in case-control studies.

Case-Control Studies↗
PubMed2000

Glutathione S-transferase polymorphisms in children with myeloid leukemia: a Children's Cancer Group study.

GSTM1 and GSTT1 are polymorphic genes. Absence of enzyme activity is due to homozygous inherited deletion of the gene, reducing detoxification of carcinogens such as epoxides and alkylating agents and potentially increasing cancer risk. We hypothesized that GST null genotype would increase risk of acute myeloid leukemia and myelodysplasia (AML/MDS) in children. DNA was extracted from bone marrow slides of 292 AML/MDS patients. PCR amplification was used to assign GSTM1 and GSTT1 genotypes for cases and controls. Given that the frequency of the null genotype varies by ethnicity and that the majority of the cases were Caucasian, analyses were restricted to 232 white (non-Hispanic) cases and 153 Caucasian non cancer controls. The frequency of GSTM1 null was significantly increased in AML/MDS cases compared with controls [64 versus 47%; odds ratio (OR), 2.0 [95% confidence interval (CI), 1.3-3.1]; P = 0.001], whereas the frequency of GSTT1 null genotype in AML/MDS cases was not statistically different from controls. AML comprises biologically distinct subtypes, and a test for homogeneity revealed a statistically significant difference among subtypes (P = 0.04; df, 8) for GSTM1 only. In particular, there was an increased frequency of GSTM1 null genotypes in French-American-British groups M3 [82%; n = 22; OR, 5.1 (95% CI, 1.6-21.3)] and M4 [72%; n = 53; OR, 2.9 (95% CI, 1.4-6.0)]. We conclude that the GSTM1 null genotype is a significant risk factor for childhood AML, particularly French-American-British groups M3 and M4. This may indicate an important role for exogenous carcinogens in the etiology of childhood AML.

Child↗
PubMed1999

Breast-feeding and risk of childhood acute leukemia.

BACKGROUND: Breast-feeding is well known to have a protective effect against infection in infants. Although the long-term effects of breast-feeding on childhood cancer have not been studied extensively, a protective effect against childhood Hodgkin's disease and lymphoma has been suggested previously from small investigations. In this study, we tested the hypothesis that breast-feeding decreases the risk of childhood acute leukemia. METHODS: A total of 1744 children with acute lymphoblastic leukemia (ALL) and 1879 matched control subjects, aged 1-14 years, and 456 children with acute myeloid leukemia (AML) and 539 matched control subjects, aged 1-17 years, were included in the analysis. Information regarding breast-feeding was obtained through telephone interviews with mothers. All leukemias combined, histologic type of leukemia (ALL versus AML), immunophenotype of ALL (early pre-B cell, pre-B cell, or T cell), and morphology of AML were assessed separately in the data analysis. RESULTS: Ever having breast-fed was found to be associated with a 21% reduction in risk of childhood acute leukemias (odds ratio [OR] for all types combined = 0.79; 95% confidence interval [CI] = 0.70-0.91). A reduction in risk was seen separately for AML (OR = 0.77; 95% CI = 0.57-1.03) and ALL (OR = 0.80; 95% CI = 0.69-0.93). The inverse associations were stronger with longer duration of breast-feeding for total ALL and AML; for M0, M1, and M2 morphologic subtypes of AML; and for early pre-B-cell ALL. CONCLUSION: In this study, breast-feeding was associated with a reduced risk of childhood acute leukemia. If confirmed in additional epidemiologic studies, our findings suggest that future epidemiologic and experimental efforts should be directed at investigating the anti-infective and/or immune-stimulatory or immune-modulating effects of breast-feeding on leukemogenesis in children.

Acute Disease↗
PubMed1999

Parental cigarette smoking and the risk of acute leukemia in children.

BACKGROUND: Studies of the relation between parental smoking and childhood leukemia have produced inconsistent results. In the largest case-control studies of childhood acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) conducted to date, the authors evaluated leukemia risk relative to parental self-report of cigarette smoking. METHODS: In telephone interviews in which a structured questionnaire was used, parents of 1842 ALL patients, 517 AML patients, and their matched controls were asked about their cigarette smoking habits before, during, and after the pregnancy with the index child. Risk of leukemia was examined by histologic type, age of the child at diagnosis, immunophenotype (for ALL), and French-American-British morphology group (for AML). RESULTS: The risk of ALL was not associated with the father's ever having smoked (odds ratio [OR] = 1.04, 95% confidence interval [CI] 0.90-1.20) or the mother's ever having smoked (OR = 1.04, 95% CI 0.91-1.19). Similarly, no significant risk of AML was observed for paternal (OR = 0.88, 95% CI 0.67-1.16) or maternal smoking (OR = 0.95, 95% CI 0.74-1.22). The relative risk of leukemia was not significantly different from the null for parental smoking in any time period during or around the index pregnancy, nor was it related to the number of cigarettes, the number of years of smoking, or the number of pack-years. A small number of sporadic, statistically significant associations were found, but overall there appeared to be no association between parental cigarette smoking and ALL or AML, or any subgroup of leukemia. CONCLUSIONS: Parental smoking while pregnant or exposure to cigarette smoke shortly after birth is unlikely to contribute substantially to the risk of childhood leukemia in North America.

Acute Disease↗
PubMed1999

Marriage in the survivors of childhood cancer: a preliminary description from the Childhood Cancer Survivor Study.

BACKGROUND: The goal of this paper is to provide a preliminary description of the marital status for a large number of childhood cancer survivors participating in the Childhood Cancer Survivor Study (CCSS). PROCEDURE: This report includes children and adolescents (< 21 years of age) diagnosed with cancer between 1970 and 1986 at 25 oncology centers in the United States and Canada who survived at least 5 years from diagnosis. Self-reported data from 10,425 survivors are used in this preliminary descriptive summary. The proportion of survivors ever married and divorced/separated is compared to the U.S. population according to age-specific groups. The median age of the survivor population at diagnosis was 7 years and 26 years at the time martial status was ascertained. Excluded from this assessment are children < 15 years of age at the time of study, those whose martial status was unknown, and those married prior to diagnosis. Data for marital status of the U.S. population, as tabulated in the Bureau of Census 1995 Update, is used as a general comparison to the survivor population. RESULTS: Overall, 32% of the survivors reported being married or living as married, 6% being divorced or separated, 0% being widowed, and 62% having never been married. In general, compared to the U.S. population, survivors were less likely to have ever married, particularly females and whites, but, once married, were less likely to divorce/separate, again particularly females and whites. Black survivors were generally found to be more likely to have married, with males and blacks more likely to divorce/separate once married. Comparison of childhood tumor types suggested that survivors of CNS tumors, particularly males, were less likely to have ever married and more likely to divorce/separate compared to those with other cancer diagnoses and the general U.S. population. CONCLUSIONS: This interim evaluation of the CCSS cohort provided preliminary data describing a suggested decreased likelihood of marriage, which may be influenced by gender and/or race. These patterns must be confirmed within the entire CCSS cohort and comparisons made with an appropriate sibling comparison group before making final conclusions.

Adolescent↗
PubMed1999

Family history of cancer in children and young adults with colorectal cancer.

BACKGROUND: Family history of colorectal cancer among adult patients has been reported in the literature. Although extremely rare in children, colorectal cancer in this population may represent a unique group in whom genetic factors play a significant etiologic role. The aim of the present study was to assess genetic contribution, as measured by family history, to the development of colorectal cancer in probands under 21 years of age at diagnosis. PROCEDURE: Detailed family histories were obtained from surviving patients or their parents. The risk [standardized incidence ratio (SIR)] of cancer in the relatives was calculated by comparing the observed and the expected incidence based on rates in the general population and person-years at risk. RESULTS: Twenty-five patients (median age at diagnosis 15 years) diagnosed with colorectal cancer at St. Jude Children's Research Center since 1964 or their surviving next of kin were available for interview. The 461 relatives contributed 18,908 person-years of follow-up. Statistically significant increased risk of colorectal cancer was present among all relatives (SIR = 6.0, 95% CI, 2.7-10.6), and the increased risk of colorectal cancer was confined to relatives of probands who were under 15 years of age at diagnosis (SIR = 10.0, 95% CI, 4.5-17.6). In addition, there was an excess of uterine/cervical cancer among all female relatives (SIR = 6.5, 95% CI, 3.2-10.9). CONCLUSIONS: The observed excess of colorectal cancer, in relatives of younger probands, suggests the need to examine these kindreds for genetic instability resulting from defects in mismatch repair genes to characterize further the patterns of risk observed.

Adolescent↗
PubMed1999

Infant vaccinations and risk of childhood acute lymphoblastic leukaemia in the USA.

Previous studies have suggested that infant vaccinations may reduce the risk of subsequent childhood leukaemia. Vaccination histories were compared in 439 children (ages 0-14) diagnosed with acute lymphoblastic leukaemia (ALL) in nine Midwestern and Mid-Atlantic states (USA) between 1 January 1989 and 30 June 1993 and 439 controls selected by random-digit dialing and individually matched to cases on age, race and telephone exchange. Among matched pairs, similar proportions of cases and controls had received at least one dose of oral poliovirus (98%), diphtheria-tetanus-pertussis (97%), and measles-mumps-rubella (90%) vaccines. Only 47% of cases and 53% of controls had received any Haemophilus influenzae type b (Hib) vaccine (relative risk (RR) = 0.73; 95% confidence interval (CI) 0.50-1.06). Although similar proportions of cases (12%) and controls (11%) received the polysaccharide Hib vaccine (RR = 1.13; 95% CI 0.64-1.98), more controls (41%) than cases (35%) received the conjugate Hib vaccine (RR = 0.57; 95% CI 0.36-0.89). Although we found no relationship between most infant vaccinations and subsequent risk of childhood ALL, our findings suggest that infants receiving the conjugate Hib vaccine may be at reduced risk of subsequent childhood acute lymphoblastic leukemia. Further studies are needed to confirm this association and, if confirmed, to elucidate the underlying mechanism.

Adolescent↗
PubMed1999

Seasonal variations in the diagnosis of childhood cancer in the United States.

Seasonal trends in month of diagnosis have been reported for childhood acute lymphoblastic leukaemia (ALL) and non-Hodgkin's lymphoma (NHL). This seasonal variation has been suggested to represent an underlying viral aetiology for these malignancies. Some studies have shown the highest frequency of diagnoses in the summer months, although this has been inconsistent. Data from the Children's Cancer Group and the Pediatric Oncology Group were analysed for seasonal incidence patterns. A total of 20,949 incident cancer cases diagnosed in the USA from 1 January 1989 through 31 December 1991 were available for analyses. Diagnosis-specific malignancies available for evaluation included ALL, acute myeloid leukaemia (AML), Hodgkin's disease, NHL, rhabdomyosarcoma, neuroblastoma, retinoblastoma, osteosarcoma, Wilms' tumour, retinoblastoma, Ewings' sarcoma, central nervous system (CNS) tumours and hepatoblastoma. Overall, there was no statistically significant seasonal variation in the month of diagnosis for all childhood cancers combined. For diagnosis-specific malignancies, there was a statistically significant seasonal variation for ALL (P = 0.01; peak in summer), rhabdomyosarcoma (P = 0.03; spring/summer) and hepatoblastoma (P = 0.01; summer); there was no seasonal variation in the diagnosis of NHL. When cases were restricted to latitudes greater than 40 degrees ('north'), seasonal patterns were apparent only for ALL and hepatoblastoma. Notably, 33% of hepatoblastoma cases were diagnosed in the summer months. In contrast, for latitudes less than 40 degrees ('south'), only CNS tumours demonstrated a seasonal pattern (P = 0.002; winter). Although these data provide modest support for a summer peak in the diagnosis of childhood ALL, any underlying biological mechanisms that account for these seasonal patterns are likely complex and in need of more definitive studies.

Adolescent↗
PubMed1999

Indoor residential radon exposure and risk of childhood acute myeloid leukaemia.

Exposure to radon has been identified as a risk factor for lung cancer in uranium miners, but evidence of adverse health effects due to indoor radon exposure is inconsistent. Ecological studies have suggested a correlation between indoor radon levels and leukaemia incidence. We evaluated the risk associated with indoor residential radon exposure within a larger interview-based case-control study of risk factors for childhood acute myeloid leukaemia (AML). A total of 173 cases and 254 controls met the eligibility criteria, and information was collected through telephone interviews with parents and analysis of alpha-track radon detectors placed in the home for a period of 1 year. No association was observed between radon exposure and risk of AML, with adjusted odds ratios of 1.2 (95% confidence interval (CI) 0.7-1.8) for 37-100 Bq m(-3) and 1.1 (95% CI 0.6-2.0) for > 100 Bq m(-3) compared with < 37 Bq m(-3). Although there was an inverse association between radon level and AML risk among children < 2 years at diagnosis, among children > or = 2 years, AML risk was increased among those with higher radon exposure. The observed association after age 2 is most likely due to chance. Overall, there was no association between residential radon and risk of childhood AML.

Acute Disease↗