title: The cyclin-dependent kinase inhibitor, p27, has no correlation with the malignant potential of GIST.
abstract: BACKGROUND
  Tumor size and mitotic activity are characteristically associated with the malignant potential and prognosis of gastrointestinal stromal tumors (GIST). However, since neither small tumor size nor low mitotic activity can rule out malignancy, additional factors that may predict malignant behavior have been suggested.
  
  
  OBJECTIVE
  To evaluate the correlation between the cyclin-dependent kinase inhibitor (CDI), p27kip1, expression and the malignant potential of GIST.
  
  
  METHODS
  Serial sections were evaluated by immunohistochemistry after staining with antibodies against p27/Kip1 and Ki-67 in surgical material obtained from 36 patients with GIST. p27kip1 staining intensity and the percentage of positive cells were investigated for association with the malignancy risk, pathological features, overall survival, and disease-free survival. Histologic grade was assigned by spindle vs. epithelioid cell histology, mucosal invasion, tumor cell necrosis or atypia and the number of mitoses.
  
  
  RESULTS
  In the multivariate model, p27kip1 expression was not significantly associated with any of the variables examined except Kit protein-CD117 (r = 0.37, p = 0.03). Comparative evaluation of p27kip1 expression in GIST cells revealed higher levels of p27kip1 in patients who died compared to those who survived (2.04 +/- 0.54 vs. 1.3 +/- 0.99, p = 0.1).
  
  
  CONCLUSIONS
  The CDI p27kip1 was not associated with malignancy of GISTs and did not serve as a predictor of survival.
authors.affiliation: Department of Gastroenterology, The E. Wolfson Medical Center, Holon, Israel. shirin@wolfson.health.gov.il
authors.forename: Haim
authors.initials: H
authors.lastname: Shirin
authors.forename: Vladimir
authors.initials: V
authors.lastname: Kravtsov
authors.forename: Mark
authors.initials: M
authors.lastname: Shahmurov
authors.forename: Vered Sehayek
authors.initials: VS
authors.lastname: Shabat
authors.forename: Ivgeni
authors.initials: I
authors.lastname: Krinshpon
authors.forename: Avi
authors.initials: A
authors.lastname: Alin
authors.forename: Ilana
authors.initials: I
authors.lastname: Avinoach
authors.forename: Yona
authors.initials: Y
authors.lastname: Avni
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000032:analysis*; D018572:Disease-Free Survival; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000032:analysis; D008297:Male; D008875:Middle Aged; D008938:Mitosis; D011379:Prognosis; D047428:Protein Kinase Inhibitors / Q000032:analysis*; D015996:Survival Rate
chemical_list: D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen; D047428:Protein Kinase Inhibitors; D050760:Cyclin-Dependent Kinase Inhibitor p27