Gut Liver.  2015 Sep;9(5):629-635. 10.5009/gnl15133.

Usefulness of Immunohistochemistry for Microsatellite Instability Screening in Gastric Cancer

• Bae YS
• Kim H
• Noh SH
• Kim H

• KMID: 2234069
• DOI: http://doi.org/10.5009/gnl15133

Abstract

BACKGROUND/AIMS
The usefulness of immunohistochemistry to screen for the microsatellite instability (MSI) phenotype in gastric cancer remains unclear. Moreover, the prognostic value of MSI phenotypes in gastric cancer has been debated.
METHODS
The clinicopathologic parameters and survival outcomes of 203 MSI-high (MSI-H) and 261 microsatellite-stable (MSS) advanced gastric cancers (AGCs) were compared. Next, we compared the immunohistochemistry results for hMLH1 and hMSH2 with those of a polymerase chain reaction (PCR)-based method. Kaplan-Meier curves and a Cox proportional hazard regression model were used to conduct survival analyses.
RESULTS
The MSI-H AGCs were correlated with older age (p<0.001), female gender (p=0.018), distal location (p<0.001), larger size (p=0.016), and intestinal type (p<0.001). Multivariate analysis revealed that the MSI-H phenotype was an independent favorable factor that was related to overall survival in patients with AGC (p<0.001). Compared with the PCR-based analysis, immunohistochemistry exhibited high sensitivity (91.1%) and specificity (98.5%) in the detection of MSI phenotypes.
CONCLUSIONS
MSI-H gastric cancers have distinct clinicopathologic features and better prognoses, which suggests the necessity of MSI analysis in gastric cancer. Immunohistochemistry can be a useful and reliable screening method in the assessment of MSI status in gastric cancer.

Keyword

Gastric cancer; Microsatellite instability; Immunohistochemistry; hMLH1; hMSH2

MeSH Terms

Adult
Aged
Aged, 80 and over
Female
Humans
Immunohistochemistry/*statistics & numerical data
Kaplan-Meier Estimate
Male
*Microsatellite Instability
Middle Aged
Phenotype
Polymerase Chain Reaction
Predictive Value of Tests
Prognosis
Proportional Hazards Models
Sensitivity and Specificity
Sex Factors
Stomach Neoplasms/*genetics/mortality