Loss of heterozygosity 1p36 and 19q13 is a prognostic factor for overall survival in patients with diffuse WHO grade 2 gliomas treated without chemotherapy.
OBJECTIVE
This study was conducted to elucidate the impact of loss of heterozygosity (LOH) for chromosomes 1p36 and 19q13 on the overall survival of patients with diffusely infiltrating WHO grade 2 gliomas treated without chemotherapy.


METHODS
We assessed the LOH status of tumors from patients harboring WHO grade 2 gliomas diagnosed between 1991 and 2000. Patients were either followed after initial biopsy or treated by surgery and/or radiation therapy (RT). Overall survival, time to malignant transformation, and progression-free survival were last updated as of March 2005.


RESULTS
Of a total of 79 patients, LOH 1p36 and LOH 19q13 could be assessed in 67 and 66 patients, respectively. The median follow-up after diagnosis was 6 years. Loss of either 1p or 19q, in particular codeletion(s) at both loci, was found to positively impact on both overall survival (log-rank P < .01), progression-free survival, and survival without malignant transformation (P < .05). Tumor volume (P < .0001), neurologic deficits at diagnosis (P < .01), involvement of more than one lobe (P < .01), and absence of an oligodendroglial component (P < .05) were also predictors of shorter overall survival. The extent of surgery was similar in patients with or without LOH 1p and/or 19q; RT was more frequently resorted to for patients without than for patients with LOH 1p/19q (30% v 60%).


CONCLUSIONS
The presence of LOH on either 1p36 or 19q13, and in particular codeletion of both loci is a strong, nontreatment-related, prognostic factor for overall survival in patients with diffusely infiltrating WHO grade 2 gliomas.
Mariani
Luigi
L
Klinik für Neurochirurgie, Universitätsspital Inselspital, CH-3010 Bern, Switzerland. luigi.mariani@insel.ch
Deiana
Gianluca
G
Vassella
Erik
E
Fathi
Ali-Reza
AR
Murtin
Christine
C
Arnold
Marlène
M
Vajtai
Istvan
I
Weis
Joachim
J
Siegenthaler
Peter
P
Schobesberger
Martina
M
Reinert
Michael M
MM
D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000235:genetics* / Q000473:pathology / Q000628:therapy; D002878:Chromosomes, Human, Pair 1; D002888:Chromosomes, Human, Pair 19; D005260:Female; D005500:Follow-Up Studies; D005910:Glioma / Q000235:genetics* / Q000473:pathology / Q000628:therapy; D006801:Humans; D019656:Loss of Heterozygosity; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016019:Survival Analysis