Background: Serum levels of 25-OH-D3 inversely correlate with the incidence of various types of cancers in the general population. Because risk factors and incidence of cancer in renal transplant recipients (RTRs) are different from the general population, this study was designed to determine whether pretransplant 25-OH-D3 levels could be predictive of cancer risk in RTRs.
Methods: Pretransplant 25-OH-D3 levels were reviewed in 363 consecutive RTRs. The impact of 25-OH-D3 levels on the development of cancer was then analyzed with respect to other known risk factors.
Results: One hundred twenty-four patients (34.2%) showed vitamin D deficiency, 185 (51%) vitamin D insufficiency, and 54 (14.8%) with normal vitamin D levels. Thirty-two cancers (8.8%) occurred in 32 patients. A higher incidence of cancer was observed in patients with vitamin D deficiency (13.7% vs. 7% for patients with vitamin D insufficiency [P=0.068] and 3.7% for those with normal vitamin D levels [P=0.007]). 25-OH-D3 levels were lower in patients who developed cancer after transplantation (13.7+/-6 vs. 18.3+/-17.8 ng/mL, P=0.022). Age (hazard ratio, 1.06; 95% confidence interval, 1.02-1.11, for each 1 year increase; P=0.009) and low 25-OH-D3 levels (hazard ratio, 1.12; 95% confidence interval, 1.04-1.23, for every 1 ng/mL decrease; P=0.021) were independent risk factors for development of cancer.
Conclusion: Pretransplant level of 25-OH-D3 is an important determinant for subsequent development of cancer after transplantation. Future studies should examine whether 25-OH-D3 supplementation can effectively decrease the incidence of cancer in RTRs.