Abstract 2345: Pre-diagnostic circulating 25-hydroxyvitamin D and prostate cancer survival: A collaborative analysis of 13 prospective studies.

Abstract Previous research suggests increased risk of prostate cancer in men with higher vitamin D serology, but there are limited data related to prostate cancer survival. In this study, we examined the association between pre-diagnostic blood concentrations of 25-hydroxyvitamin D 25(OH)D and the risk of prostate cancer-specific mortality, as well as mortality from other causes, in men diagnosed with prostate cancer. This prospective international collaborative analysis of circulating 25(OH)D, the major biochemical indicator of vitamin D status, was based on data for 12,635 incident prostate cancer cases from 13 cohorts. Multivariable-adjusted Cox proportional hazards regression models estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations between study-specific/season-standardized categories as well as clinically defined 25(OH)D categories (30, 30-50, 50-75, and ≥75 nmol/L) and death from prostate cancer (n=1,316) and other causes (n=2,129). In fully adjusted models that included demographic and lifestyle factors, as well as information on stage and grade of prostate cancer at diagnosis (available for 5,363 and 5,928 cases, respectively), men who had higher pre-diagnostic 25(OH)D concentrations experienced lower prostate cancer-specific mortality (HR for 80-percentile increase=0.75, 95% CI: 0.64-0.88; Ptrend0.001) and somewhat lower risk of mortality from other causes (HR=0.85, 95% CI: 0.75-0.96; Ptrend=0.009). When analyses were restricted to cases with complete stage and grade information (5,078 cases (40.2% of all cases) and 761 deaths from prostate cancer 57.8% of all deaths), the association between 25(OH)D and prostate cancer mortality was only slightly attenuated in the model that was further adjusted for these clinical factors (HR for 80-percentile increase=0.76, 95% CI: 0.62-0.93; Ptrend=0.009). Vitamin D was not associated with risk of death from other causes in this same subset of cases (HR=0.97, 95% CI: 0.83-1.12; Ptrend=0.7). In this pooled prospective cohort analysis, higher pre-diagnostic circulating vitamin D (25(OH)D) was associated with lower prostate cancer-specific mortality in men with prostate cancer. Further research is required to establish whether the association may be contributed to by biases such as the earlier detection of disease and thus better survival in men with higher vitamin D in these populations, as well as to investigate possible biological impacts of vitamin D on prostate cancer progression. Citation Format: Jiaqi Huang, Aurora Perez-Cornago, Ruth Travis, Timothy J. Key, Naomi Allen, Demetrius Albanes, on behalf of the Endogenous Hormones Nutritional Biomarkers and Prostate Cancer Collaborative Group. Pre-diagnostic circulating 25-hydroxyvitamin D and prostate cancer survival: A collaborative analysis of 13 prospective studies abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 2345.