Faculty Bibliography

A food frequency questionnaire for Korean Americans (KFFQ) was developed by modifying Block's Health Habits and History Questionnaire (HHHQ). The final KFFQ contained 118 food items taking into account culturally specific dietary patterns. Validation of the KFFQ was conducted to compare the nutrient intakes assessed by the KFFQ against those measured by seven-day dietary records in 73 Korean Americans. The mean nutrient values from the KFFQ differed at most by 25% from those of the dietary records with the exception of vitamin A, and 70% of the nutrients (16 out of 23 nutrients) were within 15%. Adjusted Spearman rank-order correlation coefficients for nutrients ranged between 0.45 and 0.84. The overall degree of agreement between the KFFQ and the dietary records was 68% with a range 56% to 79%. This validation study indicates that the KFFQ gives reasonably accurate estimates of the usual dietary intakes among the study population. The results also verify that it is possible to use a FFQ that is both culturally specific and comprehensive with the benefit of being easy to self-administer. This high degree of correlation between the KFFQ and the dietary records demonstrates that the KFFQ provides an easier yet accurate method in large-scale epidemiological studies of relationships between nutrition intakes and diseases in Korean Americans

OBJECTIVES: Describe the development of a questionnaire to assess past year physical activity, including activities of daily living, in a multi-ethnic/racial cohort. Describe energy expenditure (EE) patterns in the sample used for questionnaire development. METHODS: 24-hour activity recalls were collected from a convenience sample (N = 367) at four New York City health agencies (October 1999-February 2000). EE was determined at the population, subgroup, and individual level. EE distributions were compared. RESULTS: Activities identified were similar to those on established questionnaires. Subgroup and individual EE differences were noted. Median EE at the Chinese and Puerto Rican sites were lower than those at the Caribbean or Dominican sites. No clear age pattern was apparent. Overall, a greater percentage of daily EE was spent in low intensity activities. The resultant 30-minute interviewer-administered questionnaire ascertains patterns (frequency and duration) of domain-specific (recreational, household, occupational, and transportation) activity. This information combined with published intensity levels provides summary EE measures. CONCLUSION: Variation in EE levels requires information on activity type and amount. Summary activity measures can be used to rank individuals analogous to nutrient food frequency measures

BACKGROUND: Epidemiological evidence suggests that chronic inflammation may influence ovarian carcinogenesis. The study objective was to examine the association between the commonly used anti-inflammatory drug aspirin and epithelial ovarian cancer. METHODS: The authors conducted a case-control study based in the New York University Women's Health Study cohort enrolled between 1985 and 1991 in New York City. After a median follow-up period of 12 years, 68 incident cases of epithelial ovarian cancer were identified. Data about regular aspirin use were collected during the 1994-1996 follow-up questionnaire. Using a case-control study design, 10 controls per case were randomly selected among study participants who matched the case by age and menopausal status. Conditional logistic regression analysis was used to study the relationships between aspirin and epithelial ovarian cancer by generating odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Relative to no aspirin use, the OR for epithelial ovarian cancer among women who reported aspirin use three or more times per week for a period of at least 6 months was 0.60 (95% CI 0.26, 1.38), after adjustment for age at menarche, parity, oral contraceptive use, and first-degree family history of breast cancer before age 50. Among recent, within the previous 5 years, users of aspirin, the adjusted OR was 0.36 (95% CI 0.11, 1.18). CONCLUSION: Although confidence intervals included unity, the observed risk estimates seem to be compatible with previous studies suggesting that regular aspirin use could be inversely associated with risk of epithelial ovarian cancer

In large-scale epidemiological studies on endogenous sex steroids and cancer risk, direct immunoassays of circulating hormone levels have the advantage of being fast and comparatively inexpensive while requiring only small sample volumes. On the other hand, indirect assays after organic extraction and chromatographic prepurification have the advantage of reducing specific interferences and matrix effects and hence are thought to have better validity. We compared direct assays of testosterone (T, six different assays), Delta4-androstenedione (A, four assays), estrone (E(1), one assay), and 17beta-estradiol (E(2), five assays) with measurements obtained by an indirect assay in a representative subset of 20 postmenopausal women who were part of a large prospective cohort study. Within-batch reproducibilities of the subject rankings by relative hormone levels were good (intraclass correlations >0.89) for all direct assays tested. Between batches, reproducibilities generally were also acceptable (r > 0.80) to good (r > 0.90) in terms of Pearson's correlations. The between-batch reproducibility in terms of intraclass correlations was systematically lower in terms of Pearson's correlations, however, because of between-batch variations in the absolute scale of measurements. The relative validity of direct versus indirect assays in terms of the subjects' ranking by relative hormone levels was also high for most of the kits tested for T, A, and E(1) (Pearson's correlations between 0.70 and 0.89) but was high for only two kits of five tested for E(2) (correlations of 0.86 and 0.84). On an absolute scale, mean measurement values were generally higher for direct assays than for the indirect assay and, for each hormone, varied substantially, depending on the kit used. Overall, the results of this study show that, with careful selection, commercial kits for direct radioimmunoassays of steroid hormones in postmenopausal serum can be found that may allow a reliable estimation of relative risks in epidemiological studies. However, standardization of the absolute scale of assays remains problematic

The consumption of vegetables and fruit may protect against many types of cancer, but research evidence is not compelling for breast cancer. Carotenoids are pigments that are present in most plants and have known antioxidant properties. Blood concentrations of carotenoids have been proposed as integrated biochemical markers of vegetable, fruit, and synthetic supplements consumed. In a case-control study (270 cases, 270 controls) nested within a cohort in New York during 1985-1994, the carotenoids lutein, zeaxanthin, beta-cryptoxanthin, lycopene, alpha-carotene, and beta-carotene were measured in archived serum samples using liquid chromatography. There was an evident increase in the risk of breast cancer for decreasing beta-carotene, lutein, alpha-carotene, and beta-cryptoxanthin. The risk of breast cancer approximately doubled among subjects with blood levels of beta-carotene at the lowest quartile, as compared with those at the highest quartile (odds ratio = 2.21; 95% confidence interval (CI): 1.29, 3.79). The risk associated with the other carotenoids was similar, varying between 2.08 (95% CI: 1.11, 3.90) for lutein and 1.68 (95% CI: 0.99, 2.86) for beta-cryptoxanthin. The odds ratio for the lower quartile of total carotenoids was 2.31 (95% CI: 1.35, 3.96). These observations offer evidence that a low intake of carotenoids, through poor diet and/or lack of vitamin supplementation, may be associated with increased risk of breast cancer and may have public health relevance for people with markedly low intakes

Insulin-like growth factor-I (IGF-I) has mitogenic and anti-apoptotic properties and has been implicated in the development of breast, colorectum, prostate and lung cancer. IGF binding proteins (IGFBPs) are not only carrier proteins for IGFs but also hold a central position in IGF ligand-receptor interactions through influences on the bioavailability and distribution of IGFs in the extracellular environment. A case-control study nested within the New York University Women's Health Study Cohort included 93 women diagnosed with lung cancer at least 6 months after recruitment into the study. Two controls (n = 186) were matched to each case on age, date of blood sampling, menopausal status, day of menstrual cycle and questionnaire data of smoking status at the time of blood donation. Serum IGF-I, IGFBP-1, -2 and -3, insulin and cotinine were measured. Mean serum levels of IGF-I, IGFBP-1, -2 and -3 were not significantly different between the case and control groups. Univariate logistic regression analyses showed no association of lung cancer risk with serum levels of IGF-I or any of the IGFBPs. These results remained virtually the same in multivariate analyses, including adjustment for cotinine, time since last meal, BMI, IGF-I or IGFBP-3, respectively. Exclusion of cases diagnosed within 3 years of recruitment in the cohort, or restriction of the analyses to adenocarcinomas only, did not alter these results. Our study does not offer evidence in support of an association between prediagnostic serum levels of IGF-I or IGFBP-1, -2 and -3 and lung cancer risk in women

The principal epidemiologic studies of ionizing radiation and skin cancer have all shown that radiation causes basal cell carcinoma but have not found dose-related excesses of squamous cell carcinoma or malignant melanoma. The Japanese atomic bomb study indicates that doses of radiation under about 1 Gy confer less risk per unit dose than higher doses do. All available studies show that skin cancer risk is greater from radiation exposure at young ages than at older ages. Finding few excess skin cancers among irradiated African-Americans as compared to Caucasians with a comparable dose indicates that skin susceptibility to ultraviolet exposure modifies the excess risk from ionizing radiation. Available evidence indicates that the excess risk of skin cancer lasts for 45 years or more following irradiation. Several studies indicate a risk of nonmelanoma skin cancer (NMSC) following cancer therapy; however, most of the studies reporting on NMSC have not distinguished between patients who received radiotherapy versus chemotherapy. Some, but not all, follow-up studies of cancer patients have reported excesses of malignant melanoma as second malignant neoplasms. It is not clear from the studies how much, if any, of the excess melanoma risk is attributable to radiotherapy.

In this paper, we define the excess lifetime risk for a disease due to radiation exposure, and we evaluate the excess lifetime risk for an exposed group with the same age and with a mixture of ages. We propose two methods to estimate the excess lifetime risk: the standard maximum likelihood approach and a Monte-Carlo approach. Both approaches allow us to construct confidence intervals for the excess lifetime risk and perform hypothesis testing to compare two excess risks. The maximum likelihood approach is straightforward and computationally simple; however, it may not provide good approximations when the normality assumption is violated. The Monte-Carlo approach is always reliable, but often involves heavier computations and additional programming. These two approaches are illustrated and discussed based on a pooled analysis of five cohorts exposed to external radiation and followed up for subsequent thyroid cancer incidence