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

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.

Mismatch Repair Proteins and Microsatellite Instability in Colorectal Carcinoma (MLH1, MSH2, MSH6 and PMS2): Histopathological and Immunohistochemical Study

“…On the contrary, Faghani et al [ 25 ] found that there was no a statistically significant correlation between MSI and patients’ age, this can be explained by that their study was designed to determine the correlation between MSI and sporadic cases only.…”

“…On the contrary, Faghani et al [ 25 ] found that 81.8% of total MSI-H had distal tumors. This is may be due to studyng only sporadic cases and analysis of MSI frequencies by testing the BAT-26 and BAT-25 markers.…”

Molecular Biomarkers of Colorectal Cancer: A Review of Published Articles From Iran

“…The basic tests identify five markers (NR-21, BAT-26, BA T -25, NR-27 and NR-24) to devise the simplest diagnostic assay (9). Previous reports have shown significant diversity regarding the most common marker for microsatellite testing; BAT 25, BAT26 and NR21 have been reported in HNPCC and sporadic CRCs (9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28). Table 1 shows the reports from Iran that studied the frequency of MMR genes in both hereditary and sporadic colorectal cancers.…”

“…Table 1 shows the reports from Iran that studied the frequency of MMR genes in both hereditary and sporadic colorectal cancers. As it shows, the frequency of MSI in patients with HNPCC has been 29% -62.5% (9-25), there are not so many studies about the frequency of MSI in sporadic CRC from Iran; however, the reported frequencies of MMR have been from 19.4% to 66.6% (9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25).…”

“…Roughly, 90% of the activating mutations that are influential solitary amino acid replacement in the GTPase pocket and guide a block of the activity of KRAS-p21 protein, are recognized in codons 12 (GGT) and 13 (GGC) of exon 1 and almost 5% in codon 61 (CAA) situated in exon 2. The most regularly found kinds of mutations are G > A and G > T transitions (21). KRAS testing has a vital improvement in the treatment of CRCs, especially after metastasis (19,20,22).…”