Clinical Study Of 15-year Surveillance In 157 Chinese Lynch Syndrome Families

Objective To evaluate the clinical significances of concomitant colonoscopies and the best survivance interval time in 157 Chinese lynch syndrome families.Patients and MethodsPatients From April 2001 to September 2016,a total of 157 pedigrees were registered in the General Hospital of PLA Army,fulfilled AC and BG criteria(BG1-4).These families were from Henan,Beijing,Inner Mongolia,Anhui,Shangxi,Hubei,Hebei and Shandong.Our studies were approved by Ethics Committee and all patients provided informed consents.Methods(1)Molecular genetic analyses were performed using blood samples of probands from all 118 Lynch syndrome families.Germline mutations were identified in 50 of these families,32 with hMLH1 mutations and 18 with hMSH2 mutations.hMLH1 and hMSH2 gene mutations were detected by targeted DNA sequencing and multiplex ligation dependent probe amplification(MLPA),respectively.370 members in the 50 Lynch syndrome families with hMLH1 and hMSH2 gene mutations were undergone additional genetic analyses to identify mutation and non-mutation carriers,194 were mutation carries(52.4%)and 176 were non-mutation carriers(47.6%).68 were undentified MMR gene mutation families,while 39 families did not undergo molecular genetic analyses.(2)The time of regular colonoscopy surveillance group was within 2 years,while over 2 years was defined as without regular surveillance group.The examintions were performed in members who older than 20 years.Numbers of colorectal cancer,death toll,5-year survival rate,10-year survival rate were analyzed in A B and C groups.(3)Differences in the frequency distributions of categorical factors,sex,age at diagnosis,tumour location and pathology,were compared using partitions of the chi-square test.Survival distribution was estimated by the Kaplan–Meier method.Overall survival(OS)was defined as the interval between the diagnosis to death or last follow-up visit.P<0.05 was considered statistically significant.All the statistical analysis was carried out using SPSS statistical software(version 17.0).Results(1)In the three groups,the incidence of colorectal cancers in the group without regular surveillance is significantly higher than the group with regular surveillance.The5-year-life rate and the 10-year-life rate of the group with regular surveillance is much higher than the group without regular surveillance.(2)The incidence of colorectal cancer in group A is higher than that in group B.Furthermore,the 5-year-life rate and the 10-year-life rate in former group is higher than the latter.The survival rate in group C is between group A and group B.(3)In our study,the incidence of colorectal cancer increases with the extension of follow-up time interval in MMR gene mutation patients.(4)Among MMR gene mutation patients,the incidence of advanced adenomas and colorectal cancers in the group without regular surveillance is significantly higher than the regular surveillance group.(5)Among MMR gene mutation patients,the average diagnostic age of colorectal cancer patients in the group without regular surveillance is younger than the age in regular surveillance group.Most of the colorectal cancers are advanced in the previous group,while the latter contains more early carcinomas.The 5-year-life rate and the10-year-life rate of the group with regular surveillance is much higher than the group without regular surveillance.(6)In regular surveillance group with MMR gene mutation,comparing the carriers without colorectal cancers before,the advanced adenomas and colorectal cancers are more common among colorectal cancer patients.(7)The incidence of colorectal cancer and extracolonic cancer in MMR gene mutation patients are higher than the patients without MMR gene mutation.(8)There is no difference between colorectal cancer patients with MLH1 and MSH2 gene mutations.As well,there is no difference between male and female colorectal cancer patients.ConclusionsRegularly performing colonoscopic surveillance has important clinical significance for the MMR gene mutation carriers,and the patients along with their first-degree relatives whose mutation is undetectable.Repeated every 1-2 year is highly recommended.The surveillance time of MMR gene mutation patients is advised no more than 1 year.Mutated negative members were followed up with the general population.It is also important to reduce the incidence of colorectal cancer or delay the onset for colorectal cancer and diminish the overall mortality.