Gain of chromosome 7, as detected by in situ hybridization, strongly correlates with shorter survival in astrocytoma grade 2.
The clinical course of astrocytoma grade 2 (A2) is highly variable and is not reflected by morphological characteristics. Earlier studies using small series of A2 cases suggest that in situ hybridization (ISH) with chromosome-specific DNA probes allows for frequent detection of aneusomy 1, trisomy 7, and monosomy 10. The role of trisomy 7 in astrocytoma carcinogenesis is disputed, however, because of its presence in non-neoplastic brain tissue, as detected by karyotyping. Our objective was to investigate whether there was a correlation between chromosomal aberrations and survival in a series of 47 cases of A2. All cases were evaluated for numerical aberrations of chromosomes 1, 7, and 10 by ISH. Chromosomal aberrations were detected in 68% of cases of A2. Trisomy/polysomy 7 was seen in 31 cases (66%), 22 of which (47%) had a high percentage of this numerical aberration. Only 11 of these 22 cases also showed aneusomy for 1 or 10. No cells or only a few cells with aberrations were detected in non-neoplastic control samples. Using Kaplan-Meier analysis, trisomy/polysomy 7 correlated significantly with shorter survival. Hence, as determined by ISH, trisomy/polysomy 7 is absent in non-neoplastic brain tissue and is frequently detected in A2, correlating with the malignant progression of the disease.
Wessels
Peter H
PH
Department of Neurology, University Hospital Maastricht, Maastricht, Netherlands. PWES@SNEU.AZM.NL
Twijnstra
Albert
A
Kessels
Alfons G H
AG
Krijne-Kubat
Bela
B
Theunissen
Paul H
PH
Ummelen
Monique I J
MI
Ramaekers
Frans C S
FC
Hopman
Anton H
AH
D000328:Adult; D001254:Astrocytoma / Q000235:genetics* / Q000401:mortality* / Q000473:pathology; D001932:Brain Neoplasms / Q000235:genetics* / Q000401:mortality* / Q000473:pathology; D002869:Chromosome Aberrations; D002897:Chromosomes, Human, Pair 7 / Q000235:genetics*; D005784:Gene Amplification / Q000235:genetics*; D006801:Humans; D017403:In Situ Hybridization / Q000379:methods; D011379:Prognosis; D015996:Survival Rate