[Show abstract][Hide abstract] ABSTRACT: To study how a vegetarian or low meat diet influences the risk of colorectal cancer compared to a high meat diet, and to assess the explanatory role of factors associated with these diets. In the Netherlands Cohort Study - Meat Investigation Cohort (NLCS-MIC) (cohort of 10,210 individuals including 1040 self-defined vegetarians), subjects completed a baseline questionnaire in 1986, based on which they were classified into vegetarians (n = 635), pescetarians (n = 360), 1 day/week- (n = 1259), 2-5 day/week- (n = 2703), and 6-7 day/week meat consumers (n = 5253). After 20.3 years of follow-up, 437 colorectal cancer cases (307 colon, 92 rectal) were available. A non-significantly decreased risk of CRC for vegetarians, pescetarians, and 1 day/week compared to 6-7 day/week meat consumers was observed (age/sex adjusted Hazard Ratios (HR): 0.73(0.47-1.13), 0.80(0.47-1.39), and 0.72(0.52-1.00), respectively). Most of the differences in HR between these groups could be explained by intake of dietary fiber and soy products. Other (non-)dietary factors characteristic for a vegetarian or low meat diet had negligible individual effects, but attenuated the HRs towards the null when combined. Vegetarians, pescetarians, and 1 day/week meat eaters showed a non-significantly decreased risk of colorectal cancer compared to 6-7 day/week meat consumers, mainly due to differences in dietary pattern other than meat intake.
[Show abstract][Hide abstract] ABSTRACT: We aimed to estimate the proportion of Dutch postmenopausal breast cancer cases in 2010 that is attributable to lifestyle-related risk factors. We calculated population attributable fractions (PAFs) of potentially modifiable risk factors for postmenopausal breast cancer in Dutch women aged >50 in 2010. First, age-specific PAFs were calculated for each risk factor, based on their relative risks for postmenopausal breast cancer (from meta-analyses) and age-specific prevalence in the population (from national surveys) around the year 2000, assuming a latency period of 10 years. To obtain the overall PAF, age-specific PAFs were summed in a weighted manner, using the age-specific breast cancer incidence rates (2010) as weights. 95 % confidence intervals for PAF estimates were derived by Monte Carlo simulations. Of Dutch women >40 years, in 2000, 51 % were overweight/obese, 55 % physically inactive (<5 days/week 30 min activity), 75 % regularly consumed alcohol, 42 % ever smoked cigarettes and 79 % had a low-fibre intake (<3.4 g/1000 kJ/day). These factors combined had a PAF of 25.7 % (95 % CI 24.2-27.2), corresponding to 2,665 Dutch postmenopausal breast cancer cases in 2010. PAFs were 8.8 % (95 % CI 6.3-11.3) for overweight/obesity, 6.6 % (95 % CI 5.2-8.0) for alcohol consumption, 5.5 % (95 % CI 4.0-7.0) for physical inactivity, 4.6 % (95 % CI 3.3-6.0) for smoking and 3.2 % (95 % CI 1.6-4.8) for low-fibre intake. Our findings imply that modifiable risk factors are jointly responsible for approximately one out of four Dutch postmenopausal breast cancer cases. This suggests that incidence rates can be lowered substantially by living a more healthy lifestyle.
Breast Cancer Research and Treatment 06/2015; 152(1). DOI:10.1007/s10549-015-3447-7 · 3.94 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background: Previous epidemiologic research suggests a protective role of one-carbon nutrients in carcinogenesis. Folate, however, may play a dual role in neoplasms development: protect early in carcinogenesis, promote carcinogenesis at a later stage. We prospectively examined associations between intake of total folate, methionine, riboflavin, vitamin B6 and risk of lymphoid and myeloid neoplasms (including subtypes) and investigated whether alcohol modified the effects of folate. Methods: The Netherlands Cohort Study consists of 120,852 individuals who completed a baseline questionnaire in 1986, including a 150-item food-frequency questionnaire. After 17.3 years of follow-up, 1,280 cases of lymphoid and 222 cases of myeloid neoplasms were available for analysis. Results: Intakes of folate, methionine, and riboflavin were not associated with lymphoid or myeloid neoplasms. For vitamin B6, a statistically significantly increased myeloid neoplasms risk was observed (highest versus lowest quintile: HR=1.87, 95%CI=1.08-3.25). When analyzing by lymphoid and myeloid neoplasms subtypes, no clear associations were observed for most subtypes, with just a few increased risks for some subtypes and nutrients. Some risks became non-significant after excluding early cases. No interaction between alcohol and folate was observed. Conclusions: We observed a few significant positive associations; however, some of these would be expected to arise due to chance alone. Furthermore, some risks became non-significant after excluding early cases. Therefore, we conclude that there is no association between one-carbon nutrient intake and risk of lymphoid and myeloid neoplasms. Impact: This study contributes substantially to the limited and inconclusive evidence on the association with one-carbon nutrients.
[Show abstract][Hide abstract] ABSTRACT: The evidence for an association between occupational asbestos exposure and pharyngeal cancer (PhC) is limited, while for oral cavity cancer (OCC) the literature is even sparser. We studied OCC and PhC risk both separately and combined (OCPC) in relation to occupational asbestos exposure, specifically addressing the influence of potential confounders, the existence of an exposure-response relation, and the presence of interaction between asbestos and smoking.
Using the prospective Netherlands Cohort Study (N=58 279 men, aged 55-69 years), we estimated asbestos exposure by linkage to a general population job-exposure matrix (DOMJEM) and a Finnish job exposure matrix (FINJEM). After 17.3 years of follow-up, 58 OCC and 53 PhC cases were available for analysis.
No association between asbestos and risk of OCC was observed for either JEM. Hazard ratios (HR) of PhC and OCPC increased after adjusting for confounders, particularly alcohol consumption and socioeconomic status. For PhC, a multivariable-adjusted increased HR was observed for "ever" versus "never" exposed to asbestos [HR 2.20, 95% confidence interval (95% CI) 1.08-4.49] when using FINJEM, but a trend of increased risks with higher cumulative exposure could not be demonstrated for either JEM. Results for OCPC showed patterns similar to those observed for PhC. None of the cancers showed a significant interaction between asbestos and smoking.
This prospective population-based study showed no convincing evidence of an association between asbestos and risk of OCC, PhC, and OCPC as an exposure-response relation was lacking, and results were not robust against the use of different JEM. However, the potentially increased HR of PhC and OCPC observed in this and previous studies warrant further research.
Scandinavian Journal of Work, Environment & Health 05/2014; 40(4). DOI:10.5271/sjweh.3434 · 3.45 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Pancreatic cancer has few early symptoms, is usually diagnosed at late stages, and has a high case-fatality rate. Identifying modifiable risk factors is crucial to reducing pancreatic cancer morbidity and mortality. Prior studies have suggested that specific foods and nutrients, such as dairy products and constituents, may play a role in pancreatic carcinogenesis. In this pooled analysis of the primary data from 14 prospective cohort studies, 2212 incident pancreatic cancer cases were identified during follow-up among 862 680 individuals. Adjusting for smoking habits, personal history of diabetes, alcohol intake, body mass index (BMI), and energy intake, multivariable study-specific hazard ratios (MVHR) and 95% confidence intervals (CIs) were calculated using the Cox proportional hazards models and then pooled using a random effects model. There was no association between total milk intake and pancreatic cancer risk (MVHR = 0.98, 95% CI = 0.82-1.18 comparing ≥500 with 1-69.9 g/day). Similarly, intakes of low-fat milk, whole milk, cheese, cottage cheese, yogurt, and ice-cream were not associated with pancreatic cancer risk. No statistically significant association was observed between dietary (MVHR = 0.96, 95% CI = 0.77-1.19) and total calcium (MVHR = 0.89, 95% CI = 0.71-1.12) intake and pancreatic cancer risk overall when comparing intakes ≥1300 with <500 mg/day. In addition, null associations were observed for dietary and total vitamin D intake and pancreatic cancer risk. Findings were consistent within sex, smoking status, and BMI strata or when the case definition was limited to pancreatic adenocarcinoma. Overall, these findings do not support the hypothesis that consumption of dairy foods, calcium, or vitamin D during adulthood is associated with pancreatic cancer risk.
Annals of Oncology 03/2014; 25(6). DOI:10.1093/annonc/mdu019 · 7.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Acrylamide, a probable human carcinogen, is present in heat-treated carbohydrate-rich foods. Epidemiological studies have not shown a clear association between acrylamide intake and colorectal cancer risk. This may be due to the molecular heterogeneity in colorectal tumors, which was not taken into consideration before. Since the acrylamide metabolite glycidamide induces specific DNA mutations in rodents, we investigated whether acrylamide is associated with colorectal cancer risk characterized by mutations in KRAS and APC; key genes in colorectal carcinogenesis. This case-cohort analysis, within the Netherlands Cohort Study on diet and cancer, was based on 7.3 years of follow-up. Acrylamide intake was assessed with a food frequency questionnaire. Mutation analysis of codons 1286-1520 in exon 15 in APC and codons 12 and 13 in exon 1 in KRAS was performed on tumor tissue of 733 cases. Hazard ratios were calculated using Cox proportional hazards analysis. Among men, acrylamide intake was statistically significantly associated with an increased risk of particularly tumors with an activating KRAS mutation (HR 4(th) quartile vs. 1(st): 2.12 (95% CI: 1.16-3.87), p-trend: 0.01). Among women, acrylamide intake was statistically significantly associated with a decreased risk of particularly tumors with a truncating APC mutation (4(th) quartile vs. 1(st): 0.47 (95% CI: 0.23-0.94), p-trend: 0.02), but only in the highest quartile of intake. This is the first study to show that acrylamide might be associated with colorectal cancer with specific somatic mutations, differentially in men and women. More research is needed to corroborate or refute these findings.
[Show abstract][Hide abstract] ABSTRACT: To study the association between occupational asbestos exposure and pleural mesothelioma, lung cancer, and laryngeal cancer, specifically addressing risk associated with the lower end of the exposure distribution, risk of cancer subtypes, and the interaction between asbestos and smoking.
Using the Netherlands Cohort Study (n = 58,279 men, aged 55 to 69 years), asbestos exposure was estimated by linkage to job-exposure matrices. After 17.3 years of follow-up, 132 pleural mesothelioma, 2324 lung cancer, and 166 laryngeal cancer cases were available.
The multivariable-adjusted model showed overall positive associations between all levels of asbestos exposure and mesothelioma, lung cancer, and laryngeal cancer. Lung adenocarcinoma and glottis cancer showed only a positive association after prolonged higher asbestos exposure (hazard ratio per 10 years increment, 1.43 [95% confidence interval, 1.06 to 1.93] and 1.95 [95% confidence interval, 1.36 to 2.80], respectively). There was no statistically significant interaction between asbestos and smoking.
Asbestos levels encountered at the lower end of the exposure distribution may be associated with an increased risk of pleural mesothelioma, lung cancer, and laryngeal cancer.
Journal of occupational and environmental medicine / American College of Occupational and Environmental Medicine 12/2013; 56(1). DOI:10.1097/JOM.0000000000000060 · 1.63 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background:
As sodium, potassium and fluid intake are related to hypertension, an established risk factor for renal cell cancer (RCC), they may be independent risk factors for RCC.
The Netherlands Cohort Study (NLCS) with case-cohort design included 120 852 participants aged 55–69 years. At baseline, diet and lifestyle were assessed with questionnaires. After 17.3 years of follow-up, 485 RCC cases and 4438 subcohort members were available for analyses.
Sodium intake increased RCC risk (P-trend=0.03), whereas fluid and potassium intake did not. For high sodium and low fluid intake, the RCC risk additionally increased (P-interaction=0.02).
Sodium intake is a potential risk factor for RCC, particularly if fluid consumption is low.
British Journal of Cancer 12/2013; 110(3). DOI:10.1038/bjc.2013.771 · 4.84 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: There are few epidemiological data on the dietary risk factors of Barrett's oesophagus, a precursor of oesophageal adenocarcinoma. The present study investigated the association between vegetable, fruit and nitrate intake and Barrett's oesophagus risk in a large prospective cohort. The Netherlands Cohort Study recruited 120 852 individuals aged 55-69 years in 1986. Vegetable and fruit intake was assessed using a 150-item FFQ, and nitrate intake from dietary sources and drinking water was determined. After 16·3 years of follow-up, 433 cases (241 men and 192 women) of Barrett's oesophagus with specialised intestinal metaplasia and 3717 subcohort members were analysed in a case-cohort design using Cox proportional hazards models while adjusting for potential confounders. Men exhibited a lower risk of Barrett's oesophagus in the highest v. the lowest quintile of total (multivariable-adjusted hazard ratio (HR): 0·66, 95 % CI 0·43, 1·01), raw (HR 0·63, 95 % CI 0·40, 0·99), raw leafy (HR 0·55, 95 % CI 0·36, 0·86) and Brassica (HR 0·64, 95 % CI 0·41, 1·00) vegetable intake. No association was found for other vegetable groups and fruits. No significant associations were found between vegetable and fruit intake and Barrett's oesophagus risk among women. Total nitrate intake was inversely associated with Barrett's disease risk in men (HR 0·50, 95 % CI 0·25, 0·99) and positively associated with it in women (HR 3·77, 95 % CI 1·68, 8·45) (P for interaction = 0·04). These results suggest that vegetable intake may contribute to the prevention of Barrett's oesophagus. The possible differential effect in men and women should be evaluated further.
The British journal of nutrition 12/2013; 111(08):1-11. DOI:10.1017/S0007114513003929 · 3.45 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Vegetarian diets have been associated with lower risk of chronic disease, but little is known about the health effects of low meat diets and the reliability of self-reported vegetarian status. We aimed to establish an analytical cohort over-represented with vegetarians, pescetarians and 1 day/week meat consumers, and to describe their lifestyle and dietary characteristics. In addition, we were able to compare self-reported vegetarians with vegetarians whose status has been confirmed by their response on the extensive food frequency questionnaire (FFQ).Study methods: Embedded within the Netherlands Cohort Study (n = 120,852; including 1150 self-reported vegetarians), the NLCS-Meat Investigation Cohort (NLCS-MIC) was defined by combining all FFQ-confirmed-vegetarians (n = 702), pescetarians (n = 394), and 1 day/week meat consumers (n = 1,396) from the total cohort with a random sample of 2--5 days/week- and 6--7 days/week meat consumers (n = 2,965 and 5,648, respectively).
Vegetarians, pescetarians, and 1 day/week meat consumers had more favorable dietary intakes (e.g. higher fiber/vegetables) and lifestyle characteristics (e.g. lower smoking rates) compared to regular meat consumers in both sexes. Vegetarians adhered to their diet longer than pescetarians and 1 day/week meat consumers. 75% of vegetarians with a prevalent cancer at baseline had changed to this diet after diagnosis. 50% of self-reported vegetarians reported meat or fish consumption on the FFQ. Although the misclassification that occurred in terms of diet and lifestyle when merely relying on self-reporting was relatively small, the impact on associations with disease risk remains to be studied.
We established an analytical cohort over-represented with persons at the lower end of the meat consumption spectrum which should facilitate prospective studies of major cancers and causes of death using >=20.3 years of follow-up.
[Show abstract][Hide abstract] ABSTRACT: To investigate the association between exposure to occupational extremely low-frequency magnetic fields (ELF-MF) and the risk of a priori selected cancer outcomes within the prospective Netherlands Cohort Study.
120,852 men and women aged 55-69 years at time of enrollment in 1986 were followed up (17.3 years) for incident lung, breast and brain cancer, and hemato-lymphoproliferative malignancies. Information on occupational history and potential confounders such as sex, age, smoking, alcohol use, and attained educational level were collected at baseline through a self-administered questionnaire. Occupational ELF-MF exposure was assigned with a job-exposure matrix. Using a case-cohort approach, associations with cancer incidence were analyzed with Cox regression stratified by sex, using three exposure metrics: (1) ever had a job with low or high exposure to ELF-MF versus background, (2) duration of exposure, and (3) cumulative exposure.
None of the exposure metrics showed an effect on incidence for lung, breast, and brain cancer, nor any of the assessed subtypes in men and women. Of the hemato-lymphoproliferative malignancies in men, ever high exposed to ELF-MF showed a significant association with acute myeloid leukemia (AML) [hazard ratio (HR) 2.15; 95 % confidence interval (CI) 1.06-4.35] and follicular lymphoma (FL) (HR 2.78; 95 % CI 1.00-5.77). Cumulative exposure to ELF-MF showed a significant, positive association with FL but not AML among men.
In this large prospective cohort study, we found some indications of an increased risk of AML and FL among men with occupational ELF-MF exposure. These findings warrant further investigation.
Cancer Causes and Control 11/2013; 25(2). DOI:10.1007/s10552-013-0322-x · 2.74 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Red meat intake has been linked to increased colorectal cancer (CRC) risk. Although the underlying mechanisms remain unclear, experimental studies suggest a role for dietary heme iron. Because heme iron was shown to promote specific mutations, it would be insightful to link heme iron data to CRC with mutations in key-genes in an observational, population-based study. We investigated the association between dietary heme iron intake and risk of CRC with mutations in APC (adenomatous polyposis coli) and KRAS (Kirsten ras), and P53 overexpression in the Netherlands Cohort Study. After 7.3yrs of follow-up, excluding the first 2.3yrs due to incomplete coverage of the pathology registry and to avoid pre-clinical disease, adjusted hazard ratios (HR) (including adjustment for total meat) and 95% confidence intervals (CI) were calculated, using 4,026 subcohort members (aged 55-69yrs at baseline), 435 colon and 140 rectal cancer patients. When comparing the highest with the lowest tertile of intake, heme iron intake was associated with an increased risk of CRC harboring activating mutations in KRAS (HR=1.71, 95%CI: 1.15- 2.57;Ptrend=0.03) and CRC without truncating mutations in APC (HR=1.79, 95%CI: 1.23-2.60; Ptrend=0.003). We observed a positive association between heme iron intake and the risk of CRC with activating G>A mutations in KRAS (Ptrend=0.01), and overall G>A mutations in APC (Ptrend=0.005). No associations were found with CRC harboring G>T mutations in KRAS/APC. Heme iron intake was positively associated with the risk of P53 overexpressed tumors, but not with tumors without P53 overexpression (Pheterogeneity=0.12). Heme iron intake was associated with an increased risk of colorectal tumors harboring G>A transitions in KRAS and APC and overexpression of P53. These novel findings suggest that alkylating rather than oxidative DNA damaging mechanisms are involved in heme-induced colorectal carcinogenesis.
[Show abstract][Hide abstract] ABSTRACT: Selenium may prevent advanced prostate cancer (PCa), but most studies on this topic were conducted in populations with moderate to high selenium status. We investigated the association of toenail selenium, reflecting long-term selenium exposure, and advanced PCa risk in a population from the Netherlands where low selenium status is widespread.
The analysis was conducted in the prospective Netherlands Cohort Study, which included 58 279 men aged 55 to 69 years at baseline in 1986. All cohort members completed a baseline questionnaire, and approximately 79% of participants provided toenail clippings, which were used for toenail selenium measurements using instrumental neutron activation analysis. Incident advanced PCa case subjects from the entire cohort were identified during 17.3 years of follow-up. The study employed a case-cohort design for which a random subcohort was sampled at baseline. Hazard ratios and 95% confidence intervals (CIs) were estimated using Cox proportional hazards regression models. All tests were two-sided.
Complete toenail selenium data were available for 898 advanced (International Union Against Cancer stage III/IV) PCa case subjects and 1176 subcohort members. The average toenail selenium concentration of subcohort members was 0.550 µg/g. Toenail selenium was associated with a reduced risk of advanced PCa; adjusted hazard ratio for the highest vs lowest quintile was 0.37 (95% CI = 0.27 to 0.51; P trend < .001). For stage IV PCa, men in the highest vs lowest quintile of toenail selenium had an adjusted hazard ratio of 0.30 (95% CI = 0.21 to 0.45; P trend < .001).
Toenail selenium was associated with a substantial decrease in risk of advanced PCa.
JNCI Journal of the National Cancer Institute 07/2013; DOI:10.1093/jnci/djt186 · 12.58 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Flavonoids are natural antioxidants found in various foods, and a major source is black tea. Some experimental evidence indicates
that flavonoids could prevent prostate cancer. We investigated the associations between flavonoid intake, black tea consumption,
and prostate cancer risk in the Netherlands Cohort study, which includes 58,279 men who provided detailed baseline information
on several cancer risk factors. From 1986 to 2003, 3,362 prostate cancers were identified, including 1,164 advanced (stage
III/IV) cancers. Cox proportional hazards regression using the case-cohort approach was used to estimate hazard ratios and
95% confidence intervals. Intake of total catechin, epicatechin, kaempferol, and myricetin and consumption of black tea were
associated with a decreased risk of stage III/IV or stage IV prostate cancer. Hazard ratios of stage III/IV and stage IV prostate
cancer for the highest versus the lowest category of black tea consumption (≥5 versus ≤1 cups/day) were 0.75 (95% confidence
interval: 0.59, 0.97) and 0.67 (95% confidence interval: 0.50, 0.91), respectively. No associations were observed for overall
and nonadvanced prostate cancer. In conclusion, dietary flavonoid intake and black tea consumption were associated with a
decreased risk of advanced stage prostate cancer.
American journal of epidemiology 05/2013; 177(12). DOI:10.1093/aje/kws419 · 5.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background:
Prostate cancer is the most commonly diagnosed cancer in men in Europe and the United States. Numerous studies have indicated genetics to have a major role in the aetiology of this disease; as much as 42% of the risk may be explained by heritable factors. Genome-wide association studies have detected an association between prostate cancer and chromosome 8p21-23. In this study, we analysed eight microsatellite (MS) markers in that region in order to confirm previous results and narrow down the location of candidate prostate cancer genes.
292 cases and 278 controls were selected from the Netherlands Cohort Study (NLCS). The following MSs were used in the analyses: D8S136, D8S1734, D8S1742, D8S261, D8S262, D8S351, D8S511 and D8S520. Associations were evaluated using a χ(2) test and logistic regression. We checked for any effects on the association by tumour stage.
Associations that were found confirmed previous research that pointed to the 8p21-23 region. Two MSs: D8S136 (odds ratio (OR), 0.69; P=4.00 × 10(-28)), and D8S520 (OR, 0.80; P=3.37 × 10(-11)), were consistently and strongly related with prostate cancer. Genotype analysis showed an additive effect for D8S136 (P-trend=6.22 × 10(-03)) and D8S520 (P-trend=2.62 × 10(-22)), suggesting an increased risk for people with a short number of repeats on both alleles at those markers.
This study provides strong evidence that the 8p21-23 region is likely to harbour prostate cancer genes.
Prostate cancer and prostatic diseases 04/2013; 16(3). DOI:10.1038/pcan.2013.9 · 3.43 Impact Factor