Study on the relationship between microsatellite status and clinicopathological charac-teristics of colorectal cancer patients after surgery / 中国肿瘤临床

ABSTRACT

Objective:To evaluate the association of microsatellite status with clinicopathological features of colorectal cancer patients after surgery.Methods:In total,572 colorectal cancer cases with clear pathological diagnosis and clinicopathological features from the Department of Pathology,Nanjing Drum Tower Hospital from June 2014 to June 2017 were included in the study.Microsatellite status and RAS mutations were detected by polymerase chain reaction.Ki67,EGFR,MGMT,and Lgr5 were detected by immunohistochemis-try.Clinicopathological features were analyzed based on the microsatellite states.Results:In this study,we found MSI-H in 7.0% of all patients,whereas 93.0% cases showed MSS/MSI-L.Compared with MSS and MSI-L colorectal cancer cases,MSI-H colorectal cancer cases showed the following characteristics1)more likely located in the right colon,2)comparable incidences at different ages,3)ear-ly cancer stage(Ⅰ/Ⅱ)(P=0.003),4)a lower proportion of lymph node metastasis(P=0.023),5)a lower proportion of cancerous nod-ules(P=0.005),6)a lower mutation rate of KRAS(P=0.004),and no mutation of NRAS.There was no significant difference in the posi-tive rates of MGMT,EGFR,Lgr5,and Ki67 between the two groups.Conclusions:Compared with MSS/MSI-L patients,MSI-H patients have specific clinicopathological features.A lower mutation rate of KRAS/NRAS and higher methylation rate of MGMT were also found in MSI-H patients.Our results provide a basis for individual diagnosis and treatment in colorectal cancer.