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L N Kolonel

Publications and source records attributed to L N Kolonel.

At least 37 records · Page 2Linked to original sources
PubMed2000

Ethnic differences in post-menopausal plasma oestrogen levels: high oestrone levels in Japanese-American women despite low weight.

Breast cancer incidence in Japanese-American women is approaching that of US Whites. We investigated whether this shift is paralleled by similar post-menopausal plasma hormone levels in the two ethnic groups. We also included African-American and Latina women to further our understanding of possible ethnic differences in oestrogen metabolism. We measured androstenedione (A), oestrone (E1) and oestradiol (E2) in 30 Japanese-American, 39 non-Latina White ('White'), 66 African-American and 58 Latina women. The (age-adjusted) geometric mean E1 levels were 34 pg ml(-1) in Japanese-Americans, 28 pg ml(-1) in Whites, 35 pg ml(-1) in African-Americans and 31 pg ml(-1) in Latinas. After adjustment for body mass index, Japanese-Americans had the highest mean E1 value of all groups and this was statistically significantly greater than the value for Whites (P(t-test) = 0.05). The geometric mean A concentrations were also highest in Japanese-Americans. There was little ethnic difference in E2 levels. In conclusion, post-menopausal plasma oestrogen levels in Japanese-American women are at least as high as those in Whites.

Aged↗
PubMed2000

Vegetables, fruits, legumes and prostate cancer: a multiethnic case-control study.

The evidence for a protective effect of vegetables, fruits, and legumes against prostate cancer is weak and inconsistent. We examined the relationship of these food groups and their constituent foods to prostate cancer risk in a multicenter case-control study of African-American, white, Japanese, and Chinese men. Cases (n = 1619) with histologically confirmed prostate cancer were identified through the population-based tumor registries of Hawaii, San Francisco, and Los Angeles in the United States and British Columbia and Ontario in Canada. Controls (n = 1618) were frequency-matched to cases on ethnicity, age, and region of residence of the case, in a ratio of approximately 1:1. Dietary and other information was collected by in-person home interview; a blood sample was obtained from control subjects for prostate-specific antigen determination. Odds ratios (OR) were estimated using logistic regression, adjusting for age, geographic location, education, calories, and when indicated, ethnicity. Intake of legumes (whether total legumes, soyfoods specifically, or other legumes) was inversely related to prostate cancer (OR for highest relative to lowest quintile for total legumes = 0.62; P for trend = 0.0002); results were similar when restricted to prostate-specific antigen-normal controls or to advanced cases. Intakes of yellow-orange and cruciferous vegetables were also inversely related to prostate cancer, especially for advanced cases, among whom the highest quintile OR for yellow-orange vegetables = 0.67 (P for trend = 0.01) and the highest quintile OR for cruciferous vegetables = 0.61 (P for trend = 0.006). Intake of tomatoes and of fruits was not related to risk. Findings were generally consistent across ethnic groups. These results suggest that legumes (not limited to soy products) and certain categories of vegetables may protect against prostate cancer.

Aged↗
PubMed1999

Association of mis-sense substitution in SRD5A2 gene with prostate cancer in African-American and Hispanic men in Los Angeles, USA.

BACKGROUND: Prostate cancer is a very common disease in more-developed countries, but its cause is largely unknown. It is an androgen-dependent cancer, and androgens have been proposed as having a substantial role in predisposition to the disease. Thus, variations in androgen metabolism genes may affect risk of this disease. METHODS: We screened 216 African-American and 172 Hispanic men with prostate cancer, and 261 African-American and 200 Hispanic healthy men (controls), from a large prospective cohort study (the Hawaii-Los Angeles Multiethnic Cohort Study) for a mis-sense substitution in the human prostatic (or type II) steroid 5alpha-reductase (SRD5A2) gene, the product of which controls metabolic activation of testosterone to dihydrotestosterone. This mis-sense substitution results in an alanine residue at codon 49 being replaced with threonine (A49T). We also reconstructed this mutation in the SRD5A2 cDNA, and overexpressed the enzyme in mammalian tissue culture cells. FINDINGS: The A49T aminoacid substitution in the SRD5A2 gene increased the risk of clinically significant disease 7.2-fold in African-American men (95% CI=2.17-27.91; p=0.001) and 3.6-fold in Hispanic men (1.09-12.27; p=0.04). The mutant enzyme had a higher in-vitro Vmax than the normal enzyme (9.9 vs 1.9 nmol min(-1) mg(-1)). INTERPRETATION: The A49T variant of the SRD5A2 gene may be a significant contributor to the incidence of prostate cancer in African-American and Hispanic men in Los Angeles. We estimate that the population attributable risk due to this aminoacid substitution for clinically significant disease is about 8% in both populations. Increased conversion of testosterone to dihydrotestosterone catalysed by this variant steroid 5alpha-reductase enzyme may be the cause of the increased risk.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1999

Breast cancer and oral contraceptive use in Asian-American women.

Breast cancer incidence has historically been 4-7 times higher in the United States than in Asia. A previous study by the authors in Asian-American women demonstrated a substantial increase in breast cancer risk in women who migrated from Asia to the United States, with the risk almost doubling during the first decade after migration. Increased use of oral contraceptives soon after migration to the United States could possibly explain this rapid rise in risk. In a population-based case-control study of Chinese, Filipino, and Japanese-American women, aged 20-55 years, who lived in San Francisco-Oakland, California; Los Angeles, California; and Oahu, Hawaii during 1983-1987, 597 cases (70% of those eligible) and 966 controls (75%) were interviewed. Controls were matched to cases on age, ethnicity, and area of residence. Oral contraceptive (OC) use increased with time since migration; 15.0% of Asian-born women who had been in the West <8 years, 33.4% of Asian-born women who had been in the West > or =8 years, and 49.6% of Asian women born in the West had ever used OCs. However, duration of OC use (adjusted for age, ethnicity, study area, years since migration, education, family history of breast cancer and age at first full-term birth) was not associated with increased risk of breast cancer. Moreover, neither OC use before age 25 years nor before first full-term birth was associated with increased risk. Results were unchanged when restricted to women under age 45 years or under age 40 years. After adjustment for duration of OC use, women who had been in the United States > or =8 years were still at almost twice the risk of breast cancer compared with women who had been in the United States 2-7 years. This study suggests that OC use cannot explain the elevated risk observed in Asian women who migrated to the United States > or =7 years ago.

Adult↗
PubMed1999

Cytochrome P450c17alpha gene (CYP17) polymorphism predicts use of hormone replacement therapy.

We investigated whether a polymorphism in the cytochrome P450c17alpha gene (CYP17), which is associated with higher endogenous hormone levels, influences the use of hormone replacement therapy (HRT). The study included 749 postmenopausal women ages 44-75 years at baseline randomly selected from a larger multiethnic cohort. African-American, Japanese, Latina, and white women were included in the study. Women who carry the CYP17 A2/A2 genotype were about half as likely as women with the A1/A1 genotype to be current HRT users (odds ratio = 0.52; 95% confidence interval, 0.31-0.86). This association was present in all four racial/ethnic groups and for women above and below the median weight of 150 pounds. These findings suggest that the actual risk of breast cancer associated with HRT use may be higher than previously reported.

Adult↗
PubMed1999

Dietary fat and prostate cancer: current status.

Efforts to elucidate the causes of prostate cancer have met with little success to date. All that is known with certainty is that the incidence increases exponentially with age, varies by geography and by race or ethnicity, and is higher among men whose father or brother had the disease. Because the incidence changes in migrants and their offspring, exogenous factors certainly contribute to the risk of prostate cancer. Early epidemiologic studies implicated dietary fat as a likely causal factor for this cancer. However, scientific support for such an association has diminished in recent years as more epidemiologic evidence has accrued. Accordingly, we reviewed the relevant English language literature on this topic, including epidemiologic and animal studies, as well as current concepts regarding the involvement of fat in carcinogenesis to re-examine the fat-prostate cancer hypothesis. We conclude that dietary fat may indeed be related to prostate cancer risk, although the specific fat components that are responsible are not yet clear. Given the diverse effects of fatty acids on cellular biology and chemistry, it seems likely that the relationship is complex, involving the interplay of fat with other dietary factors, such as antioxidant vitamins and minerals, or with genetic factors that influence susceptibility. Some suggestions for further research are offered.

Dietary Fats↗
PubMed1999

Lifestyle factors and chronic diseases: application of a composite risk index.

BACKGROUND: Assessing a combination of modifiable lifestyle practices may be a practical tool to modify patients' health behavior in counseling. Therefore, we developed a chronic disease risk index (CDRI) and investigated its relation with chronic disease in a multiethnic cohort. METHODS: A total of 15,693 men and 16,007 women in Hawaii who reported their diet and other lifestyle behaviors between 1975 and 1980 were followed until 1994. A semi-quantitative composite CDRI with scores ranging from 1 to 10 included the rankings for smoking, alcohol use, body mass index, fat intake, and fruit and vegetable consumption. Cox's proportional hazards regression was used to estimate the relative risk for chronic diseases. RESULTS: When comparing the highest to the lowest CDRI category, the respective relative risks (RRs) for total mortality were 2.9 (95% CI 2.3-3.8) and 3.8 (95% CI 2.9-5.0) for men and women. With higher CDRIs, the RRs for cancer incidence, mortality from cancer, coronary heart disease, and stroke increased significantly. Among the five components of the CDRI, smoking had the greatest influence on chronic disease risk, followed by body mass index. CONCLUSIONS: Positive health behavior reflected by the CDRI is associated with a lower risk of cancer and with greater longevity.

Adult↗
PubMed1999

The relationship between diet and breast cancer in men (United States).

OBJECTIVES: The purpose of this paper was to investigate the relationship between food and beverage consumption and the development of breast cancer in men. METHODS: Possible relationships of dietary factors to risk of breast cancer in men were assessed in a case-control study conducted between 1983 and 1986. Cases (N = 220) were ascertained from ten population-based cancer registries. Controls (N = 291) were selected by random-digit dialing (< age 65) and from Health Care Financing Administration Medicare beneficiary lists (> or = age 65). RESULTS: No trends in risk were observed with increasing intakes of specific foods, except for an increase in risk with citrus fruits. No increase in risk with increasing amounts of specific fats, vitamins, or minerals or with amounts of protein, fiber, carbohydrate, starches, nitrites, or alcohol consumed was observed, except for an increase in risk with dietary vitamin C consumption. A decreasing trend in risk with dietary niacin and with coffee and an increasing trend in risk with tea consumption were observed. No associations were found with use of any dietary supplements, including vitamin C. CONCLUSIONS: The observed associations are not consistent with findings from studies of breast cancer in women and probably do not represent causal relationships. Dietary factors are unlikely to be strong determinants of breast cancer in men.

Adult↗
PubMed1999

Androgen metabolism and prostate cancer: establishing a model of genetic susceptibility.

The prostate is an androgen-regulated organ, which has led to longstanding interest in the role of androgens in prostate carcinogenesis. Although evidence of a hormonal etiology for prostate cancer is strong, it is almost entirely circumstantial. Much of the problem in proving a causal relationship relates to the continued difficulties in reliably measuring human tissue-specific exposure to endogenous steroid hormones. The international and racial-ethnic variations in prostate cancer incidence, combined with the effects of migration on risk patterns, have suggested that genetic factors play a central role in determining prostate cancer risk. We are developing a polygenic model of prostate carcinogenesis, focused around a series of genes involved in androgen biosynthesis, transport and metabolism. We have begun to develop this model by utilizing sequence variants to study how polymorphic markers in two genes (SRD5A2 and AR) are related to prostate cancer risk within and between racial-ethnic groups. We are now collaborating with the Whitehead Institute/MIT, Center for Genome Research, to screen for single nucleotide polymorphisms in additional genes relevant to the androgen pathway and prostate cell growth. The model when fully developed can potentially provide a basis for targeting populations for screening interventions and for implementing primary preventive strategies.

Androgens↗
PubMed1999

Aromatase and breast cancer susceptibility.

Based on experimental and epidemiological evidence it is hypothesized that estrogen increases breast cancer risk by increasing mitotic activity in breast epithelial cells. Aromatase is crucial to the biosynthesis of estrogens and may therefore play a role in breast cancer development. Supporting data for an etiological role of aromatase in breast tumor biology are several-fold. First, the association between weight and postmenopausal breast cancer risk may be mediated by aromatase. Secondly, a pilot study found a higher aromatase expression in normal breast adipose tissue from breast cancer cases as opposed to healthy women. Thirdly, experimental data in animals suggest that aromatase activity predisposes mammary tissue to preneoplastic and neoplastic changes. In a multiethnic cohort study conducted in Los Angeles and on Hawaii we investigated (i) whether the plasma estrone to androstenedione (E1/A) ratio in different ethnic groups was associated with ethnic differences in breast cancer incidence, and (ii) whether genetic variation in the CYP19 gene encoding the P450 aromatase protein was associated with breast cancer risk. The age- and weight-adjusted ethnic specific E1/A ratios x 100 among women without oophorectomy were 7.92 in African-Americans, 8.22 in Japanese, 10.73 in Latinas and 9.29 in non-Latina Whites (P=0.09). The high E1/A ratio in Latina women was not associated with a high breast cancer incidence; in fact Latina women had the lowest breast cancer incidence in the cohort observed so far. We found no consistent association of an intronic (TTTA)n repeat polymorphism with breast cancer risk in different ethnic groups. This polymorphism was not associated with differences in the plasma E1/A ratio in a way that would predict its functional relevance. We describe a newly identified TTC deletion in intron 5 of the CYP19 gene that is associated with the (TTTA)n repeat polymorphism. Neither this polymorphism, nor a polymorphism at codon 264 in exon VII of the CYP19 gene, was associated with breast cancer. We did not identify any genetic variation in exon VIII in 54 African-American subjects. We identified rare genetic variants of unknown functional relevance in the promoter 1.4 of the CYP19 gene in 3 out of 24 Latina women. Further investigation into the role of aromatase in breast cancer etiology is important, given that the potential use of aromatase inhibitors as breast cancer chemopreventives depends on these results.

Aged↗
PubMed1999

Independent and joint effects of family history and lifestyle on colorectal cancer risk: implications for prevention.

It has been suggested that, for a substantial proportion of "sporadic" colorectal cancers (CRCs), inheritance determines individual susceptibility and that lifestyle determines which susceptible individuals express cancer. Because the genetic basis of this inherited susceptibility remains undefined, we used family history of the disease as a proxy for a genetic predisposition to examine its interactions with a variety of lifestyle factors in a large population-based case-control study of CRC. The subjects were 698 male and 494 female Japanese, Caucasian, Filipino, Hawaiian, and Chinese patients diagnosed with CRC in Hawaii during 1987-1991 and 1192 population controls matched to cases on age, sex, and ethnicity. Fourteen percent of the cases and 6% of the controls reported a family history of CRC among parents or siblings. After adjusting for other covariates, significant interactions with family history were found for beef and ethanol intakes in males (P = 0.03). Relative to men without a family history and whose intake fell in the lower third, odds ratios (ORs) for CRC for men with a family history and in the upper tertile of intake were 10.8 [95% confidence interval (CI), 4.2-27.6] and 7.5 (CI, 3.1-18.2) for beef and ethanol, respectively. The corresponding ORs for men without a family history and in the upper tertile were 1.5 (CI, 1.0-2.3) and 1.4 (CI, 1.0-1.9), respectively. No interactions were detected in women. Using a summary measure of lifestyle, we found that family history was not associated with CRC among men who were at the lower-risk tertile for all of the lifestyle risk factors. In contrast, the OR for men with a family history and at the higher-risk tertile for all of the lifestyle variables was 11.7 (CI, 5.8-23.9). In the absence of a family history, this OR was 4.8 (CI, 3.2-7.2). These data suggest that family history increases the risk of sporadic CRC in men mainly through its interaction with lifestyle exposures, primarily a high beef and ethanol intake, and are consistent with recent reports of effect modifications of dietary associations by metabolic genes. Computation of population attributable risks also suggested that a comprehensive reduction in exposure to lifestyle risk factors--and more specifically to ethanol and beef for individuals with a familial predisposition for the disease--may have a large beneficial effect on CRC incidence.

Age Factors↗
PubMed1998

Androgen metabolism and prostate cancer: establishing a model of genetic susceptibility.

The prostate is an androgen-regulated organ, which has led to long-standing interest in the role of androgens in prostate carcinogenesis. Although evidence of a hormonal etiology for prostate cancer is strong, it is almost entirely circumstantial. Much of the problem in proving a causal relationship relates to the continued difficulties in reliably measuring human tissue-specific exposure to endogenous steroid hormones. The international and racial-ethnic variations in prostate cancer incidence, combined with the effects of migration on risk patterns, have suggested that whereas environmental factors are likely to be important, genetic factors might also play a central role in determining prostate cancer risk. We are developing a polygenic model of prostate carcinogenesis focused around a series of genes involved in androgen biosynthesis and androgen activation, transport, and metabolism in the prostate. In this developing model, we have initially targeted four genes based on three main criteria: (a) all encode products that play important roles in inducing androgen stimulation in the prostate; (b) all are polymorphic; and (c) all show substantial allelic variation in the polymorphic marker among the racial-ethnic groups of greatest interest in terms of prostate cancer risk. In addition to studying how the polymorphic markers of interest are related to prostate cancer development within and between racial-ethnic groups, we are concurrently evaluating whether genotypic variations correlate in the anticipated direction with biochemical parameters in vitro and in vivo. We summarize the development of this model and the state of knowledge related to each of the genes comprising the current model. We discuss the extent to which the current model can explain demographic variation in prostate cancer risk as well as the potential for future expansion of the model to incorporate environmental risk factors as well as additional genes. The model, when fully developed, can potentially provide a basis for targeting populations for screening interventions and/or preventive strategies aimed at the multigene products or at the genes themselves.

3-Hydroxysteroid Dehydrogenases↗
PubMed1998

Association of prostate cancer with vitamin D receptor haplotypes in African-Americans.

In previous studies, allelic variation in the 3' end of the vitamin D receptor gene was associated with increased risk of prostate cancer in white men. Several polymorphisms, including a BsmI restriction site and a poly(A) microsatellite, can be used interchangeably to mark the unidentified locus in whites. In African-Americans, however, these markers are not interchangeable, due to weaker linkage disequilibrium in this genomic region in this population. Here, we genotyped both the BsmI and poly(A) markers for 151 African-American prostate cancer cases (102 localized and 49 advanced) and 174 African-American male controls from a large epidemiological cohort. A direct haplotyping procedure was devised to determine BsmI/poly(A) haplotypes for double heterozygotes so that haplotypes could be used as allelic markers in standard logistic regression analyses. Using BsmI alone, b alleles were associated with a 2-fold decrease in risk of advanced prostate cancer. The association was, however, confined to haplotypes carrying a long (L) allele of the poly(A) microsatellite. BL and bL haplotypes were associated with increased and decreased risk, respectively, whereas neither BS nor bS haplotypes were associated with prostate cancer risk. An allelic variant that confers increased risk of advanced prostate cancer appears to be associated with the BsmI/poly(A) BL haplotype in African-Americans.

Aged↗
PubMed1998

Telephone vs face-to-face interviews for quantitative food frequency assessment.

OBJECTIVE: To develop and test a quantitative food frequency method for administration by telephone. DESIGN: A comparison study of telephone and face-to-face interviews was conducted among a representative sample of the five major ethnic groups in Oahu, Hawaii. Two interviews were administered 4 to 6 months apart by trained interviewers using identical questionnaires and color photographs of food items showing three different portion sizes. The order of the interviewing methods was randomly assigned. The questionnaire included 115 food items selected to estimate 80% or more of usual dietary intakes. Frequencies and quantities of each item consumed during the past year were obtained. SUBJECTS/SETTING: Subjects were recruited from the Health Surveillance Program of the Hawaii State Department of Health and consisted of 167 men and 158 women, aged 45 to 74 years, who provided a telephone number. Eighty percent of the face-to-face interviews were conducted in the subjects' homes and 20% were conducted at the workplace or the University of Hawaii Cancer Research Center, if requested. STATISTICAL ANALYSES: The paired t test was used to compare the mean daily intakes obtained by the telephone and face-to-face methods. Agreement was measured by the intraclass correlation coefficient (ICC), Pearson correlation coefficient and weighted kappa statistic. RESULTS: The means of energy and each nutrient were slightly higher in the first interview than the second, regardless of the interviewing method. Because of close correspondence among all 3 statistical measures of agreement, only the ICCs are reported. The ICCs ranged from .61 for protein and vitamin A to .69 for dietary cholesterol among men, and from .61 for vitamin C to .74 for saturated fat among women. Agreement was not significantly affected by age, gender, ethnicity, order of interview, or educational level. APPLICATIONS: Telephone interviews to obtain quantitative food frequencies are cost-efficient methods for estimating usual dietary intakes among persons in widely scattered geographic areas. Photographs of the foods in 3 portion sizes mailed in advance help the respondents estimate amounts eaten.

Aged↗
PubMed1998

Anthropometric predictors of breast cancer incidence and survival in a multi-ethnic cohort of female residents of Hawaii, United States.

OBJECTIVES: The purpose of the study was to describe the associations between height and body mass index (BMI) (wt/ht2) and breast cancer incidence and survival among female residents of Hawaii. METHODS: The study sample is a randomly-selected, multi-ethnic cohort of 17,628 women. A total of 378 incident breast cancer cases were identified via linkage to the Hawaii Tumor Registry over an average follow-up period of 14.9 years. Using age 50 as a cut-point, 86 were considered premenopausal cases, and 292 were postmenopausal. Proportional hazards analysis was used to describe the risks associated with height and BMI, after adjustment for age, education, race/ethnicity, and drinking status. For mortality analyses, there were 34 breast cancer deaths among the 365 breast cancer cases for which staging information was available. RESULTS: The risk of postmenopausal breast cancer was found to increase progressively across approximate tertiles of the distribution of height (P = 0.02 for trend test), with a significantly excess risk among women in the tallest tertile (risk ratio [RR] = 1.5, 95 percent confidence interval [CI] = 1.1-2.1). Baseline levels of BMI were related positively to breast cancer incidence among postmenopausal women, after control for the above covariates (P = 0.01 for trend test). Among postmenopausal women in the highest quintile of the BMI distribution, the RR was 1.5 (CI = 1.0-2.3, P = 0.04). Further analyses indicated the association between BMI and postmenopausal breast cancer incidence was strongest among women aged 65 years and older. After statistical control for the above covariates and stage of disease, pre-morbid levels of BMI were significantly predictive of death from breast cancer, with an approximate nine percent increase in risk per unit increase in BMI (P = 0.01). Compared with women in the lowest two quartiles, the RR among the heaviest women was 2.2 (CI = 0.9-5.4,P = 0.08). Height was not associated with risk of breast cancer mortality. CONCLUSIONS: Relative weight may be an important modifiable risk factor for both breast cancer incidence and prognosis. The association between height and breast cancer incidence is more difficult to interpret, but may underscore the importance of early life exposures in the development of breast cancer.

Adult↗
PubMed1998

Serum vitamin D metabolite levels and the subsequent development of prostate cancer (Hawaii, United States)

OBJECTIVES: Because several serum studies of vitamin D metabolites have produced equivocal results on their relation to prostate cancer risk, the purpose of this study is to evaluate this association further. METHODS: A nested case-control study in a cohort of 3,737 Japanese-American men examined from 1967 to 1970 was conducted in Hawaii (United States). At the time of examination, a single blood specimen was obtained, and the serum was frozen. After a surveillance period of over 23 years, 136 tissue-confirmed incident cases of prostate cancer were identified. Their stored sera and those of 136 matched controls were measured for the following: 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, calcium, phosphorus, and parathyroid hormone. RESULTS: There were no notable differences between cases and controls in their median serum levels of the five laboratory measurements. Odds ratios (OR) for prostate cancer, based on the quartiles of serum levels in controls, were also determined. The ORs for the highest quartiles relative to the lowest were 0.8 (95 percent confidence interval [CI] = 0.4-1.8) for 25-hydroxyvitamin D and 1.0 (CI = 0.5-2.1) for 1,25-dihydroxyvitamin D. CONCLUSION: It is possible that the lack of sufficient numbers of study subjects with low vitamin D levels affected the results. Nonetheless, the findings suggest that there is a lack of a strong association between vitamin D and prostate cancer.

Age Distribution↗