ABSTRACT
Objective To explore the clinical significance of colonoscopy follow-up in Chinese Lynch syndrome mismatch repair (MMR) gene mutation carriers.Methods The results of colonoscopy follow-up was analyzed in 194 MMR gene mutation carriers of 50 Lynch syndrome families.The follow-up period was from April 2001 to November 2016.The detection rates of advanced adenomas and colorectal cancers,five-year survival rate and ten year survival rate were compared between 123 patients of regular follow-up group (colonoscopy interval less than two years) and 71 patients of irregular follow-up group (time colonoscopy interval more than two years).T test,chi-square test and Kaplan-Meier method were performed for statistically analysis.Results The incidence of colorectal cancer of irregular follow up group was significantly higher than that of regular follow-up group (57.7％,41/71 vs 22.8％,28/123);and the difference was statistically significant (x2 =24.00,P＜0.01).The average age at diagnosis for colorectal cancer in irregular follow up group was younger than that of regular follow up group ((45.3 ± 1.9) years vs (48.7±1.8) years);and the difference was statistically significant (t=4.10,P＜0.01).In regular follow-up group,28.6％ (8/28) advanced-stage colorectal cancer (TNM Ⅲ or Ⅳ) was found,while in irregular follow up group,73.2 ％ (30/41) advanced-stage colorectal cancer was found,and there was statistically significant difference in pathological stage between two groups (x2 =4.90,P =0.032).The five year and ten-year survival rates of regular follow-up group were 96.2 ％ and 85.1 ％,respectively,which were both higher than those of irregular follow-up group (46.3 ％ and 28.7 ％);and the differences were statistically significant (x2 =13.20 and 14.80,both P＜0.05).The incidence of advanced adenomas of irregular follow up group was significantly higher than that of regular follow-up group (49.3％,35/71 vs 18.7％,23/123);and the difference was statistically significant (x2 =20.10,P＜0.05).The detection rate of advanced adenomas of MMR gene mutation carriers was higher than those without MMR mutation gene (85.4％,35/41 vs 14.6％,6/41);and the difference was statistically significant (x2 =5.20,P＜ 0.05).Conclusion Regular colonoscopy surveillance may decrease the incidence and mortality of colorectal cancer in MMR mutation carriers of Lynch syndrome families,and increase five-year and tenyear survival rates.