Risk Factors For High-grade Intraepithelial Neoplasia In Colorectal Adenomas

Backgrounds and Objective : Colorectal adenomas(CRA) is a common gastrointestinal diseases, and have received great attention from the general clinical workers as colorectal cancer(CRC) main precancerous lesions. Although most CRC originate in CRA, most of adenomas are not progress to invasive carcinoma. Earlier studies have indicated that adenomas with severe atypical hyperplasia and carcinoma in situ work as important link during development from benign adenoma to invasive carcinoma. This study is aimed at exploring endoscopic characteristics of high-grade intraepithelial neoplasia(HIN) adenomas and its related clinical risk factors, and providing help for the diagnostic work of HIN adenoma and earlier CRC to achieve the aim of early discovery, early diagnosis and early treatment. Accordingly,we could achieve objectives of intervening in "adenoma to carcinoma" sequence, and preventing the occurrence of colorectal invasive carcinoma.Patients and Methods: All objects underwent complete colonoscopy in the first division of digestive endoscopy and were diagnosed with CRA, and they are hospitalized patients in the first hospital affiliated to Dalian Medical University on January 1, 2014 to December 31,2014. According to the definition of CRA and intraepithelial neoplasia(IN) classification in the 3rd edition in 2000 《 World Health Organization classification of tumours of the digestive system》, the objects of study are divided into high-grade intraepithelial neoplasia(HIN) group and low-grade intraepithelial neoplasia(LIN) group. For patients with colorectal multiple adenomas,if HIN adenoma and LIN adenoma are founded in their colorectum at the same time, thepatient will be bring into HIN group. We analyze the correlation between HIN and patients’ age, gender, history of smoking, alcohol drinking, and hypertension, diabetes,hyperlipidemia, coronary heart disease, fatty liver,number of CRA. In addition, we analyze the correlation between HIN and adenomas’ characteristics, including location,size, shape, mucosal surface(e.g., smooth, rough, hyperaemia erosion), phylloide and pathological histology.Results: A total of 268 patients with CRA, and 387 adenomas with them, were included in this study. Subjects’ average age is(63.0 ±0.6) years, and there are men 179cases(66.8%), women 89 cases(33.2%), the ratio of men and women is about 2:1.There are 41 patients with HIN adenomas(15.3%), a total of 49 HIN adenomas(12.7%)were detected from them. Among patient factors, the univariate analysis showed that the rate of smoking, drinking, and multiple adenomas in group HIN were all significantly higher than that of group LIN(P < 0.05), which indicates that smoking, drinking, and multiple adenomas may be risk factors for HIN. When patients were stratified by gender,we researched the relevance of smoking, drinking and multiple adenomas with HIN respectively. layered chi-square test result showed that among the male patients, the rates of smoking and multiple adenoma in group HIN were significantly higher than that of group LIN(P < 0.05), while there are no significant statistical difference with the rate of drinking between the two groups(P = 0.088). There are no significant difference with the rate of smoking and multiple adenoma between the two groups among female patients(P > 0.05), and we are unable to do chi-square test because all female patients had no drinking in our research. Results suggest smoking and multiple adenoma may be risk factors for HIN in male adenoma patients not in female. we chose independent variables with P<0.05 in univariate analysis to enter the multivariate analysis regression model, the results showed that factors which can significantly affect the occurrence of HIN include smoking(OR= 2.119, 95% CI = 1.071-4.189) and adenoma multiple(OR=1.982, 95%CI= 1.003-3.918).Among adenomas characteristic factors, the univariate analysis showed that there are significant difference between group HIN and LIN in adenomas’ morphology, size,mucosal situation, phyllodes and pathological histology(P < 0.001).Under the condition of without considering the interaction among all independent variables,we chose independent variables with P<0.05 in univariate analysis to enter the multivariate analysis regression model, the results showed that factors which can significantly affect the occurrence of HIN include mucosa rough(OR = 3.563, 95% CI = 1.261-10.066) or hyperaemia erosion(OR = 3.669, 95% CI = 1.591-8.467), phyllodes adenomas(OR =2.211, 95% CI = 1.049-4.611), and pathologic histology containing ingredients of villus(OR = 4.053, 95% CI = 1.926-8.531). When the independent variable does not include the shape, mucosal surface of adenomas, phyllodes, under the condition of without considering the interaction among independent variables, regression results showed that adenoma diameter ≥10 mm(OR = 3.802, 95% CI = 1.615-8.951) and pathological tissue containing ingredients of villus(OR = 4.841, 95% CI =2.326-10.079) can significantly affect the occurrence of HIN.Conclusions: Among patients factors, smoking, adenoma multiple may be significant risk factors affecting the occurrence of HIN,and may be more significant on men. Among adenoma factors, the diameter of the adenoma≥10 mm, histological tissue of adenoma containing ingredients of villus are HIN’ significant risk factors, while the influence of mucosal lesions and adenoma phyllodes to HIN may be associated with adenoma diameter size.