Prognostic impact of severe thrombocytopenia in low-risk myelodysplastic syndrome.

Abstract

Thrombocytopenia is very common in myelodysplastic syndrome (MDS); however, its clinical impact in low-risk patients remains controversial. The authors analyzed the incidence and prognostic significance of thrombocytopenia at diagnosis in 2565 de novo MDS patients included in the Spanish MDS Registry. Thrombocytopenia (platelet count <100 × 10(9) /L) was identified in 842 patients (32.8%). Severe thrombocytopenia (platelet count <30 × 10(9) /L) was observed in 7.1% of patients and was significantly associated with a higher-risk World Health Organization subtype (P = .026) and intermediate-2/high-risk International Prognostic Scoring System (IPSS) score (P = .046). Severe thrombocytopenia was the most important prognostic factor and had negative effects on the low/intermediate-1 risk group. Median overall survival of patients with a platelet count <30 and ≥ 30 × 10(9) /L was 16 months and 71 months, respectively (hazard ratio, 4.66; 95% confidence interval, 2.74-7.90; P < .0001). The negative effect of severe thrombocytopenia in low/intermediate-1 risk patients was caused by increased risk of bleeding. MDS patients with low/intermediate-1 IPSS risk score and severe thrombocytopenia should no longer be regarded as low risk, and must be considered for disease-altering approaches at diagnosis.