Abstract B16: Association of calcium and vitamin D intake and vitamin D receptor genotypes with prostate cancer in multiethnic samples

• Published in: Cancer epidemiology, biomarkers & prevention biomarkers & prevention, 2015-10, Vol.24 (10_Supplement), p.B16-B16
• Main Authors: Batai, Ken, Murphy, Adam B., Shah, Ebony, Ruden, Maria, Newsome, Jennifer, Dixon, Michael A., Chiledum, Ahaghotu, Kittles, Rick A.
• Format: Article
• Language: English
• ISSN: 1055-9965; 1538-7755
• DOI: 10.1158/1538-7755.DISP14-B16

Background: Prostate cancer (PCa) is the most common cancer among men in the U.S., and African American (AA) men have higher incidence and mortality rate compared to European American (EA) men. Social and behavioral factors affect stage and tumor grade at diagnosis, treatment choice, and mortality. However, the cause for PCa disparities is still unclear. Several roles have been proposed for calcium, vitamin D, and the vitamin D receptor (VDR) in PCa pathogenesis and progression, but epidemiologic studies, mainly conducted in European descent populations, often show inconsistent evidence of associations. Here, we investigated the association of calcium and vitamin D intake and VDR genotypes with prostate cancer incidence and aggressiveness in multiethnic samples. Methods: The total of 1,403 individuals was included in this study (751 AAs, 481 EAs, 126 Hispanic Americans, and 45 others). Study participants were recruited from six hospitals in Chicago, IL and Washington, D.C. Calcium and vitamin D intake was evaluated using the Block calcium and vitamin D screener. Seven single-nucleotide polymorphisms (SNPs) in and around the VDR gene and 105 ancestry informative markers were genotyped. STRUCTURE was used to estimate genetic ancestry. We performed logistic regression analyses adjusting for relevant variables using SPSS. Results: In the pooled data set, calcium and vitamin D intake was not associated with PCa risk (P>0.05), but high total calcium intake (≥800 mg/day) was significantly associated with aggressive PCa (Gleason Score ≥4+3, P=0.002, OR=2.05, 95% C.I.: 1.29-3.26). In the race/ethnicity stratified analyses, we confirmed the statistically significant associations of calcium intake with aggressive PCa in AAs. High total vitamin D intake (≥600IU/day), on the other hand, revealed a protective effect against aggressive PCa (OR=0.47, 95% C.I.: 0.24-0.92, P=0.026). In EAs, total calcium intake was significantly associated with PCa aggressiveness, only when we compared PCa cases with Gleason Score ≥4+3 to cases with Gleason Score