Baseline serum folate, vitamin B12 and the risk of prostate and breast cancer using data from the Swedish AMORIS cohort
Menée en Suède à l'aide d'échantillons sanguins prélevés sur 19 775 femmes et 8 783 hommes (durée moyenne de suivi : 13 à 14 ans), cette étude analyse l'association entre les niveaux sériques de folates et de vitamine B12 et le risque de cancer de la prostate (703 cas) ou du sein (795 cas)
Résumé en anglais
Purpose : The roles of folate and vitamin B12 in prostate cancer (PCa) or breast cancer (BC) development are unclear. We investigated their roles using the prospective Swedish Apolipoprotein MOrtality RISk (AMORIS) study.
Methods : 8,783 men and 19,775 women with vitamin B12 and folate serum measurements were included. Their associations with PCa and BC risk categories were evaluated using Cox proportional hazards regression.
Results : During mean follow-up of 13 years, 703 men developed PCa. There was an inverse association between folate > 32 nmol/L and high-risk PCa [hazard ratio (HR) 0.12, 95% confidence interval (CI) 0.02–0.90], and a positive association between folate < 5 nmol/L and metastatic PCa (HR 5.25, 95% CI 1.29–21.41), compared with folate 5–32 nmol/L. No associations with vitamin B12 were found. 795 women developed BC during mean follow-up of 14 years. When restricting to the fasting population, there was a positive association between folate > 32 nmol/L and BC (HR 1.47, 95% CI 1.06–2.04).
Conclusion : High folate levels may protect against PCa and low folate levels may increase risk of metastatic PCa. High fasting folate levels may be associated with an increased BC risk. Vitamin B12 was not found to be linked with risk of PCa or BC. Longitudinal studies with serum and dietary information could help define new prevention targets and add information on the role of folate fortification.
