Results from a large observational study showed an association between circulating vitamin D levels and risk of colorectal cancer in women. These results were published online in Cancer Epidemiology, Biomarkers & Prevention.
Previous observational studies investigating levels of 25-hydroxyvitamin D (25(OH)D) in plasma or serum specimens have provided some support for an association between high levels of 25(OH)D and a decreased risk of colorectal cancer, although evidence with respect to breast and prostate cancer risks has been conflicting.
This case-cohort study was part of the Melbourne Collaborative Cohort Study, which was initiated in the early 1990s for the purpose of following healthy adults in Australia to prospectively evaluate the impact of diet and lifestyle on the development of noncommunicable diseases.
From a baseline cohort of 29,205 participants with no diagnosis of cancer, a random subcohort of 1332 women and 1664 men was selected. Cases included participants with a confirmed diagnosis of invasive adenocarcinoma of the colon or rectum, breast, or prostate by December 2007. Included in the analysis were 547 colorectal, 634 breast, and 824 prostate cancer cases.
An inverse relationship was observed between circulating levels of 25(OH)D and risk of colorectal cancer in women (hazard ratio [HR], 0.52; 95% confidence interval [CI], 0.33-0.82), but not in men (HR, 0.96; 95% CI, 0.61-1.52).
Interestingly, high circulating 25(OH)D levels were also inversely associated with BRAF V600E-mutant colorectal cancer (HR, 0.71; 95% CI, 0.50-1.01; P =.05). No significant associations between circulating levels of 25(OH)D and overall risk of breast or prostate cancer, estrogen receptor status (breast), stage, or KRAS status (in colorectal cancer) were observed.
- Heath AK, Hodge A, Ebeling PR, et al. Circulating 25-hydroxyvitamin D concentration and risk of breast, prostate, and colorectal cancers: the Melbourne Collaborative Cohort Study [published online March 6, 2019]. Cancer Epidemiol Biomarkers Prev. doi: 10.1158/1055-9965.EPI-18-1155