The prognostic impact of loss of chromosome 7 material detected by fluorescence in situ hybridization (FISH) in myeloid malignancies.

BACKGROUND: Monosomy 7 (-7) or deletion in its long arm [del(7q)] is among the most common chromosomal abnormalities in myeloid malignancies. There are prognostic variations between -7 and del(7q) in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS).

AIM: To describe the clinical characteristics, response to treatment, and survival of patients with primary AML and MDS having -7 or del(7q) detected by fluorescence in situ hybridization (FISH).

PATIENTS AND METHODS: The study was conducted on 53 patients with primary AML and MDS. They were tested for chromosome 7 abnormality using FISH technique.

RESULTS: Thirty-one patients had chromosome 7 abnormality and 22 did not. Lower complete remission and higher death rates were observed in patients with -7 (47.6% and 62%, respectively) when compared to patients with del(7q) (70% and 40%, respectively) with no significant difference (p = 0.218 and 0.101, respectively). The median overall survival (OS) of patients with -7, del(7q) and normal chromosome 7 were 32.0, 43.0 and 50.0 months, respectively, with significant statistical difference (p = 0.001). This difference was evident between patients with -7 and those with normal chromosome 7 (p = 0.001), and less evident between patients with -7 and those with del(7q) (p = 0.021).

CONCLUSION: Chromosome 7 analysis has clear impact on the outcome of myeloid malignancies. The prognostic variations between -7 and del(7q) is attributed to multiple factors. Cases with del(7q) have better outcome than cases with -7. FISH provides a powerful tool for detecting and monitoring patients with chromosome 7 abnormalities.