Cancer Prev Res (Phila). 2021 Apr 13:canprevres.0581.2020. doi: 10.1158/1940-6207.CAPR-20-0581. Online ahead of print.
ABSTRACT
Current therapies for breast cancer prevention only prevent estrogen receptor positive (Er+) disease and toxicity limits use of these agents. Vitamin D is a potential prevention therapy for both Er+ and Er- disease and is safe with few side effects. This study evaluates the effect of one-year of vitamin D supplementation on mammographic density (MD), a biomarker of breast cancer risk in a multicenter randomized controlled trial. Premenopausal women with > 25% MD and no history of cancer, were randomly assigned to 2000IU of vitamin D or placebo orally daily for 1-year. Change in percent MD was evaluated using Cumulus software after all participants completed treatment. Three hundred women enrolled between 1/2011 and 12/2013 with a mean age of 43 and diverse ethnicity (14% Hispanic, 12% African American [AA]). Supplementation significantly increased vitamin D levels compared to placebo (14.5 ng/mL vs -1.6 ng/mL; p<0.0001) with all participants on the Vitamin D arm achieving vitamin D sufficiency at 12 months. Vitamin D was safe and well tolerated. After adjustment for baseline MD, the mean between-arm difference (vitamin D vs placebo) at 1 year was -0.75 [-.26, 1.76 p=0.56]. A greater effect was seen for women with >50% MD and AA women, although neither reached significance. This randomized controlled trial demonstrated significant improvement in vitamin D levels with 2000 IU for one year, with 100% of supplemented women achieving sufficiency. However, a null effect was seen regarding change in MD for premenopausal women (the primary outcome of the study).
PMID:33849913 | DOI:10.1158/1940-6207.CAPR-20-0581
