| Background and Aim:Colorectal cancer has a high incidence rate in malignant tumor of digestive tract. In recent years, colorectal cancer incidence appears a obvious rising trend in our country. It is well known that many factors, many stages and many ways are involved in its occurrence or development, and that advanced colorectal cancer have a poor clinical curative effect and prognosis. So, early diagnosis and treatment display great significances to improve the survival rate, but it is still a medical challenge for clinical doctors. Aberrant crypt foci(ACF) were firstly described by Bird in1986in the colon carcinogen-treated rodents, then it has become one of research hotspots, including its histology changes, gene mutation, chromosome variation, chemical induction or inhibition, epidemiological characteristics and the endoscopic form. But in our country, at present the research of ACF is very rare. Although a number of studies revealed ACF may be adenoma potential biological markers, it is still controversial whether ACF is a precursor of the colon cancer. But another study suggested there were no correlation between ACF incidence or its number and gland tumor. In this study only68.5%endoscopic ACF was histologically confirmed, the results suggested that the risk may be existed when using ACF as colorectal cancer a substitute marker. There were many inconsistencies ACF incidence of rectal colon in patients with normal colon is from15%to100%, hyperplasia ACF proportion in sporadic CRC patients is from0to61%. The coincidence rate of endoscopic observation and histological characteristics in ACF also variational, from53%to92%. H. Bouzourene et al reported advanced tumor have a higher ACF count, the CRC patients have more hyperplasia ACF number. Huang Liyun reported ACF incidence in male patients is74.6%, female is69.3%, also that more than5ACF lesions may be a warning of progress tumor in a971cases of sample survey, but relations between hyperplasia ACF and colon tumor were not analyzed. So knowing about ACF characteristic change and colon cancer is important to further recognize or prevent colon cancer. For ACF endoscopic classic diagnosis is the use of chromoendoscopy, which can clearly shows that ACF lesions edge and surface characteristics of the gland, but cost a long time, is also a trival process. It is obvious that More conveniently, accurately, and quickly to find colorectal ACF lesions have a great significance for promoting or strengthening the study of ACF. NBI endoscope, which applying the optical enhancement technique, can provide images with emphasized mucosa vascular morphology and surface structure, so that can enhance the mucosal surface of the blood vessels and other structure of visibility, its visual effect can reach the same as chromoendoscopy. Jiang Bo showed that NBI(98.6%) was superior to conventional (90.5%) endoscopy in finding specific mucosa anomaly sign, especially some flat lesions or adenoma, and can reach the same effect as chromoendoscopy. But NBI endoscopy is no help for ACF diagnosis. There is no research reports whether it can improve the detection rate at present. In search a suitable endoscopy to improve the detected rate of ACF, in this study, we observed the differences of distal colon ACF deteected rate in NBI endoscopy, traditional white endoscopy and chromoendoscopy, and tried to find the advantages and disadvantages between them. This study also prospectively investigated ACF lesions incidence and its relations to colon tumor. Methods1The admitted standardFrom August2011to March2012in pingxiang people’s hospital of jiangxi province,1200patients with gastrointestinal symptoms who prepared to accept colonoscopy were divided into three groups by applying a random digital form, that is endoscopy group, narrow band endoscopy (NBI) group, indigo carmine chromoendoscopy group, each group with400samples, excluding the patients with a poor bowel preparation, infectious intestinal disease, inflammatory bowel disease, or rectum resected, all participants are informed consent.2Endoscopy operation and recordsAll endoscopic operation were completed by the same endoscopic technologist with Olympus CF-H260AZI.The way is pushing endoscopy to the ileocecal, then withdrawing out to the rectum terminal area25-30cm from anus. The lesions regularly were observed under white light in conventional endoscopy group, under NBI model in NBI endoscopy group, or after spraying10～15ml0.4%indigo carmine dyeing in the rectum terminal area25-30cm from anus with spraying pipe and suck residual dye. after using in stain endoscopy group. Operation time is when withdrawing endoscopy out to the rectum terminal area25-30cm from anus to the end.(The time of biopsy and amplification observation didn’t count). Diagnosis of ACF were standardized by combining with amplification endoscopy and pathological biopsy in the three group.Operation time, intestinal tract cleaning degree, lesions areas and ACF number (according to ACF number, patients were divided,0is level0,1-5is level I,6-10is level Ⅱ,>10is level Ⅲ), other parts of the intestinal lesions (according to the need can be divided into four categories:1. normal mucosa2. Hyperplastic polyp3adenomas and colon cancer) were recorded by a Certain person. The time was record with stopwatch, second as the unit, after Endoscopic diagnosis ACF, the samples were obtained from larger lesions by one-time biopsy forceps materials, four samples were obtained in cases of ACF number>5ACF one to two were obtained in cases of ACF number≤5, all biopsy specimens were sent for pathologic examination. 3Pathological histology diagnosisAll biopsy specimen were completed in12hours, and analyzed by two or more senior pathology doctor from department of pathology in pingxiang people’s hospital. Low or high level tumor change were discriminated according to the degree of deformed Cells and abnormal structure glands as WTO diagnose standard. Cancer was diagnosed When tumor invaded through muscularis mucosae and reached the submucosa in histology. Dysplasia as ACF pathological diagnosis was judged according to the reference standard. All pathological section were diagnosed by two senior pathologist dependently, once disagreement occurred, the third senior was joined, the results were obtained as the majority opinions.4Data analysisSelected by using SPSS13.00statistical package carries on the statistical analysis, comparison between groups by χ2test, P<0.05for difference have statistical significance. Results1ACF detected rateAccord with a condition into the group of patients with a total of1099patients, three groups were found322cases of ACF cases,48cases of pathological have hyperplasia, are mild hyperplasia. The conventional endoscopy group a total of367cases,13(3.54%) cases were found that ACF cases; Narrow band endoscopy group a total of361patients, a total of53(14.68%) cases found ACF case; And indigo carmine chromoendoscopy group a total of370patients,256(69.19cases were found that ACF cases, three methods ACF found rate have significant difference (P=0.000). chromoendoscopy group and narrow band endoscopy group more significant difference (P=0.000), narrow band endoscopy group and routine endoscopy group compared with significant difference (P=0.000), chromoendoscopy group and routine endoscopy group compared with significant difference (P=0.000).2Operation timeOperation time was significantly prolonged by Narrow band endoscopy (64.37±23.79seconds)and stain endoscopy(114.32±43.2seconds), than conventional endoscopy (38.65±6.19seconds)(P=0.000).3ACF in different diseasesACF detected rate is69.19%, hyperplasia dysplastic ACF detected rate is10.54%with stain endoscopy. In group of normal mucosa. hyperplastic polyp, adenoma, colon cancer, ACF detected rate were respectively58.21%,78.18%,82.05%,88.89%, dysplastic ACF rates were2.99%,9.09%,12.82%,50%. ACF detected rate and dysplastic ACF prevalence increased with patient histology severity (P=0.000).In group without ACF, the detected rate of hyperplastic polyps is10.53%, in group with ACF, the detected rate of hyperplastic polyps is16.8%, OR(95%CI) is2.234(1.258-3.365),2=12.36,P=0.001, it revealed that ACF can predict a significantly higher detected rate of hyperplastic polyps. In group without ACF, the detected rate of adenoma is12.58%, in group with ACF, the detected rate of adenoma is25.0%, OR(95%CI) is2.268(1.425-3.458),2=13.65, P=0.001, it revealed that ACF can predict a significantly higher detected rate of adenoma. In group without ACF, the detected rate of colorectal cancer is3.51%%, in group with ACF, the detected rate of colorectal cancer is12.5%, OR(95%CI) is2.314(1.298-4.217),2=7.231, P=0.005, it revealed that ACF can predict a significantly higher detected rate of colorectal cancerDiscussions1Traditional endoscopy had a higher missed diagnosis rate of ACF.2Chromoendoscopy had a highest detected rate lesions, but costs a longer time.3NBI endoscopy can improve the detected rate of distal colon ACF lesions, and is simple to operate, easy to generalize.4As ACF is a common lesion under colonoscopy, and further, hyperplasia ACF lesions is not rare, so our study should pay more attention to ACF.5The prevalence of ACF and dysplastic ACF are significantly increased in patients with adenoma or colon cancer. Patients with ACF in distal colon may indicate a higher incidence of colorectal adenoma or cancer. ACF may be a predictive factor of colorectal adenoma or cancer. |
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