| 3. |
- Johansson, Mattias, et al.
(författare)
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Circulating concentrations of folate and vitamin B12 in relation to prostate cancer risk : results from the European prospective investigation into cancer and nutrition study
- 2008
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Ingår i: Cancer Epidemiol Biomarkers Prev. - 1055-9965. ; 17:2, s. 279-285
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Tidskriftsartikel (refereegranskat)abstract
- Background: Determinants of one-carbon metabolism, such as folate and vitamin B12, have been implicated in cancer development. Previous studies have not provided conclusive evidence for the importance of circulating concentrations of folate and vitamin B12 in prostate cancer etiology. The aim of the present study was to investigate the relationship between prostate cancer risk and circulating concentrations of folate and vitamin B12 in a large prospective cohort. Methods: We analyzed circulating concentrations of folate and vitamin B12 in 869 cases and 1,174 controls, individually matched on center, age, and date of recruitment, nested within the European Prospective Investigation into Cancer and Nutrition cohort. Relative risks (RR) for prostate cancer were estimated using conditional logistic regression models. Results: Overall, no significant associations were observed for circulating concentrations of folate (Ptrend = 0.62) or vitamin B12 (Ptrend = 0.21) with prostate cancer risk. RRs for a doubling in folate and vitamin B12 concentrations were 1.03 [95% confidence interval (95% CI), 0.92-1.16] and 1.12 (95% CI, 0.94-1.35), respectively. In the subgroup of cases diagnosed with advanced stage prostate cancer, elevated concentrations of vitamin B12 were associated with increased risk (RR for a doubling in concentration, 1.69; 95% CI, 1.05-2.72, Ptrend = 0.03). No other subgroup analyses resulted in a statistically significant association. Conclusion: This study does not provide strong support for an association between prostate cancer risk and circulating concentrations of folate or vitamin B12. Elevated concentrations of vitamin B12 may be associated with an increased risk for advanced stage prostate cancer, but this association requires examination in other large prospective studies. (Cancer Epidemiol Biomarkers Prev 2007;17(2):279–85)
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| 4. |
- Pischon, Tobias, et al.
(författare)
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Body Size and Risk of Prostate Cancer in the European Prospective Investigation into Cancer and Nutrition
- 2008
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Ingår i: Cancer Epidemiology Biomarkers & Prevention. - Baltimore : Waverly Press. - 1538-7755 .- 1055-9965. ; 17:11, s. 3252-3261
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Tidskriftsartikel (refereegranskat)abstract
- Background: Body size has been hypothesized to influence the risk of prostate cancer; however, most epidemiologic studies have relied on body mass index (BMI) to assess adiposity, whereas only a few studies have examined whether body fat distribution predicts prostate cancer. Methods: We examined the association of height, BMI, waist and hip circumference, and waist-hip ratio with prostate cancer risk among 129,502 men without cancer at baseline from 8 countries of the European Prospective Investigation into Cancer and Nutrition (EPIC), using Cox regression, with age as time metric, stratifying by study center and age at recruitment, and adjusting for education, smoking status, alcohol consumption, and physical activity. Results: During a mean follow-up of 8.5 years, 2,446 men developed prostate cancer. Waist circumference and waist-hip ratio were positively associated with risk of advanced disease. The relative risk of advanced prostate cancer was 1.06 (95% confidence interval, 1.01-1.1) per 5-cm-higher waist circumference and 1.21 (95% confidence interval, 1.04-1.39) per 0.1-unit-higher waist-hip ratio. When stratified by BMI, waist circumference and waist-hip ratio were positively related to risk of total, advanced, and high-grade prostate cancer among men with lower but not among those with higher BMI (P-interaction for waist with BMI, 0.25, 0.02, and 0.05, respectively; P-interaction for waist-hip ratio with BMI, 0.27, 0.22, and 0.14; respectively). Conclusions: These data suggest that abdominal adiposity may be associated with an increased risk of advanced prostate cancer. This association may be stronger among individuals with lower BMI; however, this finding needs confirmation in future studies. (Cancer Epidemiol Biomarkers Prev 2008;17(11):3252-61)
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