Clinical Characteristics And MSI Of MPCs Patients With Colorectal Cancer

Objective: To analyze the clinical characteristics and MSI of MPCs(Multiple primary cancers)with CRC(Colorectal Cancer).Methods: From January 1,2015 to December 31,2018,clinical data of 224 CRC patients who had been diagnosed by pathology in the fourth Hospital of Wuhan were retrospectively analyzed,and the expression of MLH1、MSH2、MSH6 and PMS2 of each CRC patient was detected by immunohistochemical method.To further explore the correlation between MSI and MPCs of CRC.Conclusions: Of all patients with CRC,18.3%(41/224)were MPCs.There was no significant difference in the sex,age,colorectal cancer site and TNM stage.Most patients are more than 50 years old in both MPCs patients with CRC and single CRC patients,each takes 87.8%(36/41)and88.0 %(161/183).The most common location is rectum in both of them,each takes 47.0%(19/41)and 42.7%(78/183).I-II stage is more common in MPCs patients with CRC,each takes65.9%(27/41)and 59.0%(108/183).Among 41 MPCs patients with CRC,the ratio of men to women is approximately 1:1,and the average age is 61 between the age from 28 to 86,MPCs patients are mainly 50-75 years old.There were 8 patients in SC(Synchronous carcinoma,SC)and33 patients in MC(Metachronous carcinoma).The majority of SC are the right colon,but rectum is the majority of MC.CRC is more common in phase III-IV when found as a second primary cancer.In extracolonic organ,there are 43 tumors,digestive system [40.0%(17/ 43)])was the most commonly occurring system and stomach [20.9%(9/43)]was the most common lesion.Colorectal extraintestinal cancer is also more common in the I-II stage.The interval between primary(FPC) and secondary primary(SPC)cancer was 0-696 months(0,58 years),The average interval was90.5 months.There were more cases within 2 years and 10 years after FPC was diagnosised than other periods.The MSI-H takes more percentage in MPCs patients with CRC than patients with single CRC(p<0.05),the difference was statistically significant.Results: The rectum is the most common lesion site in patients with single CRC.The stomach is the most common extracolonic organ of MPCs patients with CRC.Compared with colon cancer,rectal cancer has a higher risk of developing MPCs.With MSI-H colorectal cancer patients have a higher risk of developing into MPCs patients.