P5 Putra et al.

Comparasion Microsatellite Instability And Variation Mismatch Repair Protein Expression In Colorectal Cancer

Teguh Pribadi Putra [1,2]; Santoso Cornain [1,2]; Ening Krisnuhoni [1]; Ria Kodariah [1]; Ahmad Rusdan Utomo [2]

[1] Master Program in Biomedical Sciences, Faculty of medicine University of indonesia [2] Stem Cell and Cancer Institute (SCI), PT Kalbe Farma Tbk. Jakarta Indonesia

Background: The prevalence of tumor / cancer in Indonesia is 1.4 per 1000 population with incidence of colorectal cancer (CRC) as many as 27,600. Expression of MMR incomplete (partial loss) on the CRC could potentially cause a state of MSS or microsatellite instability (MSI). The purpose of this study was to compare the microsatellite instability with MMR protein expression variation in CRC.

Methods: There have been analyzes fragments based on PCR using probe BAT 25 and BAT 26 in 34 cases of CRC with MMR with immunohistochemistry (IHC) used MutL homolog 1 (MLH1) and muts protein homolog 2 (MSH2).

Results: Based on the kappa value, there high concordance between microsatellite instability with MMR protein expression with value of 0.917 sensitivity 92% and specificity 99%. Results fragment analysis on 10 cases of partial loss MMR status compared with the positive (proficient) in the sample, there is a kappa value 0.542 conformity with sensitivity 98% and specificity of 75%.

Conclusion: Examination of IHC MMR by fragment analysis has high compatibility. IHC MMR can be used to determine the status of microsatellites in CRC. In partial loss status should be continued extended testing with fragment analysis based on PCR.