Pre-treatment red blood cell distribution width provides prognostic information in multiple myeloma

The red blood cell distribution width (RDW), a credible marker for abnormal erythropoiesis, has recently been studied as a prognostic factor in oncology, but its role in multiple myeloma (MM) hasn't been thoroughly investigated.

We performed a retrospective study in 162 patients with multiple myeloma. Categorical parameters were analyzed using Pearson chi-squared test. The Mann-Whitney and Wilcoxon tests were used for group comparisons. Comparisons of repeated samples data were analyzed with the general linear model repeated-measures procedure. The Kaplan-Meier product-limit method was used to determine OS and PFS, and the differences were assessed by the log-rank test.

High RDW baseline was significantly associated with indexes including haemoglobin, bone marrow plasma cell infiltration, and cytogenetics risk stratification. After chemotherapy, the overall response rate (ORR) decreased as RDW baseline increased. In 24 patients with high RDW baseline, it was revealed RDW value decreased when patients achieved complete remission (CR), but increased when the disease progressed. The normal-RDW baseline group showed both longer overall survival (OS) and progression-free survival (PFS) than the high-RDW baseline group.

Our study suggests pre-treatment RDW level is a prognostic factor in MM and should be regarded as an important parameter for assessment of therapeutic efficiency.