title: Prognosis of gastrointestinal stromal tumors.
abstract: OBJECTIVE
  Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors (GIMT) of the gut. The aim of this retrospective study is to correlate the histological risk factors with the survival of our patients operated for GIST.
  
  
  METHODS
  In our department, from 1980 to October 2003, 15 patients were operated for GIST. Their mean age was 58 years old and 8 of them were males; 10 (67%) were localized in the stomach and 5 (33%) in the small bowel. In 7 cases liver metastases were present at laparotomy and 4 of them also had peritoneal diffusion. We performed immunohistochemistry for c-Kit, SMA and S100p. Mitotic index (MI) and size neoplasm were the main pathological criteria for malignity. The patients with c-kit (CD117) positive neoplasms were divided according to NIH Consensus Conference risk class, MI, tumor size, localization, SMA or S100p presence, liver metastasis and peritoneal metastasis to compare the different 5-year survival rates. Survival analysis was performed using Kaplan-Meier method and log-rank test and a p < 0.05 was considered as significant.
  
  
  RESULTS
  Global survival rate after 5 years was 40% and the mortality was, in all cases, due to GIST. In our experience gender, age, tumor size, localization and S100p positivity did not play any role in predicting the prognosis of GIST. On the contrary high MI and SMA positivity are significantly associated to a lower survival rate (33% vs. 86% and 39% vs. 100% at 5 years, respectively). Finally patients with metastases at laparotomy have a significantly lower 5-year survival rate (hepatic 29% vs. 100%, hepatic and peritoneal 25% us. 78%).
  
  
  CONCLUSIONS
  In our experience high MI and in some cases SMA expression can be considered assessed risk factors. On the other hand, criteria of benign behavior did not completely predict the long-term clinical outcome.
authors.affiliation: Department of Surgical and Gastroenterological Science, University of Padua, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Bertin
authors.forename: Imerio
authors.initials: I
authors.lastname: Angriman
authors.forename: Marco
authors.initials: M
authors.lastname: Scarpa
authors.forename: Roberto
authors.initials: R
authors.lastname: Mencarelli
authors.forename: Riccardo
authors.initials: R
authors.lastname: Ranzato
authors.forename: Cesare
authors.initials: C
authors.lastname: Ruffolo
authors.forename: Lino
authors.initials: L
authors.lastname: Polese
authors.forename: Maurizio
authors.initials: M
authors.lastname: Iacobone
authors.forename: Davide F
authors.initials: DF
authors.lastname: D'Amico
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000378:metabolism / Q000401:mortality*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D008940:Mitotic Index; D011379:Prognosis; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism; D012189:Retrospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity; D016019:Survival Analysis
chemical_list: D019009:Proto-Oncogene Proteins c-kit