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Biomedical subjects

A F Olshan

Publications and source records attributed to A F Olshan.

At least 19 recordsLinked to original sources
PubMed2005

Relation between ambient air quality and selected birth defects, seven county study, Texas, 1997-2000.

A population-based case-control study investigated the association between maternal exposure to air pollutants, carbon monoxide, nitrogen dioxide, ozone, sulfur dioxide, and particulate matter <10 microm in aerodynamic diameter during weeks 3-8 of pregnancy and the risk of selected cardiac birth defects and oral clefts in livebirths and fetal deaths between 1997 and 2000 in seven Texas counties. Controls were frequency matched to cases on year of birth, vital status, and maternal county of residence at delivery. Stationary monitoring data were used to estimate air pollution exposure. Logistic regression models adjusted for covariates available in the vital record. When the highest quartile of exposure was compared with the lowest, the authors observed positive associations between carbon monoxide and tetralogy of Fallot (odds ratio = 2.04, 95% confidence interval: 1.26, 3.29), particulate matter <10 microm in aerodynamic diameter and isolated atrial septal defects (odds ratio = 2.27, 95% confidence interval: 1.43, 3.60), and sulfur dioxide and isolated ventricular septal defects (odds ratio = 2.16, 95% confidence interval: 1.51, 3.09). There were inverse associations between carbon monoxide and isolated atrial septal defects and between ozone and isolated ventricular septal defects. Evidence that air pollution exposure influences the risk of oral clefts was limited. Suggestive results support a previously reported finding of an association between ozone exposure and pulmonary artery and valve defects.

Air Pollutants↗
PubMed2004

Childhood and maternal infections and risk of acute leukaemia in children with Down syndrome: a report from the Children's Oncology Group.

Children with Down syndrome (DS) are highly susceptible to acute leukaemia. Given the potential role of infections in the aetiology of leukaemia in children without DS, we investigated whether there was an association between early-life infections and acute leukaemia in children with DS. Maternal infections during pregnancy were also examined. We enrolled 158 incident cases of acute leukaemia in children with DS (97 acute lymphoblastic leukaemia (ALL) and 61 acute myeloid leukaemia (AML)) diagnosed at Children's Oncology Group institutions between 1997 and 2002. DS controls (N=173) were selected from the cases' primary care clinics and frequency matched on age at leukaemia diagnosis. Data were collected on demographics, child's medical history, mother's medical history, and other factors by maternal interview. Analyses were conducted using unconditional logistic regression adjusted for potential confounders. A significant negative association was observed between acute leukaemia and any infection in the first 2 years of life (adjusted odds ratio (OR)=0.55, 95% confidence interval (CI) (0.33-0.92); OR=0.53, 95% CI (0.29-0.97); and OR=0.59, 95% CI (0.28-1.25) for acute leukaemia combined, ALL, and AML respectively). The association between acute leukaemia and maternal infections during pregnancy was in the same direction but not significant. This study offers support for the hypothesis that early-life infections may play a protective role in the aetiology of acute leukaemia in children with DS.

Acute Disease↗
PubMed2003

Diet, GSTM1 and GSTT1 and head and neck cancer.

A decreased incidence of squamous cell carcinoma of the head and neck (SCCHN) associated with fruit and vegetable intake may act through chemopreventive compounds, which may be more available to persons homozygous for the deletion genotypes of the glutathione S-transferase (GST). We evaluated interactions between fruits and vegetables and GSTM1 and GSTT1 on incidence of SCCHN using data from a case-control study of 149 cases and 180 age- and gender-matched controls. After adjustment for age, gender, race, tobacco and alcohol use, weekly consumption of four or more servings of raw vegetables was inversely associated with SCCHN [odds ratio (OR) = 0.66, 95% confidence intervals (CI) 0.30-1.3]. Contrary to expectation, relatively high intake of cooked vegetables (14 or more weekly servings) and legumes (two or more weekly servings) were associated with increased incidence (OR = 2.5, 95% CI 1.1-6.0; OR = 2.5, 95% CI 1.2-5.2, respectively). In general, our results did not suggest a clear or consistent pattern of modification by GST genotypes of the association between foods and SCCHN. For example, eating cruciferous vegetables, foods of a priori interest, and having the GSTM1-deletion genotype was not associated with the expected reduction in incidence compared with abstaining from cruciferous vegetable intake and having the GSTM1-present genotype. Among non-consumers of cruciferous vegetables, the GSTM1-deletion genotype was inversely associated with SCCHN (OR = 0.55, 95% CI 0.07-4.2). Raw vegetables were associated with a reduction in incidence only among persons with the GSTM1-deletion genotype (OR = 0.69, 95% CI 0.29-1.6), whereas either factor alone had a null association. Future research of GST-diet interactions and SCCHN would benefit from larger, population-based studies.

Adult↗
PubMed2002

A case-control study of tobacco use and other non-occupational risk factors for t(14;18) subtypes of non-Hodgkin's lymphoma (United States).

OBJECTIVE: Non-Hodgkin's lymphoma (NHL) encompasses diverse subtypes, and analyzing NHL as a single outcome may mask associations. In a new approach we evaluated associations with subtypes defined by the t(14;18) translocation, reasoning that cases within these subtypes would have more common risk factors than all NHL combined. METHODS: Archival biopsies from cases in a population-based NHL study were assayed for t(14;18) using polymerase chain reaction amplification. Exposures in 68 t(14;18)-positive and 114-negative cases were compared with 1245 controls. The expectation-maximization algorithm was used to fit polytomous regression models based on all available information, including data from 440 unclassified cases. RESULTS: Family history of hemolymphatic cancer was associated with t(14;18)-negative NHL (odds ratio (OR) 2.4, 95% confidence interval (CI) 1.4 3.9). but not t(14;18)-positive NHL. Cigarette smoking was weakly associated with t(14;18)-positive NHL (OR 1.7, CI 0.9-3.3), but ORs decreased as smoking increased. Chewing tobacco was associated with t(14;18)-positive NHL, particularly when used before age 18 (OR 2.5. CI 1.0-6.0, 13 exposed cases). Odds ratios for both case-subtypes were doubled among hair-dye users. CONCLUSIONS: Cigarette smoking was not clearly associated with t(14;18)-positive NHL. Family history may be a marker for factors that act specifically through t(14;18)-negative pathogenic mechanisms.

Adolescent↗
PubMed2002

Occupational exposure assessment in case-control studies: opportunities for improvement.

Community based case-control studies are an efficient means to study disease aetiologies, and may be the only practical means to investigate rare diseases. However, exposure assessment remains problematic. We review the literature on the validity and reliability of common case-control exposure assessment methods: occupational histories, job-exposure matrices (JEMs), self reported exposures, and expert assessments. Given the variable quality of current exposure assessment techniques, we suggest methods to improve assessments, including the incorporation of hygiene measurements: using data from administrative exposure databases; using results of studies identifying determinants of exposure to develop questionnaires; and where reasonable given latency and biological half life considerations, directly measuring exposures of study subjects.

Case-Control Studies↗
PubMed2001

Parental occupational exposures to chemicals and incidence of neuroblastoma in offspring.

To evaluate the effects of parental occupational chemical exposures on incidence of neuroblastoma in offspring, the authors conducted a multicenter case-control study, using detailed exposure information that allowed examination of specific chemicals. Cases were 538 children aged 19 years who were newly diagnosed with confirmed neuroblastoma in 1992-1994 and were registered at any of 139 participating hospitals in the United States and Canada. One age-matched control for each of 504 cases was selected through random digit dialing. Self-reported exposures were reviewed by an industrial hygienist, and improbable exposures were reclassified. Effect estimates were calculated using unconditional logistic regression, adjusting for child's age and maternal demographic factors. Maternal exposures to most chemicals were not associated with neuroblastoma. Paternal exposures to hydrocarbons such as diesel fuel (odds ratio (OR) = 1.5; 95% confidence interval (CI): 0.8, 2.6), lacquer thinner (OR = 3.5; 95% CI: 1.6, 7.8), and turpentine (OR = 10.4; 95% CI: 2.4, 44.8) were associated with an increased incidence of neuroblastoma, as were exposures to wood dust (OR = 1.5; 95% CI: 0.8, 2.8) and solders (OR = 2.6; 95% CI: 0.9, 7.1). The detailed exposure information available in this study has provided additional clues about the role of parental occupation as a risk factor for neuroblastoma.

Adolescent↗
PubMed2001

GSTM1, GSTT1, and the risk of squamous cell carcinoma of the head and neck: a mini-HuGE review.

Squamous cell carcinoma of the head and neck (SCCHN) is a group of cancers of epithelial origin that may provide an ideal model for the study of gene-environment interaction. SCCHN includes squamous cell carcinomas of the oral cavity, pharynx, and larynx. Approximately 90% of the attributable risk for oral cancer and 80% of the attributable risk for larynx cancer results from tobacco use. Tobacco smoking has been demonstrated to increase the risk of SCCHN in a dose-response fashion. Polymorphisms of carcinogen-metabolizing enzymes, known to be involved in metabolism of carcinogens found in tobacco smoke, are relatively common in most populations. This paper provides a concise review of the 24 published studies that evaluated the risk of SCCHN in relation to two deletion polymorphisms of the glutathione S-transferase family: GSTM1 and GSTT1. Patterns of risk based on the site of the tumor and on nationality are presented, as are some methodological weaknesses of the studies. The results of these studies are inconsistent, with some reporting weak-to-moderate associations and others finding no elevation in risk for the main effect of the gene. Few studies have directly evaluated the interaction with tobacco. Well-designed, population-based studies of adequate size are needed.

Americas↗
PubMed2001

Comparison of assessment methods for pesticide exposure in a case-control interview study.

In epidemiologic studies, much of the variation in disease risk estimates associated with occupational pesticide exposure may be due to variation in exposure classification. The authors compared five different methods of using interview information to assess occupational pesticide exposure in a US-Canada case-control study of neuroblastoma (1992-1994). For each method, exposure assignment was compared with that of a reference method, and neuroblastoma effect estimates were calculated. Compared with the reference method, which included a complete review of occupation, industry, job tasks, and exposure-specific activities, the use of occupation-industry groups alone or in combination with general job task information diluted the exposed group by including individuals who were unlikely to have been truly exposed. The effect estimates representing associations between each exposure method and neuroblastoma were different enough to influence the study's conclusions, especially when the exposure was rare (for maternal occupational pesticide exposure, the odds ratio was 0.7 using the reference exposure assessment method and 3.2 using the occupation-industry group exposure assessment method). Exposure-specific questions about work activities can help investigators distinguish truly exposed individuals from those who report exposure but are unlikely to have been exposed above background levels and from those who have not been exposed but are misclassified as exposed because of their employment in an occupation-industry group determined a priori to be exposed.

Adult↗
PubMed2001

An application of hierarchical regression in the investigation of multiple paternal occupational exposures and neuroblastoma in offspring.

BACKGROUND: We used hierarchical regression to study the effects of 46 paternal occupational exposures on the incidence of neuroblastoma in offspring. METHODS: The study population included 405 cases and 302 controls. The effect of each exposure was estimated using both conventional maximum likelihood and hierarchical regression. RESULTS: Using hierarchical regression, overall precision was greatly enhanced compared to the conventional analysis. In addition, adjustment of effect estimates based on prespecified prior distributions of the true effect parameters allowed a more consistent interpretation across the entire panel of exposures. Estimates for several metals and solvents were shrunk close to the null value, whereas estimates for several thinner solvents, diesel fuel, solders, wood dust, and grain dust remained moderately elevated. CONCLUSIONS: Hierarchical regression may mitigate some of the problems of the conventional approach by controlling for correlated exposures, enhancing the precision of estimates, and providing some adjustment of estimates based on prior knowledge.

Adult↗
PubMed2001

Diagnostic radiation and the risk of multiple myeloma (United States).

OBJECTIVE: To evaluate the relationship between cumulative lifetime exposure to diagnostic radiation and the risk of multiple myeloma using data from a large, multi-center, population-based case-control study. METHODS: Study subjects included a total of 540 cases with newly diagnosed multiple myeloma and 1998 frequency-matched population controls living in three areas of the United States (Georgia, Michigan, New Jersey). Information on exposure to diagnostic X-rays was obtained by personal interview. RESULTS: No association was found between case-control status and the total number of reported diagnostic X-rays of any type (odds ratio (OR) for 20 or more compared to less than 5 X-rays = 0.9, 95% confidence interval (95% CI) = 0.7-1.2). There was no evidence of an excess risk of multiple myeloma among individuals who reported exposure to 10 or more diagnostic X-rays that impart a relatively high radiation dose to the bone marrow, as compared to individuals reporting no such exposures (OR 0.7, 95% CI 0.4-1.3). CONCLUSIONS: These data suggest that exposure to diagnostic X-rays has a negligible impact, if any, on risk of developing multiple myeloma.

Adult↗
PubMed2001

Association of pregnancy history and birth characteristics with neuroblastoma: a report from the Children's Cancer Group and the Pediatric Oncology Group.

Previous studies have suggested a relationship between reproductive history, pregnancy and birth factors, and the risk of neuroblastoma. We conducted a case-control telephone interview study that included a total of 504 children under the age of 19 years with newly diagnosed neuroblastoma identified by two national collaborative clinical trials groups, the Children's Cancer Group and the Pediatric Oncology Group. A total of 504 controls, matched to cases on age, were identified by random digit dialing. Conditional logistic regression was used to estimate the matched odds ratio (OR) and 95% confidence interval (CI) with adjustment for household income, and maternal race and education. In addition, case subgroups defined by age at diagnosis, tumour MYCN oncogene amplification status, and stage were evaluated. A suggestive pattern of increased risk was seen for a greater number of prior pregnancies, history of previous miscarriages and induced abortions, with nearly a twofold increase in risk for two or more prior induced abortions (OR = 1.9, 95% CI [1.0,3.7]). No association was found for the following diseases or conditions during pregnancy: hepatitis, rubella, measles, mumps, chickenpox, mononucleosis, vaccinations, morning sickness, pre-eclampsia, bleeding, proteinuria, anaemia, urinary tract infections, heart disease, kidney disease, liver disease and diabetes. A weak association was found for hypertension during pregnancy. Several labour and delivery factors were related to an increased risk, including threatened miscarriage, anaesthetic during labour (specifically epidural) and caesarean delivery. We found associations between premature delivery (<33 weeks: OR = 1.9, 95% CI [0.7,4.8]), very low birthweight (<1500 g: OR = 2.6, 95% CI [0.7,10.3]) and risk of neuroblastoma. There was no consistent pattern of increased risk found for most factors within subgroups defined by age at diagnosis, stage or MYCN status.

Adolescent↗
PubMed2001

Risk of head and neck cancer and the alcohol dehydrogenase 3 genotype.

Squamous cell carcinoma of the head and neck (SCCHN), including the oral cavity, pharynx and larynx, is an excellent tumor model to evaluate gene-environment interactions, including alcohol and alcohol-metabolizing enzymes such as alcohol dehydrogenase (ADH). We conducted a hospital-based case-control study including 182 cases with newly diagnosed SCCHN and 202 controls with non-neoplastic conditions of the head and neck that required surgery. The joint effects of lifetime alcohol use and the presence of the ADH3 'rapid' allele (ADH3(*)1) was evaluated in relation to the risk of SCCHN. Logistic regression was used to estimate the interaction between alcohol use and ADH3 genotype with adjustment for tobacco use, age, sex and race. The interaction was evaluated on both the multiplicative and additive scales. The risk of SCCHN was increased nearly 6-fold with consumption of 40 or more alcoholic beverages per week [odds ratio (OR) = 5.9; 95% confidence interval (CI) = 2.0-17.7; adjusted for age, sex, race and years of tobacco use]. We did not find any increase in risk for ADH3*1 homozygotes (OR = 0.9; CI = 0.4-1.9) or heterozygotes (OR = 0.8; CI = 0.4-1.7) relative to ADH3(*)2 homozygotes. There was no suggestion of an interaction between any alcohol use variable and the ADH3(*)1 genotype. For example, the interaction term, including the continuous variable average number of drinks per week and the ADH3 genotypes, was non-significant (P = 0.22). The study does not indicate an important role for the ADH3 (*)1 polymorphism in SCCHN, but larger numbers are needed to more precisely estimate the interaction, if any, with ADH3.

Alcohol Dehydrogenase↗
PubMed2001

Residential pesticide exposure and neuroblastoma.

Neuroblastoma is the most common neoplasm in children under 1 year of age. We examined the relation between residential exposure to pesticides and neuroblastoma, using data from a case-control study of risk factors for neuroblastoma. Incident cases of neuroblastoma (N = 538) were identified through the Pediatric Oncology Group and the Children's Cancer Group. One age-matched control was identified for each case by random digit dialing. Telephone interviews with each parent collected information on residential exposure to pesticides. Pesticide use in both the home and garden were modestly associated with neuroblastoma [odds ratio (OR) = 1.6 (95% confidence interval [95% CI] = 1.0-2.3, and OR = 1.7 (95% CI = 0.9-2.1), respectively]. Compared with infants [OR = 1.0 (95% CI = 0.6-2.0)], stronger associations were found for garden pesticides in children diagnosed after 1 year of age [OR = 2.2 (95% CI = 1.3-3.6)], which suggests that pesticides may act through a mechanism more common for neuroblastomas in older children. There was no evidence of differential pesticide effects in subgroups of neuroblastoma defined by MYCN oncogene amplification or tumor stage.

Canada↗
PubMed2001

Parental occupational exposures to electromagnetic fields and radiation and the incidence of neuroblastoma in offspring.

We examined parental occupational exposures to electromagnetic fields and radiation and the incidence of neuroblastoma in offspring. Cases were 538 children diagnosed with neuroblastoma between 1992 and 1994 in the United States or Canada. Age-matched controls were selected by random-digit dialing. Occupational exposures to electrical equipment and radiation sources were classified by an industrial hygienist, and average exposures to extremely low frequency magnetic fields were estimated using a job exposure matrix. Maternal exposure to a broad grouping of sources that produce radiofrequency radiation was associated with an increased incidence of neuroblastoma (odds ratio = 2.8; 95% confidence interval = 0.9-8.7). Paternal exposure to battery-powered forklifts was positively associated with neuroblastoma (odds ratio = 1.6; 95% confidence interval = 0.8-3.2), as were some types of equipment that emit radiofrequency radiation (odds ratios congruent with 2.0); however, the broad groupings of sources that produce ELF fields, radiofrequency radiation, or ionizing radiation were not associated with neuroblastoma. Paternal average extremely low frequency magnetic field exposure >0.4 microTesla was weakly associated with neuroblastoma (odds ratio = 1.6; 95% confidence interval = 0.9-2.8), whereas maternal exposure was not. Overall, there was scant supportive evidence of strong associations between parental exposures in electromagnetic spectrum and neuroblastoma in offspring.

Case-Control Studies↗
PubMed2001

Agricultural risk factors for t(14;18) subtypes of non-Hodgkin's lymphoma.

The t(14;18) translocation is a common somatic mutation in non-Hodgkin's lymphoma (NHL) that is associated with bcl-2 activation and inhibition of apoptosis. We hypothesized that some risk factors might act specifically along t(14;18)-dependent pathways, leading to stronger associations with t(14;18)-positive than t(14;18)-negative non-Hodgkin's lymphoma. Archival biopsies from 182 non-Hodgkin's lymphoma cases included in a case-control study of men in Iowa and Minnesota (the Factors Affecting Rural Men, or FARM study) were assayed for t(14;18) using polymerase chain reaction amplification; 68 (37%) were t(14;18)-positive. We estimated adjusted odds ratios (OR) and 95% confidence intervals (CI) for various agricultural risk factors and t(14;18)-positive and -negative cases of non-Hodgkin's lymphoma, based on polytomous logistic regression models fit using the expectation-maximization (EM) algorithm. T(14;18)-positive non-Hodgkin's lymphoma was associated with farming (OR 1.4, 95% CI = 0.9-2.3), dieldrin (OR 3.7, 95% CI = 1.9-7.0), toxaphene (OR 3.0, 95% CI = 1.5-6.1), lindane (OR 2.3, 95% CI = 1.3-3.9), atrazine (OR 1.7, 95% CI = 1.0-2.8), and fungicides (OR 1.8, 95% CI = 0.9-3.6), in marked contrast to null or negative associations for the same self-reported exposures and t(14;18)-negative non-Hodgkin's lymphoma. Causal relations between agricultural exposures and t(14;18)-positive non-Hodgkin's lymphoma are plausible, but associations should be confirmed in a larger study. Results suggest that non-Hodgkin's lymphoma classification based on the t(14;18) translocation is of value in etiologic research.

Adult↗
PubMed2000

Occupation and adult gliomas.

Lifetime job histories from a population-based, case-control study of gliomas diagnosed among adults in the San Francisco Bay area between August 1991 and April 1994 were evaluated to assess occupational risk factors. Occupational data for 476 cases and 462 controls were analyzed, with adjustment for age, gender, education, and race. Imprecise increased risks were observed for physicians and surgeons (odds ratio (OR) = 3.5, 95% confidence interval (CI): 0.7, 17.6), artists (OR = 1.9, 95% CI: 0.5, 6.5), foundry and smelter workers (OR = 2.6, 95% CI: 0.5, 13.1), petroleum and gas workers (OR = 4.9, 95% CI: 0.6, 42.2), and painters (OR = 1.6, 95% CI: 0.5, 4.9). Legal and social service workers, shippers, janitors, motor vehicle operators, and aircraft operators had increased odds ratios only with longer duration of employment. Physicians and surgeons, foundry and smelter workers, petroleum and gas workers, and painters showed increased risk for both astrocytic and nonastrocytic tumors. Artists and firemen had increased risk for astrocytic tumors only, while messengers, textile workers, aircraft operators, and vehicle manufacturing workers showed increased risk only for nonastrocytic tumors. Despite study limitations, including small numbers for many of the occupational groups, a high percentage of proxy respondents among cases, and lack of specific exposure information, associations were observed for several occupations previously reported to be at higher risk for brain tumors generally and gliomas specifically.

Adult↗
PubMed2000

Evidence of recall bias in volunteered vs. prompted responses about occupational exposures.

BACKGROUND: Recall bias remains a concern in case-control studies, although few investigations have found evidence of differential recall. This study examined whether differences in occupational exposure reporting occur in volunteered vs. prompted questionnaire responses. METHODS: In a large, population-based, case-control study of a childhood cancer, neuroblastoma, we calculated odds ratios for broad occupational exposure groups on the assumption that in the absence of recall bias, risk estimates for such broad groupings should be close to the null value. RESULTS: Prompted exposures and work activities showed little evidence of differential recall by parents of cases and controls (all OR < 1.2), but case parents were more likely to volunteer information about other exposures or activities (ORs: 1.35-1.71). Case mothers were also more likely than control mothers to report activities involving indirect exposure (OR = 1.41). CONCLUSIONS: These findings suggest that prompted exposure questions are less likely to be subject to recall bias than open-ended questions.

Case-Control Studies↗