Prognostic significance of cytogenetic abnormalities of chromosome arm 12p in childhood acute lymphoblastic leukemia : A report from the Children's Cancer Group

✍ Scribed by Nyla A. Heerema; Harland N. Sather; Martha G. Sensel; Mei K. Lee; Raymond Hutchinson; James B. Nachman; Beverly J. Lange; Peter G. Steinherz; Bruce Bostrom; Paul S. Gaynon; Fatih M. Uckun

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 124 KB
• Volume: 88
• Category: Article
• ISSN: 0008-543X
• DOI: 10.1002/(sici)1097-0142(20000415)88:8<1945::aid-cncr25>3.0.co;2-6

✦ Synopsis

Background:

The authors have determined the prognostic significance of cytogenetically detectable 12p abnormalities, which are frequent in children with acute lymphoblastic leukemia (all), in a large cohort of patients treated on risk-adjusted protocols of the children's cancer group (ccg).

Methods:

The presence of an abnormal 12p was identified among 1880 children with newly diagnosed all; outcome was assessed by standard life table methods.

Results:

A total of 174 cases (9%) had cytogenetically detectable 12p abnormalities; the majority of cases had a balanced translocation, a del(12p), or an add(12p). in the overall cohort, event free survival (efs) at 6 years was similar for patients with or without a 12p abnormality (76%, sd = 6%, vs. 75%, sd = 2%, respectively; p = 0.60). among patients with pseudodiploidy, an abnormal 12p conferred improved outcome (p = 0.008; relative risk = 0.51; 95% confidence interval [ci], 0.31-0.85). there was a trend for improved efs for those with abnormalities in both chromosome 12 homologues (p = 0.16; relative risk = 0.39; 95% ci, 0.10-1.55) and those with low hyperdiploidy (p = 0.07; relative risk = 0.44; 95% ci, 0.18-1.09). among t-lineage all patients, there was a trend for worse outcome for abnormal versus normal 12p (p = 0.14; relative risk = 1.97; 95% ci, 0.78-4.93). there was no difference in efs for the 12 patients with a dic(9;12) compared with patients lacking an abnormal 12p.

Conclusions:

These data suggest that although a cytogenetically detectable 12p aberration is a favorable risk factor for children with all and pseudodiploidy, it is not prognostic for the overall group of pediatric all patients treated with contemporary therapies of the ccg.