Circulating Vitamin D Levels and Risk of Colorectal Cancer in Women

Menée sur 274 patientes atteintes d'un cancer colorectal et sur 274 témoins, cette étude évalue l'association entre les niveaux plasmatiques de la 25-hydroxy-vitamine D (un métabolite de la vitamine D) avant diagnostic de la maladie et le risque de développer un cancer colorectal

Résumé en anglais

Observational data on the association between circulating 25(OH)D and colorectal cancer risk are limited in women. To determine whether prediagnostic levels of 25(OH)D were associated with risk of incident colorectal cancer in the Women's Health Study (WHS), we conducted a nested case-control study using 274 colorectal cases and 274 controls. Each case was matched to a control by age, ethnicity, fasting status at the time of blood collection, time of day when blood was drawn, and month of blood draw. Conditional logistic regression was used to estimate the odds ratio (OR) and 95% confidence interval (CI) for colorectal cancer by 25(OH)D quartiles. Mean plasma 25(OH)D was lower in cases versus controls (21.9 vs 23.9 ng/mL, p=0.01). In multivariable-adjusted logistic regression models, plasma 25(OH)D was significantly and inversely associated with odds of colorectal cancer (quartile 4 [Q4] versus quartile 1 [Q1]: OR (95% CI): 0.45 (0.25-0.81), ptrend 0.02). Additionally, we observed a somewhat lower risk of colorectal cancer mortality after adjustment for matching variables, randomization treatment and other risk factors (Q4:Q1 OR[95%CI]: 0.40(0.17-0.97); ptrend 0.05). In this cohort of healthy women, we found a significant inverse association between prediagnostic 25(OH)D levels and risk of incident colorectal cancer, and a borderline significant inverse association between prediagnostic 25(OH)D levels and colorectal cancer mortality. These results support a possible association between plasma 25(OH)D and risk of colorectal cancer in women.