Gut Liver.  2016 Sep;10(5):781-785. 10.5009/gnl15376.

Microsatellite Instability Status of Interval Colorectal Cancers in a Korean Population

• Lee KW
• Park SK
• Yang HJ
• Jung YS
• Choi KY
• Kim KE
• Jung KU
• Kim HO
• Kim H
• Chun HK
• Park DI

• KMID: 2412076
• DOI: http://doi.org/10.5009/gnl15376

Abstract

BACKGROUND/AIMS
A subset of patients may develop colorectal cancer after a colonoscopy that is negative for malignancy. These missed or de novo lesions are referred to as interval cancers. The aim of this study was to determine whether interval colon cancers are more likely to result from the loss of function of mismatch repair genes than sporadic cancers and to demonstrate microsatellite instability (MSI).
METHODS
Interval cancer was defined as a cancer that was diagnosed within 5 years of a negative colonoscopy. Among the patients who underwent an operation for colorectal cancer from January 2013 to December 2014, archived cancer specimens were evaluated for MSI by sequencing microsatellite loci.
RESULTS
Of the 286 colon cancers diagnosed during the study period, 25 (8.7%) represented interval cancer. MSI was found in eight of the 25 patients (32%) that presented interval cancers compared with 22 of the 261 patients (8.4%) that presented sporadic cancers (p=0.002). In the multivariable logistic regression model, MSI was associated with interval cancer (OR, 3.91; 95% confidence interval, 1.38 to 11.05).
CONCLUSIONS
Interval cancers were approximately four times more likely to show high MSI than sporadic cancers. Our findings indicate that certain interval cancers may occur because of distinct biological features.

Keyword

Colorectal neoplasms; Microsatellite instability; Colonoscopy

MeSH Terms

Aged
Colonoscopy
Colorectal Neoplasms/diagnosis/*genetics
DNA Mismatch Repair/*genetics
Female
Humans
Male
*Microsatellite Instability
Middle Aged
Republic of Korea