Plasma B-vitamins and one-carbon metabolites and the risk of breast cancer in younger women.

PURPOSE: We examined the association of plasma B-vitamins and metabolites, and related genetic variants, with risk of breast cancer among predominantly premenopausal women. METHODS: We conducted a nested case-control study within the Nurses' Health Study II. From blood samples collected in 1996-1999 and follow-up through 2007, plasma measures were available for 610 cases and 1207 controls. Unconditional multivariable logistic regression was used to estimate relative risks (RR) of breast cancer and 95% confidence intervals (CIs). We examined whether associations varied by methylenetetrahydrofolate reductase (MTHFR) and dihydrofolate reductase polymorphisms, breast cancer risk factors, or tumor characteristics. RESULTS: Plasma vitamin B12 was associated with a 64% higher risk of breast cancer comparing the highest versus lowest quintile (95% CI 1.17-2.29, p-trend = 0.02). Plasma folate (comparable RR = 1.18, 95% CI 0.84-1.66), pyridoxal 5'-phosphate (RR = 1.18, 95% CI 0.85-1.64), homocysteine (RR = 0.93, 95% CI 0.67-1.28), cysteine (RR = 1.14, 95% CI 0.81-1.62), and cysteinylglycine (RR = 0.93, 95% CI 0.66-1.31) were not associated with overall breast cancer risk. Folate was significantly positively associated with invasive and estrogen receptor-positive/progesterone receptor-positive breast cancer, and this association was suggestively stronger for bloods collected post-fortification. Several nutrient/breast cancer associations varied across subgroups defined by age, smoking, alcohol, multivitamin use, and MTHFR status (p-interaction < 0.05). CONCLUSIONS: Overall, plasma B-vitamins and metabolites were not associated with lower breast cancer risk. Plasma vitamin B-12 was positively associated with higher risk of overall breast cancer, and plasma folate was positively associated with risk of invasive breast cancer. Additionally, there may be associations in subgroups defined by related genetic variants, breast cancer risk factors, and tumor factors. Further studies in younger women and in the post-fortification era are needed to confirm these findings.

Plasma B-vitamin and one-carbon metabolites and risk of breast cancer before and after folic acid fortification in the United States.

Prior epidemiologic findings for plasma folate and B-vitamins and breast cancer risk are inconsistent and have not assessed the influence of folic acid fortification. Therefore, we examined the associations of plasma folate, B12 , pyridoxal 5'-phosphate (PLP), homocysteine, cysteine and cysteinylglycine with breast cancer risk, before and after fortification. We conducted a nested case-control study within the prospective Nurses' Health Study. In 1989-1990 (pre-fortification), 32,826 women donated a blood sample and 18,743 donated an additional blood sample in 2000-2001 (post-fortification). Between the first blood collection and 2006, 1874 incident breast cancer cases with at least one blood sample and 367 with two were 1:1 matched to controls. Conditional logistic regression was used to estimate relative risks (RR) and 95% confidence intervals (CI) adjusting for breast cancer risk factors. Overall, higher plasma folate, B12 , PLP, homocysteine, cysteine and cysteinylglycine levels were not associated with breast cancer risk. Associations did not vary by in situ/invasive, hormone receptor status, or tumor molecular subtype. Additionally, associations were null before and after fortification. For example, the RR (95% CI) for the highest versus lowest tertile of 1990 (pre-fortification) plasma folate with 1990-2000 follow-up was 0.93 (0.75-1.16) and for the 2000 plasma folate (post-fortification) with 2000-2006 follow-up the RR (95% CI) was 1.17 (0.79-1.74). Plasma folate, B12 , PLP, homocysteine, cysteine and cysteinylglycine were not significantly associated with breast cancer overall, before and after fortification, or with specific tumor molecular subtypes. However, long term associations (>8 years) after the implementation of fortification could not be examined.

Dietary fat intake and risk of non-Hodgkin lymphoma in 2 large prospective cohorts.

Background: Dietary fat intake may contribute to non-Hodgkin lymphoma (NHL) pathogenesis by influencing carcinogen exposure or through immune modulation.Objective: We aimed to evaluate NHL risk associated with total and specific dietary fat intake.Design: We evaluated associations within the Nurses' Health Study (NHS) (n = 88,598) and the Health Professionals Follow-Up Study (HPFS) (n = 47,531) using repeated validated dietary assessments. We confirmed 1802 incident NHL diagnoses through 2010. Using multivariable Cox proportional hazards models, we estimated hazard ratios (HRs) for all NHL and common subtypes associated with a 1-SD increase in cumulative mean intakes of total, animal, saturated, trans, and vegetable fats and marine fatty acids. We pooled sex-specific HRs using random-effects meta-analysis.Results: Over 24-30 y of follow-up, neither total nor specific dietary fats were significantly associated with NHL risk overall. Higher total, animal, and saturated fat intakes were positively associated with the risk of the chronic lymphocytic leukemia/small lymphocytic lymphoma subtype among women only (253 cases; P-trend ≤ 0.05), driven by strong associations during 1980-1994. From baseline through 1994, among women and men combined, total fat intake was borderline-significantly positively associated with NHL overall (pooled HR per SD: 1.13; 95% CI: 0.99, 1.29) and was significantly associated with diffuse large B cell lymphoma (pooled HR per SD: 1.47; 95% CI: 1.06, 2.05), with similar trends for animal and saturated fat intake. For women only, trans fat was significantly positively associated with all NHL. In contrast, during 1994-2010, there was little evidence for associations of dietary fat intake with NHL overall or by subtype.Conclusion: Previous observations of an increased risk of NHL associated with intakes of total, animal, saturated, and trans fat with 14 y of follow-up did not persist with longer follow-up.

Alcohol consumption and breast cancer risk by estrogen receptor status: in a pooled analysis of 20 studies.

BACKGROUND: Breast cancer aetiology may differ by estrogen receptor (ER) status. Associations of alcohol and folate intakes with risk of breast cancer defined by ER status were examined in pooled analyses of the primary data from 20 cohorts. METHODS: During a maximum of 6-18 years of follow-up of 1 089 273 women, 21 624 ER+ and 5113 ER- breast cancers were identified. Study-specific multivariable relative risks (RRs) were calculated using Cox proportional hazards regression models and then combined using a random-effects model. RESULTS: Alcohol consumption was positively associated with risk of ER+ and ER- breast cancer. The pooled multivariable RRs (95% confidence intervals) comparing ≥ 30 g/d with 0 g/day of alcohol consumption were 1.35 (1.23-1.48) for ER+ and 1.28 (1.10-1.49) for ER- breast cancer (Ptrend ≤ 0.001; Pcommon-effects by ER status: 0.57). Associations were similar for alcohol intake from beer, wine and liquor. The associations with alcohol intake did not vary significantly by total (from foods and supplements) folate intake (Pinteraction ≥ 0.26). Dietary (from foods only) and total folate intakes were not associated with risk of overall, ER+ and ER- breast cancer; pooled multivariable RRs ranged from 0.98 to 1.02 comparing extreme quintiles. Following-up US studies through only the period before mandatory folic acid fortification did not change the results. The alcohol and folate associations did not vary by tumour subtypes defined by progesterone receptor status. CONCLUSIONS: Alcohol consumption was positively associated with risk of both ER+ and ER- breast cancer, even among women with high folate intake. Folate intake was not associated with breast cancer risk.

Magnesium, vitamin D status and mortality: results from US National Health and Nutrition Examination Survey (NHANES) 2001 to 2006 and NHANES III.

BACKGROUND: Magnesium plays an essential role in the synthesis and metabolism of vitamin D and magnesium supplementation substantially reversed the resistance to vitamin D treatment in patients with magnesium-dependent vitamin-D-resistant rickets. We hypothesized that dietary magnesium alone, particularly its interaction with vitamin D intake, contributes to serum 25-hydroxyvitamin D (25(OH)D) levels, and the associations between serum 25(OH)D and risk of mortality may be modified by magnesium intake level. METHODS: We tested these novel hypotheses utilizing data from the National Health and Nutrition Examination Survey (NHANES) 2001 to 2006, a population-based cross-sectional study, and the NHANES III cohort, a population-based cohort study. Serum 25(OH)D was used to define vitamin D status. Mortality outcomes in the NHANES III cohort were determined by using probabilistic linkage with the National Death Index (NDI). RESULTS: High intake of total, dietary or supplemental magnesium was independently associated with significantly reduced risks of vitamin D deficiency and insufficiency respectively. Intake of magnesium significantly interacted with intake of vitamin D in relation to risk of both vitamin D deficiency and insufficiency. Additionally, the inverse association between total magnesium intake and vitamin D insufficiency primarily appeared among populations at high risk of vitamin D insufficiency. Furthermore, the associations of serum 25(OH)D with mortality, particularly due to cardiovascular disease (CVD) and colorectal cancer, were modified by magnesium intake, and the inverse associations were primarily present among those with magnesium intake above the median. CONCLUSIONS: Our preliminary findings indicate it is possible that magnesium intake alone or its interaction with vitamin D intake may contribute to vitamin D status. The associations between serum 25(OH)D and risk of mortality may be modified by the intake level of magnesium. Future studies, including cohort studies and clinical trials, are necessary to confirm the findings.

Alternate-day, low-dose aspirin and cancer risk: long-term observational follow-up of a randomized trial.

BACKGROUND: Recent evidence suggests that daily aspirin use decreases cancer risk, particularly for colorectal cancer, but evidence for alternate-day use is scant. OBJECTIVE: To examine the association between long-term, alternate-day, low-dose aspirin and cancer in healthy women. DESIGN: Observational follow-up of a randomized trial. SETTING: Female health professionals. PARTICIPANTS: 39,876 women aged 45 years or older in the Women's Health Study (ClinicalTrials.gov: NCT00000479), 33 682 of whom continued observational follow-up. INTERVENTION: 100 mg of alternate-day aspirin or placebo through March 2004, with a median 10-year follow-up. Posttrial follow-up continued through March 2012. MEASUREMENTS: Cancer incidence. RESULTS: A total of 5071 cancer cases (including 2070 breast, 451 colorectal, and 431 lung cancer cases) and 1391 cancer deaths were confirmed. Over the entire follow-up, aspirin had no association with total (hazard ratio [HR], 0.97 [95% CI, 0.92 to 1.03]; P = 0.31), breast (HR, 0.98 [CI, 0.90 to 1.07]; P = 0.65), or lung (HR, 1.04 [CI, 0.86 to 1.26]; P = 0.67) cancer. Colorectal cancer was reduced in the aspirin group (HR, 0.80 [CI, 0.67 to 0.97]; P = 0.021), primarily for proximal colon cancer (HR, 0.73 [CI, 0.55 to 0.95]; P = 0.022). The difference emerged after 10 years, with a posttrial reduction of 42% (HR, 0.58 [CI, 0.42 to 0.80]; P < 0.001). There was no extended effect on cancer deaths or colorectal polyps. More gastrointestinal bleeding (HR, 1.14 [CI, 1.06 to 1.22]; P < 0.001) and peptic ulcers (HR, 1.17 [CI, 1.09 to 1.27]; P < 0.001) occurred in the aspirin group. LIMITATIONS: Not all women received extended follow-up, and posttrial ascertainment bias cannot be ruled out. Gastrointestinal bleeding, peptic ulcers, and polyps were self-reported during extended follow-up. CONCLUSION: Long-term use of alternate-day, low-dose aspirin may reduce risk for colorectal cancer in healthy women.

A prospective analysis of body size during childhood, adolescence, and adulthood and risk of non-Hodgkin lymphoma.

The etiology of non-Hodgkin lymphoma (NHL) is poorly understood. Obesity is associated with inflammation, a cytokine milieu conducive to lymphocyte proliferation, and has been associated with NHL risk in some epidemiologic studies. To prospectively examine NHL risk in relation to adult and earlier life obesity, we documented 635 incident NHL diagnoses among 46,390 men in the Health Professionals Follow-up Study and 1,254 diagnoses among 116,794 women in the Nurses' Health Study over 22 to 32 years of follow-up. Using multivariable Cox proportional hazards models, we estimated cohort-specific incidence rate ratios (RR) and 95% confidence intervals (CI) for risk of NHL and major histologic subtypes associated with cumulative average middle and young adult (ages, 18-21 years) body mass index (BMI) and adolescent and childhood somatotype. NHL risk was modestly increased in men (but not women) with a cumulative average middle adult BMI ≥ 30 kg/m(2) (vs. 15-22.9 kg/m(2); RR, 1.28; 95% CI, 0.92-1.77; Ptrend = 0.05). In meta-analyses across cohorts, higher young adult BMI was associated with increased risk of all NHL (pooled RR per 5 kg/m(2), 1.19; 95% CI, 1.05-1.37), diffuse large B-cell lymphoma (DLBCL), and follicular lymphoma (all Ptrend ≤ 0.02). Adolescent somatotype was also positively associated with all NHL, DLBCL, and follicular lymphoma in pooled analyses (all Ptrend ≤ 0.03), whereas childhood somatotype was positively associated with NHL overall among women only (Ptrend < 0.01). These findings in two large prospective cohorts provide novel evidence that larger body size in childhood, adolescence, and young adulthood predicts increased risk of NHL, and particularly of DLBCL and follicular lymphoma.

Fruit and vegetable intake and risk of breast cancer by hormone receptor status.

BACKGROUND: Estrogen receptor-negative (ER(-)) breast cancer has few known or modifiable risk factors. Because ER(-) tumors account for only 15% to 20% of breast cancers, large pooled analyses are necessary to evaluate precisely the suspected inverse association between fruit and vegetable intake and risk of ER(-) breast cancer. METHODS: Among 993 466 women followed for 11 to 20 years in 20 cohort studies, we documented 19 869 estrogen receptor positive (ER(+)) and 4821 ER(-) breast cancers. We calculated study-specific multivariable relative risks (RRs) and 95% confidence intervals (CIs) using Cox proportional hazards regression analyses and then combined them using a random-effects model. All statistical tests were two-sided. RESULTS: Total fruit and vegetable intake was statistically significantly inversely associated with risk of ER(-) breast cancer but not with risk of breast cancer overall or of ER(+) tumors. The inverse association for ER(-) tumors was observed primarily for vegetable consumption. The pooled relative risks comparing the highest vs lowest quintile of total vegetable consumption were 0.82 (95% CI = 0.74 to 0.90) for ER(-) breast cancer and 1.04 (95% CI = 0.97 to 1.11) for ER(+) breast cancer (P (common-effects) by ER status < .001). Total fruit consumption was non-statistically significantly associated with risk of ER(-) breast cancer (pooled multivariable RR comparing the highest vs lowest quintile = 0.94, 95% CI = 0.85 to 1.04). CONCLUSIONS: We observed no association between total fruit and vegetable intake and risk of overall breast cancer. However, vegetable consumption was inversely associated with risk of ER(-) breast cancer in our large pooled analyses.

Association between sex hormones and colorectal cancer risk in men and women.

BACKGROUND & AIMS: There is observational and clinical evidence that indicates that sex hormones affect development of colorectal cancer in men and women. However, the relationship between endogenous sex hormone levels and colorectal cancer is unclear. METHODS: We collected data on lifestyle, medical history, and diet (through 2008), along with blood samples, from the Nurses' Health Study, the Women's Health Study, the Health Professional Follow-up Study, and the Physicians' Health Study II. We measured plasma levels of estrone, estradiol, testosterone, sex hormone binding globulin (SHBG), and C-peptide among 730 women (293 cases of colorectal cancer and 437 healthy individuals as controls) and 1158 men (439 colorectal cancer cases and 719 controls) and used unconditional logistic regression to estimate relative risks (RRs) and 95% confidence intervals. All statistical tests were 2-sided. RESULTS: Total testosterone, SHBG, and the ratio of estradiol to testosterone were associated with colorectal cancer in men after adjustments for matching and risk factors for colorectal cancer, including body mass index and plasma levels of C-peptide. The RRs in the highest relative to the lowest quartile were 0.62 for testosterone (95% confidence interval, 0.40-0.96), 0.65 for SHBG (95% confidence interval, 0.42-0.99), and 2.63 for the ratio (95% confidence interval, 1.58-4.36) (P values for trend ≤ .02). However, in women, only the ratio of estradiol to testosterone was (inversely) associated with colorectal cancer after adjustments for all factors (RR, 0.43; 95% confidence interval, 0.22-0.84; P value for trend = .03). CONCLUSIONS: On the basis of combined data from 4 population studies, there appears to be an association between levels of sex hormones and colorectal cancer risk in men. There also appears to be an inverse association between the ratio of estradiol to testosterone and colorectal cancer in postmenopausal women.

Effect of combined folic acid, vitamin B(6), and vitamin B(12) on colorectal adenoma.

BACKGROUND: Folic acid, vitamin B(6), and vitamin B(12) act in concert in the one-carbon metabolism and may protect against colorectal neoplasia. We examined the effect of combined B-vitamin treatment on the occurrence of colorectal adenoma. METHODS: The Women's Antioxidant and Folic Acid Cardiovascular Study was a randomized, double-blind, placebo-controlled trial of 5442 female health professionals at high risk for cardiovascular disease from April 1998 through July 2005. Participants were randomly assigned to receive a combination pill of folic acid (2.5mg), vitamin B(6) (50mg), and vitamin B(12) (1mg) or placebo. This study included 1470 participants who were followed up for as long as 9.2 years and underwent an endoscopy at any point during follow-up. We estimated relative risks using a generalized linear model with a natural logarithm link function and Poisson distributed errors. All statistical tests were two-sided. RESULTS: The risk of colorectal adenoma was similar among participants receiving treatment (24.3%, 180 of 741 participants) vs placebo (24.0%, 175 of 729 participants) (multivariable adjusted relative risk = 1.00, 95% confidence interval = 0.83 to 1.20). Treatment was not associated with the risk of adenoma when data were analyzed by subsite, size, stage, and the number of adenomas. There was no statistically significant effect modification by alcohol intake, history of cancer or adenoma, or baseline plasma levels or intakes of folate, vitamin B(6), or vitamin B(12). CONCLUSION: Our results indicate no statistically significant effect of combined folic acid, vitamin B(6), and vitamin B(12) treatment on colorectal adenoma among women at high risk for cardiovascular disease.

The aromatase gene (CYP19A1) variants and circulating hepatocyte growth factor in postmenopausal women.

BACKGROUND: Estrogen and androgen have been linked to the regulation of circulating hepatocyte growth factor (HGF), an adipose tissue-derived cytokine. It is possible that the CYP19A1 gene which alters sex hormones production may influence HGF levels. We examined the association between the CYP19A1 gene variants and plasma HGF concentrations. DESIGN: We evaluated 45 common and putative functional variants of CYP19A1 and circulating levels of HGF among 260 postmenopausal women who later developed colorectal cancer from the Women's Health Initiative Observational Cohort. As the distribution of HGF levels was highly skewed, we transformed HGF concentrations for all women into a log-, ranked-, or normal score-scale value. Multiple linear regression with adjustment for age was used to evaluate the associations. RESULTS: We observed an association between the rs7172156, rs1008805, rs6493494, rs749292, and rs11636639 variants and HGF levels in ranked and normal score scales (corrected p values ≤0.02), although the association of these 5 SNPs with log-scale HGF was not significant (corrected p values ≥0.16). The associations remained unchanged after additional adjustment for hormone therapy use and estradiol levels. These 5 SNPs, which were in linkage disequilibrium (pairwise D'≥97%, r(2)≥56%), constituted a block with 2 common haplotypes accounting for 82% frequency. The most common haplotype, TCCCA, was associated with lower ranked- or normal score-transformed HGF levels (corrected p values ≤0.001), whereas the second most common haplotype, CTTCA, was associated with higher ranked- or normal score-transformed HGF levels (corrected p values ≤0.02). CONCLUSION: Our findings of a potential association between the CYP19A1 variants and circulating HGF levels warrant confirmation in studies with larger sample size.

Postmenopausal hormone therapy is associated with a reduced risk of colorectal cancer lacking CDKN1A expression.

Experimental studies have shown that estrogen- or progesterone-activated signaling leads to growth inhibition effects on colon cancer cells through the upregulation of several cell-cycle regulators. However, epidemiologic studies evaluating hormone therapy use and colorectal cancer risk by the status of cell-cycle regulators are lacking. In this study, we used data from the prospective Nurses' Health Study to evaluate whether the association between hormone therapy use and colorectal cancer risk differs by the molecular pathologic status of microsatellite instability (MSI) and expression of cell-cycle-related tumor biomarkers, including CDKN1A (p21, CIP1), CDKN1B (p27, KIP1), and TP53 (p53) by immunohistochemistry. Duplication Cox regression analysis was used to determine an association between hormone therapy use, cancer risk, and specific tumor biomarkers in 581 incident colon and rectal cancer cases that occurred during 26 years of follow-up among 105,520 postmenopausal women. We found a difference between hormone therapy use and colorectal cancer risk according to CDKN1A expression (P(heterogeneity) = 0.01). Current hormone therapy use was associated with a reduced risk for CDKN1A-nonexpressed [multivariate relative risk (RR), 0.61; 95% confidence interval (CI), 0.46-0.82] but not for CDKN1A-expressed (RR, 1.32; 95% CI, 0.76-2.31) tumors. The lower risk for CDKN1A-nonexpressed but not for CDKN1A-expressed cancers was also present among current users of estrogen-alone therapy. We found no significant difference in the relations between hormone therapy use and cancer risk according to MSI, CDKN1B, or TP53 status. Together, our molecular pathological epidemiology findings suggest a preventive effect of hormone therapy against colorectal carcinogenesis that depends, in part, on loss of cyclin-dependent kinase inhibitor CDKN1A.

Carotenoid intakes and risk of breast cancer defined by estrogen receptor and progesterone receptor status: a pooled analysis of 18 prospective cohort studies.

BACKGROUND: Epidemiologic studies examining associations between carotenoid intakes and risk of breast cancer by estrogen receptor (ER) and progesterone receptor (PR) status are limited. OBJECTIVE: We investigated these associations in a pooled analysis of 18 cohort studies. DESIGN: Of 1,028,438 participants followed for a maximum follow-up of 26 y across studies, 33,380 incident invasive breast cancers were identified. Study-specific RRs and 95% CIs were estimated by using Cox proportional hazards regression and then pooled by using a random-effects model. RESULTS: α-Carotene, ß-carotene, and lutein/zeaxanthin intakes were inversely associated with the risk of ER-negative (ER-) breast cancer (pooled multivariable RRs of the comparison between the highest and lowest quintiles): α-carotene (0.87; 95% CI: 0.78, 0.97), ß-carotene (0.84; 95% CI: 0.77, 0.93), and lutein/zeaxanthin (0.87; 95% CI: 0.79, 0.95). These variables were not inversely associated with the risk of ER-positive (ER+) breast cancer (pooled multivariable RRs for the same comparison): α-carotene (1.04; 95% CI: 0.99, 1.09), ß-carotene (1.04; 95% CI: 0.98, 1.10), and lutein/zeaxanthin (1.00; 95% CI: 0.93, 1.07). Although the pooled RRs for quintile 5 for ß-cryptoxanthin were not significant, inverse trends were observed for ER- and ER+ breast cancer (P-trend ≤ 0.05). Nonsignificant associations were observed for lycopene intake. The associations were largely not appreciably modified by several breast cancer risk factors. Nonsignificant associations were observed for PR-positive and PR-negative breast cancer. CONCLUSIONS: Intakes of α-carotene, ß-carotene, and lutein/zeaxanthin were inversely associated with risk of ER-, but not ER+, breast cancer. However, the results need to be interpreted with caution because it is unclear whether the observed association is real or due to other constituents in the same food sources.

The VITamin D and OmegA-3 TriaL (VITAL): rationale and design of a large randomized controlled trial of vitamin D and marine omega-3 fatty acid supplements for the primary prevention of cancer and cardiovascular disease.

Data from laboratory studies, observational research, and/or secondary prevention trials suggest that vitamin D and marine omega-3 fatty acids may reduce risk for cancer or cardiovascular disease (CVD), but primary prevention trials with adequate dosing in general populations (i.e., unselected for disease risk) are lacking. The ongoing VITamin D and OmegA-3 TriaL (VITAL) is a large randomized, double-blind, placebo-controlled, 2 x 2 factorial trial of vitamin D (in the form of vitamin D(3) [cholecalciferol], 2000 IU/day) and marine omega-3 fatty acid (Omacor fish oil, eicosapentaenoic acid [EPA]+docosahexaenoic acid [DHA], 1g/day) supplements in the primary prevention of cancer and CVD among a multi-ethnic population of 20,000 U.S. men aged ≥ 50 and women aged ≥ 55. The mean treatment period will be 5 years. Baseline blood samples will be collected in at least 16,000 participants, with follow-up blood collection in about 6000 participants. Yearly follow-up questionnaires will assess treatment compliance (plasma biomarker measures will also assess compliance in a random sample of participants), use of non-study drugs or supplements, occurrence of endpoints, and cancer and vascular risk factors. Self-reported endpoints will be confirmed by medical record review by physicians blinded to treatment assignment, and deaths will be ascertained through national registries and other sources. Ancillary studies will investigate whether these agents affect risk for diabetes and glucose intolerance; hypertension; cognitive decline; depression; osteoporosis and fracture; physical disability and falls; asthma and other respiratory diseases; infections; and rheumatoid arthritis, systemic lupus erythematosus, thyroid diseases, and other autoimmune disorders.

Sunlight exposure, vitamin D, and risk of non-Hodgkin lymphoma in the Nurses' Health Study.

PURPOSE: Case-control studies suggest increased sun exposure reduces non-Hodgkin lymphoma (NHL) risk. Evidence from prospective cohort studies, however, is limited and inconsistent. We evaluated the association between ambient ultraviolet radiation (UV) exposure and NHL in a nationwide cohort of women, the Nurses' Health Study (NHS). METHODS: Between 1976 and 2006, we identified 1064 incident NHL cases among 115,482 women in the prospective NHS. Exposures assessed included average annual UV-B flux based on residence at various times during life, vitamin D intake, and predicted plasma 25-hydroxyvitamin D levels. We estimated incidence rate ratios (RRs) and 95% confidence intervals (CIs) for risk of all NHL and histologic subtypes using Cox proportional hazards models. RESULTS: NHL risk was increased for women residing in areas of high ambient UV radiation (UV-B flux >113 R-B count × 10(-4)) compared to those with lower exposure (<113), with positive linear trends at all time points. The multivariable-adjusted RR for high UV area at age 15 was 1.21 (95% CI: 1.00, 1.47; p-trend < 0.01). There was no evidence of statistical heterogeneity by subtype, although power was limited for subtype analyses. We observed no association between vitamin D measures and risk of NHL overall or by subtype. CONCLUSIONS: Our findings do not support the hypothesis of a protective effect of UV radiation exposure on NHL risk. We found no association between vitamin D and NHL risk.

Predicting adherence to tamoxifen for breast cancer adjuvant therapy and prevention.

Treatment with the selective estrogen receptor modulator (SERM) tamoxifen for 5 years has produced dramatic breast cancer-related benefits in (a) the adjuvant setting, with 30% to 50% reductions in recurrence, contralateral disease, and mortality and (b) the prevention setting of healthy high-risk women, where tamoxifen reduces the risk of invasive and noninvasive breast cancer by 50%. Despite these striking data, adherence to tamoxifen is low, and low adherence is associated with poor survival. Although toxicity is a major predictor of poor adherence after starting therapy, pretreatment (baseline) predictors of poor tamoxifen adherence have been minimally studied. The adherence-survival link underscores the critical need to identify early predictors of poor adherence, and recent work is beginning to address this need. A major baseline predictor of poor adherence to prevention is current smoking, which is interestingly absent from studies of adherence to adjuvant therapy. Other important prevention adherence factors include breast cancer risk, extremes of age, non-white ethnicity, low socioeconomic status, and alcohol use. The strongest adjuvant therapy predictors are age (especially very young), ethnicity, and socioeconomic status. Future studies involving prospective systematic evaluation of these and other potential predictors in endocrine chemoprevention (e.g., other SERMs and aromatase inhibitors) are critical, as is the development of effective/targeted interventions to improve adherence and thus treatment outcomes in at-risk women.

Estrogen and progesterone-related gene variants and colorectal cancer risk in women.

BACKGROUND: Observational studies and randomized trials have suggested that estrogens and/or progesterone may lower the risk for colorectal cancer. Inherited variation in the sex-hormone genes may be one mechanism by which sex hormones affect colorectal cancer, although data are limited. METHOD: We conducted a comprehensive evaluation of single nucleotide polymorphisms (SNPs) in genes encoding 3 hormone receptors (ESR1, ESR2, PGR) and 5 hormone synthesizers (CYP19A1 and CYP17A1, HSD17B1, HSD17B2, HSD17B4) among 427 women with incident colorectal cancer and 871 matched controls who were Caucasians of European ancestry from 93676 postmenopausal women enrolled in the Women's Health Initiative Observational cohort. A total of 242 haplotype-tagging and functional SNPs in the 8 genes were included for analysis. Unconditional logistic regression with adjustment for age and hysterectomy status was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: We observed a weak association between the CYP17A1 rs17724534 SNP and colorectal cancer risk (OR per risk allele (A) = 1.39, 95% CI = 1.09-1.78, corrected p-value = 0.07). In addition, a suggestive interaction between rs17724534 and rs10883782 in 2 discrete LD blocks of CYP17A1 was observed in relation to colorectal cancer (empirical p value = 0.04). Moreover, one haplotype block of CYP19A1 was associated with colorectal cancer (corrected global p value = 0.02), which likely reflected the association with the tagging SNP, rs1902584, in the block. CONCLUSION: Our findings offer some support for a suggestive association of CYP17A1 and CYP19A1 variants with colorectal cancer risk.

Eighteen insulin-like growth factor pathway genes, circulating levels of IGF-I and its binding protein, and risk of prostate and breast cancer.

BACKGROUND: Circulating levels of insulin-like growth factor I (IGF-I) and its main binding protein, IGF binding protein 3 (IGFBP-3), have been associated with risk of several types of cancer. Heritable factors explain up to 60% of the variation in IGF-I and IGFBP-3 in studies of adult twins. METHODS: We systematically examined common genetic variation in 18 genes in the IGF signaling pathway for associations with circulating levels of IGF-I and IGFBP-3. A total of 302 single nucleotide polymorphisms (SNP) were genotyped in >5,500 Caucasian men and 5,500 Caucasian women from the Breast and Prostate Cancer Cohort Consortium. RESULTS: After adjusting for multiple testing, SNPs in the IGF1 and SSTR5 genes were significantly associated with circulating IGF-I (P < 2.1 × 10(-4)); SNPs in the IGFBP3 and IGFALS genes were significantly associated with circulating IGFBP-3. Multi-SNP models explained R(2) = 0.62% of the variation in circulating IGF-I and 3.9% of the variation in circulating IGFBP-3. We saw no significant association between these multi-SNP predictors of circulating IGF-I or IGFBP-3 and risk of prostate or breast cancers. CONCLUSION: Common genetic variation in the IGF1 and SSTR5 genes seems to influence circulating IGF-I levels, and variation in IGFBP3 and IGFALS seems to influence circulating IGFBP-3. However, these variants explain only a small percentage of the variation in circulating IGF-I and IGFBP-3 in Caucasian men and women. IMPACT: Further studies are needed to explore contributions from other genetic factors such as rare variants in these genes and variation outside of these genes.

Intakes of vitamins A, C, and E and use of multiple vitamin supplements and risk of colon cancer: a pooled analysis of prospective cohort studies.

OBJECTIVE: To evaluate the associations between intakes of vitamins A, C, and E and risk of colon cancer. METHODS: Using the primary data from 13 cohort studies, we estimated study- and sex-specific relative risks (RR) with Cox proportional hazards models and subsequently pooled RRs using a random effects model. RESULTS: Among 676,141 men and women, 5,454 colon cancer cases were identified (7-20 years of follow-up across studies). Vitamin A, C, and E intakes from food only were not associated with colon cancer risk. For intakes from food and supplements (total), the pooled multivariate RRs (95% CI) were 0.88 (0.76-1.02, >4,000 vs. ≤ 1,000 µg/day) for vitamin A, 0.81 (0.71-0.92, >600 vs. ≤ 100 mg/day) for vitamin C, and 0.78 (0.66-0.92, > 200 vs. ≤ 6 mg/day) for vitamin E. Adjustment for total folate intake attenuated these associations, but the inverse associations with vitamins C and E remained significant. Multivitamin use was significantly inversely associated with colon cancer risk (RR = 0.88, 95% CI: 0.81-0.96). CONCLUSIONS: Modest inverse associations with vitamin C and E intakes may be due to high correlations with folate intake, which had a similar inverse association with colon cancer. An inverse association with multivitamin use, a major source of folate and other vitamins, deserves further study.

A prospective study of Epstein-Barr virus antibodies and risk of non-Hodgkin lymphoma.

Severe immunosuppression is an established risk factor for non-Hodgkin lymphoma (NHL), but an association with subclinical immune dysfunction is unclear. We conducted a case-control study nested in the Physicians' Health Study and the Nurses' Health Study cohorts to determine whether patterns of antibody response to Epstein-Barr virus (EBV) were associated with NHL risk. We measured antibody titers against viral capsid antigen, early antigen, and Epstein-Barr nuclear antigen (EBNA-1 and EBNA-2) in blood samples collected before diagnosis from 340 cases and 662 matched controls. Using conditional logistic regression, we estimated rate ratios (RRs) and 95% confidence intervals (CIs) for elevated versus normal titers and the ratio of anti-EBNA-1 to anti-EBNA-2 titers (≤ 1.0 vs > 1.0). We found no association between EBV serostatus, elevated titers, or an EBNA-1/EBNA-2 ratio ≤ 1.0 and NHL risk overall. For chronic lymphocytic leukemia/small lymphocytic lymphoma, suggestive associations were noted for elevated anti-EBNA-2 (RR, 1.74; 95% CI, 0.99-3.05), anti-viral capsid antigen (RR, 1.58; 95% CI, 0.79-3.14), and EBNA-1/EBNA-2 ratio ≤ 1.0 (RR, 1.52; 95% CI, 0.91-2.55). There was no evidence of heterogeneity by subtype. Overall, we found no evidence that EBV antibody profile predicts NHL risk in immunocompetent persons, with the possible exception of chronic lymphocytic leukemia/small lymphocytic lymphoma.