Impact of vitamin D level at diagnosis and transplantation on the prognosis of hematological malignancy: a meta-analysis

Abstract

Vitamin D deficiency impairs prognosis in many types of cancer; however, its significance in each subtype of hematological malignancies is unclear. In addition, data on the association between pre-transplant vitamin D levels and outcomes of hematopoietic stem cell transplantation (HSCT) are inconsistent. This systematic review and meta-analysis aimed to elucidate the impact of vitamin D levels at diagnosis or pre-HSCT on the prognosis of hematological malignancies. A total of 30 articles and abstracts were extracted from PubMed, Embase, Cochrane Library databases, and conference proceedings. Fixed and random-effect models were used to analyze primary outcomes: overall survival (OS) and progression-free survival (PFS). Lower vitamin D level was significantly associated with poorer OS and PFS in myeloid (hazard ratio [HR]: 1.39, 95% confidence interval [CI] 1.06-1.82; HR: 2.03, 95%CI 1.23-3.32, respectively) and lymphoid malignancies (HR: 2.07, 95%CI 1.79-2.40; HR:1.91, 95%CI 1.61-2.25, respectively), as well as outcomes of several lymphoma subtypes individually. Furthermore, pre-transplant lower vitamin D level was associated with poorer OS in both autologous and allogeneic HSCT (HR: 1.65, 95%CI 1.04-2.61; HR: 1.50, 95%CI 1.03-2.18, respectively). Despite the relatively small number of studies evaluated, these data suggest the importance of vitamin D status in outcomes of hematological malignancies (PROSPERO registration number: CRD42020205821).