title: Prognostic significance of Ki67 expression in malignant peritoneal mesothelioma.
abstract: OBJECTIVE
  Although Ki67 measurement by immunohistochemistry has been widely used as a prognostic index in cancers, it has not been reported in malignant peritoneal mesothelioma (MPM). Hence, this study examines the prognostic significance of Ki67 in MPM.
  
  
  METHODS
  Specimens from 42 MPM patients were screened for Ki67 expression using immunohistochemistry. Ki67 expression was classified into 2 groups on the basis of expression (<25%=low; ≥25%=high) using standard methods. Using Kaplan-Meier survival analysis, the significance of Ki67 was assessed in different clinicopathologic categories.
  
  
  RESULTS
  High expression of Ki67 (≥25% by immunohistochemical evaluation) was correlated with poor survival in the overall group (P=0.001); male sex (P=0.001); female sex (P=0.001); epithelioid tumors (P=0.001): male epithelioid (P=0.001), female epithelioid (P=0.003); peritoneal cancer index (PCI): PCI<20 (P=0.001), PCI≥20 (P=0.002); and age at diagnosis (AAD): AAD<60 years (P=0.001), AAD≥60 years (P=0.004). Independent of Ki67, male sex (P=0.007), sarcomatoid histology (P=0.001), PCI≥20 (P=0.013), and AAD≥60 years (P=0.004) correlated with poor survival. Multivariate analysis showed that only AAD≥60 years (P=0.049) and high Ki67 expression for all tumors (P=0.031), male sex (P=0.038), female sex (P=0.021), epithelioid tumors (P=0.044), and AAD<60 years (P=0.029) were statistically significant.
  
  
  CONCLUSIONS
  Ki67 expression affects prognosis in MPM patients and helps to predict survival within the various clinicopathologic categories.
authors.affiliation: Department of Surgery, St. George Hospital, University of New South Wales, Kogarah, NSW, Australia.
authors.forename: Krishna
authors.initials: K
authors.lastname: Pillai
authors.forename: Mohammad H
authors.initials: MH
authors.lastname: Pourgholami
authors.forename: Terence C
authors.initials: TC
authors.lastname: Chua
authors.forename: David L
authors.initials: DL
authors.lastname: Morris
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002945:Cisplatin / Q000008:administration & dosage; D065426:Cytoreduction Surgical Procedures; D004317:Doxorubicin / Q000008:administration & dosage; D005260:Female; D006801:Humans; D006979:Hyperthermia, Induced / Q000379:methods; D007150:Immunohistochemistry; D007263:Infusions, Parenteral; D053208:Kaplan-Meier Estimate; D019394:Ki-67 Antigen / Q000378:metabolism*; D008175:Lung Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000628:therapy; D008297:Male; D008654:Mesothelioma / Q000378:metabolism* / Q000401:mortality / Q000628:therapy; D000086002:Mesothelioma, Malignant; D008875:Middle Aged; D010534:Peritoneal Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000628:therapy; D011379:Prognosis; D055815:Young Adult
chemical_list: D019394:Ki-67 Antigen; D004317:Doxorubicin; D002945:Cisplatin