Vitamin D and Breast Cancer Survival
Creators: name: University Of California Office Of The President
Publisher: name: University of California Office of the President
publisherIdentifier: https://ror.org/00dmfq477
publisherIdentifierScheme: ROR
Year: 2024

description: There are notable racial/ethnic disparities in survival following breast cancer diagnosis in U.S. women. African Americans and, to a lesser extent, Hispanics have poorer survival than non-Hispanic Whites. The proposed study aims to address these racial/ethnic disparities in relation to vitamin D, a hormone that has been linked to breast cancer progression, metastasis and survival in experimental and some ecological and epidemiological studies. Racial/ethnic differences in vitamin D status in U.S. women are well described and appear to parallel the racial/ethnic differences in breast cancer survival, with African Americans and Hispanics in general having lower serum vitamin D levels and higher prevalence of vitamin D deficiency than non- Hispanic Whites. 
 
 
 
 
 
 
 
 The goals of the study are to better substantiate whether an individual’s vitamin D status and vitamin D receptor (VDR) gene polymorphisms are associated with survival following breast cancer; and to determine whether racial/ethnic differences in vitamin D status can explain part of the racial/ethnic disparities in breast cancer survival in U.S. women. 
 
 
 
 
 
 The specific aims of our project include:
 
 
 
 
 
 
 
 - To determine whether breast cancer-specific survival and all-cause survival are associated with a) measures of vitamin D status, including serum 25(OH)-vitamin D levels, sun exposure, dietary and supplemental vitamin D intake; and b) VDR polymorphisms.
 
 - To determine how much of the differences in breast cancer-specific survival and all-cause survival between African Americans and non-Hispanic Whites observed in our study can be accounted for by their differences in serum vitamin D levels.
 
 - To determine the extent to which associational effects determined in Aims 1 and 2 compare to those determined by causal analyses.
 
 
 
 
 
 
 
 
 
 
 
 To address these aims we will build upon existing data and biospecimen resources for
 
 2,244 female invasive breast cancer cases aged 35-79 years from a multiethnic population-based case-control study that ascertained newly diagnosed cases through the Greater Bay Area Cancer Registry. By linking to the Cancer Registry, we will obtain updates on vital status and cause of death. We will perform survival analysis to determine whether vitamin D-related exposures are associated with death after breast cancer diagnosis after adjusting for known breast cancer prognostic factors. We will apply rigorous statistical methods to address the question of how much of the observed difference in survival between African Americans and non-Hispanic whites can be accounted for by their difference in serum vitamin D levels.
 
 
 
 
 
 
 
 Having a suboptimal serum vitamin D level is a widespread health problem facing U.S. women and particularly those with breast cancer. If improvement of vitamin D status can indeed extend breast cancer survival, it will benefit an enormously large number of breast cancer patients. Moreover, because modifying vitamin D status through supplementation can be achieved in a simple, safe, and low cost manner, it can provide a conceivably cost effective means to achieve our goal of reducing disparities and improving breast cancer survival in all women.