The Correlation between Microsatellite Instability and the Features of Sporadic Colorectal Cancer in the North Part of Iran

Masoumeh Faghani,Fariborz Mansour-Ghanaei,Keyvan Aminian,Alireza Tarang,Azadeh Javadi,Saba Fakhrieh Asl,Ramin Seighalani

doi:10.1155/2012/756263

Abstract

Background. The aim of this study was to determine the correlation between MSI and sporadic colorectal cancer in Guilan province, North part of Iran. Materials and Methods. A total of 96 patients who underwent resection for sporadic colorectal cancer in Guilan province were studied. No patients had positive family history of cancers. The frequencies of MSI were analyzed by testing the BAT-26 and BAT-25 markers. Results. MSI analysis revealed that 22.9% of the tumors (22 patients) were microsatellite instability positive and 77.1% (74 patients) were microsatellite instability negative. The highest rate of MSI (40.9%) was found in the rectal region. MSI-H status was seen more frequently in distal tumors (P = 0.04, odds ratio = 3.13, 0.96–10.14). Conclusions. Distal tumor location and MSI may associate with special clinicopathological features. It seems that there may be correlation with underlying genetic and immunologic mechanisms.

Highlights

Colorectal cancer (CRC) is one of the major public health problems in the world
Data analysis revealed 64.5% of sporadic CRCs samples located in distal or left colic (Table 3)
Microsatellites are repeated sequences that are highly susceptible to misalignment during replication, resulting in a 100-fold increase in their mutation rate [18]. These noncoding mono- and dinucleotide repeats are scattered in the genome, accumulate alterations in mismatch repair (MMR)-deficient tumors, and are used to assess the MSI phenotype [19]

Summary

Introduction

Colorectal cancer (CRC) is one of the major public health problems in the world. CRC is one of the most common forms of cancer in western countries [1] and is the third most common cancer in males and the second in females [2]. Most of CRCs are sporadic, but 5% to 10% of colorectal cancers are associated with a primary genetic factor [5, 6]. Hereditary nonpolyposis colorectal cancer (HNPCC), the most common syndrome, is secondary to an inherited mutation in one of the DNA mismatch repair (MMR) genes (hMLH1, hMSH2, hMSH6, and hPMS2). The aim of this study was to determine the correlation between MSI and sporadic colorectal cancer in Guilan province, North part of Iran. A total of 96 patients who underwent resection for sporadic colorectal cancer in Guilan province were studied. Distal tumor location and MSI may associate with special clinicopathological features. It seems that there may be correlation with underlying genetic and immunologic mechanisms

Objectives

Methods

Results

Conclusion