Colorectal Laterally Spreading Tumors Canceration Associated Risk Factors

AimWhen colorectal cancer is found early and treatmented effectively, the survival rate willbe greatly improved.5-year survival rate of early colorectal cancer after surgery can be as highas90%. Adenomatous colorectal polyps are the most important precancerous lesions, Removalof adenomatous polyps by colonoscopy in patients can make the risk of colorectal cancermortality in10-years due to lower than53%in. The research on colorectal adenomatouspolyps as the most important precancerous is a top priority of colorectal cancer-relatedresearch in the field. Laterally spreading tumors are a special form of colorectal adenomatouspolyps. It usrally needs dyeing endoscopy as assistive technologies to show the polypsobviously. It is expressed as a flat surface colonic mucosa lesions. It was along the mucosalsurface of the colon wall lateral growth, minimal invasion to the deep. It is different from thecommon adenomas at form, occurrence and development. Its incidence is not low, and closelyassociated with colorectal cancer.LST is a colorectal adenoma. It belongs to colorectal precancerous lesions. Causativegene of colorectal cancer may also exist the same effect on LST. Wnt signaling pathway isclosely related to the incidence of colorectal cancer. β-catenin protein in the Wnt signalingpathway is a very important key system elements. CTNNB1gene mutation in exon III site canaffect structure and function of β-catenin protein, lead to excessive activation of the Wntpathway. In order to clarify laterally spreading tumors clinicopathological features, risk factorsfor laterally spreading tumor Canceration, we designed this study.Method252cases with electronics colonoscopy examination was retrospectively selectedbetween May2009to May2013in Changhai Hospital, Second Military Medical UniversityColorectal Surgery Department for the study, which was diagnosed as LST. A total of240cases of PA as control. The clinical and pathological data was collected and statisticallyanalysised.148cases with electronics colonoscopy examination was retrospectively selectedbetween May2009to March2013in Changhai Hospital, Second Military Medical UniversityColorectal Surgery Department for the second part study, which was diagnosed as LST. A totalof53cases of PA as control. Genomic DNA was extracted. The CTNNB1gene wassequencied, then screening mutations. Bioinformatics application methods was used toselected six SNP loci in four genes, as follows: TGFBR2-rs104893815，TGFBR2-rs34833812， DCC-rs2229080， SRC-rs121913314， PTPRJ-rs1566734， PTPRJ-rs121434507. SNP polymorphism was detected by sequencing.Result51346patients received colonoscopy examination in in Changhai Hospital, SecondMilitary Medical University Colorectal Surgery Department between May2009to May2013.There are252cases LST, detection was rate of0.49%. LST-G170cases(67.5%), Nodularmixed LST109cases(43.3%), Uniform particle LST61cases(24.2%); LST-NG82cases(32.5%), Flat elevated LST80cases(31.7%), False depressed LST2cases(0.8%). In LSTgroup, male130cases(51.6%), female122cases(48.4%), age61.06±11.06; In PA group, male169cases(70.4%), female71cases(29.6%), age58.17±10.65.The proportion of male in LST group was significantly less than in PA group. LST groupof people over the age of60constitute significantly higher than the PA group; LST groupconstitutes over60years the proportion of the population was significantly higher than the PAgroup; Rectum LST can account for half the total number of LSTs. Rectum particle type LSTcan be accounted for nearly2/3of the total particle type LST. Non-particle type LST and PAdistribution at the site was no significant difference. LST group mean lesion diameter (35.10±2.25) was significantly greater than the PA group (18.12±8.68). LST-G has larger diameterthan the other two groups. Lesion diameter difference between the non-particle type LST andPA was not significant. The average number of polyps per patient coexist (2.56±3.02) in LSTgroups was significantly less than the PA group (3.76±3.87). no difference exists between thetwo subgroups. PA patients prefer the presence of multiple polyps, up o58.8%. villousadenoma and tubular villous adenoma in LST group were significantly more than the PAgroup. Particle type LST has more tubular villous adenoma (48.2%). Non-particle type LSThas more serrated adenoma (64.6%), but less yubular villous adenoma (11.0%), different withPA. LST group was significantly higher at pathological grade than PA group; Particle type LST,non-granular type LST and PA, among the three groups there is also a significant difference atpathological lesion grade. Particle type LST pathological level was significantly higher thanthe other two groups. Use the logistic regression analysis to study the variousclinicopathological factors and laterally spreading tumor cancer risk relationship. Polyplocation, polyp diameter are laterally spreading tumor colon cancer risk related factors; Thegreater the lesion diameter the higher the risk. Rectal LST has lower risk of canceration. Usethe logistic regression analysis to study the various clinicopathological factors and PA cancerrisk relationship. Patient age, polyp location, polyp diameter, single lesion are cancer riskrelated factors. The elder the age, the greater the diameter of polyps the higher the cacer risk.In the rectal PA, single lesion, the risk of cancer is reduced. CTNNB1gene sequencing, Exon3 are all wild-type, no mutation was detected. Among the six SNP loci in four genes,3loci hasonly one genotype,with no statistical value. The other3loci was analyzed by Chi-square testwith the3group, there was no statistically significant difference, p＞0.05. Application ofnon-parametric test for SNP genotyping of these three genes were correlated with pathologicalgrading data, there is a correlation between DCC-rs2229080and pathological grade,p=0.009＜0.05.ConclusionLST is on a very special form of colorectal mucosal lesions; Age of onset of LST is in50-70years of age; LST ofen occur in the rectum; It’s average diameter is generally greaterthan polypoid adenomas; Nearly half of the LSTs is as a single lesion; LST-G tend to betubular villous adenoma. LST-NG tend to be serrated adenoma. LST malignant potential ishigher than PA. Lesion diameter is cancer risk factor of LST. Serrated adenomas, villousadenomas, rectal LST is negative correlation cancer risk factors of LST.In LST occurrence during carcinogenesis, Wnt/β-catenin signaling pathway may playan important role. β-catenin protein accumulation is unrelated to CTNNB1mutation, may becaused by other gene regulatory. Statistical analysis showed that there is a correlation betweenthe level of SNP genotype data and Pathological grade in DCC-rs2229080of LST.DCC-rs2229080SNP genotype may have malignant potential associated with LST.Detection of DCC-rs2229080SNP genotype may contribute to the clinical screening ofpatients with malignant potential LST. It is likely to develop principles to guide clinicaldiagnosis and treatment as a certain reference. In our study, the6loci in4gene was analyzedby Chi-square test with the3group, there was no statistically significant difference. The resultsuggest that the3signalling pathway may have nothing to do with the LST occurrence andcanceration.