The heterogeneous prognosis of patients with myelodysplastic syndrome and chromosome 5 abnormalities: How does it relate to the original lenalidomide experience in MDS?

BACKGROUND: To define the prognosis in myelodysplastic syndrome (MDS) and deletion 5q with or without other cytogenetic abnormalities. METHODS: Patients with MDS (<20% blasts) and evaluable cytogenetic studies (1966-present) were reviewed. Outcome of patients with deletion 5q or with loss of chromosome 5 (monosomy 5) was analyzed. RESULTS: Of 2743 patients analyzed, 287 (10%) had deletion 5q and 216 (8%) had monosomy 5 abnormalities. The median survival was 9 months with deletion 5q, 6 months with monosomy 5, and 17 months without a chromosome 5 abnormality. Considering patients with deletion 5q, the median survival was 33 months with deletion 5q alone, 17 months with deletion 5q and 1 additional abnormality, but only 6 months to 12 months with deletion 5q and ≥2 abnormalities or chromosome 7 abnormality. Only 93 patients (3.4% of total) had lower risk MDS (international prognostic scoring system low or intermediate 1) and deletion 5q; their median survival was 29 months (2-year survival 60%), and ranged from 13-41 months depending on the presence or absence of additional chromosomal abnormalities. Among 198 patients with MDS with deletion 5q and <10% blasts (a subset now often offered lenalidomide), the median survival was 12 months. Monosomy 5 was significantly more frequently associated with advanced MDS and with other chromosomal abnormalities. CONCLUSIONS: This study provided baseline expectations of outcome in different MDS subsets and deletion 5q.