Chromosome abnormalities in secondary myelodysplastic syndromes

Specific chromosome abnormalities occur in most cases of secondary myelodysplastic syndromes (MDS), broadly defined to include acute nonlymphocytic leukaemia (ANLL). To explore their relation with the type of prior cancer and its treatment, and their use in predicting response of the secondary MDS to therapy, 216 patients from the literature were analyzed. Abnormal karyotypes were grouped into 10 nonoverlapping categories, depending first upon the presence of abnormalities of chromosomes 5 and 7 (‐5, 5q‐, ‐7, 7q‐), then upon specific rearrangements seen in de novo ANLL, and finally upon other structural or numerical abnormalities. Karyotype correlated with type of prior cancer (p = .002). ‐5, ‐7 and additional whole chromosomes were associated primarily (67–86 %) with prior haematologic malignancies, and the specific rearrangements and 5q‐ groups (70–71 %) with prior solid tumors. Karyotype also correlated with prior therapy (p = .0009). ‐5, ‐7 and 7q‐ were highly (> 85 %) associated with chemotherapy (alone or with radiotherapy); the 5q‐, specific rearrangements, normal, and “other” structural abnormalities groups were often (29–60 %) associated with radiotherapy alone. Finally, karyotype also predicted achievement of complete remission (CR); 5q‐ and ‐5 were associated with the lowest CR rate (13 %), specific rearrangements and other structural abnormalities with the highest (65 %). Prospective studies are required to determine if karyotype is an independent risk factor.