title: High Wilms' tumour gene (WT1) expression and low mitotic count are independent predictors of survival in diffuse peritoneal mesothelioma.
abstract: OBJECTIVE
  To evaluate the use of the Wilms' tumour gene (WT1) marker and histomorphological parameters as indicators of prognosis in malignant peritoneal mesothelioma (MPM).
  
  
  RESULTS
  Histological samples of 31 MPM were stained immunohistochemically for the WT1 protein. The results were quantified by recording the number of stained nuclei, and then correlated with patient survival. Statistical correlation was evaluated for tumour histotype, mitotic count (MC), nuclear grade (NG), necrosis, lymphoid response (grade of inflammation) and desmoplasia with regard to survival. High-grade histology (solid epithelioid, pure sarcomatoid or biphasic tumours), high NG, MC more than five per 10 per high-power field (HPF), necrosis and desmoplasia were associated with a significantly worse prognosis. Patients with MPM with low WT1 expression (≤25% of positive cells) survived for a significantly shorter time compared to those with high WT1 expression (>25% of positive cells) (P = 0.0001). The 50% survival time of subjects with low WT1 expression was 2.9 months [95% confidence interval (CI): 2.05-3.71] versus 31.5 months (95% CI: 20.4-42.5) for those with high WT1 expression. On multivariate analysis, WT1 and MC were found to be associated independently with survival (P = 0.002; P = 0.005, respectively).
  
  
  CONCLUSIONS
  Our study suggests that low WT1 expression and high MC may be indicative of an unfavourable prognosis in patients with advanced malignant peritoneal mesothelioma.
authors.affiliation: Department of Pathology, Di Venere Hospital, Carbonara, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Scattone
authors.forename: Gabriella
authors.initials: G
authors.lastname: Serio
authors.forename: Andrea
authors.initials: A
authors.lastname: Marzullo
authors.forename: Pietro
authors.initials: P
authors.lastname: Nazzaro
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Corsi
authors.forename: Maria Pia
authors.initials: MP
authors.lastname: Cocca
authors.forename: Marilena
authors.initials: M
authors.lastname: Mattoni
authors.forename: Alessandra
authors.initials: A
authors.lastname: Punzi
authors.forename: Mattia
authors.initials: M
authors.lastname: Gentile
authors.forename: Antonia Lucia
authors.initials: AL
authors.lastname: Buonadonna
authors.forename: Antonio
authors.initials: A
authors.lastname: Pennella
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism; D002452:Cell Count; D002467:Cell Nucleus / Q000378:metabolism / Q000473:pathology; D005260:Female; D016162:Genes, Wilms Tumor; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008654:Mesothelioma / Q000378:metabolism / Q000401:mortality / Q000473:pathology*; D008875:Middle Aged; D008940:Mitotic Index; D009336:Necrosis; D010534:Peritoneal Neoplasms / Q000378:metabolism / Q000401:mortality / Q000473:pathology*; D011237:Predictive Value of Tests; D015996:Survival Rate; D025721:WT1 Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D025721:WT1 Proteins