Clinical Features Of Colorectal Serrated Polyps

Background and Aims:Colorectal cancer(CRC)is one of the most common cancers in the worldwide.Colorectal serrated polyps(SPs)were once considered benign lesions,but now there is increasing evidence that SPs is closely related to colorectal cancer.Currently,serrated polyps are classified by the World Health Organization(WHO)into three distinct subtypes: Hyperplastic polyp(HP),sessile serrated adenoma/polyp(SSA/P)with or without cytological dysplasia,and traditional serrated adenoma(TSA),and each has specific features.However,few Asian studies have investigated the comprehensive clinical features of colorectal serrated polyps.To address this issue and also provide more evidence for the management of colorectal serrated polyps in clinical practice,we evaluated the detection rate and the features of serrated polyps in a Chinese symptomatic patient population and to compare the differences between China and the west,so as to reduce the incidence of colorectal tumors and improve the prognosis.Methods:All consecutive symptomatic patients who underwent routine colonoscopy at the Digestive Endoscopy Center of Tianjin Medical University General Hospital,between January 2010 and December 2014,were investigated.The indications for colonoscopy were due to various symptoms,such as abdominal pain,diarrhea,and change of bowel habits.The pathological sections of suspected colorectal serrated polyps were revaluated and reclassified by one experienced pathologist(Wen Jing Song)using the WHO criteria.The demographic and clinicopathological data of all colorectal serrated polyps with a final diagnosis and classification were further collected,including patient age and gender,lesion size,polyp number,and location.All statistical analyses were performed using SPSS 19.0(SPSS Inc,Chicago,IL,USA)for Windows.Risks of colorectal serrated polyps were compared by Chi?square test or Fisher’s exact test.Means and standard deviation were calculated for continuous variables.Logistic regression analysis was used to evaluate the odds ratio(OR)and 95% confidence interval(CI)for colorectal synchronous AN(s AN).Age,gender,size,location,and dysplasia were selected as possible confounding factors.The level of statistically significance was set at two?tailed P < 0.05.Result:1.Detected rate of colorectal serrated polyps: A total of 28,981 symptomatic patients undergoing colonoscopy from 2010 to 2014 were collected in this study.The overall prevalence of colorectal serrated polyps in the current study was about0.53%(153/28,981).Among the 153 serrated polyps,HP,SSA/P,and TSA accounted for 41.2%(63/153),7.2%(11/153),and 51.6%(79/153),respectively.2.Sex and age:The mean age was 57.4 ± 13.6 years,and HP,SSA/P,and TSA were56.2 ± 13.0 years,60.3 ± 9.4years,58.0 ± 14.4years.However,there was no significant difference in the subtype’s distribution in gender and age.3.Clinical features:The main indications for colonoscopy were abdominal discomfort in 47.2% patients,abdominal pain in 15.9% patients,the change of bowel habits in10.3% patients,and diarrhea in 9.3% patients.4.Colorectal serrated polyp numbers:A total of 9191 individuals(31.7%)were found with at least one colorectal polyp and 149 individuals had at least one serrated polyp.Among the 149 patients,a total of 153 serrated polyps were detected.5.Locations:Serrated polyps(53.6% in the distal colon),HPs(60.3% in distal colon),SSA/Ps(54.5% in proximal colon),and TSAs(50.6% in proximal colon)showed no significant difference in anatomic location which was different from previous studies.6.Size and shape:The serrated polyps in the present study tended to have a small diameter(<10 mm).Furthermore,LSPs(diameter ≥10 mm)have a pooled prevalence of 0.2%(21/9191)of all polyps,and the proportion of LSPs in all serrated polyps was13.7%(21/153).7.Dysplasia : 58.2%(89/153)serrated adenomas were found with dysplasia,Moreover,14 patients with serrated polyps were found with synchronous advanced colorectal neoplasia,and large serrated polyps(LSPs),especially large HPs,might have an association with synchronous advanced neoplasia(AN).Conclusion:1.In this study,the detection rates of colorectal serrated polyps and sessile serrated adenoma/polyp were relatively low,while the detection rates of traditional serrated adenoma were relatively high.The distribution pattern of the three subtypes is obviously different from that of western countries.2.Serrated polyps are more common in males.With age,the detection rate of serrated adenomas shows a trend of steady increase,while the hyperplastic polyps show a peak at 60-69 years old.3.Large serrated polyps(diameter≥10mm)may be associated with an increased risk of s AN.If encountering with such patients in the clinical,we should as far as possible completely resect the lesions,with close follow-up and timely reexamination.4.Further studies are needed to evaluate the detection and the subtype distribution of colorectal serrated polyps in Chinese population.This study can provide references for clinicians to improve their understanding of colorectal serrated polyps.