title: Molecular key to understand the gastric cancer biology in elderly patients-The role of microsatellite instability.
abstract: OBJECTIVE
  Microsatellite instability (MSI) in gastric cancer (GC) is associated with older age. We present the clinicopathological results of younger and older patients with MSI GC.
  
  
  METHODS
  We analyzed 472 patients with GC. MSI analysis was done on fresh frozen tissue using five quasimonomorphic mononucleotide repeats: NR-21, NR-24, NR-27, BAT-25, and BAR-26. Clinical and pathological analysis was performed for different age groups.
  
  
  RESULTS
  We observed better survival in elderly MSI GC patients compared to younger patients. The percentage of MSI GC increases gradually with increasing age, accounting for 48% of patients over the age of 85 years. A difference in survival was seen between MSI and MSS groups of patients older than 65 years, while no statistical difference was seen for younger groups. Multivariate analysis revealed that MSI status has a significant prognostic factor in patients aged over 70 years (MSS vs. MSI; HR 1.82, P = 0.013).
  
  
  CONCLUSIONS
  MSI is an important prognostic factor above all in elderly GC patients. It is associated with favorable prognosis and may help in planning different approaches to treatment in this subgroup. J. Surg. Oncol. 2017;115:344-350. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of General Surgery and Surgical Oncology, University of Siena, Siena, Italy.
authors.forename: Karol
authors.initials: K
authors.lastname: Polom
authors.affiliation: Department of General Surgery and Surgical Oncology, University of Siena, Siena, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Marrelli
authors.affiliation: Department of Molecular and Translational Medicine, Section of Pharmacology and University Center DIFF-Drug Innovation Forward Future, University of Brescia, Brescia, Italy.
authors.forename: Giandomenico
authors.initials: G
authors.lastname: Roviello
authors.affiliation: Department of General Surgery and Surgical Oncology, University of Siena, Siena, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Pascale
authors.affiliation: Department of General Surgery and Surgical Oncology, University of Siena, Siena, Italy.
authors.forename: Costantino
authors.initials: C
authors.lastname: Voglino
authors.affiliation: University of Medical Sciences, Poznan, Poland.
authors.forename: Henry
authors.initials: H
authors.lastname: Rho
authors.affiliation: Department of Medicine, Surgery and Neurosciences, Unit of Endoscopy and Gastroenterology, University of Siena, Siena, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Marini
authors.affiliation: Department of Medicine, Surgery and Neurosciences, Unit of Endoscopy and Gastroenterology, University of Siena, Siena, Italy.
authors.forename: Raffaele
authors.initials: R
authors.lastname: Macchiarelli
authors.affiliation: Department of General Surgery and Surgical Oncology, University of Siena, Siena, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Roviello
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D053842:Microsatellite Instability; D008875:Middle Aged; D013274:Stomach Neoplasms / Q000235:genetics* / Q000473:pathology
keywords: age; stomach cancer; treatment