In the cytogenetic analysis of patients with myeloid malignancies, chromosome 7 abnormalities have an important impact on disease pathogenesis, treatment, response and prognosis. The most common chromosomal abnormalities in myeloid malignancies are monosomy 7 (-7), deletion of its long arm [del(7q)], and interstitial deletion of chromosome 7.
Chromosome 7 analysis is a major clinical determinant in myeloid malignancies with varying prognoses. The prognostic factors for -7 and del(7q) are not well established; however, several studies show that patients with -7 and del(7q) have worse survival than those without these chromosomal abnormalities.
7del can be detected by conventional cytogenetics or by interphase fluorescence in situ hybridization (FISH). FISH is a sensitive and useful tool for the detection of chromosome 7 abnormalities in adult myeloid malignancies, but it should not be used as a primary screening test for chromosomal abnormalities.
FISH-detected cytogenetic abnormalities are associated with a poor prognosis in AML and MDS. This study aimed to analyze the clinical characteristics, treatment response and overall survival of patients with primary AML and MDS who had -7 or del(7q) detected by FISH.
The study included 53 patients with primary AML and MDS who were cytogenetically abnormal by interphase fluorescence in situ hybridization. Among them, 31 patients were found to have a chromosome 7 abnormality. Among them, 21 patients had monosomy 7 and 10 patients had del(7q).
The study revealed that CR was achieved in the patients with -7 but not with del(7q) and that a higher rate of death was observed in the -7 group when compared to the del(7q) group. The study also revealed that splenomegaly, lymphadenopathy and hemoglobin levels were not significantly different between the -7 and del(7q) groups.