Prognostic value of low platelets in MDS patients with del(5q)

Abstract

7078 The most common (10–15%) chromosomal abnormality found in myelodysplastic syndromes (MDS) is an interstitial deletion of the long arm of chromosome 5 (del(5q)). The recent finding that lenalidomide is efficacious for MDS patients with del(5q) as either the sole abnormality or as part of a complex karyotype has focused renewed interest in the prognostic characteristics of these patients. We analyzed 189 patients with del(5q), 70 having isolated and 119 having additional chromosomal abnormalities. The median survival for the isolated del(5q) patient was 2.45 years and for those with complex abnormalities was 0.63 years (p=0.001). Each of these groups was then divided by IPSS category; median survival for Low/Int1 (n=56) was 2.46 years and 0.49 years for Int2/High (n=10, p=0.019).Thus our median survival times match previously published results and we have a representative dataset. Since 5q- syndrome patients with normal to high platelets have the best survival, platelet count may be of prognostic significance. We determined the median platelet count for our dataset to be 115,000 and analyzed median survival for patients with greater (n=89) or less (n=88) than the median value. Survival for those with higher platelet counts was 2.6 years, but dropped to 0.54 years with lower counts (p=0.0001). We then analyzed each of these two groups independently for survival based on IPSS, blast % and karyotype. Median survival for patients with >115,000 platelets and either Low/Int1-risk (n=62), <5% blasts (n=46) or an isolated del(5q) (n=46) was 2.95–3.0 years. The survival of these patients dramatically decreased (0.63 years) if they had Int2/High IPSS (n=19) or >10% blasts (=11). The presence of additional chromosomal abnormalities decreased survival to 1.85 years (n=28). A different range of survival times occurred with patients that had <115,000 platelets. Their median survival based on Low/Int1 IPSS (n=20), <5% blasts (n=18) or isolated del(5q)(n=20) was only 0.68–0.84 years. Int2/High IPSS (n=64), >5% blasts (n=50) or additional chromosomal abnormalities (n=68) lowered survival to 0.44–0.49 years. Thus lower platelet counts in del(5q) MDS patients with favorable IPSS (median survival 0.84 years), <5% blasts (median survival 0.68 years) or isolated del(5q) (median survival 0.74 years) appear to have poor prognosis. No significant financial relationships to disclose.