Maree T. Brinkman

Dietary patterns and risk of breast cancer

Background:Evidence is emerging that prudent/healthy dietary patterns might be associated with a reduced risk of breast cancer.Methods:Using data from the prospective Melbourne Collaborative Cohort Study, we applied principal factor analysis to 124 foods and beverages to identify dietary patterns and estimated their association with breast cancer risk overall and by tumour characteristics using Cox regression.Results:During an average of 14.1 years of follow-up of 20 967 women participants, 815 invasive breast cancers were diagnosed. Among the four dietary factors that we identified, only that characterised by high consumption of fruit and salad was associated with a reduced risk, with stronger associations observed for tumours not expressing oestrogen (ER) and progesterone receptors (PR). Compared with women in the lowest quintile of the factor score, the hazard ratio for women in the highest quintile was 0.92 (95% confidence interval (CI)=0.70–1.21; test for trend, P=0.5) for ER-positive or PR-positive tumours and 0.48 (95% CI=0.26–0.86; test for trend, P=0.002) for ER-negative and PR-negative tumours (test for homogeneity, P=0.01).Conclusion:Our study provides additional support for the hypothesis that a dietary pattern rich in fruit and salad might protect against invasive breast cancer and that the effect might be stronger for ER- and PR-negative tumours.

Consumption of animal products, their nutrient components and postmenopausal circulating steroid hormone concentrations

Background/Objectives:Little is known about nutritional factors that influence circulating concentrations of steroid hormones, which are consistently associated with risk of breast cancer for postmenopausal women. We aimed to investigate the association between consumption of animal products and the plasma concentrations of steroid hormones and sex hormone-binding globulin (SHBG).Subjects/Methods:Cross-sectional analysis was conducted on plasma from 766 naturally postmenopausal women. We measured plasma concentrations of steroid hormones and SHBG, and estimated dietary intakes using a 121-item food frequency questionnaire. Log-transformed values of hormone concentrations were regressed on quartiles of intake of meat and dairy products among food items, and fats, proteins and cholesterol among nutrient intake.Results:Total red and fresh red meat consumption was negatively associated with SHBG levels (P for trend=0.04 and <0.01, respectively). Mean SHBG concentrations were ∼8% and 13% lower for women in the highest quartile compared with the lowest quartile of total red and fresh red meat consumption, respectively. Positive associations were observed between dairy product consumption and total and free estradiol concentrations (P for trend=0.02 and 0.03, respectively). Mean concentrations of total and free estradiol were 15 and 14% higher for women in the highest quartile of dairy product consumption than for those in the lowest quartile, respectively. No associations were observed with consumption of processed meat, chicken, fish, eggs, cholesterol, fats or protein.Conclusions:Our study suggests that greater consumption of total red and fresh red meat and dairy products might influence circulating concentrations of SHBG and estradiol, respectively. Confirmation and further investigation is required.

Association between selected dietary scores and the risk of urothelial cell carcinoma: A prospective cohort study

Studies investigating the association of food and nutrient consumption with the risk of urothelial cell carcinoma (UCC) have produced mixed results. We used three common dietary scores, the Mediterranean Diet Score (MDS), the Alternate Healthy Eating Index 2010 (AHEI‐2010) and the Dietary Inflammatory Index (DII) to assess the evidence of an association between diet and the risk of UCC. Over a median follow‐up time of 21.3 years, 379 incident UCC cases were diagnosed. Dietary scores were calculated using data from a 121‐item food frequency questionnaire administered at baseline. We used Cox models to compute hazard ratios (HR) for the association between dietary scores (per one standard deviation) and UCC risk. In order to reflect overall adherence to a healthy diet, a metascore was constructed by summing the quintiles of each of the three scores. None of the dietary scores was associated with the risk of UCC overall. A healthier diet was found to be inversely associated with the risk of invasive (MDS: HR = 0.86, 95% CI: 0.74–1.00, metascore: HR = 0.84, 95% CI: 0.71–0.98), but not superficial disease (heterogeneity between subtypes p = 0.04 and p = 0.03, respectively). Results were consistent but weaker for the DII and the AHEI‐2010. We found some evidence of effect modification by smoking, in particular for the metascore (Current: HR = 0.77, 95% CI: 0.58–1.01, Former: HR = 0.77, 95% CI: 0.64–0.92, Never: HR = 1.01, 95% CI: 0.81–1.26, p for heterogeneity = 0.05). A healthy diet may be protective against the risk of invasive, but not superficial, UCC. Promoting healthy dietary habits may help lower the risk of invasive UCC, especially for current and former smokers.

Cohort Profile: The Melbourne Collaborative Cohort Study (Health 2020)

Cohort Profile: The Melbourne Collaborative Cohort Study (Health 2020) R L Milne,* A S Fletcher, R J MacInnis, A M Hodge, A H Hopkins, J K Bassett, F J Bruinsma, B M Lynch, P A Dugué, H Jayasekara, M T Brinkman, L V Popowski, L Baglietto, G Severi, K O’Dea, J L Hopper, M C Southey, D R English and G G Giles Cancer Epidemiology & Intelligence Division, Cancer Council Victoria, Melbourne, VIC, Australia, Centre for Epidemiology and Biostatistics, University of Melbourne, Parkville, VIC, Australia, Physical Activity Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, VIC, Australia, Centre de Recherche en Epidémiologie et Santé des Populations, Université Paris-Saclay, Villejuif, France, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy, Human Genetics Foundation (HuGeF), Turin, Italy, Centre of Population Health Research, University of South Australia, Adelaide, SA, Australia and Genetic Epidemiology Laboratory, University of Melbourne, Parkville, VIC, Australia

Validity and calibration of the FFQ used in the Melbourne Collaborative Cohort Study

OBJECTIVE To evaluate the reliability and validity of the FFQ administered to participants in the follow-up of the Melbourne Collaborative Cohort Study (MCCS), and to provide calibration coefficients. DESIGN A random sample stratified by country of birth, age, sex and BMI was selected from MCCS participants. Participants completed two FFQ and three 24 h recalls over 1 year. Reliability was evaluated by intraclass correlation coefficients (ICC). Validity coefficients (VC) were estimated from structural equation models and calibration coefficients obtained from regression calibration models. SETTING Adults born in Australia, Greece or Italy. SUBJECTS Nine hundred and sixty-five participants consented to the study; of these, 459 participants were included in the reliability analyses and 615 in the validity and calibration analyses. RESULTS The FFQ showed good repeatability for twenty-three nutrients with ICC ranging from 0·66 to 0·80 for absolute nutrient intakes for Australian-born and from 0·51 to 0·74 for Greek/Italian-born. For Australian-born, VC ranged from 0·46 (monounsaturated fat) to 0·83 (Ca) for nutrient densities, comparing well with other studies. For Greek/Italian-born, VC were between 0·21 (Na) and 0·64 (riboflavin). Calibration coefficients for nutrient densities ranged from 0·39 (retinol) to 0·74 (Mg) for Australian-born and from 0·18 (Zn) to 0·54 (riboflavin) for Greek/Italian-born. CONCLUSIONS The FFQ used in the MCCS follow-up study is suitable for estimating energy-adjusted nutrients for Australian-born participants. However, its performance for estimating intakes is poorer for southern European migrants and alternative dietary assessment methods ought to be considered if dietary data are to be measured in similar demographic groups.

Genome-wide measures of DNA methylation in peripheral blood and the risk of urothelial cell carcinoma: a prospective nested case-control study

Background:Global DNA methylation has been reported to be associated with urothelial cell carcinoma (UCC) by studies using blood samples collected at diagnosis. Using the Illumina HumanMethylation450 assay, we derived genome-wide measures of blood DNA methylation and assessed them for their prospective association with UCC risk.Methods:We used 439 case–control pairs from the Melbourne Collaborative Cohort Study matched on age, sex, country of birth, DNA sample type, and collection period. Conditional logistic regression was used to compute odds ratios (OR) of UCC risk per s.d. of each genome-wide measure of DNA methylation and 95% confidence intervals (CIs), adjusted for potential confounders. We also investigated associations by disease subtype, sex, smoking, and time since blood collection.Results:The risk of superficial UCC was decreased for individuals with higher levels of our genome-wide DNA methylation measure (OR=0.71, 95% CI: 0.54–0.94; P=0.02). This association was particularly strong for current smokers at sample collection (OR=0.47, 95% CI: 0.27–0.83). Intermediate levels of our genome-wide measure were associated with decreased risk of invasive UCC. Some variation was observed between UCC subtypes and the location and regulatory function of the CpGs included in the genome-wide measures of methylation.Conclusions:Higher levels of our genome-wide DNA methylation measure were associated with decreased risk of superficial UCC and intermediate levels were associated with reduced risk of invasive disease. These findings require replication by other prospective studies.

Iodine status in Melbourne adults in the early 1990s and 2007–08

Objective: To investigate the iodine status of Melbourne adults in 1992–94 and 2007–08, and to assess dietary iodine intake to enable comparison with recommended Nutrient Reference Values.

International pooled study on diet and bladder cancer: the bladder cancer, epidemiology and nutritional determinants (BLEND) study: design and baseline characteristics

BackgroundIn 2012, more than 400,000 urinary bladder cancer cases occurred worldwide, making it the 7th most common type of cancer. Although many previous studies focused on the relationship between diet and bladder cancer, the evidence related to specific food items or nutrients that could be involved in the development of bladder cancer remains inconclusive. Dietary components can either be, or be activated into, potential carcinogens through metabolism, or act to prevent carcinogen damage.Methods/designThe BLadder cancer, Epidemiology and Nutritional Determinants (BLEND) study was set up with the purpose of collecting individual patient data from observational studies on diet and bladder cancer. In total, data from 11,261 bladder cancer cases and 675,532 non-cases from 18 case–control and 6 cohort studies from all over the world were included with the aim to investigate the association between individual food items, nutrients and dietary patterns and risk of developing bladder cancer.DiscussionThe substantial number of cases included in this study will enable us to provide evidence with large statistical power, for dietary recommendations on the prevention of bladder cancer.

Dietary intake of nutrients involved in one-carbon metabolism and risk of urothelial cell carcinoma: A prospective cohort study: One-carbon metabolism nutrients and UCC risk

Nutrients involved in one‐carbon metabolism may play a role in carcinogenesis through DNA replication, repair and methylation mechanisms. Most studies on urothelial cell carcinoma (UCC) have focused on folate. We sought to examine the association between B‐group vitamins and methionine intake and UCC risk, overall and by subtype, and to test whether these associations are different for population subgroups whose nutritional status may be compromised. We followed participants in the Melbourne Collaborative Cohort Study (N = 41,513) for over 20 years and observed 500 UCC cases (89% originating in the bladder; superficial: 279, invasive: 221). Energy‐adjusted dietary intakes of B vitamins (B1, B2, B3, B5, B6, B8, B9 and B12) and methionine were estimated from a 121‐item food frequency questionnaire administered at baseline (1990–1994), using the residuals method. We used Cox regression models to compute hazard ratios (HRs) of UCC risk per standard deviation (SD) of log‐transformed nutrient intakes and 95% confidence intervals, adjusted for potential confounders. We investigated associations by tumor subtype, and tested interactions with sex, country of birth, smoking and alcohol drinking. The risk of UCC appeared not to be associated with intake of B‐group vitamins or methionine, and findings were consistent across tumor subtypes and across demographic and lifestyle characteristics of the participants. A potential interaction between vitamin B1 and alcohol drinking was observed (all participants: HR per 1 SD = 0.99 (0.91–1.09), never drinkers: HR = 0.81 (0.69–0.97), p‐interaction = 0.02), which needs to be confirmed by other studies. Our findings do not indicate that dietary intake of nutrients involved in one‐carbon metabolism are associated with UCC risk.

Circulating concentrations of B group vitamins and urothelial cell carcinoma: Plasma B vitamins and urothelial cell carcinoma

B‐group vitamins, as components of the one carbon metabolism pathway, are involved in DNA synthesis, repair and methylation. Our aim was to investigate associations between circulating plasma levels of B vitamins and urothelial cell carcinoma (UCC). We conducted a nested case–control study of UCC within the Melbourne Collaborative Cohort Study. B vitamins were measured in pre‐diagnostic plasma samples. Conditional logistic regression was used to estimate odds ratios (OR) for UCC risk associated with circulating B vitamins in 363 matched cases and controls. In a case‐only analysis (N = 390), hazard ratios (HR) for overall survival associated with plasma B vitamins were estimated using Cox regression. There were no strong associations between UCC risk and pre‐diagnostic levels of plasma B vitamins. No heterogeneity in UCC risk was observed by subtype (invasive or superficial), sex, smoking status or alcohol intake. There was no heterogeneity by country of birth for most B vitamins, except for folate (p‐homogeneity = 0.03). In UCC cases, there were no strong associations between plasma B vitamins and overall survival. We found no associations between pre‐diagnostic plasma concentrations of B‐group vitamins and UCC risk or survival.