Refractory cytopenia with unilineage dysplasia: analysis of prognostic factors and survival in 126 patients.

According to the revised WHO classification of 2008, dysplasia in > or = 10% of one bone marrow lineage and one cytopenia constitutes the low-risk category of unilineage cytopenia and unilineage dysplasia (UCUD). We retrospectively reclassified, according to WHO, low-risk MDS from our database and found 126 subjects with these features at diagnosis: 79 patients were categorized as refractory anemia (RA), 23 patients as refractory neutropenia (RN), and 24 as refractory thrombocytopenia (RT). We did not find differences between the three subgroups as regards sex, median age, and cytogenetic aberrations. Lower PMN count (0.8 x 10(9)/L) was observed in the RN category, as well as lower platelet count in the RT category (51 x 10(9)/L). Moreover, we found a lower rate of patients requiring RBC transfusions, during the disease course, in the RT category (45.8%) as compared to RA (62%) and RN (69%) groups (p = 0.05); a lower incidence of infections at diagnosis in the RT category (20.8%) compared to RA (32%) and RN (43%) categories (p = 0.03); and a higher incidence of hemorrhagic symptoms at diagnosis in the RT category (41.6%) and RN category (26%) as compared to the RA group (5%) (p = 0.001). Application of different scoring systems (Bournemouth and Spanish scores, WPSS) revealed a low OS in high-risk patients within the RT category, compared to RA and RN categories, although unlikely to reflect the consequences of low OS found in the former category. Statistically significant differences were also evidenced in the incidence of acute myeloid leukemia (AML) evolution and overall survival: 7/79 (8%) patients with the RA category evolved to AML in a median time of 89 months, whereas 4/23 (17%) of the RN category and 1/24 (4%) of the RT category experienced disease progression, in a median time of 33.8 and 12.8 months, respectively (p = 0.03). The RT category had a lower overall survival (15.9 months) as compared to RA (48.2 months) and RN (35.9 months) categories (p < 0.001). In conclusion, in our study, application of the revised 2008 WHO classification confirmed the importance of separating patients with unilineage dysplasia for prognostic disease assessment; from our results it seems that the RT category has a worse outcome.