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Pancreatic Neoplasms: HELP
Articles by William Kopp
Based on 2 articles published since 2010
(Why 2 articles?)

Between 2010 and 2020, William Kopp wrote the following 2 articles about Pancreatic Neoplasms.
+ Citations + Abstracts
1 Article Vitamin D-binding protein and pancreatic cancer: a nested case-control study. 2015

Piper, Marina R / Freedman, D Michal / Robien, Kim / Kopp, William / Rager, Helen / Horst, Ronald L / Stolzenberg-Solomon, Rachael Z. ·From the Nutritional Epidemiology Branch (MRP and RZS-S) and the Radiation Epidemiology Branch (DMF), Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD · the Departments of Epidemiology and Biostatistics and Exercise Science, Milken Institute School of Public Health, George Washington University, Washington, DC (KR) · the Clinical Support Laboratory, Leidos Biomedical Research Inc./Frederick National Laboratory for Cancer Research, Frederick, MD (WK and HR) · and Heartland Assays Inc., Iowa State University, Ames, IA (RLH). ·Am J Clin Nutr · Pubmed #25904602.

ABSTRACT: BACKGROUND: Vitamin D-binding protein (DBP) is the primary carrier of 25-hydroxyvitamin D [25(OH)D] in the circulation. One prospective study in male smokers found a protective association between DBP and pancreatic cancer, particularly among men with higher 25(OH)D concentrations. OBJECTIVE: The objective was to examine the association between DBP and pancreatic cancer risk in an American population. DESIGN: We conducted a nested case-control study in the Prostate, Lung, Colorectal, and Ovarian Cancer screening trial cohort of men and women aged 55-74 y at baseline. Between 1993 and 2010, 295 incident pancreatic adenocarcinoma cases were reported (follow-up to 15.1 y). Two controls (n = 590) were matched to each case by age, race, sex, and month of blood draw. We calculated smoking- and diabetes-adjusted ORs and 95% CIs with the use of conditional logistic regression. RESULTS: DBP concentration was not significantly associated with pancreatic cancer overall [highest (≥7149.4 nmol/L) vs. lowest (<3670.4 nmol/L) quintile; OR: 1.75; 95% CI: 0.91, 3.37; P-trend = 0.25]. For serum 25(OH)D compared with the referent (50 to <75 nmol/L), individuals in the highest group had a significantly higher risk (≥100 nmol/L; OR: 3.23; 95% CI: 1.24, 8.44), whereas those in the lowest group had no significant association (<25 nmol/L; OR: 2.50; 95% CI: 0.92, 6.81). Further adjustment for DBP did not alter this association. CONCLUSION: Our results do not support the hypothesis that serum DBP or 25(OH)D plays a protective role in pancreatic cancer. This trial was registered at clinicaltrials.gov as NCT00339495.

2 Article Impact of circulating vitamin D binding protein levels on the association between 25-hydroxyvitamin D and pancreatic cancer risk: a nested case-control study. 2012

Weinstein, Stephanie J / Stolzenberg-Solomon, Rachael Z / Kopp, William / Rager, Helen / Virtamo, Jarmo / Albanes, Demetrius. ·Nutritional Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD 20982, USA. ·Cancer Res · Pubmed #22232734.

ABSTRACT: High concentrations of circulating 25-hydroxyvitamin D [25(OH)D] have been associated with elevated pancreatic cancer risk. As this is contrary to an expected inverse association between vitamin D status and cancer, we examined whether vitamin D binding protein (DBP), the primary carrier of vitamin D compounds in circulation, plays a role in this relationship. Prediagnostic serum DBP and 25(OH)D were studied in relation to risk of pancreatic cancer in a nested case-control study of 234 cases and 234 controls in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study of Finnish men. ORs and 95% CIs were estimated using logistic regression, and statistical tests were two-sided. We found that DBP and 25(OH)D were correlated (r = 0.27, P < 0.0001), and DBP was inversely associated with pancreatic cancer risk (OR = 0.66, 95% CI = 0.39-1.12, for the highest vs. lowest quartile; P(trend) = 0.02). Importantly, this association seemed to have a threshold between quartiles 2 to 4 and quartile 1, and was primarily evident among men with concurrent high 25(OH)D concentrations (OR = 0.33, 95% CI = 0.16-0.70 for highest vs. lowest quartile; P(trend) = 0.002), with no association in men with lower serum 25(OH)D (OR = 1.28, 95% CI = 0.62-2.61 for highest vs. lowest quartile, P(trend) 0.63, P(interaction) = 0.01). Men with higher 25(OH)D concentrations and serum DBP below the median showed greatly elevated risk of pancreatic cancer (OR = 5.01, 95% CI 2.33-10.78, for highest vs. lowest quartile; P(trend) < 0.0001), while risk was weakly inversely associated with serum 25(OH)D when DBP concentrations were higher (P(interaction) = 0.001). Taken together, our findings indicate that higher DBP concentrations may sequester more 25(OH)D and reduce free 25(OH)D bioavailability. Simultaneous examination of DBP and 25(OH)D may be important in determining the association of vitamin D with cancer risk.