Abstract 3297: Prediagnostic circulating concentrations of vitamin D binding protein and survival among colorectal cancer patients

Abstract

Abstract Higher total 25-hydroxyvitamin D [25(OH)D] levels are associated with an improvement in survival among colorectal cancer (CRC) patients, but the relationships between plasma vitamin D binding protein (VDBP), bioavailable or free 25(OH)D, and CRC survival remain unknown. In two prospective cohort studies, the Health Professionals Follow-Up Study and the Nurses’ Health Study, we examined the association between prediagnostic plasma levels of VDBP, bioavailable 25(OH)D, and free 25(OH)D and survival among 604 participants diagnosed with CRC between 1991 and 2011. Plasma 25(OH)D and VDBP were directly measured, while bioavailable and free 25(OH)D were calculated using a validated formula based on total 25(OH)D, VDBP, and albumin levels. Cox proportional hazards models were used to estimate hazard ratios (HRs) for overall and CRC-specific mortality, adjusted for other prognostic markers and potential confounders. During the follow-up, there were 279 deaths, 177 of which were due to CRC (63%). Higher VDBP levels were associated with a significant improvement in overall and CRC-specific survival (Ptrend=0.005 and 0.02, respectively). Compared to patients in the lowest quartile, those in the highest quartile of VDBP had a multivariable-adjusted HR of 0.61 (95% confidence interval [CI], 0.42-0.89) for overall mortality and 0.56 (95% CI, 0.35-0.92) for CRC-specific mortality. The results remained similar after further adjustment for total 25(OH)D levels. In contrast, no association with overall or CRC-specific mortality was observed for bioavailable or free 25(OH)D levels. In conclusion, higher prediagnostic plasma VDBP levels were associated with improved survival among CRC patients. The clinical utility of VDBP as a prognostic marker warrants further exploration, as well as research into underlying mechanisms of action. Citation Format: Chen Yuan, Mingyang Song, Brian M. Wolpin, Jeffrey A. Meyerhardt, Shuji Ogino, Bruce W. Hollis, Andrew T. Chan, Charles S. Fuchs, Kana Wu, Molin Wang, Stephanie A. Smith-Warner, Edward L. Giovannucci, Kimmie Ng. Prediagnostic circulating concentrations of vitamin D binding protein and survival among colorectal cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3297.