Abstract 2785: A pooled analysis of circulating 25(OH)D and ovarian cancer risk
Authors: Danforth Kim N. , Zheng Wei , Tworoger Shelley S. , Goodman Marc T. , Arslan Alan A. , Patel Alpa V. , McCullough Marjorie L. , Weinstein Stephanie J. , Helzlsouer Kathy J. ,   for the Vitamin D Pooling Project Investigators.
Published: February 2011

Abstract
Although the pathogenesis of ovarian cancer is poorly understood, experimental mechanism studies suggest that vitamin D might reduce ovarian cancer through induction of apoptosis or growth inhibition. Epidemiologic studies of sunlight exposure, dietary vitamin D, and genetic variation in the vitamin D receptor also support a role for vitamin D in ovarian carcinogenesis. However, few prospective studies have examined associations between ovarian cancer and circulating 25-hydroxyvitamin D [25(OH)D], a biologically integrated measure of dietary and non-dietary vitamin D exposure. Therefore, we examined associations between 25(OH)D and ovarian cancer risk in a prospective study of 516 cases and 770 controls from seven cohort studies in the Cohort Consortium Vitamin D Pooling Project of Rarer Cancers (VDPP): the CLUE Study (CLUE), the Cancer Prevention Study II Nutrition Cohort (CPS-II), the Multiethnic Cohort (MEC), the Nurses’ Health Study (NHS), the New York University Women's Health Study (NYU-WHS), the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO), and the Shanghai Women's Health Study (SWHS). Cases and controls were matched on age at blood collection, race/ethnicity, and date of blood draw. Circulating vitamin D levels were measured using the DiaSorin LIAISON 25(OH)D TOTAL assay. Quality control samples consisted of cohort-specific samples and standard samples provided by the National Institute of Standards and Technology. Using data from all VDPP batches (including other cancer sites), the intrabatch CV by cohort ranged from 3.8% to 16.4% and interbatch CV ranged from 4.8% to 17%. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using conditional logistic regression for the main analyses and unconditional logistic regression for stratified analyses. Blood samples were obtained a median of 5.9 years prior to cancer diagnosis (range 2.7-10.2 years). Compared to the a priori reference category of 50 to &lt;75 nmol/L, no statistically significant associations were observed for the following 25(OH)D categories: &lt;25 nmol/L (OR=1.08, 95% CI: 0.64-1.81), 25 to &lt;37.5 nmol/L (OR=1.27, 95% CI: 0.88-1.85), 37.5 to &lt;50 nmol/L (OR=1.03, 95% CI: 0.75-1.40), 75 to &lt;100 nmol/L (OR=1.10, 95% CI: 0.77-1.59), or &gt;100 nmol/L (OR=1.11, 95% CI: 0.61-2.05) (p-trend=0.65). Results also were null for analyses stratified by tumor subtype and age at blood draw. In analyses stratified by body mass index (BMI), there was some suggestion of an inverse relationship between 25(OH)D and ovarian cancer risk among overweight women (p-trend=0.01 among women with a BMI &gt; 25 kg/m2). Overall, results from the VDPP do not support an association between circulating 25(OH)D and ovarian cancer risk.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2785.