Analysis of urinary estrogens, their oxidized metabolites, and other endogenous steroids by benchtop orbitrap LCMS versus traditional quadrupole GCMS

Estrogens and other endogenous steroids are known risk markers for cancer. Gas chromatography (GC) with mass spectrometry (MS) has traditionally predominated the analysis of estrogens and other endogenous steroids, but liquid chromatography (LC) MS is increasingly favored. Direct comparisons of the two technologies have hitherto not been performed. Steroids were analyzed from 232 urine samples of 78 premenopausal women in a blinded fashion by benchtop orbitrap LCMS and single quadrupole GCMS. Sixteen steroidal estrogens including oxidized metabolites could be analyzed by LCMS. LCMS-GCMS Spearman rank correlations of the major estrogens E(1), E(2), E(3), 16α-OHE(1), and 2-OHE(1) were very high (r = 0.72-0.91), and absolute concentrations also agreed (<5% difference for E(1), E(2), E(3), 16α-OHE(1)). LCMS allowed reinterrogation of the acquired data due to orbitrap technology, which permitted post-analysis quantitation of progesterone, cortisol, and cortisone (LCMS-GCMS Spearman rank correlations = 0.80-0.84; absolute difference, <7%; n = 137). GCMS allows the measurement of a wide range of steroids including non-polar analytes that escape the presented LCMS assay. In contrast, orbitrap-based LCMS can detect more estrogens, is faster, less costly, allows post-data acquisition reinterrogation of certain analytes that had not been targeted a priori, and requires much less urine.

A comparison of breast density measures between mothers and adolescent daughters

Background

Based on the importance of breast density as a predictor of breast cancer risk, we examined the heritable component of breast measures in mothers and daughters using Dual Energy X-ray Absorptiometry (DXA).

Methods

We recruited 101 mothers ≥30 years and their daughters aged 10-16 years through Kaiser Permanente Hawaii. Scans of both breasts were taken using a DXA system in research mode, calibrated to distinguish fibroglandular and fatty breast tissue. We calculated correlation coefficients between mothers and daughters for breast volume, absolute fibroglandular volume (FGV), and %FGV and performed multiple linear regression to include relevant covariates.

Results

Breast volume and absolute FGV in daughters were lower than in mothers and were positively associated with % total body fat and Tanner breast stage. In contrast, %FGV in daughters was higher than in mothers and was inversely associated with % total body fat. Although unadjusted correlations between mothers and daughters were significant for breast volume and absolute FGV (r = 0.28 and p < 0.01 for both), models adjusted for demographic variables, Tanner stage, and % total body fat indicated significant associations only among the more mature girls (Tanner stages 4&5). There was no significant association between %FGV of mothers and daughters.

Conclusions

These results indicate that the heritability of breast volume and amount of dense tissue is measurable in adolescence, but percent breast density shows no relation between mothers and daughters at that time. Further study of breast tissue composition during adolescence and in young women may enhance understanding of breast cancer risk later in life.

Estrogen levels in nipple aspirate fluid and serum during a randomized soy trial

BACKGROUND

On the basis of hypothesized protective effect, we examined the effect of soy foods on estrogens in nipple aspirate fluid (NAF) and serum, possible indicators of breast cancer risk.

METHODS

In a crossover design, we randomized 96 women who produced 10 μL or more NAF to a high- or low-soy diet for 6 months. During the high-soy diet, participants consumed 2 soy servings of soy milk, tofu, or soy nuts (∼50 mg of isoflavones per day); during the low-soy diet, they maintained their usual diet. Six NAF samples were obtained using a FirstCyte aspirator. Estradiol (E(2)) and estrone sulfate (E(1)S) were assessed in NAF and estrone (E(1)) in serum only, using highly sensitive radioimmunoassays. Mixed-effects regression models accounting for repeated measures and left-censoring limits were applied.

RESULTS

Mean E(2) and E(1)S were lower during the high-soy than the low-soy diet (113 vs. 313 pg/mL and 46 vs. 68 ng/mL, respectively) without reaching significance (P = 0.07); the interaction between group and diet was not significant. There was no effect of the soy treatment on serum levels of E(2) (P = 0.76), E(1) (P = 0.86), or E(1)S (P = 0.56). Within individuals, NAF and serum levels of E(2) (r(s) = 0.37; P < 0.001) but not of E(1)S (r(s) = 0.004; P = 0.97) were correlated. E(2) and E(1)S in NAF and serum were strongly associated (r(s) = 0.78 and r(s) = 0.48; P < 0.001).

CONCLUSION

Soy foods in amounts consumed by Asians did not significantly modify estrogen levels in NAF and serum.

IMPACT

The trend toward lower estrogen levels in NAF during the high-soy diet counters concerns about adverse effects of soy foods on breast cancer risk.

The preventable proportion of type 2 diabetes by ethnicity: the multiethnic cohort

PURPOSE

To estimate the population-attributable risk (PAR) associated with modifiable risk factors for diabetes among Caucasians, Native Hawaiians, and Japanese Americans in the Hawaii component of the Multiethnic Cohort.

METHODS

This analysis is based on 74,970 cohort participants ages 45-75 years who completed a questionnaire on demographics, diet, and lifestyle factors in 1993-1996. After a mean follow-up time of 12.1 (0.01-14.4) years, 8,559 diabetes cases were identified by self-report, a medication questionnaire, and through health plan linkages. Hazard ratios for diabetes and partial PARs for single and different combinations of modifiable risk factors were estimated.

RESULTS

Overweight, physical inactivity, high meat intake, no alcohol consumption, and smoking were positively associated with diabetes risk in all ethnic groups. The estimated PARs suggested that among men, 78%, and among women, 83%, of new diabetes cases could have been avoided if all individuals had been in the low risk category for all of the modifiable risk factors. The slightly lower PARs in Japanese Americans were not significantly different from those in Caucasian and Native Hawaiian subjects.

CONCLUSIONS

Although PARs varied slightly over ethnicity, our findings do not support ethnic-specific prevention strategies; interventions targeted at multiple behaviors are needed in all ethnic groups.

Diabetes and urothelial cancer risk: the Multiethnic Cohort study

BACKGROUND

It is important to understand the adverse health sequelae that may result from the rising incidence of diabetes. Diabetics may have an increased risk for urothelial cancer but the evidence from prospective studies and ethnically diverse populations is sparse.

METHOD

We examined this association in the Multiethnic Cohort (MEC) that was conducted in Hawaii and Los Angeles with nearly 186,000 participants in five ethnic groups. Over a median 10.7 years of follow-up, 918 incident cases of urothelial cancer (89% bladder and 11% other urinary tract sites) were identified through tumor registry linkages.

RESULTS

A self-reported diagnosis of diabetes was associated with an increased risk of urothelial cancer (relative risk=1.25; 95% confidence interval: 1.04-1.50). The association was not explained by body mass index, physical activity, or smoking. There was some suggestion that the risk was higher in women, Whites and African Americans, and past smokers. The risk associated with diabetes for in situ and localized cancer was similar to that for regional and distant cancer.

CONCLUSION

This study demonstrates that the increased urothelial cancer risk with diabetes in this multiethnic population is very similar to that observed in mostly White or Asian populations. Whether or not the elevated risk is moderated by the degree of control of the hyperglycemia associated with diabetes will need to be determined in future studies.

The volume of nipple aspirate fluid is not affected by 6 months of treatment with soy foods in premenopausal women

Based on the hypothesis that soy food consumption may influence breast tissue activity, we examined its effect on the production of nipple aspirate fluid (NAF), a possible indicator of breast cancer risk. Of 310 premenopausal women screened, 112 (36%) produced at least 10 μL of NAF, the minimum for study participation. In a crossover design, we randomized 96 women to 2 groups who, in reverse order, consumed a high-soy diet with 2 soy servings/d (1 serving = 177 mL soy milk, 126 g tofu, or 23 g soy nuts) and a low-soy diet with <3 servings/wk of soy for 6 mo each separated by a 1-mo washout period. During each diet period, 3 NAF samples were obtained (baseline and 3 and 6 mo) using a FirstCyte Aspirator and 4 urine samples (baseline and 1, 3, and 6 mo) were analyzed for isoflavonoids by liquid chromatography tandem MS. Adherence to the study protocol according to 24-h dietary recalls and urinary isoflavonoid excretion was high. The drop-out rate was 15% (n = 14); 82 women completed the intervention. The 2 groups produced similar mean NAF volumes at baseline (P = 0.95) but differed in age and previous soy intake and in their response to the intervention (P = 0.03). In both groups, NAF volume decreased during the first 3 mo of the high-soy diet period and returned to baseline at 6 mo, but there was no effect of the high-soy diet on NAF volume (P = 0.50 for diet; P-interaction = 0.21 for diet with time). Contrary to an earlier report, soy foods in amounts consumed by Asians did not increase breast tissue activity as assessed by NAF volume.

Food intake of individuals with and without diabetes across different countries and ethnic groups

BACKGROUND/OBJECTIVES

Given the importance of nutrition therapy in diabetes management, we hypothesized that food intake differs between individuals with and without diabetes. We investigated this hypothesis in two large prospective studies including different countries and ethnic groups.

SUBJECTS/METHODS

Study populations were the European Prospective Investigation into Cancer and Nutrition Study (EPIC) and the Multiethnic Cohort Study (MEC). Dietary intake was assessed by food frequency questionnaires, and calibrated using 24h-recall information for the EPIC Study. Only confirmed self-reports of diabetes at cohort entry were included: 6192 diabetes patients in EPIC and 13 776 in the MEC. For the cross-sectional comparison of food intake and lifestyle variables at baseline, individuals with and without diabetes were matched 1:1 on sex, age in 5-year categories, body mass index in 2.5 kg/m(2) categories and country.

RESULTS

Higher intake of soft drinks (by 13 and 44% in the EPIC and MEC), and lower consumption of sweets, juice, wine and beer (>10% difference) were observed in participants with diabetes compared with those without. Consumption of vegetables, fish and meat was slightly higher in individuals with diabetes in both studies, but the differences were <10%. Findings were more consistent across different ethnic groups than countries, but generally showed largely similar patterns.

CONCLUSIONS

Although diabetes patients are expected to undergo nutritional education, we found only small differences in dietary behavior in comparison with cohort members without diabetes. These findings suggest that emphasis on education is needed to improve the current behaviors to assist in the prevention of complications.

Factors affecting survival among women with breast cancer in Hawaii

BACKGROUND

Given previous reports of ethnic differences in breast cancer survival among Hawaii's population, we investigated the role of adherence to treatment standards, treatment toxicity, preexisting chronic conditions, and obesity in the survival of 382 prospectively studied breast cancer patients representing six ethnic groups.

METHODS

Participants were recruited from several hospitals in Honolulu. Information on tumor characteristics and treatment was abstracted from medical records. Based on the Physicians Data Query (PDQ®), we assessed compliance with recommended treatment guidelines. Vital status and cause of death data were obtained through linkage with the Hawaii Tumor Registry. Cox proportional hazard models were used to compute hazard ratios for predictors of survival.

RESULTS

After a median follow-up time of 13.2 ± 3.7 years, 115 deaths had occurred, 43 from breast cancer and 72 from other causes. After adjustment, we observed only small differences in survival by ethnicity that were not statistically significant. In addition to advanced disease stage, obesity at diagnosis was a significant independent predictor of worse and receiving PDQ-recommended treatment of better breast cancer-specific and all-cause survival. Developing high-grade toxicity was associated with worse breast cancer survival, whereas comorbidity and older age at diagnosis were associated with higher all-cause mortality. Hormone receptor status, menopausal status, and type of health insurance were not associated with survival.

CONCLUSIONS

These findings suggest that given access to healthcare, breast cancer patients experience similar survival rates. Although more information about mechanisms of action would be useful, it appears reasonable to recommend weight control to breast cancer survivors.

Mammographic density and hormone receptor expression in breast cancer: the Multiethnic Cohort Study

BACKGROUND

It is unclear whether mammographic breast density, a strong risk factor for breast cancer, predicts subtypes of breast cancer defined by estrogen receptor (ER) and/or progesterone receptor (PR) expression.

METHODS

In a nested case-control study, we compared the breast density of 667 controls and 607 breast cancer cases among women of Caucasian, Japanese, and Native Hawaiian ancestry in the Hawaii component of the Multiethnic Cohort Study. A reader blinded to disease status performed computer assisted density assessment on prediagnostic mammograms. Receptor status was obtained from the statewide Hawaii Tumor Registry. Tumors were classified into ER+PR+ (n=341), ER-PR- (n=50), ER+PR-/ER-PR+ (n=64), and unstaged/unknown (n=152). Mean percent density values were computed for women with more than one mammogram. Polytomous logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) while adjusting for confounders.

RESULTS

Mean percent density was significantly greater for ER+PR+ but not for ER-PR- tumors compared to controls after adjusting for age: 37.3%, 28.9% versus 29.4%, respectively. The overall OR per 10% increase in percent density were similar for ER+PR+ and ER+PR-/ER-PR+ tumors: 1.26 (95% CI 1.17-1.36) and 1.23 (95% CI 1.07-1.42), respectively. However, percent density was not found to be a predictor for ER-PR- tumors (OR 1.00, 95% CI 0.84-1.18). The results did not differ by ethnicity, nor by menopausal status, parity, or HRT use.

CONCLUSIONS

Our findings indicate that within a multiethnic population, women with higher breast density have an increased risk for ER+PR+ but not ER-PR- tumors.

Abstract B25: Mammographic density and risk of breast cancer by body weight: A combined analysis of four case-control studies

Background. Breast density assessed from mammography is a strong predictor of breast cancer risk, but the strength of the association may vary with adiposity. To examine effect modification by adiposity, we combined data from four case-control studies on breast density that represented an ethnically diverse population with a wide variation in level of adiposity as measured by body mass index (BMI, kg/m2).

Methods. We combined data from four case-control studies representing different locations: California, Hawaii and Minnesota in the United States, and Gifu in Japan. All studies included incident breast cancer cases diagnosed between 1994 and 2002 and matched controls representing the underlying case population. One mammographic image per subject was selected, specifically the mammogram at diagnosis for the studies from California, Minnesota, and Japan and the closest prediagnostic mammogram for Hawaii. Percent density was measured by one reader, who was blinded to case status, using a computer-assisted method. Self-reported anthropometric measures were used to classify women as normal, overweight, and obese according to ethnic-specific BMI cut points (&lt;23, 23-27.4, and ≥27.5 for Asian women and &lt;25, 25-29.9, and ≥30 for other ethnic groups). Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (95% CI) and to evaluate interactions using the likelihood ratio while adjusting for potential confounders, including age and ethnicity. Heterogeneity across studies was marginally significant as assessed by examining density-by-study interaction (P = 0.09) and, therefore, we also adjusted for study-site.

Results. The study included 1,699 cases and 2,422 controls of diverse ethnicity: 45% Caucasian, 40% Asian, 9% African-American, and 7% Other. Of these women, we classified 34% as overweight and19% as obese. Age-adjusted mean percent density was significantly greater for cases than for controls: 31.7% versus 28.9%, respectively (P &lt; 0.001). BMI was inversely associated with breast density; the estimated age-adjusted mean percent density was 36.5%, 26.8%, and 19.3% for normal, overweight, and obese, respectively (Ptrend &lt; 0.001). The overall OR for a 10% higher percent density was 1.15 (95% CI: 1.05, 1.18) with higher estimates in overweight (OR: 1.19, 95% CI: 1.09, 1.29) and obese (OR: 1.25, 95% CI: 1.11, 1.41) than normal BMI (OR: 1.11, 95% CI: 1.05, 1.18). The effect modification by BMI was statistically significant (Pinteraction = 0.01).

Conclusions. Our findings confirm that the elevated risk of breast cancer associated with breast density differs by level of adiposity, with a higher risk for overweight and obese than normal BMI. Further research is needed to understand the underlying biological reasons for these noted differences in association by adiposity.

Citation Information: Cancer Prev Res 2010;3(12 Suppl):B25.

Abstract CN06-02: Soy foods and cancer risk: How does the relation vary in individuals with different ethnicity, diet, and lifestyle?

Soy foods have been part of traditional Asian diets for many centuries, while soy products were introduced in Western countries only a few decades ago. Migrants from Asia maintained their food habits to a certain degree when they moved to the U.S., but they also adopted Western foods (1). Inspired by studies among migrants and by the low incidence rates for several cancers among Asians, research into the protective effects of isoflavones in soy foods was initiated. Due to their estrogen-like structure, much of the research has focused on hormone-dependent cancers, i.e., breast, endometrial, ovarian, and prostate cancer, but some work on colorectal cancer has also been performed. During years of experimental and epidemiologic research, it has become evident that not all populations may derive the same benefit from consuming soy foods. One of the more consistent findings in soy research is the fact that epidemiologic studies report a stronger protective effect of soy foods against breast cancer among women who grew up in Asian countries and in those who consumed soy foods throughout childhood and adolescence (2). This presentation will focus on epidemiologic studies that have investigated the association between soy foods and cancer risk among populations with different ethnic backgrounds. In addition, some underlying mechanisms that may be responsible for ethnic differences, such as intestinal equol production, genetic polymorphisms, and timing of exposure will be discussed.

Epidemiologic studies among women of Asian, primarily Japanese and Chinese, ancestry show a more consistent protective effect against breast cancer than investigations among Western populations; the odds ratio (OR) was 0.71 (95% CI: 0.60-0.85) among Asians when the highest and lowest intake group were compared, while soy food was unrelated to breast cancer risk in Western studies (OR = 1.04; 95%CI: 0.97-1.11) (2). Similarly, a meta-analysis of prostate cancer studies found a lower risk associated with soy consumption only among Asian (OR = 0.52; 95%CI: 0.33-0.81) but not Western populations (OR = 0.99; 95% CI: 0.85-1.16) (3). On the other hand, meta-analyses for endometrial, ovarian, and colorectal cancer described only small differences in associations by ethnicity (4, 5). Recent case-control analyses nested within the Multiethnic Cohort in Hawaii and Los Angeles examined urinary isoflavone excretion as a biomarker of soy intake and reported similar results for breast but not prostate cancer. While the risk associated with breast cancer was 0.69 (95% CI: 0.51-0.92) among Japanese Americans and 0.98 (95% CI: 0.61-1.55) among Caucasians (6), the risk estimates did not differ by ethnicity for prostate cancer (7). Evidence from observational and intervention studies also suggests possible differential effects of soy intake on biomarkers of breast cancer risk (8-10), e.g., mammographic density and concentrations of serum estrogens and testosterone, urinary estrogen metabolite patterns, IGF-I, and PSA. Whereas the higher intake and possibly the type of soy foods in Asian populations may explain the observations for breast and prostate cancer risk (11), bioavailability of bioactive substances may also be a contributing factor (12). For example, the capacity of the intestinal bacteria to metabolize the isoflavone dadzein into the metabolite equol varies across populations and may confer a greater protection against disease than the other isoflavonoids (13, 14). Another reason that not all individuals may benefit from soy food exposure to the same degree is genetic variation. Genetic polymorphisms may alter enzyme activity or modulate the expression of genes involved in pathways influenced by isoflavones and relevant to cancer risk. Menopausal status, obesity, and other dietary components are other causes for isoflavones to exert differential actions across populations. Alternatively, the overall effect of soy foods on carcinogenesis may depend on the time of life when isoflavones were administered because isoflavones have estrogenic and anti-estrogenic effects. A number of case-control studies that assessed soy intake during childhood or adolescence found a stronger protection for early life than adult soy intake. Since experimental studies indicate that estrogen exposure in young animals induces protection against cancer development, the weak estrogenic effects of isoflavones in soy beans, if consumed early in life, may achieve or accelerate differentiation of breast tissue structures similar to an early pregnancy and, thereby, make the tissue less susceptible to carcinogens and prevent tumor development later in life.

Since the reports about beneficial effects of soy against cancer come primarily from Asian populations who have consumed soy foods since childhood and whose diet and lifestyle differs in many other ways from Western countries, the expectations of individuals in Western countries who start eating soy products later in life may not be fulfilled. Therefore, future research in different populations should focus on how soy affects cancer risk throughout life.

References:

1. Kolonel LN, Wilkens L.R. Migrant Studies. In: Schottenfeld D, Fraumeni JF, editors. Cancer Epidemiology and Prevention. New York: Oxford University Press; 2006. 189-201.

2. Wu AH, Yu MC, Tseng CC, Pike MC. Epidemiology of soy exposures and breast cancer risk. Br J Cancer 2008;98:9-14.

3. Yan L, Spitznagel EL. Soy consumption and prostate cancer risk in men: a revisit of a meta-analysis. Am J Clin Nutr 2009;89:1155-1163.

4. Yan L, Spitznagel EL, Bosland MC. Soy consumption and colorectal cancer risk in humans: a meta-analysis. Cancer Epidemiol Biomarkers Prev 2010;19:148-158.

5. Myung SK, Ju W, Choi HJ, Kim SC. Soy intake and risk of endocrine-related gynaecological cancer: a meta-analysis. BJOG 2009;116:1697-1705.

6. Goodman MT, Shvetsov YB, Wilkens LR et al. Urinary phytoestrogen excretion and postmenopausal breast cancer risk: the multiethnic cohort study. Cancer Prev Res (Phila Pa) 2009;2:887-894.

7. Park SY, Wilkens LR, Franke AA et al. Urinary phytoestrogen excretion and prostate cancer risk: a nested case-control study in the Multiethnic Cohort. Br J Cancer 2009;101:185-191.

8. Maskarinec G, Verheus M, Tice J. Epidemiologic studies of isoflavones & mammographic density. Nutrients 2010;2:35-48.

9. Fuhrman BJ, Pfeiffer R, Xu X et al. Soy intake is associated with increased 2-hydroxylation and decreased 16alpha-hydroxylation of estrogens in Asian-American women. Cancer Epidemiol Biomarkers Prev 2009;18:2751-2760.

10. Takata Y, Maskarinec G, Rinaldi S, Kaaks R, Nagata C. Serum insulin-like growth factor-I levels among women in Hawaii and Japan with different levels of tofu intake. Nutr Cancer 2006;56:136-142.

11. Messina M, Nagata C, Wu AH. Estimated Asian adult soy protein and isoflavone intakes. Nutr Cancer 2006;55:1-12.

12. Vergne S, Sauvant P, Lamothe V et al. Influence of ethnic origin (Asian v. Caucasian) and background diet on the bioavailability of dietary isoflavones. Br J Nutr 2009;102:1642-1653.

13. Setchell KD, Brown NM, Lydeking-Olsen E. The clinical importance of the metabolite equol-a clue to the effectiveness of soy and its isoflavones. J Nutr 2002;132:3577-3584.

14. Lampe JW. Emerging research on equol and cancer. J Nutr 2010;140:1369S-1372S.

Citation Information: Cancer Prev Res 2010;3(12 Suppl):CN06-02.

Associations between obesity and serum lipid-soluble micronutrients among premenopausal women

Elucidating potential pathways that micronutrients may reduce/promote chronic disease may contribute to our understanding of the underlying etiology of disease and their utility as markers of risk. In the current study, we examined associations of serum lipid-soluble micronutrients with body mass index (BMI). We hypothesized that obesity may differentially influence serum micronutrient levels, thereby affecting risk for chronic disease incidence and mortality. Baseline serum samples from 180 premenopausal women from a nutritional trial were analyzed for leptin, C-reactive protein, 25-hydroxyvitamin D, carotenoids, and tocopherols. Participants were stratified into normal-weight (18.5-24.9), overweight (25-29.9), and obese (>or=30) subgroups by BMI (in kilograms per square meter). Differences in serum biomarkers among BMI subgroups were adjusted for Asian ethnicity and smoking status. As expected, obese individuals had significantly higher serum levels of leptin and C-reactive protein (Ps < .05) compared with normal-weight women. gamma-Tocopherol levels were significantly higher in obese individuals (P < .05), whereas alpha-tocopherol levels did not differ among BMI subgroups. Serum levels of 25-hydroxyvitamin D and carotenoids (except lycopene) were significantly lower in obese than in normal-weight women (Ps < .05). The associations between BMI and carotenoids were independent of dietary intake. The obesity-associated reduction for total provitamin A carotenoids (45%) was approximately 3-fold greater than that observed for non-provitamin A carotenoids (16%). Our results indicate potential influences of obesity on serum levels of lipid-soluble micronutrients and suggest that metabolism of provitamin A carotenoids may contribute to the differences observed.

Consistent association of type 2 diabetes risk variants found in europeans in diverse racial and ethnic groups

It has been recently hypothesized that many of the signals detected in genome-wide association studies (GWAS) to T2D and other diseases, despite being observed to common variants, might in fact result from causal mutations that are rare. One prediction of this hypothesis is that the allelic associations should be population-specific, as the causal mutations arose after the migrations that established different populations around the world. We selected 19 common variants found to be reproducibly associated to T2D risk in European populations and studied them in a large multiethnic case-control study (6,142 cases and 7,403 controls) among men and women from 5 racial/ethnic groups (European Americans, African Americans, Latinos, Japanese Americans, and Native Hawaiians). In analysis pooled across ethnic groups, the allelic associations were in the same direction as the original report for all 19 variants, and 14 of the 19 were significantly associated with risk. In summing the number of risk alleles for each individual, the per-allele associations were highly statistically significant (P<10⁻⁴) and similar in all populations (odds ratios 1.09–1.12) except in Japanese Americans the estimated effect per allele was larger than in the other populations (1.20; P_het = 3.8×10⁻⁴). We did not observe ethnic differences in the distribution of risk that would explain the increased prevalence of type 2 diabetes in these groups as compared to European Americans. The consistency of allelic associations in diverse racial/ethnic groups is not predicted under the hypothesis of Goldstein regarding “synthetic associations” of rare mutations in T2D.

Single rare causal alleles and/or collections of multiple rare alleles have been suggested to create “synthetic associations” with common variants in genome-wide association studies (GWAS). This model predicts that associations with common variants will not be consistent across populations. In this study, we examined 19 T2D variants for association with T2D risk in 6,142 cases and 7,403 controls from five racial/ethnic populations in the Multiethnic Cohort (European Americans, African Americans, Latinos, Japanese Americans, and Native Hawaiians). In racial/ethnic pooled analysis, all 19 variants were associated with T2D risk in the same direction as previous reports in Europeans, and the sum total of risk variants was significantly associated with T2D risk in each racial/ethnic group. The consistent associations across populations do not support the Goldstein hypothesis that rare causal alleles underlie GWAS signals. We also did not find evidence that these markers underlie racial/ethnic disparities in T2D prevalence. Large-scale GWAS and sequencing studies in these populations are necessary in order to both improve the current set of markers at these risk loci and identify new risk variants for T2D that may be difficult, or impossible, to detect in European populations.

IGF1, IGFBP1, and IGFBP3 genes and mammographic density: the Multiethnic Cohort

Insulin-like growth factor-I (IGF-I) has mitogenic properties and stimulates cell growth. In this analysis, we investigated the relation between common genetic variation in IGF1, IGFBP1, and IGFBP3, and mammographic density among 819 women of Hawaiian, European, and Japanese ancestry from the Multiethnic Cohort Study. Mammographic density was assessed using a quantitative computer-assisted method. Previously identified tag single nucleotide polymorphisms (SNPs) for IGF1 (26 tag SNPs) and IGFBP1/IGFBP3 (22 tag SNPs) were genotyped among the 819 women. Mixed models were conducted to evaluate the associations between genetic variation and mammographic density. Two SNPs were borderline statistical significantly associated with mammographic density: rs35539615 on IGFBP1 (p = 0.05) and rs2453839 on IGFBP3 (p = 0.01). Rs35767on IGF1 (p = 0.03) was also associated with mammographic density, although in opposite direction of what was expected from previous findings with IGF-I levels. The majority of SNPs were, however, not associated with mammographic density. Analyses stratified by ethnicity showed similar results as the overall analyses for IGF1 and IGFBP1. However, for 4 SNPs in the IGFBP3 gene, the minor allele was associated with lower mammographic density in Japanese Americans and higher mammographic density in Caucasians. Given the large number of SNPs tested and the few borderline significant results, we only found weak evidence that genetic variations in IGFBP1 or IGFBP3 may be related to mammographic density. Ethnicity may modify these relations.

Comparison of breast density measured by dual energy X-ray absorptiometry with mammographic density among adult women in Hawaii

BACKGROUND

While use of mammography is limited, due to concerns related to radiation exposure, dual energy X-ray absorptiometry (DXA), commonly available in medical care settings, is characterized by low radiation exposure.

METHODS

In the current paper, we compared breast density measured by DXA with mammographic density in 101 adult women who had a screening mammogram during the last 2 years. DXA scans of both breasts were taken using a clinical DXA system calibrated to measure breast density. The total projected breast area was manually delineated on each image and percent fibroglandular volume density (%FGV), absolute fibroglandular volume, total breast area and volume were computed. After digitizing mammographic films, total breast area, dense area, and percent density (PD) were estimated using computer-assisted mammographic density assessment.

RESULTS

Both DXA and mammographic measures showed high correlations between left and right breasts ranging from 0.85 to 0.98 (p<0.0001). Mean %FGV was 38.8±14.3%, and mean percent density was 31.9±18.2% for craniocaudal views and 28.3±16.2% for mediolateral views. The correlation between the two measures was 0.76 for both views (p<0.0001). Associations with common risk factors showed similar patterns for DXA and mammographic densities; in particular, the inverse associations with BMI and age at menarche were evident for both methods. Multilinear regression with stepwise selection indicated an explained variance of 0.56 for %FGV alone and of 0.58 for %FGV plus number of children.

CONCLUSION

Despite some differences in methodology, the current comparison suggests that DXA may provide a low-radiation option in evaluating breast density.

Circulating 25-hydroxyvitamin D and risk of non-hodgkin lymphoma: Cohort Consortium Vitamin D Pooling Project of Rarer Cancers

Case-control studies generally suggesting an inverse association between sun exposure and non-Hodgkin lymphoma (NHL) have led to speculation that vitamin D may protect against lymphomagenesis. To examine this hypothesis, the authors conducted a pooled investigation of circulating 25-hydroxyvitamin D (25(OH)D) and subsequent NHL risk within 10 cohorts participating in the Cohort Consortium Vitamin D Pooling Project of Rarer Cancers. The authors analyzed measurements from 1,353 cases and 1,778 controls using conditional logistic regression and other methods to estimate the association of 25(OH)D with NHL. No clear evidence of association between categories of 25(OH)D concentration and NHL was observed overall (P(trend) = 0.68) or by sex (men, P(trend) = 0.50; women, P(trend) = 0.16). Findings for other measures (continuous log(25(OH)D), categories of 25(OH)D using sex-/cohort-/season-specific quartiles as cutpoints, categories of season-adjusted residuals of predicted 25(OH)D using quartiles as cutpoints) were generally null, although some measures of increasing 25(OH)D were suggestive of an increased risk for women. Results from stratified analyses and investigations of histologic subtypes of NHL were also null. These findings do not support the hypothesis that elevated circulating 25(OH)D concentration is associated with a reduced risk of NHL. Future research investigating the biologic basis for the sunlight-NHL association should consider alternative mechanisms, such as immunologic effects.

Mammographic density as a predictor of breast cancer outcome

Evaluation of: Cil T, Fishell E, Hanna W et al.: Mammographic density and the risk of breast cancer recurrence after breast-conserving surgery. Cancer 115, 5780–5787 (2009). This clinical investigation explored mammographic density, a strong etiologic risk factor for breast cancer, as a predictor of local breast cancer recurrence. The authors reported that women with intermediate and high breast density had a significantly elevated risk of developing a local breast cancer recurrence. However, this effect was observed only among patients who had not received radiotherapy. Only two previous reports have shown that mammographic density may be a prognostic factor, but the studies disagree on the role of radiotherapy as an effect modifier. Future studies that incorporate additional risk factors, such as obesity, need to examine the role of mammographic density in larger patient populations before including breast density in treatment decision models.

Abstract 2780: Mammographic density and breast cancer tumor characteristics in the Multiethnic Cohort Study

Mammographic density (MD), a strong risk factor for breast cancer, may reflect proliferation of breast epithelial and stromal cells in response to cumulative exposure to endogenous and exogenous hormones. Whether MD predicts subtypes of breast cancer defined by expression of the estrogen (ER+) and/or progesterone (PR+) receptor is unclear. Because factors associated with higher MD are associated with ER+PR+ breast cancers, we hypothesized that women with higher percent MD (dense breast tissue area to total breast area) would have a higher risk for ER+PR+ and a lower risk for ER-PR- breast cancers as compared to women with lower percent MD. In a nested case-control study, we compared the MD of 667 controls and 607 breast cancer cases among women of Caucasian, Japanese and Native Hawaiian ancestry in the Hawaii component of the Multiethnic Cohort Study. A reader blinded to disease status performed computer assisted density assessment on prediagnostic mammograms. Receptor status for breast cancers was obtained from the statewide Hawaii Tumor Registry. Tumors were classified into ER+PR+ (n=341), ER-PR- (n=50), ER+PR-/ER-PR+ (n=64) and unstaged/unknown (n=152). Mean density values were computed for women with more than one mammogram and modeled using polytomous logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) while adjusting for confounders. Mean percent MD was significantly greater for ER+PR+, but not for ER-PR- breast cancers compared to controls after adjusting for age: 37.3%, 28.9%, versus 29.4%, respectively. The overall ORs for a 10% increase in percent MD were similar for all breast cancer cases and for ER+PR+ and ER+PR-/ER-PR+ cancer subtypes: 1.22 (95% CI, 1.14-1.30), 1.25 (95% CI, 1.16-1.35) and 1.23 (95% CI, 1.07-1.42), respectively. Percent MD was not found to be a predictor for ER-PR- subtypes (OR for a 10% increase = 1.00, 95% CI, 0.84, 1.18). Our findings indicate that within a multiethnic population, women with higher MD have an increased risk for ER+PR+, but not ER-PR- breast cancer. Breast cancer subtypes are suspected to have diverse etiologies that respond to different treatments. Our findings support specific models of hormone-related triggers for the increased breast cancer risk associated with MD. Research supported by NCI grants: R37CA54281, R01CA85265 and R25CA90956.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2780.

Abstract LB-395: Alcohol intake and risk of non-Hodgkin's lymphoma: The Multiethnic Cohort

Evidence from case-control studies suggests an inverse association between alcohol intake and risk of non-Hodgkin's lymphoma (NHL), which might be due to immunemodulatory effects of alcohol. Results from prospective studies are sparse and less consistent. Therefore, we examined the relationship between intake of alcohol and NHL risk within the prospective Multiethnic Cohort (MEC).

Between 1993 and 1996, residents of Hawaii and the county of Los Angeles, aged 45-75 years, entered the cohort by completing a questionnaire on demographics, lifestyle and diet. Portion size and consumption frequency of beer, wine, and liquor was assessed. The study population comprised 193,041 participants of Caucasian, African American, Japanese American, Latino and Native Hawaiian ancestry. NHL cases were identified via record linkage with cancer registries. Hazard ratios (HR) and 95% confidence intervals (CI) of NHL or subtypes associated with alcohol intake were calculated using Cox regression with age as underlying time metric. Models were adjusted for age at baseline, sex, ethnicity, body mass index and education. Furthermore, we tested for effect modification by sex, ethnicity, and smoking status.

During a mean follow-up time of 9.1 years, 939 incident cases of NHL occurred, including 311 cases of diffuse large B-cell lymphoma (DLBCL), 152 of follicular lymphoma (FL), and 198 of small lymphocytic lymphoma/chronic lymphocytic leukemia (SLL/CLL). Overall, 39% of men and 62% of women were classified as non-drinkers, while 30% of men and 10% of women reported &gt; 1 drink/day. We found no association between alcohol intake and overall risk of NHL. As compared to non-drinkers, the respective HRs for participants with ≤ 1 and &gt; 1 drink/day were 1.02 (95% CI 0.88-1.19) and 1.03 (95% CI 0.86-1.24) in multivariate adjusted models. We found no interaction between alcohol intake and sex (pinteraction = 0.63) or smoking (pinteraction = 0.40). Stratified by ethnicity, HRs tend to increase with alcohol intake in Caucasians, while in Latinos those with &gt; 1 drink/day had a lower risk of NHL than non-drinkers, but the test for interaction of alcohol intake and ethnicity was not significant (pinteraction = 0.14). However, among NHL subtypes, participants with &gt; 1 drink/day had a HR of 0.69 (95% CI 0.49-0.98) for DLBCL, of 1.93 (95% CI 1.24-3.00) for FL, and of 0.86 (95% CI 0.59-1.26) for SLL/CLL as compared to non-drinkers.

Our findings regarding DLBCL support previous studies reporting an inverse association between alcohol intake and NHL risk, but the absence of an overall effect and the positive association with FL disagree with published evidence. The small number of NHL cases per subtype, the ethnic heterogeneity of our study population, and the large proportion of non-drinkers should be kept in mind when interpreting these findings.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-395.

Abstract 2805: A pooled investigation of circulating 25-hydroxyvitamin D and non-Hodgkin lymphoma: The Cohort Consortium Vitamin D Pooling Project of Rarer Cancers

Findings from several epidemiologic studies suggest that exposure to solar ultraviolet radiation may be associated with a reduced risk of non-Hodgkin lymphoma (NHL). These observations have led to speculation that vitamin D may protect against lymphomagenesis. To investigate this hypothesis, the authors conducted a pooled investigation of circulating 25-hydroxyvitamin D [25(OH)D] and subsequent NHL risk within ten cohorts participating in the Cohort Consortium Vitamin D Pooling Project of Rarer Cancers. Prediagnostic samples of serum or plasma from 1,353 cases and 1,778 controls were assayed for 25(OH)D by immunoassay at a single laboratory. Odds ratios (ORs) and 95% confidence intervals (CIs) relating categories of 25(OH)D concentration with NHL risk were calculated using conditional logistic regression models, with 50-&lt;75 nmol/L used as the reference category. Analyses of common NHL histologic subtypes were performed using polytomous regression modeling.

Overall, no evidence of association with NHL risk was observed for either low 25(OH)D concentration (&lt;25 nmol/L: OR 1.08, 95% CI 0.78-1.50) or high concentration (≥100 nmol/L: OR 0.86, 95% CI 0.57-1.27), and a test for trend was not statistically significant (P = 0.68).

Analyses of other measures of 25(OH)D {continuous log[25(OH)D], categories of 25(OH)D using sex/cohort/season-specific cutpoints, categories of season-adjusted residuals of predicted 25(OH)D} were similarly null, as were results from stratified analyses and investigations of histologic subtypes of NHL. These findings do not support the hypothesis that elevated circulating 25(OH)D levels are associated with reduced NHL risk. Future research investigating the biologic basis for the sunlight-NHL association should consider alternative mechanisms, such as immunologic effects.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2805.

Abstract 3768: Comparison of breast density measured by dual energy x-ray Absorptiometry (DXA) with mammographic density among adult women

Mammographic density, the distribution of fat, connective, and epithelial tissues in the female breast, is strongly associated with breast cancer and has been used as a biomarker for breast cancer risk among adult women. While use of mammography is limited due to concerns about radiation exposure, Dual Energy X-ray Absorptiometry (DXA), commonly available in medical care settings, has very low radiation. In this analysis, we compared breast density measured by DXA with mammographic density among adult women. We recruited 101 participants aged 30 years and older with a normal mammogram (defined as BIRADS categories 1 through 3) through Kaiser Permanente Hawaii. After completing a questionnaire asking for demographic, reproductive, anthropometric, and medical information, all women received DXA scans of both breasts, as well as of the whole body, using a GE Lunar Prodigy Bone Densitometer. On the DXA scans, the breast image was manually outlined and the following measures were computed: percent fibroglandular volume density (% FGV), absolute fibroglandular volume, total breast area, and volume. After digitizing the most recent craniocaudal (CC) and mediolateral (ML) mammograms, total breast area, dense area, and percent density were estimated using a computer-assisted method (Cumulus). For the overall population, mean % FGV was 38.8±14.3%, and mean percent density was 31.9±18.2% for CC views and 28.3±16.2% for ML views. Both DXA and mammographic measures showed high correlations between left and right breasts ranging from 0.85 to 0.98 (p &lt;0.0001). When comparing DXA and mammographic measures, the correlation coefficients between % FGV and percent density were 0.76 for both CC and ML views (p &lt;0.0001). Associations with common risk factors showed similar patterns for DXA and mammographic densities; in particular, the inverse associations with BMI and age at menarche were evident for both methods. Multilinear regression with stepwise selection indicated an explained variance of 0.57 for % FGV alone and 0.58 for % FGV plus parity. The current comparison suggests that DXA has the potential to provide a low-radiation option to evaluate breast density for women who do not undergo mammography. This may allow improved individualized risk assessment to identify women for targeted prevention strategies.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3768.

The relation of leptin and adiponectin with breast density among premenopausal women

The adipocytokine leptin may increase breast cancer risk, while adiponectin may be protective. We examined the association of the two circulating markers with mammographic density, a strong predictor of breast cancer risk. For 183 premenopausal participants of a nutritional trial, mammograms performed at baseline, year 1 and year 2 were assessed for density using a computer-assisted method. Serum samples obtained at the same time were analyzed for leptin and adiponectin by enzyme-linked immunosorbent assay. We applied mixed models to incorporate the repeated measurements while adjusting for confounders including body mass index (BMI). At baseline, the mean age of the participants was 42.6+/-2.9 years; 40% were of Asian ancestry. Leptin was lower and adiponectin higher in normal weight than overweight women. Neither marker was related to absolute breast density. The significant inverse association of leptin with percent density disappeared when BMI was added to the model. After stratification by weight, percent density decreased with higher leptin levels in normal weight women, whereas it increased among overweight participants. After adjustment for BMI, the positive association between percent density and adiponectin was greatly reduced and no longer significant. These results do not support a strong association of leptin or adiponectin with breast cancer risk as assessed by mammographic density. In contrast, the findings suggest the possibility that the inverse association of BMI with breast cancer risk in premenopausal women is mediated by adipocytokines.

Dietary patterns and risk for diabetes: the multiethnic cohort

OBJECTIVE The high diabetes incidence among Japanese Americans and Native Hawaiians cannot be explained by BMI. Therefore, we examined the influence of three dietary patterns of "fat and meat," "vegetables," and "fruit and milk" on diabetes risk in the Hawaii component of the Multiethnic Cohort with 29,759 Caucasians, 35,244 Japanese Americans, and 10,509 Native Hawaiians. RESEARCH DESIGN AND METHODS Subjects aged 45-75 years completed a baseline food frequency questionnaire. After 14 years of follow-up, 8,587 subjects with incident diabetes were identified through self-reports or health plan linkages. Risk was assessed using Cox regression stratified by age and adjusted for ethnicity, BMI, physical activity, education, total energy, smoking, alcohol intake, marital status, and hypertension. RESULTS Fat and meat was significantly associated with diabetes risk in men (hazard ratio 1.40 [95% CI 1.23-1.60], P(trend) < 0.0001) and women (1.22 [1.06-1.40], P(trend) = 0.004) when extreme quintiles were compared. Except in Hawaiian women, the magnitude of the risk was similar across ethnic groups although not always significant. After stratification by BMI, fat and meat remained a predictor of disease primarily among overweight men and among overweight Japanese women. Vegetables lowered diabetes risk in men (0.86 [0.77-0.95], P(trend) = 0.004) but not in women, whereas fruit and milk seemed to be more beneficial in women (0.85 [0.76-0.96], P(trend) = 0.005) than in men (0.92 [0.83-1.02], P(trend) = 0.04). CONCLUSIONS Foods high in meat and fat appear to confer a higher diabetes risk in all ethnic groups, whereas the effects of other dietary patterns vary by sex and ethnicity.

Soy consumption and histopathologic markers in breast tissue using tissue microarrays

This study examined the relation of soy intake with hormonal and proliferation markers in benign and malignant breast tissue using tissue microarrays (TMAs). TMAs with up to 4 malignant and 4 benign tissue samples for 268 breast cancer cases were constructed. Soy intake in early life and in adulthood was assessed by questionnaire. The TMAs were stained for estrogen receptor (ER) alpha, ERbeta, progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2/neu), proliferating cell nuclear antigen (PCNA), and Ki-67 using standard immunohistochemical methods. Logistic regression was applied for statistical analysis. A higher percentage of women showed positive marker expression in malignant than in benign tissue. With one exception, HER2/neu, no significant associations between soy intake and pathologic markers were observed. Early life soy intake was associated with lower HER2/neu and PCNA staining of malignant tissue. In benign tissue, early life soy intake showed higher ER and PR expression, but no difference in proliferation markers. The results of this investigation provide some assurance that soy intake does not adversely affect markers of proliferation. TMAs were shown to be a useful tool for epidemiologic research.

Cancer protective properties of cocoa: a review of the epidemiologic evidence

Due to their high concentration of catechins and procyanidins, bioactive compounds with distinct properties, cocoa and chocolate products may have beneficial health effects against oxidative stress and chronic inflammation, risk factors for cancer and other chronic diseases. This review focuses on the epidemiologic evidence for protective effects against cancer and overall mortality. The very small number of observational epidemiologic studies offers weak support for a reduction in mortality and little data related to cancer, whereas several intervention studies, despite their short duration, have reported some favorable changes in biomarkers assessing antioxidant status but very few findings related to inflammatory markers. In moderation, cocoa products may offer strong antioxidant effects in combination with a pleasurable eating experience. The benign profile of its fatty acids in combination with the low content of sugar of dark chocolate should lessen concerns about the adverse effects of cocoa products. Future nutritional trials need to assess a larger number of biomarkers that may be relevant for cancer risk, whereas epidemiologic studies require valid dietary assessment methods to examine the association of cocoa products with cancer risk in larger populations and to distinguish possible cancer protective effects of cocoa products from those due to other polyphenolic compounds.

Epidemiologic studies of isoflavones & mammographic density

Isoflavones, phytoestrogens in soy beans with estrogen-like properties, have been examined for their cancer protective effects. Mammographic density is a strong predictor of breast cancer. This review summarizes studies that have examined the association between isoflavones and breast density. Observational investigations in Hawaii and Singapore suggest slightly lower breast density among women of Asian descent with regular soy intake, but two larger studies from Japan and Singapore did not observe a protective effect. The findings from seven randomized trials with primarily Caucasian women indicate that soy or isoflavones do not modify mammographic density. Soy foods and isoflavone supplements within a nutritional range do not appear to modify breast cancer risk as assessed by mammographic density.

Dietary fiber, magnesium, and glycemic load alter risk of type 2 diabetes in a multiethnic cohort in Hawaii

The influence of dietary fiber, magnesium (Mg), and glycemic load (GL) on diabetes was examined in the Hawaii component of the Multiethnic Cohort. The 75,512 Caucasian, Japanese American, and Native Hawaiian participants aged 45-75 y at baseline completed a FFQ. After 14 y of follow-up, 8587 incident diabetes cases were identified through self-reports and health plans. We applied Cox regression stratified for age at cohort entry and adjusted for ethnicity, BMI, physical activity, education, and total energy with further stratifications by sex and ethnicity. When comparing extreme quintiles, total fiber intake was associated with reduced diabetes risk among all men [hazard ratio (HR): 0.75; 95% CI: 0.67, 0.84; P-trend < 0.001) and women (HR: 0.95; 95% CI: 0.85, 1.06; P-trend = 0.05). High intake of grain fiber reduced diabetes risk significantly by 10% in men and women. High vegetable fiber intake lowered risk by 22% in all men but not women. Mg intake reduced risk (HR = 0.77 and 0.84 for men and women, respectively) and, due to its strong correlation with fiber (r = 0.83; P < 0.001), may explain the protective effect of fiber. The top GL quintile was associated with a significantly elevated diabetes incidence in Caucasian men and in all women except Japanese Americans. Overall, several associations were more pronounced in Caucasians than in the other groups. These findings suggest that protection against diabetes can be achieved through food choices after taking into account body weight, but, due to differences in commonly consumed foods, risk estimates may differ by ethnic group.

Mammographic density and matrix metalloproteinases in breast tissue

Mammographic density is a strong risk factor for breast cancer, yet the underlying histopathologic correlates are not clear. Matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) play important roles in multiple stages of tumorigenesis. This study examined the association between mammographic density and expression of MMPs 1, 3, 9, and 12 and TIMP3 in benign and malignant breast tissue of 277 women with mainly Caucasian and Japanese ancestry. Tissue microarrays with up to 4 benign and 4 malignant cores per woman were stained immunohistochemically and evaluated. Digitized prediagnostic mammograms were assessed for densities using a computer-assisted method. General linear models adjusted for known confounders were applied to estimate mean densities by staining category. Strong expression of all MMPs was about twice as frequent in malignant as in benign tissue, while TIMP3 expression in stromal tissue was higher in benign than malignant cores. For MMP3 and 9, less than 10% of cores stained positive; thus, they were not further analyzed. None of the markers showed a statistically significant association with breast density in the entire study population and ethnic-specific results were conflicting and difficult to explain. Although not statistically significant, mean density was consistently lower with more extensive TIMP3 expression in stromal and epithelial tissue. These findings indicate that the higher breast cancer risk in women with dense breasts may be influenced by lower TIMP3 expression. However, future investigations into activities and ratios of additional proteases and their inhibitors as well as other pathways, such as inflammation, are needed.

Common immune-related risk factors and incident non-Hodgkin lymphoma: the multiethnic cohort

Severe immune dysfunction is an established risk factor of lymphoma, but the role of moderate alterations of immunity is not clear and prospective investigations are needed. We examined several immune-related disorders and medications in relation to non-Hodgkin lymphoma (NHL) in the Multiethnic Cohort. Over 215,000 subjects of African American, Caucasian, Japanese American, Latino and Native Hawaiian ancestry aged 45-75 years completed a questionnaire, including information on medical history, in 1993-1996. After exclusions, we performed Cox regression among 193,050 cohort members including 939 incident NHL cases while adjusting for sex, age, ethnicity, education, body mass index and alcohol intake. Self-reported diabetes was not associated with NHL overall, but was positively associated with risk among Japanese Americans [hazard ratio (HR) = 1.55; 95% confidence interval (CI): 1.10-2.17]. Participants with a history of blood transfusion were at increased risk with HR = 1.39 (95% CI: 1.06-1.84) in men and HR = 1.22 (95% CI: 0.94-1.58) in women, especially for the diffuse large B-cell lymphoma subtype. History of asthma or other allergies was associated with elevated risk only among Latinos (HR = 1.46; 95% CI: 1.07-2.00) who also showed a significant relation between current use of antihistamines and NHL (HR = 1.80; 95% CI: 1.09-2.97). Use of nonsteroidal anti-inflammatory drugs was not associated with NHL. Our findings from this large prospective study support a moderate risk for NHL related to blood transfusions, current long-term antihistamine use and diabetes, but the associations were limited to certain ethnic groups and require further replications.

Diabetes incidence based on linkages with health plans: the multiethnic cohort

OBJECTIVE

Using the Hawaii component of the Multiethnic Cohort (MEC), we estimated diabetes incidence among Caucasians, Japanese Americans, and Native Hawaiians.

RESEARCH DESIGN AND METHODS

After excluding subjects who reported diabetes at baseline or had missing values, 93,860 cohort members were part of this analysis. New case subjects were identified through a follow-up questionnaire (1999-2000), a medication questionnaire (2003-2006), and linkage with two major health plans (2007). We computed age-standardized incidence rates and estimated hazard ratios (HRs) for ethnicity, BMI, education, and combined effects of these variables using Cox regression analysis.

RESULTS

After a total follow-up time of 1,119,224 person-years, 11,838 incident diabetic case subjects were identified with an annual incidence rate of 10.4 per 1,000 person-years. Native Hawaiians had the highest rate with 15.5, followed by Japanese Americans with 12.5, and Caucasians with 5.8 per 1,000 person-years; the adjusted HRs were 2.65 for Japanese Americans and 1.93 for Native Hawaiians. BMI was positively related to incidence in all ethnic groups. Compared with the lowest category, the respective HRs for BMIs of 22.0-24.9, 25.0-29.9, and > or =30.0 kg/m(2) were 2.10, 4.12, and 9.48. However, the risk was highest for Japanese Americans and intermediate for Native Hawaiians in each BMI category. Educational achievement showed an inverse association with diabetes risk, but the protective effect was limited to Caucasians.

CONCLUSIONS

Within this multiethnic population, diabetes incidence was twofold higher in Japanese Americans and Native Hawaiians than in Caucasians. The significant interaction of ethnicity with BMI and education suggests ethnic differences in diabetes etiology.

Breast cancer risk and hysterectomy status: the Multiethnic Cohort study

OBJECTIVE

The main objective was to examine the association between simple hysterectomy (without bilateral oophorectomy) and breast cancer risk. Because hysterectomy prevalence varies by ethnicity, the secondary objective was to examine whether inclusion of women with hysterectomies affects the estimates of breast cancer risk by ethnicity.

METHODS

The Multiethnic Cohort study was assembled between 1993 and 1996 and included 68,065 women from Hawaii and Los Angeles, aged 45-75 years, without any missing information or bilateral oophorectomy. Hysterectomy status was self-reported. After 7.7 years median follow-up, 1,862 cases of invasive breast cancer were identified. Proportional hazards models were used to estimate relative risks (RR) while controlling for known risk factors.

RESULTS

Prevalence of simple hysterectomy varied from 12% to 29% among the ethnic groups (White, African American, Native Hawaiian, Japanese American, and Latina). Overall, hysterectomy was not associated with breast cancer risk (RR = 0.98). Although the RRs were nonsignificantly elevated by 15% in White women and nonsignificantly reduced by 15% in Latinas of non-US origin, the variation by ethnicity was not significant (p(interaction) = 0.48). The breast cancer risk associated with ethnicity was very similar when estimated with and without women with hysterectomies.

CONCLUSIONS

This study suggests that simple hysterectomy status does not alter breast cancer risk. Therefore, inclusion of women with simple hysterectomies does not substantially change estimated risk of breast cancer by ethnicity.

Mammographic density and epithelial histopathologic markers

BACKGROUND

We explored the association of mammographic density, a breast cancer risk factor, with hormonal and proliferation markers in benign tissue from tumor blocks of pre-and postmenopausal breast cancer cases.

METHODS

Breast cancer cases were recruited from a case-control study on breast density. Mammographic density was assessed on digitized prediagnostic mammograms using a computer-assisted method. For 279 participants of the original study, we obtained tumor blocks and prepared tissue microarrays (TMA), but benign tissue cores were only available for 159 women. The TMAs were immunostained for estrogen receptor alpha (ERalpha) and beta (ERbeta), progesterone receptor (PR), HER2/neu, Ki-67, and Proliferating Cell Nuclear Antigen (PCNA). We applied general linear models to compute breast density according to marker expression.

RESULTS

A substantial proportion of the samples were in the low or no staining categories. None of the results was statistically significant, but women with PR and ERbeta staining had 3.4% and 2.4% higher percent density. The respective values for Caucasians were 5.7% and 11.6% but less in Japanese women (3.5% and -1.1%). Percent density was 3.4% higher in women with any Ki-67 staining and 2.2% in those with positive PCNA staining.

CONCLUSION

This study detected little evidence for an association between mammographic density and expression of steroid receptors and proliferation markers in breast tissue, but it illustrated the problems of locating tumor blocks and benign breast tissue samples for epidemiologic research. Given the suggestive findings, future studies examining estrogen effects in tissue, cell proliferation, and density in the breast may be informative.

Breast Cancer Treatment Among Women of Different Ethnicity in Hawaii

BACKGROUND

An analysis of breast cancer survival for Hawaii's multiethnic women in the 1970s and 1980s showed that Hawaiian and Filipino women experienced a worse survival than their Caucasian and Japanese counterparts even after controlling for stage at diagnosis. We conducted this study to test for ethnic differences in treatment compliance with established guidelines while adjusting for stage at diagnosis and other disease characteristics.

METHODS

A total of 406 newly diagnosed breast cancer patients identified through the Hawaii Tumor Registry were available for this project. Two hundred fifty-nine patients of the sample were from Hawaii's predominant fee-for-service multiple private office/community hospital setting and 147 patients were members of a Health Maintenance Organization (HMO). The primary measures assessed were treatment received, ethnicity, age at diagnosis, cancer stage, hormone receptor status, comorbidity, and treatment toxicities. Physician's Data Query (PDQ) guidelines were used as the standard of care. We examined whether there were ethnic-related differences in compliance with PDQ treatment guidelines according to stage at diagnosis.

RESULTS

Overall, 25 percent of the sample did not receive treatment that was specifically recommended by PDQ guidelines and 7 percent received treatment that was not recommended by PDQ for the patients' stage of disease. There were no statistically significant ethnic-related differences in compliance with PDQ guidelines. Although not statistically significant, Caucasians and Japanese were less likely than other groups to receive axillary lymph node sampling/dissection and Chinese were more likely than other groups to receive chemotherapy when it was not specifically recommended by the PDQ. There was no difference in adherence to PDQ guidelines between the sample treated in a fee-for-service setting and the sample treated by the HMO. Hawaiians and Chinese experienced lower levels of Grade 3 and 4 chemotherapy-related toxicities than other groups.

CONCLUSION

The results of this study do not suggest that treatment compliance with established guidelines differs by ethnicity. Our unexpected finding that Hawaiian and Chinese women experienced lower levels of Grade 3 and 4 chemotherapy-related toxicities deserves further investigation.

Association of leptin, 25-hydroxyvitamin D, and parathyroid hormone in women

Vitamin D deficiency and adipocytokines have been implicated in the etiology of aging-related diseases such as cancer, osteoporosis, and diseases of the cardiovascular system. The association between elevated parathyroid hormone (PTH) and low 25-hydroxyvitamin D (25-OH-VitD) in plasma is used to define vitamin D deficiency, yet their associated mechanistic pathways are unclear. Utilizing plasma samples from women in a previous intervention study, we measured plasma 25-OH-VitD, leptin, adiponectin, PTH, and lipid levels. We observed strong positive associations for leptin with PTH, gamma -tocopherol, and body mass index (BMI) and inverse associations with 25-OH-VitD and adiponectin. Although commonly accepted that vitamin D deficiency causes hyperparathyroidism, we observed this association primarily in individuals with elevated leptin levels, suggesting that leptin may be an important modifier of this effect consistent with 25-OH-VitD-mediated inhibition of leptin. Leptin was highly correlated with the BMI/25-OH-VitD ratio (r = 0.80; P < 0.0001), consistent with a model in which BMI (adiposity) and 25-OH-VitD are the primary determinants of circulating leptin and PTH levels. This model may explain the failure of some studies to observe elevated PTH in vitamin D deficient adolescents and provides important insight into epidemiological studies exploring the associations of these individual biomarkers with chronic disease risk and mortality.

Inflammatory markers in a randomised soya intervention among men

The present analysis investigated the effect of soya foods on serum levels of six inflammatory markers, leptin, adiponectin, monocyte attractant protein 1 (MCP-1), macrophage inflammatory protein-1b (MIP-1b), IL-6 and C-reactive protein (CRP), and their relationship with BMI and lifetime soya intake. We randomised twenty-four men to a high- (two daily servings with 30-35 mg isoflavones per serving) or a low-soya diet for 3 months. After a 1-month washout period, the men crossed over to the other treatment. We used a multiplex bead immunoassay to measure leptin, adiponectin, MCP-1 and MIP-1b and ELISA assays for IL-6 and CRP. The statistical analysis applied mixed models that incorporated the four repeated measurements. The men had a mean age of 58.7 (sd 7.2) years and a mean BMI of 28.4 (sd 4.9) kg/m2. We observed no significant intervention effect of the soya treatment on any of the six markers. After adjustment for age and ethnicity, highly significant associations of BMI and body weight with leptin and MCP-1 emerged. Men with high soya intake early in life also had higher levels of leptin and MCP-1, whereas no association was seen for soya intake during adulthood. MIP-1b, adiponectin, IL-6 and CRP were not related to BMI, body weight or soya intake at any time in life. No intervention effect of soya foods on markers of inflammation was observed in this small study, but adiposity and early-life soya intake were related to higher leptin and MCP-1 levels.

Various doses of soy isoflavones do not modify mammographic density in postmenopausal women

Soy isoflavones have functional similarity to human estrogens and may protect against breast cancer as a result of their antiestrogenic activity or increase risk as a result of their estrogen-like properties. We examined the relation between isoflavone supplementation and mammographic density, a strong marker for breast cancer risk, among postmenopausal women. The Osteoporosis Prevention Using Soy (OPUS) study, a multi-site, randomized, double-blinded, and placebo-controlled trial assigned 406 postmenopausal women to 80 or 120 mg/d of isoflavones each or a placebo for 2 y. Percent densities were assessed in digitized mammograms using a computer-assisted method. The mammogram reader did not know the treatment status and the time of mammograms. We applied mixed models to compare breast density by treatment while considering the repeated measures. The mammographic density analysis included 358 women, 88.2% of the OPUS participants; 303 had a complete set of 3 mammograms, 49 had 2, and 6 had only 1 mammogram. At baseline, the groups were similar in age, BMI, and percent density, but mean breast density differed by study site (P = 0.02). A model with all mammograms did not show a treatment effect on any mammographic measure, but the change over time was significant; breast density decreased by 1.6%/y across groups (P < 0.001). Stratification by age and BMI did not reveal any effects in subgroups. In this randomized 2-y trial, isoflavone supplements did not modify breast density in postmenopausal women. These findings offer reassurance that isoflavones do not act like hormone replacement medication on breast density.

Inflammatory markers in a 2-year soy intervention among premenopausal women

BACKGROUND

Epidemiologic evidence supports a role of soy foods in breast cancer etiology. Because chronic inflammation appears to be a critical component in carcinogenesis, we examined the potential anti-inflammatory effects of soy foods.

METHODS

The original 2-year dietary intervention randomized 220 premenopausal women of whom 183 women (90 in the intervention group and 93 in the control group) were included in the current investigation; 40% were of Asian ancestry. The intervention group consumed two daily soy servings containing 50 mg of isoflavones (aglycone equivalents), whereas the controls maintained their regular diet. Five serum samples obtained at month 0, 3, 6, 12, and 24 were analyzed for interleukin (IL)-6, C-reactive protein (CRP), leptin, and adiponectin by ELISA. For statistical analysis, mixed models were applied to incorporate the repeated measurements.

RESULTS

The levels of all analytes were lower in Asian than Caucasian women. Overweight women had significantly higher levels of CRP, IL-6, and leptin and lower levels of adiponectin than normal weight women. We did not observe a significant effect of soy foods on the four markers, but leptin increased in the control and not in the intervention group (p = 0.20 for group-time effect); this difference was significant for Asian (p = 0.01) and obese women (p = 0.005).

CONCLUSION

During this 2-year intervention, soy foods did not modify serum levels of CRP, IL-6, leptin, and adiponectin in premenopausal women although leptin levels remained stable among women in the intervention group who were obese or of Asian ancestry. Further studies with diverse markers of inflammation are necessary to clarify the specific effect of soy on immune responses.

Association between breast cancer susceptibility loci and mammographic density: the Multiethnic Cohort

Introduction

Mammographic density is a strong risk factor for breast cancer. Our objective was to examine its association with polymorphisms identifying breast cancer susceptibility loci that were ascertained in recent genome-wide association studies.

Methods

Subjects were 825 women who participated in previous case–control studies of mammographic density and genetic factors nested within the Multiethnic Cohort study and were from three ethnic groups (White, Japanese American, Native Hawaiian). Eight polymorphisms (rs2981582 in FGFR2, rs3803662 and rs12443621in TOX3, rs3817198 in LSP1, rs981782 and rs10941679 near HCN1/MRPS30, rs889312 in MAP3K1, and rs13387042 at 2q) were examined. Mammographic density was quantified with a computer-assisted method as the percent dense area: the area of radiologically dense fibroglandular tissue relative to the total breast area that also includes radiologically lucent fatty tissue.

Results

The polymorphism rs12443621 in TOX3 was associated with percent dense area; women with at least one G allele (previously associated with increased breast cancer risk) had 3% to 4% higher densities than women with two A alleles. The polymorphism rs10941679 near HCN1/MRPS30 was also associated with percent dense area; women who were homozygous for the G allele (previously associated with increased breast cancer risk) had 4% to 5% lower densities than women with at least one A allele. The other polymorphisms were not associated with percent dense area.

Conclusions

The available data suggest that the effects of most of these polymorphisms on breast cancer are not mediated by mammographic density. Some effects may have been too small to be detected. The association with rs12443621 may provide clues as to how variation in TOX3 influences breast cancer risk.

Diabetes prevalence and body mass index differ by ethnicity: the Multiethnic Cohort

OBJECTIVE

The high prevalence of diabetes in non-Caucasian populations is reported not only for Native Hawaiians who suffer from high rates of obesity, but also for Japanese with a relatively low body weight. The objectives of this study were to estimate the prevalence of diabetes among participants of the Multiethnic Cohort (MEC) and to examine the association of body mass index (BMI) with self-reported diabetes by ethnicity.

DESIGN

Cross-sectional analysis of baseline questionnaire at cohort entry.

PARTICIPANTS

187,439 MEC subjects in Hawaii and California from five ethnic groups.

MAIN OUTCOME MEASURES

Participants completed a 26-page, self-administered survey with questions concerning anthropometrics, demographic, medical, lifestyle, and food consumption behavior. Age-adjusted prevalence of diabetes was calculated by sex and ethnicity and stratified by BMI. Prevalence ratios were determined using logistic regression while adjusting for variables that are known to be related to diabetes. The c statistic was computed to compare models with different confounders.

RESULTS

The prevalence of self-reported diabetes in the MEC was 11.6%. The age-adjusted diabetes prevalence ranged from 6.3% in Caucasians to 10.2% in Japanese, 16.1% in Native Hawaiians, 15.0% in African Americans, and 15.8% in Latinos. After adjustment for known risk factors, the prevalence ratio by ethnicity ranged between 2.1 (African American and Latino), 2.8 (Japanese), and 3.0 (Native Hawaiian) as compared to Caucasians. These differences were observed among all BMI categories.

CONCLUSIONS

Ethnic differences in the prevalence of diabetes persisted after stratification by BMI. The prevalence of diabetes was at least two-fold higher in all ethnic groups than among Caucasians.

Breast density assessment in adolescent girls using dual-energy X-ray absorptiometry: a feasibility study

Breast density, the radiographically opaque fraction of the breast in a mammogram, is one of the strongest biomarkers of breast cancer risk. However, younger populations do not typically have mammograms due to radiation concerns. This study explored a commercially available dual-energy X-ray absorptiometer (DXA) system as a low-dose method to measure breast fibroglandular density in adolescent girls. Eighteen girls (13-14 years old) indicated their breast development according to Tanner and underwent three dedicated DXA scans, two of their left and one of their right breasts. Total projected breast area was manually delineated on each image and percent fibroglandular volume density (%FGV), absolute fibroglandular volume (FGV), total breast area, and volume were computed. It was possible to image breasts representing all five Tanner stages; %FGV ranged from 31.9% to 92.2% with a mean of 71.1 +/- 14.8%, whereas FGV ranged from 80 to 270 cm(3) with a mean of 168 +/- 54 cm(3). Left and right breast %FGV were highly correlated (r(p) = 0.97, P < 0.0001) and of the same magnitude (P = 0.18). However, left total volume and FGV were larger than the right by 38 cm(3) (P = 0.04) and 19 cm(3) (P = 0.02), respectively. Total volume and FGV increased by Tanner stage, whereas %FGV did not. Our method had excellent precision for %FGV and moderate precision for FGV (root mean square SDs of 2.4% and 16.6 cm(3)). These pilot data indicate that dedicated DXA breast scans may be useful in studies exploring breast density in girls.

Soy intake is related to a lower body mass index in adult women

BACKGROUND

Experimental and epidemiologic studies suggest that soy may promote weight loss.

AIM OF THE STUDY

The goal of this study was to examine the relation of soy intake with body weight over the lifespan of women with Caucasian, Japanese, and Native Hawaiian ancestry.

METHODS

We assessed the relation between lifetime soy consumption and body mass index (BMI) among 1,418 women in Hawaii. All subjects reported anthropometric measures, regular diet, and soy intake throughout life. The lifetime soy questionnaire was completed again by a subset of 356 women 5 years after study entry and the kappa values indicated moderate agreement. We regressed soy intake on BMI at study entry and at age 21 while controlling for confounding variables, computed least square means, and performed trend tests.

RESULTS

Higher soy consumption in adulthood was related to a lower BMI (P=0.02). This association was only significant for Caucasian women and for postmenopausal subjects. The women in the highest category also experienced a smaller annual weight change since age 21 (by 0.05 kg/year) than the low soy intake group (P=0.02). We observed no association between early life soy intake and BMI. High vegetable consumption was significantly associated with a higher soy intake among Caucasian women.

CONCLUSIONS

In this study, women consuming more soy during adulthood had a lower BMI, but the relation was primarily observed for Caucasian and postmenopausal subjects. This indicates that the association may be due to other nutritional factors and behaviors common in women with high soy intake.

Nonsteroidal antiinflammatory drugs and breast cancer risk: the multiethnic cohort

Previous studies on nonsteroidal antiinflammatory drugs (NSAIDs) and breast cancer have produced mixed results. Incident invasive cases of breast cancer from the Multiethnic Cohort (African Americans, Caucasians, Japanese Americans, Latinas, and Native Hawaiians from Hawaii and California) were identified from 1993 to 2002. Data on aspirin, acetaminophen, and other NSAID (ibuprofen, naproxen, indomethacin) use were based on a self-administered questionnaire at baseline (1993-1996). Multivariate Cox proportional hazards models provided estimates of hazard rate ratios and 95% confidence intervals. The authors observed no associations between breast cancer risk and duration of aspirin use for current or past users (hazard rate ratio = 1.05, 95% confidence interval: 0.88, 1.25 and hazard rate ratio = 1.04, 95% confidence interval: 0.84, 1.27 for > or =6 years of use, respectively) compared with nonusers. However, duration of current other NSAID use was protective (hazard rate ratio = 0.70, 95% confidence interval: 0.51, 0.95 for > or =6 years of use; p(trend) = 0.01) against the risk of breast cancer, while past use was not (hazard rate ratio = 0.90, 95% confidence interval: 0.62, 1.30 for > or =6 years of use). Analyses by ethnicity and hormone receptor status showed that the protective effect of current other NSAID use was limited to Caucasians and African Americans and to women with at least one positive hormone receptor. This study found duration of current other NSAID use to be protective against breast cancer risk.