The prognostic value of circulating myeloblasts in patients with myelodysplastic syndromes.

The prognostic value of peripheral blasts (PB) is not well-studied in patients with myelodysplastic syndromes (MDS). We evaluated the impact of PB on overall survival (OS) and transformation to acute myeloid leukemia (AML) in a large cohort. The MDS database at the Moffitt Cancer Center was retrospectively reviewed to identify patients with ≥ 1% PB (PB-MDS) and those without PB (BM-MDS). We also assessed the correlation between PB and gene mutations. One thousand seven hundred fifty-eight patients were identified, among whom 13% had PB near the time of diagnosis. PB-MDS patients were more likely to be younger with trilineage cytopenia, complex karyotype, higher-risk disease, transfusion dependence, and therapy-related MDS. The rate of AML transformation was 49 vs. 26% (p < 0.005) and median OS was 16.5 vs. 45.8 months (p < 0.005) in the PB-MDS and BM-MDS groups, respectively. In Cox regression analysis, the presence of PB was an independent prognostic covariate for OS, HR 1.57 (95% CI 1.2-2). Among 51 patients with an available gene panel, the rate of ≥ 1 gene mutation in the PB-MDS group (n = 4) was 100% compared to 81% in the BM-MDS group (n = 47). The presence of PB in MDS is an adverse independent prognostic variable that refines prognostic discrimination.