Polysomy of chromosomes 1 and/or 19 is common and associated with less favorable clinical outcome in oligodendrogliomas: fluorescent in situ hybridization analysis of 84 consecutive cases.
It is well established that the combined del(1)(p36) and del(19)(q13) is a positive prognostic molecular event in oligodendroglial tumors. However, very little is known about the frequency or impact of polysomy status for chromosomes 1/19. We examined 84consecutive pure oligodendrogliomas (68 World Health Organization [WHO] grade II and 16 WHO grade III) and analyzed them for del(1)(p36) and del(19)(q13) by fluorescent in situ hybridization. Polysomy status was recorded with accompanying deletion status, WHO grade, recurrence-free survival, and overall survival. Codeletion of 1p/19q was detected in 48% of cases and correlated with superior patient survival (p < 0.01), as expected. Of 84 cases, 36 (43%) showed polysomy of chromosome 1, 30 (36%) demonstrated polysomy of chromosome 19, and 28 (33%) had copolysomies of chromosomes 1/19. The presence of polysomy of either/or both chromosomes, regardless of deletion status, correlated with younger patient age at initial diagnosis (p < 0.01). Combined polysomy was associated with higher histologic tumor grade (p = 0.04) and conferred poor survival likelihood (p = 0.03). We conclude that polysomy of 1 and/or 19 is a relatively frequent occurrence in oligodendrogliomas and usually confers an unfavorable outcome.
Department of Pathology, and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, Indiana 46202-4108, USA.
Andrea L
AL
Wiens
Liang
L
Cheng
Elizabeth C
EC
Bertsch
Karen A
KA
Johnson
Shaobo
S
Zhang
Eyas M
EM
Hattab
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001932:Brain Neoplasms / Q000175:diagnosis / Q000235:genetics* / Q000401:mortality; D002648:Child; D002869:Chromosome Aberrations; D002872:Chromosome Deletion; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics*; D002888:Chromosomes, Human, Pair 19 / Q000235:genetics*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009837:Oligodendroglioma / Q000175:diagnosis / Q000235:genetics* / Q000401:mortality; D012189:Retrospective Studies; D012737:Sex Factors; D016019:Survival Analysis; D055815:Young Adult