title: Clinicopathological correlation of cell proliferation, apoptosis and p53 in cerebellar pilocytic astrocytomas.
abstract: We have analysed 78 cerebellar pilocytic astrocytomas to assess whether histopathology, cell proliferation, apoptosis rate, p53 immunoreactivity, or flow cytometry could predict their long-term behaviour. Classic pilocytic/microcystic pattern was seen in 62 patients and 16 patients had mixed pattern with an additional non-pilocytic glial component. The overall 5-year survival was 93%, complete resection providing 100% survival. The four patients who died during the follow-up were more than 14 years of age, their primary operation had been incomplete and three of them were mixed variants. In 15 cases the tumour recurred giving a recurrence-free 5-year survival of 77%. The proliferation indices were low: Ki-67MIB-1 (median 2.0%), PCNA (1.2%) and S-phase fraction (4.4%). The Ki-67MIB-1-labelling index was significantly higher in young patients, but did not differ between the classic and mixed variants. Twenty-two per cent of the tumours were aneuploid with a significantly higher S-phase fraction than in diploid tumours. p53 seems to act as ardian of the genome' in pilocytic astrocytomas, because aberrant/increased expression of p53 and aneuploidy associated with enhanced apoptosis. Only patient age (P = 0.01), radicality of the primary operation (P = 0.0001) and histology (classic vs mixed, P=0.008) significantly correlated with survival. The poorer prognosis of the mixed variant suggests that this may represent a distinct entity. Although none of the novel parameters significantly predicted recurrence or survival, they indicate substantial biological variation among cerebellar pilocytic astrocytomas.
authors.affiliation: Department of Pathology, Tampere University Hospital.
authors.forename: H
authors.initials: H
authors.lastname: Haapasalo
authors.forename: S
authors.initials: S
authors.lastname: Sallinen
authors.forename: P
authors.initials: P
authors.lastname: Sallinen
authors.forename: P
authors.initials: P
authors.lastname: Helén
authors.forename: J
authors.initials: J
authors.lastname: Jääskeläinen
authors.forename: T T
authors.initials: TT
authors.lastname: Salmi
authors.forename: A
authors.initials: A
authors.lastname: Paetau
authors.forename: L
authors.initials: L
authors.lastname: Paljärvi
authors.forename: T
authors.initials: T
authors.lastname: Visakorpi
authors.forename: H
authors.initials: H
authors.lastname: Kalimo
mesh_terms: D000293:Adolescent; D000328:Adult; D017209:Apoptosis / Q000502:physiology*; D001254:Astrocytoma / Q000737:chemistry / Q000401:mortality / Q000473:pathology*; D014408:Biomarkers, Tumor / Q000032:analysis*; D002455:Cell Division / Q000502:physiology; D002528:Cerebellar Neoplasms / Q000737:chemistry / Q000401:mortality / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000032:analysis*; D011003:Ploidies; D015996:Survival Rate; D016159:Tumor Suppressor Protein p53 / Q000032:analysis*
chemical_list: D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins; D016159:Tumor Suppressor Protein p53