title: Utility of Ki67 immunostaining in the grading of pineal parenchymal tumours: a multicentre study.
abstract: OBJECTIVE
  Pineal parenchymal tumours (PPTs) are rare neoplasms that are divided into pineocytoma (PC), pineoblastoma (PB) and PPT of intermediate differentiation (PPTID). Factors affecting the survival of patients with PPTs are morphological subtype and histological grading according to mitotic index and neurofilament immunostaining. Grading criteria to distinguish PPTIDs are difficult to define, particularly when using small specimens. The Ki67 labelling index (LI) might be helpful in distinguishing between grade II and III PPTIDs. Our study was performed to assess the predictive value of the Ki67 LI in a large cooperative series of PPTs and to evaluate whether inclusion of this data would improve and refine the World Health Organization classification.
  
  
  METHODS
  A retrospective analysis of 33 PPTs was performed. The histological features of the tumours were reviewed and Ki67 LI scoring was evaluated by immunohistochemistry. Data were correlated with the patients' survival.
  
  
  RESULTS
  The mean Ki67 LI was significantly different for tumour grades (0 in PC, 5.2 ± 0.4 in PPTID grade II, 11.2 ± 2.0 in PPTID grade III, 36.4 ± 6.2 in PB; P < 0.0001). However, there was no statistically significant difference in either overall or disease-free survival evaluated by the Kaplan-Meier method for patients with different grade tumours or Ki67 LI, possibly due to the different clinical management of patients in different centres.
  
  
  CONCLUSIONS
  The Ki67 LI may be a useful additional tool for grading PPTs, more particularly in small tumour samples.
authors.affiliation: Inserm U1028, Centre de Recherche en Neurosciences, Equipe Neurooncologie et Neuroinflammation, Université de Lyon, France.
authors.forename: M
authors.initials: M
authors.lastname: Fèvre-Montange
authors.forename: A
authors.initials: A
authors.lastname: Vasiljevic
authors.forename: D
authors.initials: D
authors.lastname: Frappaz
authors.forename: J
authors.initials: J
authors.lastname: Champier
authors.forename: A
authors.initials: A
authors.lastname: Szathmari
authors.forename: M-H
authors.initials: MH
authors.lastname: Aubriot Lorton
authors.forename: F
authors.initials: F
authors.lastname: Chapon
authors.forename: A
authors.initials: A
authors.lastname: Coulon
authors.forename: I
authors.initials: I
authors.lastname: Quintin Roué
authors.forename: M-B
authors.initials: MB
authors.lastname: Delisle
authors.forename: D
authors.initials: D
authors.lastname: Figarella-Branger
authors.forename: A
authors.initials: A
authors.lastname: Laquerrière
authors.forename: C
authors.initials: C
authors.lastname: Miquel
authors.forename: J-F
authors.initials: JF
authors.lastname: Michiels
authors.forename: M
authors.initials: M
authors.lastname: Péoch
authors.forename: M
authors.initials: M
authors.lastname: Polivka
authors.forename: F
authors.initials: F
authors.lastname: Fauchon
authors.forename: A
authors.initials: A
authors.lastname: Jouvet
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D001932:Brain Neoplasms / Q000378:metabolism / Q000401:mortality / Q000473:pathology*; D002648:Child; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D019394:Ki-67 Antigen / Q000032:analysis* / Q000096:biosynthesis; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading / Q000379:methods*; D010870:Pineal Gland / Q000378:metabolism / Q000473:pathology*; D010871:Pinealoma / Q000378:metabolism / Q000401:mortality / Q000473:pathology*; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen