The 5q deletion syndrome is described as having a favourable outcome in MDS. However, little data is available concerning del(5q) and additional karyotype anomalies or taking into account bone marrow blast count. We screened the MDS registries of Düsseldorf, Germany and Lausanne, Switzerland in order to obtain data on patients with karyotype anomalies including del(5q). In both registries 1073 patients were karyotyped at diagnosis. 198 patients with del(5q) with or without other karyotype anomalies and 105 patients with complex karyotype anomalies without del(5q) were analysed. 106 patients showed del(5q) as single anomaly, 23 had 1 additional karyotype anomaly, 69 had 2 or more additional anomalies and were therefore classified as complex karyotype. In the group with del(5q) only, mean survival was 76 months as compared to 42 months in patients with a normal karyotype. In the group with 1 additional anomaly mean survival was 47 months (p=0.02), in the group with 2 or more additional anomalies 7 months (p=0.0005). Survival differed significantly in each subgroup when patients presenting less than 10% of bone marrow blasts where compared to patients with 10% or more. Patients with del(5q) only show a median survival of 12 months when presenting with more than 10% medullary blasts. Patients with a complex karyotype including del(5q) with less than 5% medullary blasts had a median survival of 12 months, but median survival was only 6 months in patients with elevated medullary blasts. By multivariate analyses, we found that additional karyotype anomalies, followed by an elevated medullary blast count above 10% are the most important independent prognostic parameters. Furthermore, we compared the subgroups with del(5q) and 2 or more additional karyotype anomalies (n=69) to patients with complex karyotype anomalies not including del(5q) (n=105). Median survival of the group with complex karyotype anomalies including del(5q) was 7 months as compared to 12 months in the group without del(5q) (p=0.02). 12 months after diagnosis, 30% of the group with del(5q) in a complex karyotype was alive as compared to 45% of the group with a complex karyotype without del(5q). Disease related death was noted in 77% of patients with a complex karyotype and del(5q) and 73% without del(5q). Therefore, our data show that the prognosis of survival in patients with del(5q) is highly dependent on the number of additional karyotype anomalies as well as medullary blast count. The prognosis of MDS patients with del(5q) is associated with an extremely poor prognosis when diagnosed within a complex karyotype. Although there are no substantial differences in clinical, haematological and morphological data between patients with or without del(5q), the median survival differs significantly.
Disclosure: No relevant conflicts of interest to declare.