Trends in childhood brain tumor incidence, 1973-2009.

In the mid-1980s, there was a rise in incidence rates of childhood brain tumors (CBT) in the United States that appeared to stabilize at a higher rate in the early 1990 s. An updated analysis of the pattern of CBT over the past 2 decades, with commentary on whether the elevated incidence rate has continued, is past due. We used Surveillance, Epidemiology and End Results (SEER) data to examine trends in incidence of CBT from 1973 through 2009. We examined age-adjusted incidence rates (AAIRs) and secular trends for all malignant brain tumors combined (SEER classification) by histologic tumor type and anatomic site. The incidence of CBT remained stable from 1987 to 2009 [annual percent change (APC) = 0.10; 95 % confidence intervals (CI) -0.39 to 0.61] with an AAIR for all CBT of 3.32 (95 % CI 3.22-3.42). The stability of rates in these two decades contrast the change that occurred in the mid-1980s (1983-1986), when the incidence of CBT increased by 53 % (APC = 14.06; 95 % CI 4.05-25.0). From 1983 to 1986, statistically significant rate increases were observed for pilocytic astrocytoma, PNET/medulloblastoma, and mixed glioma. Further, the rate of increase in pilocytic astrocytoma was similar to the rate of decrease for astrocytomas NOS from 1981 to 2009, suggesting a change from a more general to more specific classification. After the increase in rates in the mid-1980s, rates of CBT over the past two decades have stabilized. Changes in incidence rates of subtypes of tumors over this time period reflect changes both in classification of CBT and in diagnostic techniques.

Ambient air pollution and brain cancer mortality.

OBJECTIVE: Growing evidence that ultrafine particles in ambient air can cause brain lesions in animals led us to investigate whether particulate components of air pollution may be associated with brain cancer risk in humans. Air pollution has been associated with respiratory disorders and cardiovascular morbidity and mortality, but associations between air pollutants and brain cancer have not been investigated in adults. METHODS: The analyses included 1,284 deaths due to brain cancer from the Cancer Prevention Study-II, an ongoing prospective mortality study of adults in the United States and Puerto Rico conducted by the American Cancer Society. Air pollution data from national databases for metropolitan areas were combined with residential history and vital status data to estimate exposure to particulate and gaseous air pollution. RESULTS: We found no elevated risk for estimated measures of air pollutants, an unanticipated reduction in risk was found between gaseous air pollutants and brain cancer mortality. CONCLUSION: The findings do not provide evidence of increased risk of brain cancer mortality due to air pollutants.

Comparing self-reported disease outcomes, diet, and lifestyles in a national cohort of black and white Seventh-day Adventists.

INTRODUCTION: Few epidemiologic cohort studies on the etiology of chronic disease are powerful enough to distinguish racial and ethnic determinants from socioeconomic determinants of health behaviors and observed disease patterns. The Adventist Health Study-2 (AHS-2), with its large number of respondents and the variation in lifestyles of its target populations, promises to shed light on these issues. This paper focuses on some preliminary baseline analyses of responses from the first group of participants recruited for AHS-2. METHODS: We administered a validated and pilot-tested questionnaire on various lifestyle practices and health outcomes to 56,754 respondents to AHS-2, comprising 14,376 non-Hispanic blacks and 42,378 non-Hispanic whites. We analyzed cross-sectional baseline data adjusted for age and sex and performed logistic regressions to test differences between responses from the two racial groups. RESULTS: In this Seventh-day Adventist (Adventist) cohort, blacks were less likely than whites to be lifelong vegetarians and more likely to be overweight or obese. Exercise levels were lower for blacks than for whites, but blacks were as likely as whites not to currently smoke or drink. Blacks reported higher rates of hypertension and diabetes than did whites but lower rates of high serum cholesterol, myocardial infarction, emphysema, and all cancers. After we eliminated skin cancer from the analysis, the age-adjusted prevalence of cancer remained significantly lower for black than for white women. The prevalence of prostate cancer was 47% higher for black men than for white men. CONCLUSION: The profile of health habits for black Adventists is better than that for blacks nationally. Given the intractable nature of many other contributors to health disparities, including racism, housing segregation, employment discrimination, limited educational opportunity, and poorer health care, the relative advantage for blacks of the Adventist lifestyle may hold promise for helping to close the gap in health status between blacks and whites nationally.

Descriptive epidemiology of vestibular schwannomas.

Vestibular schwannomas, commonly termed acoustic neuromas, arise from the vestibular branch of the eighth cranial nerve (acoustic nerve) and are benign, slow-growing brain tumors that negatively impact patient quality of life. They are thought to account for the majority of intracranial nerve sheath tumors. To describe incidence rate patterns and trends of primary nerve sheath tumors of the brain/CNS and the subset of vestibular schwannomas in two population-based incidence registries, data were obtained from 11 Central Brain Tumor Registry of the United States (CBTRUS) collaborating state registries and the Los Angeles County Cancer Surveillance Program (LACCSP) (1975-1998). Average annual incidence rates were tabulated by age, gender, race, year, and region and were age-adjusted to the year 2000 U.S. standard population. Multiplicative Poisson regression models were used to compare trends in primary nerve sheath tumors of the brain/CNS overall and in subgroups, including vestibular schwannomas, controlling for age, gender, race, microscopic confirmation, and region. Joinpoint regression analysis was used to identify any sharp changes in incidence over time. The overall incidence of primary nerve sheath tumors of the brain/CNS was 1.1 per 100,000 person-years (CBTRUS, 1995-1999 and LACCSP, 1995-1998). The incidence of vestibular schwannomas was similar for both data sets: 0.6 per 100,000 person-years (CBTRUS, 1995-1999) and 0.8 per 100,000 person-years (LACCSP, 1995-1998). Moreover, the incidence of primary nerve sheath tumors of the brain/CNS overall (CBTRUS, 1985-1999 and LACCSP, 1975-1998) and of vestibular schwannomas (CBTRUS, 1992-1999 and LACCSP, 1992-1998) increased over time. However, the incidence of benign schwannomas in sites other than the acoustic nerve either decreased (CBTRUS, 1992-1999) or experienced no significant change (LACCSP, 1992-1998). While improvements in diagnosis and reporting may explain some of these trends, further consideration of potential etiologic factors may be warranted.

Effects of human immunodeficiency virus on protracted amenorrhea and ovarian dysfunction.

OBJECTIVE: To characterize ovarian failure and prolonged amenorrhea from other causes in women who are both human immunodeficiency virus (HIV) seropositive and seronegative. METHODS: This was a cohort study nested in the Women's Interagency HIV Study, a multicenter U.S. study of HIV infection in women. Prolonged amenorrhea was defined as no vaginal bleeding for at least 1 year. A serum follicle stimulating hormone more than 25 milli-International Units/mL and prolonged amenorrhea were used to define ovarian failure. Logistic regressions, chi2, and t tests were performed to estimate relationships between HIV-infection and cofactors with both ovarian failure and amenorrhea from other causes. RESULTS: Results were available for 1,431 women (1,139 HIV seropositive and 292 seronegative). More than one half of the HIV positive women with prolonged amenorrhea of at least 1 year did not have ovarian failure. When adjusted for age, HIV seropositive women were about three times more likely than seronegative women to have prolonged amenorrhea without ovarian failure. Body mass index, serum albumin, and parity were all negatively associated with ovarian failure in HIV seropositive women. CONCLUSION: HIV serostatus is associated with prolonged amenorrhea. It is difficult to ascertain whether the cause of prolonged amenorrhea is ovarian in HIV-infected women without additional testing. LEVEL OF EVIDENCE: II-2.

Prior hospitalization for epilepsy, diabetes, and stroke and subsequent glioma and meningioma risk.

We conducted a case-control study to evaluate the preclinical association between epilepsy, diabetes, and stroke and primary adult brain tumors. We first identified all 1,501 low-grade glioma, 4,587 high-grade glioma (HGG), and 4,193 meningioma cases reported to the Swedish Cancer Registry from 1987 to 1999. Next, controls (137,485) were randomly selected from the continuously updated Swedish Population Registry and matched to cases diagnosed that year on age and sex. Finally, cases and controls were linked to the Swedish Hospital Discharge Registry (1969-1999). We found that > or =8 years before HGG diagnosis (or control reference year) there was an elevated risk of HGG among people discharged with epilepsy [odds ratio (OR), 3.01; 95% confidence interval (95% CI), 1.73-5.22]. Two to 3 years before HGG diagnosis, this risk increased (OR, 5.33; 95% CI, 3.58-7.93) and was especially strong among people ages <55 years (OR, 13.49; 95% CI, 6.99-25.94). During this 2- to 3-year prediagnostic period, we also found an increased risk of HGG among people discharged with meningitis (OR, 3.02; 95% CI, 1.06-8.59) or viral encephalitis (OR, 12.64; 95% CI, 2.24-71.24). Results are similar for glioblastoma multiforme, low-grade glioma, and meningioma. In contrast, risk of HGG among people discharged with diabetes or stroke does not increase until year of brain tumor diagnosis. The occurrence of excess epilepsy > or =8 years before HGG diagnosis suggests a relatively long preclinical phase, but excess diabetes or stroke appear late in HGG development.

Psychometric performance of the NEI VFQ-25 in visually normal Latinos: the Los Angeles Latino Eye Study.

PURPOSE: To characterize the psychometric performance of the National Eye Institute 25-item Visual Function Questionnaire (NEI VFQ-25) in visually normal Latinos (Mexican Americans). METHODS: The Los Angeles Latino Eye Study (LALES) is a population-based study to assess the prevalence of eye disease and self-reported visual functioning in Latinos aged 40 or more years. Self-reported visual functioning was assessed by using English and Spanish versions of the NEI VFQ-25. Psychometric properties of the NEI VFQ-25, including internal consistency of the subscales and the individual items, were assessed through the Multi-trait Analysis Program-Revised (MAP-R) analysis. Adjusted mean and median subscale scores were compared between English and Spanish speakers to identify any systematic differences. RESULTS: Of the 1917 participants from two census tracts, 1171 participants with no visual impairment were included in this analysis. The mean age of the participants was 52.3 years, 57% of the participants were female, and 67.5% of the participants were Spanish speaking. Median scores for Spanish-speaking participants were significantly lower than those of the English-speaking participants on four subscales: Ocular Pain, General Vision, Vision-Specific Mental Health, and General Health (P < 0.05). Internal consistency for three of eight measurable subscales for the study group was poor (Cronbach alpha < 0.6). CONCLUSIONS: This study reveals psychometric inconsistencies in the NEI VFQ-25 when administered to visually normal Latinos. The difference in mean subscale scores between Spanish and English speakers must be integrated into the development of population norms of visual function. Further detailed psychometric evaluation is needed to determine the validity of this instrument in Latino populations.

Binocular visual acuity summation and inhibition in an ocular epidemiological study: the Los Angeles Latino Eye Study.

PURPOSE: To characterize binocular visual acuity summation and inhibition in participants of a population-based ocular epidemiologic study. METHODS: A complete ophthalmic examination of Latinos, aged 40 or more years, measured binocular and monocular distance visual acuities by a standard early-treatment diabetic retinopathy study (ETDRS) protocol. The proportions of participants who demonstrated binocular summation (i.e., binocular visual acuity was better than the better eye visual acuity by five or more letters), binocular inhibition (i.e., binocular visual acuity was worse than the better eye visual acuity by five or more letters), and visual impairment (visual acuity worse than 20/40) were calculated. RESULTS: In 1831 individuals, on average, binocular visual acuity was better than better eye visual acuity. Prevalence rates of binocular summation and inhibition were 21% and 2%, respectively. Compared with participants less than 65 years old or those with equivalent interocular visual acuity, older participants (> or =65 years) and those with interocular differences in visual acuity were more likely to demonstrate binocular inhibition (P < 0.01). The rate of visual impairment was significantly lower, when using binocular visual acuity than when using better eye or the American Medical Association (AMA) algorithm (5.2% vs. 6.9% and 9.5%, respectively P < 0.01). Participants with binocular inhibition had greater self-reported problems with driving activities (P < 0.05). CONCLUSIONS: The large proportion of individuals demonstrating binocular summation and inhibition suggests that in clinical or research settings, binocular visual acuity should be considered a primary measure of visual impairment, because it better equates the state in which the person usually functions.

Lifestyle and other risk factors for thyroid cancer in Los Angeles County females.

PURPOSE AND METHODS: We conducted a population-based case-control study of thyroid cancer. Cases were 292 women, aged 15-54 when diagnosed between the years 1980 and 1983 (145 diagnosed in 1980-81 and 147 diagnosed in 1982-83). Female neighborhood controls (n = 292) were matched to each case on birth-year and race. RESULTS: Among women < 35 years, thyroid disease in first-degree relatives increased thyroid cancer risk [odds ratio (OR) = 2.0, 95% confidence interval (CI) = 1.1-3.7]. Risk was not associated with fish consumption, although high childhood consumption of shellfish decreased thyroid cancer risk (OR = 0.2, 95% CI = 0.05-0.7 for consumption at least a few times weekly). Among papillary thyroid cancers (82% of cases), frequent adult consumption of saltwater fish decreased risk. Cancer risk was reduced with consumption of certain vegetables, wine, and tea. Other dietary variables, including milk, beer and hard liquor, and coffee were not related to thyroid cancer risk. Among the papillary sample, risk increased with longer use of multivitamins (OR = 2.9, 95% CI = 1.2-7.4 for > 10 years of use). Smoking and body mass were not associated with thyroid cancer risk. CONCLUSIONS: These results suggest a role of family history of thyroid disease and certain dietary variables in the etiology of thyroid cancer in adult females.

Alcohol consumption and risk of adult-onset acute myeloid leukemia: results from a Los Angeles County case-control study.

Few studies have examined the role of alcohol consumption in risk of adult acute myeloid leukemia (AML). Two previous case-control studies resulted in inconsistent findings. We report data from a Los Angeles County population-based case-control study in which 164 matched case-control pairs were asked about lifetime history of alcohol consumption and 136 cases were subtyped according to the French-American-British (FAB) criteria. Estimated categorical odds ratios (OR) adjusted for smoking and education were suggestive of a possible protective effect but trend tests were non-significant. Analyses by FAB subtype did not reveal subtype-specific associations but generally suffered from lack of power. Larger studies are needed to more thoroughly investigate the relationship between alcohol consumption and AML risk.

Maternal prenatal exposure to nitrosatable drugs and childhood brain tumours.

BACKGROUND: A compelling hypothesis was proposed that childhood brain tumours are associated with maternal exposure to N-nitroso compounds during the prenatal period. Many common drugs, such as antihistamines, aspirin, and antibiotics, are nitrosatable and depending upon the product, potentially carcinogenic. We hypothesized that maternal ingestion of certain subgroups of nitrosatable drug products during pregnancy increases the risk of brain tumour development in offspring. METHODS: Data were collected as part of a population-based case-control study of childhood brain tumours and mothers' self-reported exposure to therapeutic drugs and dietary nitrites. Cases were enrolled from three US West Coast SEER tumour registries: Seattle-Puget sound, Los Angeles County, and the San Francisco-Oakland Bay Area. Tumours were grouped into three major histological tumour subtypes: astroglial, primitive neural ectodermal tumours, and all remaining glial tumours ('other glial'). Therapeutic drugs reported by mothers were translated into active chemical compounds and classified as secondary amines, tertiary amines, amides, or none of the three. Risk estimates were computed according to classes of nitrosatability, potential carcinogenicity, teratogenicity, and predicted end product. RESULTS: We found no significant association between maternal use of nitrosatable drugs, either overall or within any of the nitrosatable drug classifications, and subsequent development of brain tumours in children. Nitrite consumption from cured meats was not an effect modifier. However, exposure to nitrosoephedrine during pregnancy was associated with significantly increased risk of 'other glial' tumours (OR = 3.1; 95% CI: 1.1-9.2). CONCLUSIONS: These findings do not support an association between maternal use of nitrosatable drugs during pregnancy and brain tumour risk in offspring. While exposure to the nitrosation end product nitrosoephedrine was associated with increased risk for other glial tumours, the finding was not specific to any one type of tumour.

Household water source and the risk of childhood brain tumours: results of the SEARCH International Brain Tumor Study.

BACKGROUND: The period in utero is a time of increased vulnerability. Offspring of pregnant women exposed to carcinogenic substances in drinking water may be more likely to develop cancer. We examined whether household water source and the presence of nitrates or nitrites in residential water were associated with increased risks of childhood brain tumours (CBT). METHODS: We used data from a multicentre, case-control study with maternal information on residential water source, and nitrate/nitrite levels of tap water measured by dipstick. Subjects included 836 CBT cases and 1485 controls from five countries. RESULTS: The risks of CBT associated with reliance on well water (versus public water) during pregnancy varied widely, with significantly increased risks noted in two (of seven) regions and a decreased risk observed in one region. CBT risk did not increase with increasing nitrate levels. However, our results based on tap water tested in the pregnancy residences suggest the risk of astrocytoma may be associated with increasing levels of nitrite (odds ratio [OR] = 4.3, 95% CI: 1.4, 12.6 for nitrite levels of 1-<5 mg/l nitrite ion; OR = 5.7, 95% CI: 1.2, 27.2 of nitrite > or =5 mg/l). CONCLUSIONS: These results should be interpreted with caution because women's recollection of water sources may have contained inaccuracies, and nitrate and nitrite measurements, available for only a portion of subjects, were often obtained years after the pregnancies occurred. However, our results suggest a need for closer evaluation of well water content in some regions and the possibility that a nitrite-related water exposure may be associated with CBT.

Using focus groups to develop a culturally sensitive methodology for epidemiological surveys in a Latino population: findings from the Los Angeles Latino Eye Study (LALES).

BACKGROUND: Many standardized survey instruments are initially developed in English-speaking populations. These instruments may not be culturally appropriate for other ethnic groups, such as Latinos. METHODS: The Los Angeles Latino Eye Study (LALES) was designed to determine the prevalence of blindness, visual impairment, and ocular diseases; risk factors for these diseases; and general and ocular healthcare use among non-institutionalized adult Latinos in suburban Los Angeles County, California. The LALES investigators used focus groups to develop questionnaires and to devise culturally sensitive methods for implementing this epidemiologic study in a Latino population. Eighty-four respondents were administered the in-home questionnaire and then scheduled into one of 6 in-home focus groups, allowing participants to reflect in groups about the study, their participation, and the state of the instruments and the translations. FINDINGS: Overall, respondents reported that the questionnaire was well written, easy to understand, and very clear. Recommendations from participants included: 1) keep questions brief; 2) minimize the number of response choices; 3) keep phrasing clear; 4) simplify technical terms; 5) provide test results immediately after the clinical examination; and 6) hire Spanish-speaking staff to increase participants' trust and confidence. CONCLUSION: Focus groups assisted in yielding a culturally appropriate survey research tool and methodology for this population-based study in a Latino community.

Radiation exposure from diagnostic imaging: agreement between self-report and medical records.

Data on diagnostic imaging procedures from a highly structured interview were compared to medical records in a case-control study of radiography and acute myelogenous leukemia. Three hundred and twenty-eight cases and 315 controls (78% of participants) had medical records available from an average of 71% of providers. Proxies were used for 49% of cases because of rapid fatality. Mean agreement (number of procedures in medical records subtracted from number in interview) showed similar levels of overreporting in cases [0.6; 95% confidence interval (CI): 0.0, 1.1] and controls (0.7; CI: 0.2, 1.3) with few procedures (<= 10). Most participants with more procedures underreported exposure, and underreporting increased with increasing exposure, especially among cases [mean (CI) agreement = -2.1 (-4.3, 0.0) for 11-20 procedures, -6.4 (-13.6, 0.7) for >20 procedures] and case proxies. High-dose, fluoroscopic, and non-routine procedures were self-reported more accurately than low-dose, non-fluoroscopic, and routine procedures, respectively (p < 0.01 for each comparison), and tended to be underreported. Case-control differences in agreement were non-significant for these categories of procedures. We conclude that diagnostic imaging procedures of most interest to the AML-radiography hypothesis are self-reported accurately but that underreporting does occur and might lead to attenuated risk estimates.

The potential impact of incomplete radiography histories in epidemiologic studies that rely on prepaid health plan records.

Members of prepaid health plans are often considered a group for which complete histories of exposure to medically-related risk factors are known. In a population-based case-control study of radiography as a risk factor for acute myelogenous leukemia, extensive retrospective exposure data from an average of 71% of subjects' health care providers were collected. It was determined that at least 21% of prepaid health plan members received diagnostic imaging procedures outside of their plans over the 10-y period of interest and that these "outside" procedures constituted 43% of their total red bone marrow dose from all radiographic imaging. Procedures significantly more likely to have been received outside of prepaid health plans were conventional spine x rays (p = 0.004) and coronary angiograms (p < 0.0001). All "outside" coronary angiograms and 50% of "outside" spine x rays were received at hospitals. Epidemiologic studies that restrict exposure to that received within prepaid health plans may miss a substantial portion of exposure, resulting in underestimated risk estimates and a loss of statistical power.

Estimation of radiographic doses in a case-control study of acute myelogenous leukemia.

Radiation exposure from dental and medical radiography is inherently difficult to estimate. Because no single resource is available for this type of data, gathering the information needed to estimate exposure in epidemiologic studies is a labor-intensive, imprecise process. For a case-control study of adult-onset acute myelogenous leukemia in Los Angeles County and radiography, a database was created of estimates of dose to the red bone marrow for each radiographic procedure reported by subjects in interviews and recorded in subjects' medical records. Resources used included the medical literature as well as personal communications with radiology experts. Dose estimates for each procedure based on this database are reported. Methods and complications are contrasted with a past effort to estimate dose from dental radiography for a case-control study of parotid gland tumors. Among the more difficult aspects of medical radiography dose estimation are the wide variety of examinations performed, the continually-changing environment of diagnostic imaging, and the number of variables that contribute to the delivered dose to an individual from a specific imaging procedure.

Parental smoking and risk of childhood brain tumors by functional polymorphisms in polycyclic aromatic hydrocarbon metabolism genes.

BACKGROUND: A recent meta-analysis suggested an association between exposure to paternal smoking during pregnancy and childhood brain tumor risk, but no studies have evaluated whether this association differs by polymorphisms in genes that metabolize tobacco-smoke chemicals. METHODS: We assessed 9 functional polymorphisms in 6 genes that affect the metabolism of polycyclic aromatic hydrocarbons (PAH) to evaluate potential interactions with parental smoking during pregnancy in a population-based case-control study of childhood brain tumors. Cases (N = 202) were ≤10 years old, diagnosed from 1984-1991 and identified in three Surveillance, Epidemiology, and End Results (SEER) registries in the western U.S. Controls in the same regions (N = 286) were frequency matched by age, sex, and study center. DNA for genotyping was obtained from archived newborn dried blood spots. RESULTS: We found positive interaction odds ratios (ORs) for both maternal and paternal smoking during pregnancy, EPHX1 H139R, and childhood brain tumors (P(interaction) = 0.02; 0.10), such that children with the high-risk (greater PAH activation) genotype were at a higher risk of brain tumors relative to children with the low-risk genotype when exposed to tobacco smoke during pregnancy. A dose-response pattern for paternal smoking was observed among children with the EPHX1 H139R high-risk genotype only (OR(no exposure) = 1.0; OR(≤3 hours/day) = 1.32, 95% CI: 0.52-3.34; OR(>3 hours/day )= 3.18, 95% CI: 0.92-11.0; P(trend )= 0.07). CONCLUSION: Parental smoking during pregnancy may be a risk factor for childhood brain tumors among genetically susceptible children who more rapidly activate PAH in tobacco smoke.

Childhood brain tumors and maternal cured meat consumption in pregnancy: differential effect by glutathione S-transferases.

BACKGROUND: Some epidemiologic studies suggest that maternal consumption of cured meat during pregnancy may increase risk of brain tumors in offspring. We explored whether this possible association was modified by fetal genetic polymorphisms in genes coding for glutathione S-transferases (GSTs) that may inactivate nitroso compounds. METHODS: We assessed six GST variants: GSTM1 null, GSTT1 null, GSTP1(I105V) (rs1695), GSTP1(A114V) (rs1138272), GSTM3*B (3-bp deletion), and GSTM3(A-63C) (rs1332018) within a population-based case-control study with data on maternal prenatal cured meat consumption (202 cases and 286 controls born in California or Washington, 1978-1990). RESULTS: Risk of childhood brain tumor increased with increasing cured meat intake by the mother during pregnancy among children without GSTT1 [OR = 1.29; 95% confidence interval (95% CI), 1.07-1.57 for each increase in the frequency of consumption per week] or with potentially reduced GSTM3 (any -63C allele; OR = 1.14; 95% CI, 1.03-1.26), whereas no increased risk was observed among those with GSTT1 or presumably normal GSTM3 levels (interaction P = 0.01 for each). CONCLUSIONS: Fetal ability to deactivate nitrosoureas may modify the association between childhood brain tumors and maternal prenatal consumption of cured meats. IMPACT: These results support the hypothesis that maternal avoidance during pregnancy of sources of some nitroso compounds or their precursors may reduce risk of brain tumors in some children.

Childhood brain tumors, residential insecticide exposure, and pesticide metabolism genes.

BACKGROUND: Insecticides that target the nervous system may play a role in the development of childhood brain tumors (CBTs). Constitutive genetic variation affects metabolism of these chemicals. METHODS: We analyzed population-based case-control data to examine whether CBT is associated with the functional genetic polymorphisms PON1C-108T, PON1Q192R, PON1L55M, BCHEA539T, FMO1C-9536A, FMO3E158K, ALDH3A1S134A, and GSTT1 (null). DNA was obtained from newborn screening archives for 201 cases and 285 controls,

HIV as a risk factor for lung cancer in women: data from the Women's Interagency HIV Study.

PURPOSE: Prior reports of an increased risk of lung cancer in HIV-infected individuals have not always included control groups, nor considered other risk factors such as tobacco exposure. We sought to determine the role of HIV infection and highly active antiretroviral therapy (HAART) on lung cancer incidence in 2,651 HIV-infected and 898 HIV-uninfected women from the Women's Interagency HIV Study (WIHS). METHODS: A prospective study of the incidence rates of lung cancer was conducted, with cases identified through medical records, death certificates, and state cancer registries. Standardized incidence ratios (SIRs) were calculated to compare lung cancer incidence among HIV-infected and uninfected WIHS participants, with population-based expectations using the Surveillance, Epidemiology, and End Results registry. Behavioral characteristics in the WIHS were compared to US women by age and race adjusting the population-based data from the National Health and Nutritional Examination Survey (NHANES) III. RESULTS: Incidence rates of lung cancer were similar among HIV-infected and uninfected WIHS women. Lung cancer SIRs were increased in both HIV-infected and -uninfected women compared with population expectations, but did not differ by HIV status. Among HIV-infected women, lung cancer incidence rates were similar in pre-HAART and HAART eras. All WIHS women with lung cancer were smokers; the risk of lung cancer increased with cumulative tobacco exposure. WIHS women were statistically more likely to smoke than US women studied in NHANES III. CONCLUSION: HIV infection is strongly associated with smoking behaviors that increase lung cancer risk. The role of HIV itself remains to be clarified.