| Background:Colorectal cancer(CRC)is one of the most common malignant tumors in the world.In 2018,there were more than 1.8 million newly diagnosed CRC worldwide,and 881,000 persons died of CRC.Epidemiological studies in China have shown that the incidence rate of CRC has increased from 12.8/100,000 in 2003 to 17.5/100,000 in 2014,and the mortality rate has increased from 5.9/100,000 in 2003 to 7.9/100,000 in 2011.From 2004 to 2013,the incidence of CRC in Guangzhou showed an upward trend year by year.During the past ten years,the number of newly diagnosed cases reached 26,579,and the crude incidence rate was 33.77 per 100,000.CRC has become the second common malignant tumor in Guangzhou.Adenomatous polyps are common precursor lesions of CRC,about 70-90% of CRC developed from adenomatous polyps.It generally needs to undergo the following evolution process: normal intestinal mucosa?small polyps?larger polyps?dysplasia?cancer?metastatic cancer.The adenoma?carcinoma sequence often takes 8-10 years or more,thus there was enough timeframe for the prevention and treatment of all sorts of precursor lesions of CRC.CRC Screening plays an important role in reducing the incidence and mortality of colorectal cancer.Active screening and timely treatment of precancerous lesions and early cancer will help control the incidence of CRC.There was study shows that for every 1.0% increase in the detection rate of adenoma,the risk of interval colorectal cancer will be reduced by 3.0%.In recent decades,the United States,Japan and other countries have adopted large-scale population CRC Screening,and the incidence and mortality of CRC have declined.Large-scale population screening started later in China than in the United States and Japan,the participation rate in colonoscopy screening is lower,too,and there is a large difference in screening compliance rate among regions.In China,the first organized CRC screening began in 1970 s,in Haining and Jiashan,Zhejiang Province.In recent years,large-scale population screening had been carried out successively in Shanghai,Tianjin and other places in China,which had achieved well results.In November 2010,Yuexiu District started CRC screening program,which is the first District in Guangzhou to carry out CRC screening,two steps screening strategies were adopted,for the initial screening,residents finished the questionnaire and/or FOBT in community health centers to identify high-risk groups.The second step,for the high-risk persons,the free colonoscopy screening was recommended,and most the colonoscopy examinations were conducted in two national triple A,first-class hospitals on Saturday mornings.All colonoscopy related examinations,including the intestinal cleanser mannitol and the pathological examination were free.For some residents selected anesthesia colonoscopy or sedative colonoscopy,they need to pay the sedation costs or anesthesia costs only.In 2015,Guangzhou conducted the CRC screening in whole region,and the above two steps were used,but not all colonoscopy screening were free.Up to December 31,2017,there were 371046 residents participated the initial screening,and 51272(16.51%)cases were identified with high-risk,of which,14338(27.96%)cases accepted colonoscopy screening.However,the compliance rate of screening colonoscopy is still lower,and there were regional differences between Districts.Baiyun District was another District in Guangzhou,mainly in rural areas,compared with Yuexiu District,the transportation is relatively inconvenient and medical resources are relatively poor.In Baiyun District,most colonoscopies screening were conducted in primary hospitals,only few colonoscopies screening conducted in a national triple A,first-class hospital and the screening colonoscopies were not free.Purposes:By analyzing the data of the residents who participated in the primary screening and colonoscopy screening were analyzed retrospectively,the affective factors which influencing the high-risk persons' colonoscopy compliance and the results of colonoscopies were analyzed,too.By comparing the colonoscopy compliance,the detection rate of lesions,and characteristics of high-risk groups whose did not participate in colonoscopy screening in Yuexiu District and Baiyun District,we assess the effectiveness of different screening strategies.Our study aims to explore the differences in the detection rates of various lesions,the location of colorectal polyp,and the pathological types of polyp in screening residents between different genders and age groups in Guangzhou,and to provide a theoretical basis for the strategy modification in next CRC-screening.Methods:Part ?: The first part of this study is aimed to residents in Baiyun District and Yuexiu District who were identified with high-risk persons.Firstly,we retrospectively analyzed the data of residents who participated in colorectal cancer screening in Yuexiu District and Baiyun District on June 1,2015 to December 31,2018,and analyzed the data of residents who were positive for initial screening stage and in compliance with colonoscopy screening,then the factors affecting colonoscopy compliance of residents were explored.Secondly,for high-risk residents at Yuexiu District and Baiyun District were divided into two groups,the colonoscopy compliance rate with different characteristics and the results of the colonoscopies were analyzed.Thirdly,the high-risk residents who had not taken colonoscopy screening in two Districts were followed up by telephone.On this basis,for those who have not taken colonoscopy by follow-up telephone,we would organize experts to go to the community to make lectures about colorectal cancer screening and consultation,and followed up whether the participating residents had taken colonoscopy.Part ?: The second part of the research object are 19642 residents who participated in colonoscopy screening in Guangzhou from January 2015 to January 2019.We retrospectively analyzed the colonoscopy data of them and the results of colonoscopy,especially the pathological type,anatomical location distribution,disease detection rate and other data of colorectal polyps,in order to explore the differences of location and pathology type distribution of colorectal polyps among residents in different genders and age groups.Result:Part ?:1.From January 2015 to December 2018,19870 residents with high-risk groups(positive for primary screening)in two districts(Baiyun district and Yuexiu district)were screened out,and 6304 patients participated in colonoscopy screening,with the overall colonoscopy compliance rate of 31.7%.The colonoscopy compliance of male residents(33.7%)was higher than that of female(30.4%).The colonoscopy compliance rate among residents aged <40,40-49,50-59,60-69,70-79,age> 80 years old were 36.1%,40.3%,38.1%,30.5%,23.2%,9.1%.The colonoscopy screening compliance of residents with FOBT results were follows: 32.1% for all negative,32.4% for positive for one time and 43.5% for two positives.For all positive(FOBT positive twice and positive with questionnaire),the colonoscopy compliance rates were 47.5%,higher than those with single positive result(30.4%).2.Male,younger age group,being followed-up,married state,high education,with urban residents medical insurance,history of diarrhea,history of chronic constipation,history of mucus bloody stool,history of intestinal polyps,first-degree relatives history of intestinal cancer,positive result of the first FOBT and positive result of the second FOBT are favorable factors for residents' compliance with the colonoscopy.3.The colonoscopy compliance rates with residents in Yuexiu District were higher than in Baiyun District between the following factors: genders,age groups(age ?80 years excluded),whether questionnaire negative or positive,also results of FOBT and FOBT results combined with questionnaire(P<0.05).In 2015,2016 and 2017,the colonoscopy compliance in Yuexiu District had higher than in Baiyun District.The detection rates of colorectal adenoma,non-advanced adenoma,and advanced adenoma in Yuexiu District were 28.1%,15.5%,12.6%,which were higher than those in Baiyun District(The detection rates of Baiyun District were 15.2%,9.8%,5.5% respectively,all P<0.05),but its detection rate of colorectal cancer(2.1%)was lower than that of Baiyun District(2.1%vs.3.3%,P<0.05).4.In this study,the high-risk persons which not taking part in colonoscopies were followed up by telephone.A total of 1217 persons were followed up,560 cases accepted the call,the response rate was 46.01%(560/1217).After the following-up,351 residents(62.7%)refused colonoscopy again,During the period of follow-up,164 persons had completed the colonoscopy,and 45 persons said they would take colonoscopies later.Whether had experienced colonoscopy,expectation of expert lectures,influence of expert lectures or the acceptability of serum methods screening,there were no difference for residents which refused colonoscopy between in two districts(all P>0.05).Residents in Yuexiu District who still refused colonoscopy had higher awareness of colonoscopy than residents in Baiyun District(54.0% vs.31.5%,P<0.05).The top reasons for the high-risk persons who did not undergo colonoscopy in the two districts were follows: "No symptoms"(38.5%),"Fear of pain"(22.8%),and "negative result of another FOBT"(13.1%).They said If they "have symptoms"(56.4%),"can take free colonoscopy"(17.4%)and "take painless colonoscopy"(9.7%),they were willing to take colonoscopy screening.Of course,the answer to "free colonoscopy" comes from residents of Baiyun District.In addition,we conducted expert lectures and answering questions for the residents who did not participate in the colonoscopy screening,and followed up.A total of 200 residents participated in the lecture,later 56 persons finally participated in the colonoscopy screening,the overall compliance rate of colonoscopy was 27.5%(55/200).Part ?:1.From January 2015 to January 2019,A total of 19642 high-risk fished colonoscopy screening in this CRC screening project,including 8288 males and 11354 females,and 10670 cases(54.3%)were detected some lesions.Among them,there were 559 residents with colorectal cancer(2.8%),3154 residents with colorectal adenoma(16.1%),1241 residents with advanced adenoma(6.3%),860 residents(4.3%)with chronic inflammation,677 residents(3.4%)with ulcers or other lesions,51 residents(0.25%)with inflammatory bowel disease.The detection rates of colorectal polyps,adenoma,advanced adenoma and colorectal cancer in male residents were 52.4%,19.5%,8.3% and 3.9%,respectively,while the above lesions in females were 36.8%,13.5%,4.9% and 2.1%,respectively.The detection rate of lesions in males are higher than those in females(P<0.001).The detection rates of colorectal polyps in residents younger than 50 years,50-59 years,60-69 years and older than 70 years were 25.4%,37.0%,46.2% and 51.4%,respectively;the detection rates of colorectal adenoma were 8.6 %,12.8%,17.3%,20.2%,the detection rates of advanced adenoma were 2.7%,4.7%,17.1%,7.9%,and the detection rates of colorectal cancer were 0.8%,1.8%,3.2%,4.4%,there were differences in various types of lesions between age groups(all P<0.001),With age increase,the detection rates of colorectal polyps,colorectal adenoma,advanced adenoma and colorectal cancer gradually increased.2.Our study found that the colorectal polyps in the screening population are mostly located in the sigmoid colon(45.07%),rectum(30.66%),and ascending colon(28.73%).Tubular adenoma(56.65%)is the most common types of colorectal polyps.The proportion of tubular adenoma and the tubular villous adenomaof colorectal polys in males were higher than that in females(all P<0.05).Males have a higher proportion of bilateral polyps than females(29.8% vs.19.7%,P<0.05).Besides,the proportion of females with colorectal polyps in the right colon(34.1% vs.28.5%,P<0.05)was higher than that of males.The proportion of right colonic polyps of residents aged <50 years,50-59 years,60-69 years,age ?70 years was 24.4%,27.9%,32.6%,34.6% respectively.With increasing age,residents have a higher proportion of polyps in the right colon.Conclusion:1.A,first-class hospital,the screening colonoscopy arranging on the weekends,offering free colonoscopy and opening related clinics are conducive to improving the compliance of colonoscopy.2.Inadequate understanding of the knowledge about colorectal cancer and precancerous lesions,fear of colonoscopy are the main reasons for residents to refuse colonoscopy.Follow-up and community lectures are helpful to improve the colonoscopy compliance for high-risk persons who have not take colonoscopies.3.Screening colonoscopy compliance in Guangzhou is affected by a variety of factors.4.The detection rates of colorectal polyps,adenoma,advanced adenoma and colorectal cancer are higher in males and older residents than in females and younger residents,respectively,and also the proportion of bilateral colorectal polyps are higher.5.The incidence rates of right-sided colon polyps are higher in females and older residents than in males and younger residents respectively. |
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