Sole abnormalities of chromosome 7 in myeloid malignancies: Spectrum, histopathologic correlates, and prognostic implications

Among 6,565 consecutive abnormal cytogenetic reports at our institution, 3,192 (49%) constituted sole abnormalities, of which 230 (7%) involved chromosome 7: monosomy 7 (n = 98), 7q- (n = 51), der(1;7)(q10;p10) (n = 44), balanced translocations (n = 15), ring 7 (n = 13), and 7p- (n = 9). The most frequent histopathologic correlates were myelodysplastic syndromes (MDS; 28%), acute myeloid leukemia (AML; 17%), secondary or therapy-related MDS/AML (13%), primary myelofibrosis (PMF; 7%), and chronic myelomonocytic leukemia (6%). Monosomy 7 was the most frequent in each one of these disease categories except PMF where 7q- was more frequent. In primary MDS, patients with der(1;7)(q10;p10) (n = 13), compared to those with monosomy 7 (n = 30) or 7q- (n = 15), were less likely (P = 0.04) to display excess blasts or multilineage dysplasia but overall and leukemia-free survival adjusted for these variables revealed no significant difference between the three groups (P = 0.57 and 0.81, respectively). The current study does not prognostically distinguish monosomy 7 from 7q- or der(1;7), in MDS.