Study On The Application Of Potimized Bowel Preparation Plan In Colorectal Eraly Cancer Screening

Objective As an important part of screening and one of the feasible measures to improve the early diagnosis rate of colorectal cancer,the specific impact of bowel preparation on the results of colonoscopy screening is still limited.This study is to explore the optimization of bowel preparation in early colon cancer screening.Methods This study is a retrospective,single center study.The subjects of colonoscopy screening are long-term residents living in Nanning who are evaluated as high risk（comprehensive evaluation system of individual cancer risk of National Cancer Center of China）.Endoscopy screening was from the Endoscopic Center of Guangxi Tumor Hospital.The intestinal preparation of the screened patients was divided into 2-L PEG group or 3-L PEG group.The main outcome measures were the positive rate of colonoscopy and cecal intubation rate.The secondary outcome measures included the positive rate of colonoscopy,the quality of intestinal cleansing（Boston score）,the qualified rate of intestinal cleansingpreparation,and the relationship between the diagnostic efficacy and the dosage of PEG in different BMI and pathological biopsy results.Results A total of 435 patients were selected.Among the patients received colonoscopy screening,compared with the 2-L PEG dose group,the positive rate of full colonoscopy and cecum intubation rate in 3-L PEG dose group were improved（the positive rate of colonoscopy was 31.4%vs 40.9%,P=0.04;The cecum intubation rate is 92.8%vs 99.2%,P<0.01）.For women,the best diagnostic efficacy can be obtained when PEG/BMI parameter is 5.16m²·10^-3（sensitivity 71.49%,specificity 80.00%,AUC=0.752,P<0.01）.For patients whose colonoscopy successfully entered to the ileocecal area,compared with the 2-L PEG dose group,3-L PEG dose group can improve the intestinal tract cleansingscore and the qualified rate of bowel preparation（males,BPS≥6,73.5%vs 96.1%,P=0.03,BPS:6.18±0.38 vs 7.93±1.25,P<0.001;Females,BPS≥6,76.8%vs 97.8%,P<0.001,BPS:6.18±0.38 vs8.16±1.14,P<0.001）.For males aged 61-74 years old,the diagnostic efficacy were the best when PEG/BMI parameter is 6.16m²·10^-3（sensitivity 70.83%,specificity 67.65%,AUC=0.703,P<0.01）.After successfully entered the ileocecal area and in the patients who had tissue biopsies for suspected lesions,compared with the 2-L dose group,the 3-L PEG dose group improved the positive rate of colonoscopy,adenoma detection rate and bowel preparation quality of patients aged 61-74 years（positive rate of colonoscopy,31.5%vs 53.7%,P=0.01;Adenoma detection rate was 16.7%vs32.8%,P=0.04,BPS≥6,74.6%vs 96.7%,P<0.001.Total colon 6.41±1.46 vs8.02±1.22,P<0.001）;For men aged 61-74,the diagnostic efficacy were the best when PEG/BMI parameter is 5.96m²·10^-3.（sensitivity 77.78%,specificity61.16%,AUC=0.709,P<0.01）.Conclusions Endoscopic screening of early colon cancer,for the high-risk population.Based on the routine diet preparation of painless enteroscope and oral administration of dimethylsilicone oil defoamer,compared with the 2-L PEG dose group,taking 3-L PEG in different doses can obtain better intestinal cleaning efficiency and screening efficiency;when the focus of the screening is certain known specific circumstances,some people can obtain good screening efficiency without taking 3-L PEG completely.