title: Microsatellite instability & survival in patients with stage II/III colorectal carcinoma.
abstract: OBJECTIVE
  The two key aspects associated with the microsatellite instability (MSI) as genetic phenomenon in colorectal cancer (CRC) are better survival prognosis, and the varying response to 5-fluorouracil (5-FU)-based chemotherapy. This study was undertaken to measure the survival of surgically treated patients with stages II and III CRC based on the MSI status, the postoperative 5-FU treatment as well as clinical and histological data.
  
  
  METHODS
  A total of 125 consecutive patients with stages II and III (American Joint Committee on Cancer, AJCC staging) primary CRCs, were followed prospectively for a median time of 31 months (January 2006 to December 2009). All patients were assessed, operated and clinically followed. Tumour samples were obtained for cytopathological verification and MSI grading.
  
  
  RESULTS
  Of the 125 patients, 21 (20%) had high MSI (MSI-H), and 101 patients (80%) had MSI-L or MSS (low frequency MSI or stable MSI). Patients with MSS CRC were more likely to have recurrent disease (P=0.03; OR=3.2; CI 95% 1-10.2) compared to those with MSI-H CRC. Multi- and univariate Cox regression analysis failed to show a difference between MSI-H and MSS groups with respect to disease-free, disease-specific and overall survival. However, the disease-free survival was significantly lower in patients with MSI-H CRC treated by adjuvant 5-FU therapy (P=0.03).
  
  
  CONCLUSIONS
  MSI-H CRCs had a lower recurrence rate, but the prognosis was worse following adjuvant 5-FU therapy.
authors.affiliation: Center for Gastroenterology and Hepatology, Zvezdara University Clinical Center; School of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Markovic
authors.initials: M
authors.lastname: Srdjan
authors.affiliation: Genetic Laboratory, Institute for Endocrinology, Clinical Center of Serbia, Belgrade, Serbia.
authors.forename: Antic
authors.initials: A
authors.lastname: Jadranka
authors.affiliation: Center for Colorectal Surgery, Clinical Center of Serbia, Belgrade, Serbia.
authors.forename: Dimitrijevic
authors.initials: D
authors.lastname: Ivan
authors.affiliation: School of Medicine, University of Western Sydney, Campbelltown; New South Wales, Australia.
authors.forename: Zogovic
authors.initials: Z
authors.lastname: Branimir
authors.affiliation: Center for Gastroenterology and Hepatology, Zvezdara University Clinical Center; School of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Bojic
authors.initials: B
authors.lastname: Daniela
authors.affiliation: Center for Gastroenterology and Hepatology, Zvezdara University Clinical Center; School of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Svorcan
authors.initials: S
authors.lastname: Petar
authors.affiliation: Center for Colorectal Surgery, Clinical Center of Serbia; School of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Markovic
authors.initials: M
authors.lastname: Velimir
authors.affiliation: Genetic Laboratory, Institute for Endocrinology, Clinical Center of Serbia; School of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Krivokapic
authors.initials: K
authors.lastname: Zoran
mesh_terms: D000328:Adult; D000368:Aged; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000473:pathology; D018572:Disease-Free Survival; D005260:Female; D005472:Fluorouracil / Q000627:therapeutic use; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D053842:Microsatellite Instability / Q000187:drug effects*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000235:genetics* / Q000473:pathology; D011379:Prognosis; D016016:Proportional Hazards Models
chemical_list: D005472:Fluorouracil