Analysis Of Detection And Clinical Features Of Colorectal Cancer Under Colonoscopy

Background and purposeColorectal cancer(CRC)is a major public health issue and one of the most common malignancies in the gastrointestinal tract,with high morbidity and mortality worldwide.And the incidence of young CRC patients is increasing.The"adenomas-cancer" sequence theory has been recognized by the academic community;colon polyps can be cancerous and progress to colon cancer.This provides a theoretical basis for the early diagnosis and treatment of CRC.Some colon polyps are also considered to be precancerous.Among them,intraepithelial neoplasia is considered as an important precancerous lesion of colorectal cancer,and the incidence of colorectal adenoma with high grade intraepithelial neoplasia(HGIN)is relatively higher.In addition,the early symptoms of CRC are not obvious,so early detection of colon adenoma and resection is the key to early diagnosis and early treatment of CRC.Colonoscopy is one of the means of CRC screening.To clarify the effectiveness of colonoscopy screening,recent changes in the clinical features of CRC,and clinical features of young CRC patients are important for improving the CRC screening program and diagnosis and treatment.Therefore,we conducted a single-center retrospective study to describe the clinical features and detection rates of CRC and to analyze changes in these characteristics over a 10.year period and to analyze the clinical characteristics of young CRC patients,and provide more evidence for improving the strategy of screening and early diagnosis and early treatment of CRC.MethodsWe conducted a retrospective analysis of all patients who underwent colonoscopy and had a definite pathological diagnosis of CRC and HGIN at the Southern Hospital of Southern Medical University between January 2008 and December 2017.We compared patients diagnosed with CRC into the first and the second five years(the first five years 2008-2012,the second five years 2013-2017).We compared characteristics of CRC patients in the first five years of the study with those in the second five years,and the trends in the detection rates of CRC and HGIN.At the same time,we also compared the clinical features of CRC patients younger than 50 years and older than 50 years.ResultsA total of 130,344 patients underwent colonoscopy in 2008-2017.3,393 patients were diagnosed with CRC.Among them,there were 1317 cases in the first five years and 2076 cases in the second five years.Within ten years,2157 cases(63.57%)were male and 1236 cases(36.43%)were male.The ratio of male to female was 1.75:1.The age range is 15-94 years old,with a median age of 59 years.Of these,2145(63.22%)were 50-75 and 2729(80.43%)were 40-75 years of age.Fecal trait changes and abdominal pain were the main causes of colonoscopy.29(2.80%)and 75(4.27%)underwent colonoscopy for physical examination,in the first and second five years,respectively(p=0.047).Colonoscopy due to change in fecal trait was performed in 593(57.18%)and 929(52.84%)patients in the first and second five years,respectively(p=0.026).Significant differences were also noted for colonoscopy due to change in bowel habit[273(26.33%)and 377(21.44%)in the first and second five-year periods,respectively,p= 0.026].The most common site of CRC was the rectum,followed by the sigmoid colon.The percentage of lesions in the sigmoid colon was higher in the second than in the first five years(22.69%vs 18.60%,p=0.004).Conversely,the proportion of rectum CRC was lower in the second than in the first five years(46.29%vs 51.56%,p＝0.003).Adenocarcinoma accounted for a large proportion of the histological types in CRC patients.There was a significant increase in the number of patients with histological adenocarcinoma in the second five-year period compared to the first(9.15%vs 6.38%,p=0.004).The detection rate of CRC decreased significantly in the second five years(3.15%vs.2.35%;p<0.001).Conversely,the detection rate of high grade intraepithelial neoplasia(HGIN)increased significantly in the same period(1.10%vs.1.29%,p=0.004).The two group,younger than 50 years and older than 50 years,both groups are more common in men.Colonoscopy mainly due to fecal trait changes,abdominal pain and fecal habits changes.The most common site of CRC was the rectum,followed by the sigmoid colon.Adenocarcinoma accounted for a large proportion of the histological types in CRC patients of both group.The histological grade was mainly moderately and highly differentiated,and the TNM stage was more common in stage Ⅱ,stage Ⅲ and stage IV.Compared with the two groups,the number of young CRC women was relatively high.274(38.43%)and 693(33.29%)underwent colonoscopy for abdominal pain,in younger and older 50 years old,respectively(p=0.014).Colonoscopy due to abdominal mass was performed in 16(2.24%)and 21(1.01%)patients in younger and older 50 years old,respectively(p=0.021).The number of colonoscopy due to fecal traits changes was relatively small(339,47.55%vs.1183,56.82%,p<0.001).The percentage of lesions in the transverse colon and descending colon was relatively high(transverse colon:8.92%vs.3.72%,p=0.011,descending colon:5.55%vs 3.40%,p=0.006).There was a significant decrease in the number of patients with histological adenocarcinoma in young patients compared to the older(82.59%vs 96.52%,p<0.001).Conversely,the proportion of signet-ring cell carcinoma was higher in younger than 50 than in older than 50.first five years(1.02%vs 0.36%,p=0.01).Compare to older than 50 years,the percentage of cases with poorly differentiated CRC was relatively higher in CRC of younger than 50 years(13.62%vs.6.88%,p<0.001).However,the proportion of moderately differentiated CRC cases was relatively lower in CRC of younger than 50 years(49.58%vs.55.34%,p= 0.009).The number of TNM CRC patients with stage Ⅱ was relatively smaller in CRC of younger than 50 years(28.40%vs.33.77%,p=0.030),mainly in stages Ⅲ and Ⅳ.ConclusionsWhile the recommended screening age for colonoscopy is>50 years,several patients in the 40-49 year age group were diagnosed with CRC.The number of people undergoing colonoscopy for physical examination had increased significantly.Most lesions accumulate in the rectosigmoid segment.In recent years,the commonest site of CRC has changed to the proximal colon.Adenocarcinoma is the main histological classification of CRC.The histological grade was mainly moderately differentiated adenocarcinoma,and the moderately differentiated adenocarcinoma was significantly increased,and the highly differentiated adenocarcinoma was significantly reduced.The detection rate of HGIN generally increased,while the CRC detection rate showed a downward trend.Compared with the CRC group of older than 50 years old,the young CRC had obvious reasons for colonoscope.More histological classification was signet ring cell carcinoma.The histological grade was more poorly differentiated.-The TNM stage was mainly concentrated in the relatively late stage.