| Abstract: |
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. (C) 2000 American Cancer Society. |
| Keywords: |
adolescent; cancer survival; child; preschool child; school child; treatment outcome; child, preschool; disease-free survival; retrospective studies; major clinical study; cancer risk; chromosome; antineoplastic combined chemotherapy protocols; cohort analysis; cytogenetics; risk factor; acute lymphoblastic leukemia; childhood cancer; risk assessment; infant; lymphatic leukemia; chromosome aberrations; children; chromosome analysis; chromosome 12p; diploidy; chromosomes, human, pair 12; leukemia, lymphocytic, acute; chromosome disorders; humans; prognosis; human; male; female; priority journal; article; 12p
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