Survival Analysis of Myelodysplastic Syndrome (MDS) Patients with Abnormal Karyotype - A Single Group Experience

MDS are a heterogeneous group of hematologic disorders associated with clonal evolution of abnormal erythroid, myeloid and megakaryocytic lineages. Risk of transformation to acute myeloid leukemia (AML) is determined by IPSS score. Common chromosomal aberrations include abnormalities of 5, 7, 8, 20 and Y. The present survival analysis is unique in that only one team of experts was involved in diagnosis and management of these patients over more than two decades.

Data of patients with abnormal karyotype either at first presentation or during the course of MDS was collected retroactively. FAB, IPSS and WHO classification were used. Dates of death were retrieved from social security death index. Statistical analyses were performed by using SPSS version 18.

Of 709 patients with abnormal karyotypes, 292(41%) were classified as RA (or refractory cytopenias), 80 (11%) RARS, 253(36%) RAEB, 45(6%) CMMoL and 34(5%) RAEB-t and 5 (1%) were unclassified. There were 271 (37%) females and 438 (63%) males with a median age of 67 yrs and 68 yrs respectively. The most frequent abnormalities affected chromosome 5 (279 or 40%); del5q/-5 with other changes was seen in 233 (83. 5 %) and isolated del5q/-5 in 79 (28. 3%). Chromosome 7 abnormalities were found in 181 (25. 5%) patients with 38 (21%) having isolated del7q/-7. Chromosomal 8 abnormality was seen in 174 (24. 5%) patients and 71 (41%) had isolated trisomy 8. Other frequently involved chromosomes were 20 and Y affecting 158 (22. 3%) and 55 (7. 8%) patients respectively. Complex karyotype with 3 or more chromosomal aberrations was seen in 201 (28. 3%) patients.

Data on 700 patients was available for analysis when all chromosomal aberrations were considered according to various IPSS risk categories. The median survival was 73 months for low risk (74 patients), 33. 7 months for int-1 (303 patients), 13 months for int-2 (227 patients) and 11. 5 months for high risk (96 patients) (p=0. 000) groups.

By cytogenetic abnormalities, the best median survival of 82 months (39/229) was seen in patients with del5q/-5 and low risk disease. Other risk groups with de5q/-5 showed 32, 11 and 9 months in int-1, int-2 and high risk disease respectively (p=<0. 05). The worst median survival was in patients with high risk disease and del7q/-7 (7. 4 months, 33/127) and in patients with complex karyotype (8 months, 55/197).

Deletion 5q patients show the best median survival among low and int-1 risk groups. Our data show considerable improvement in median survival of high risk patients compared to the earlier reported survival (11. 5 versus 4 months) which probably reflects improvement due to the use of hypomethylating agents. This improvement in survival gains more significance when considering the fact that we have used the data of only those patients with chromosomal aberrations.

No relevant conflicts of interest to declare.