Orally Active Vitamin D for Potential Chemoprevention of Post-transplant Malignancy
Menée entre 2007 et 2010 sur 218 patients ayant reçu une greffe de rein (âge : de 40 à 59 ans ; 63,3 % d'hommes), cette étude japonaise évalue l'effet chimiopréventif de formes actives de la vitamine D (calcitriol et alfacalcidol), administrées par voie orale, sur le risque de cancer du rein
Background and objective: Post-transplant malignancy (PTM) is a limiting factor both for patient and allograft survival in kidney transplant recipients (KTRs). We hypothesized that active vitamin D compounds (AVDs) could reduce PTM development in KTRs. Design: Ambulatory KTRs in a Japanese prospective cohort were followed from August 2007 to November 2010. The outcome of interest was newly diagnosed PTM. A propensity score (PS) of having received AVDs was estimated using 26 clinically relevant factors. We used the Cox proportional hazards model with stratification by PS tertiles on the assumption that baseline hazard functions differ among tertiles. As sensitivity analyses, we used inverse probability weighting and PS matching. Results: Among 218 participants, the median age was 50 (interquartile range [IQR], 40-59) years, 63.3% were male, median time since transplantation was 11.2 (IQR, 5.2-17.1) years, and mean estimated GFR was 41.3 (SD, 15.6) ml/min per 1.73 m2. At baseline, 42.2% had been treated with AVDs mainly for glucocorticoid-induced osteoporosis. AVDs used were calcitriol (58.7%) and alfacalcidol (41.3%). During follow-up, PTM developed in 5.4% of 92 AVD users and 8.7% of 126 non-users. Poor vitamin D status was common in the participants, but the serum 25-hydroxyvitamin D level was not significantly associated with PTM in Cox regression analysis. After stratifying patients by PS tertiles, we found that AVDs were significantly associated with a lower risk of PTM (HR 0.25 [0.07-0.82]). Sensitivity analyses yielded similar results. Conclusions: AVDs are potential chemopreventive agents against PTM in KTRs.