Introduction

Nearly 40% of patients with newly diagnosed multiple myeloma are vitamin D deficient (Br J Haematol. 2008;142(3):492-4). Low vitamin D levels are associated with a higher ISS (International staging system) stage, higher creatinine, and higher serum C-reactive protein levels at diagnosis (Am J Hematol. 2009;84(7):397-400). Along with its key role in bone metabolism, vitamin D promotes differentiation, inhibits proliferation and is pro-apoptotic at the cellular level. In our retrospective study, we assessed the prognostic effect of pre-transplant vitamin D levels in patients with multiple myeloma (MM) undergoing their first autologous stem cell transplant (ASCT).

Methods

All patients who underwent an ASCT for MM since 2010 were identified from the Wake Forest University Comprehensive Cancer Center registry. 25-hydroxy vitamin D levels checked within 90 prior to ASCT were recorded, along with key clinical variables as noted in table 1. Receiver operating characteristic (ROC) analysis was employed to define best discriminant levels for predicting mortality. Survival was calculated from the date of transplant to the date of death or last follow up. The JMP (SAS Institute) statistical package was used for all calculations.

Results

A total of 176 patients received ASCT for MM from 2010 to 2015, of whom 158 (90%) had pre-transplant vitamin D levels checked within 90 days of ASCT and were included in the analysis. Most patients (140/158, 89%) underwent ASCT within one year of MM diagnosis. ROC analysis identified a 25-OH vitamin D level of ≤ 23 ng/mL (AUC 0.57) as best discriminant level for predicting mortality. Using this cut-off, vitamin D deficiency was identified in 60% (94/158) patients. Low vitamin D levels were significantly associated with younger age at MM diagnosis and ASCT (P =0.001). There were no other significant differences in the baseline characteristics of patients with low versus normal vitamin D levels (Table 1). Survival from the time of transplant was inferior in vitamin D deficient patients compared to those with normal levels (HR 2.55, 95% CI 1.08-7.03; P= 0.03). Median survival in vitamin D deficient patients was 25 months versus 32 months in those with normal vitamin D levels (P= 0.03). Multivariable analysis in the context of ISS and ASBMT disease risk confirmed the independent prognostic relevance of vitamin D levels (P= 0.01).

Conclusion

Low pre-transplant vitamin D levels are associated with an inferior survival in patients with multiple myeloma who undergo an ASCT. Further studies are needed to determine whether repleting vitamin D in vitamin D deficient patients improves outcomes.

Prognostic impact of pre-transplant vitamin D levels in MM patients undergoing an autologous stem cell transplant

Disclosures

No relevant conflicts of interest to declare.

Author notes

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Asterisk with author names denotes non-ASH members.

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