Cyclooxygenase-2 in oligodendroglial neoplasms.
BACKGROUND
Although increased expression of cyclooxygenase-2 (COX-2) has been described in association with a variety of neoplasms, including tumors of astrocytic derivation, limited data are available on COX-2 expression in oligodendrogliomas.


METHODS
The current study retrospectively reviewed 53 oligodendrogliomas and 7 oligodendroglioma-predominant oligoastrocytomas (mixed gliomas) for COX-2 expression and MIB-1 proliferative index (by immunohistochemistry) and for chromosome 1p status (by fluorescence in situ hybridization).


RESULTS
Patients included 35 males and 25 females, with a mean age of 41 years (range, 12-73 years) at the time of surgery. Forty-four tumor specimens were classified as World Health Organization (WHO) Grade II neoplasms and 16 as WHO Grade III tumors. MIB-1 labeling indices (marker of cell proliferation) ranged from 0 to 22.3 (mean 4.5). Twenty-eight tumor specimens demonstrated allelic loss on chromosome 1p. Positive staining was observed in 17 tumor specimens with COX-2 antibody. COX-2-positive tumor specimens were also evaluated with CD68 (macrophage/microglial cell marker) by coimmunolabeling to confirm that the observed COX-2 immunostaining was not due to immunoreactive macrophages or microglial cells. COX-2 expression, lack of allelic loss at chromosome 1p, and high proliferation indices were associated with decreased survival (P = 0.002, P = 0.009, and P = 0.015, respectively). No correlation with outcome was found with patient gender, age at diagnosis, or histologic grade.


CONCLUSIONS
Chromosome 1p, COX-2 immunoreactivity, and MIB-1 labeling indices correlated with outcome and were associated with decreased survival. There was not a one-to-one correspondence between COX-2 immunoreactivity and lack of allelic loss at chromosome 1p. Tumors with expression of COX-2 by immunohistochemistry may, in theory, benefit from treatment with therapeutic agents that inhibit COX-2.
D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D014408:Biomarkers, Tumor / Q000032:analysis*; D001707:Biopsy, Needle; D001932:Brain Neoplasms / Q000201:enzymology* / Q000401:mortality / Q000473:pathology; D002648:Child; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009837:Oligodendroglioma / Q000201:enzymology* / Q000401:mortality / Q000473:pathology; D011336:Probability; D011379:Prognosis; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics / Q000378:metabolism*; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D016019:Survival Analysis; D013997:Time Factors
D014408:Biomarkers, Tumor; D011451:Prostaglandin-Endoperoxide Synthases