| Purpose:The first part: Screening of colorectal tumors in Yan’an urban area by the use of plasma methylation of plasma Septin9 gene(PCR fluorescent probe method)in Yan’an University Affiliated Hospital;Analysis of risk factors for positive plasma methylation of Septin9 gene;The second part: Analysis of plasma methylation of Septin9 gene in colorectal adenoma,compared with fecal occult blood test,to explore its clinical application value.Method:The first part: Screened some teachers(1151 cases)in Yan’an city from June 2016 to March 2017.This study adopted cross-sectional surveys and cluster sampling surveys,questionnaires and early plasma methylation of Septin9.Sieves,colonoscopy,and pathological examinations were used to screen high-risk colon cancer patients and colorectal lesions.The 1151 teacher screening samples were divided into positive(level-raising)and negative(level-normal)groups based on plasma Septin9 methylation test results.Logistic regression analysis was used to investigate the risk factors for positive plasma methylation of Septin9.The second part: From June 2016 to June 2017,the Department of Gastroenterology and Inpatient Department of the Department of Gastroenterology of the Affiliated Hospital of Yan’an University has completed colonoscopy and pathological examination.The patients diagnosed with colorectal adenomas,inflammatory or hyperplastic polyps,and signed informed consent Plasma Septin9 methylation was detected.The study was divided into three groups: 1.Colorectal adenoma group: 97 cases of clinical samples;2.Inflammatory or hyperplastic polyp: 84 cases of clinical samples;3.Normal control group: 81 cases of teacher screening samples.According to the results of pathological examination,the components of colorectal adenomas were high-grade intraepithelial neoplasia,advanced adenomas without high-grade intraepithelial neoplasia,and non-advanced adenomas.SPSS19.0 software package was used for statistical analysis.The positive rate of methylation of plasma Septin9 gene was compared among all groups,and the positive rate of methylation of plasma Septin9 gene and the positive rate of plasma Septin9 methylation were compared between the clinical and pathological features of each group and FOBT.The positivity rate was compared using the χ2 test.At the test level of α=0.05,P<0.05 was considered statistically significant.Between the two groups,the P value was corrected by Bonferroni to <0.05/group.Result:The first part:1.A total of 1151 cases were screened and 63 cases(5.47%)were positive for methylation of plasma Septin9 gene and 1088 cases(94.53%)were negative.Of the 63 positive cases,14(22.22%)had colonoscopy and(or)pathological examinations,and138(12.68%)had colonoscopy and/or pathological examination.2.152 cases of patients in complete colonoscopy were detected in 71 cases of colorectal lesion detection rate 46.71%(71/152),wherein the eight cases of colorectal adenoma,the detection rate was 5.26%(8/152),Inflammatory polyps or hyperplastic polyps in 11 cases,the detection rate was 7.24%(11/152),41 cases of superficial colitis,the detection rate was 26.97%(41/152),5 cases of ulcerative colitis,The detection rate was 3.29%(5/152).There were 2 cases of colon diverticula.The detection rate was1.32%(2/152).There were 4 cases of colon black lesion.The detection rate was 2.63%(4/152).3.Multivariate logistic regression analysis of positive plasma(suprasing)and negative(normal)plasma levels of the Septin9 methylation test revealed that the risk factors for positive plasma methylation of the Septin9 gene were: age ≥60 years(OR = 2.256,95% CI: 1.093-4.983;P = 0.015)and family history of colorectal neoplasms(OR = 5.452,95% CI: 1.682-17.667;P = 0.005).The second part:The positive rate of plasma methylation of Septin9 in 21 cases(21/262)was positive,the positive rate was 8.02%,among which 14 cases(14/97)were positive in adenoma,positive rate was 14.43%;inflammatory or hyperplastic polyp In 4 cases(4/84),the positive rate was 4.76%;in the normal control group,3 cases(3/81)were positive and the positive rate was 3.70%.There was a statistically significant difference between the three groups(adenomas,inflammatory or hyperplastic polyps group and normal control group)(χ 2=8.667,P<0.05),that is,the positive rate of plasma Septin9 methylation was not identical in the three groups.Further differences between groups were not statistically significant(χ2 =4.701,5.882,0.114,P < 0.017).2.Detection of plasma methylation of Septin9 in high-grade intraepithelial neoplasia,histopathological histological type was tubular villus,the positive rate was higher in age≥60 years,38.46%(5/13),26.67%(4/15),respectively.),25.00%(6/24)and 23.91%(11/46),of which the difference was statistically significant in terms of age and progression(χ2=4.990,10.587,P<0.05).The positive rate of plasma methylation of the Septin9 gene in gender,adenoma number,pathological type and adenoma size was not statistically different(χ2=0.907,0.206,0.703,2.883,P>0.05).3.The positive rate of plasma methylation of Septin9 gene in patients with colorectal adenoma was 14.43%(14/97),and the positive rate of FOBT was 12.37%(12/97).The positive rate of plasma Septin9 and the positive rate of FOBT test were not statistically significant(χ2=0.178,P=0.833).Conclusion:1.This study found that age ≥ 60 years and family history of colorectal cancers are risk factors for increased plasma methylation of the Septin9 gene.2.This study found that the positive rate of plasma methylation of the Septin9 gene was significantly higher in colorectal adenomas than in non-colorectal adenomas,but not in colorectal adenomas.3.This study found that plasma methylation of the Septin9 gene compared with the FOBT test has a higher test efficacy in colorectal precancerous lesions(such as adenomas). |
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