Prevalence Of Proximal Neoplasia Research Articles

Association of distal hyperplastic polyps and proximal neoplastic lesions: a prospective study of 5613 subjects

Current evidence of whether distal hyperplastic polyps (HPs) are markers of proximal neoplasia (PN) is mixed. We evaluated the association between distal neoplasia and synchronous PN in asymptomatic subjects. We recruited 5819 Chinese asymptomatic screening participants 50 to 70 years of age who underwent colonoscopy in Hong Kong from 2008 to 2014, of whom 206 subjects with distal advanced neoplasia or cancer were excluded. The association between distal pathology (tubular adenomas [TAs], HPs, no polyps) and proximal pathology (PN, proximal advanced neoplasia [PAN]) was assessed by multivariate regression models, overall and stratified by the Asia Pacific Colorectal Screening scoring system (scores of 4-7, high risk; scores of 0-3, lower risk). The prevalence of PN in the no distal polyps group, distal HPs group, and distal TAs group was 14.8%, 19.3%, and 29.4%, respectively. The corresponding prevalence of PAN was 1.8%, 3.2%, and 3.5%. Participants with distal HPs did not have significantly higher odds of PN (adjusted odds ratio [AOR] 1.24; 95% confidence interval [CI], 0.97-1.59; P = .089), and their association with PAN was marginally significant (AOR 1.77; 95% CI, 1.00-3.13; P = .052), except in lower risk subjects for whom the odds of PAN were marginally higher in the distal HPs group than the no distal polyps group (AOR 1.97; 95% CI, 1.01-3.85; P = .048). Overall, the distal polyps group had significantly lower odds of PN than the distal TAs group (AOR 0.55; 95% CI, 0.40-0.76; P < .001). The increased risk of PN and PAN among those with distal HPs was modest. A direct association between distal HPs and PN is lacking, and this implies a need for a multivariate assessment of the risk of PAN. Recommending colonoscopy for every patient with distal HPs detected by screening sigmoidoscopy is not supported by this study.

The Relationship Between Distal and Proximal Colonic Neoplasia: A Meta-Analysis

OBJECTIVESTo investigate the association between proximal colonic neoplasia and distal lesions as a function of the lesion type. The extent to which health, demographic, and study characteristics moderate this association was also examined.DATA SOURCESGoogle Scholar, Web of Science, Scopus, and PubMed.STUDY ELIGIBILITY CRITERIAStudies allowing the calculation of OR of proximal neoplasia(PN) and proximal advanced neoplasia (PAN) for distal hyperplastic polyps (HP), nonadvanced adenomas (NAA), adenomas (AD), and advanced neoplasia (AN); also, studies for which the proportions of subjects with isolated (i.e., not accompanied by distal lesions) PN (IPN) and PAN (IPAN) over the total number of subjects with PN or PAN could be calculated.STUDY APPRAISAL AND SYNTHESIS METHODSThirty-two studies were included for calculating OR between proximal neoplasia and distal lesions and 40 studies for proportions of IPN and IPAN. Subgroup analyses were conducted for presence of symptoms, prevalence of PN and PAN, age, proportion of males, geographic region, study design, and demarcation point.RESULTSThe association between distal lesions and proximal neoplasia increased with the severity of the distal lesions. Odds of PN were higher in subjects with HP compared to subjects with a normal distal colon. Odds of PN and PAN were higher in subjects with NAA, AD, and AN than in subjects with a normal distal colon. PAN were more strongly associated with distal lesions in asymptomatic populations, in young populations, and in populations with a low prevalence of PAN. In approximately 60% of the subjects with PN and PAN, these neoplasia were isolated.LIMITATIONSThe present results may be affected by publication bias and dichotomization in the subgroup analyses. Limitations related to the individual studies include self-selection, lesion misclassification and misses, and technological advances leading to changes in the detection of lesions during the time span of the included studies.CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGSAll types of distal lesions are predictive of PN. All types of distal neoplasia are predictive of PAN. The association between distal lesions and proximal neoplasia increases with the severity of the distal lesion. The association between distal lesions and proximal advanced neoplasia is stronger in low-risk groups as compared to high-risk groups.

Colonoscopy by a Family Physician: Detecting Proximal Neoplasia in Asymptomatic Adults

Flexible sigmoidoscopy (FS) is considered an adequate screening test in average risk (AR) patients. The purpose of this study was to determine the diagnostic yield of FS in detecting colonic neoplasia between AR and high risk (HR) patients. We present a chart review of 559 outpatient colonoscopies performed by a family physician from September 2003 to October 2007. The prevalence of neoplasia and diagnostic yield of FS was compared between groups. The overall prevalence of neoplasia was 23.1% (AR) and 32.8% (HR); p = 0.02. The prevalence of proximal neoplasia not detectable by FS was 10.2% (AR) and 14.5% (HR); p = 0.16. The diagnostic yield of FS in each group was 56%; FS would have missed 44% of polyps regardless of patient risk. The high rate of colonic neoplasia not detected by FS (44%) suggests that FS alone is inadequate for screening in AR patients.

Colonoscopic screening of an average-risk population for colorectal neoplasia

The role of screening colonoscopy in an asymptomatic, average-risk population remains to be determined. Moreover, the value of screening colonoscopy in individuals older than 75 years and for right-sided lesions has recently been questioned. The aims were to assess: (i) the risk of colorectal neoplasia in a large consecutively screened asymptomatic average-risk population, aged 40-85 years; (ii) whether colonoscopy is better than sigmoidoscopy for primary screening; and (iii) the prevalence of right-sided lesions at different ages. This prospective study, analyzed data from 1563 consecutive, asymptomatic, average-risk individuals, aged 40-85 years, who underwent screening colonoscopy. Overall, neoplastic lesions were detected in 262 individuals (17% of the study population), of whom 75 had advanced lesions (5% of population) and nine had colorectal cancers (CRC) (0.6% of population). The prevalence of all lesions increased with age, with the highest percentages in the > 75 age group (26.5% with neoplastic and 6 % with advanced lesions). Higher age was also associated with relatively more right-sided lesions. In particular the prevalence of proximal neoplasia, without concurrent distal neoplasia, increased from 5% in those < 50 years to 24% in those > 75 years. Those with distal lesions had a higher overall risk for proximal lesions (odds ratio [OR] 3.2); nevertheless flexible sigmoidoscopy alone would have missed up to 40% of all lesions and up to 3.5% of advanced neoplastic lesions in this patient subgroup. Screening colonoscopy in asymptomatic, average-risk individuals is mandatory, as noteworthy numbers of advanced colorectal neoplasias have been detected in all age groups, especially in those aged > 75. Most importantly, many of the detected lesions were proximal and would not be revealed by sigmoidoscopy alone.

Risk Analyses for Sigmoidoscopy As a Screening Tool Based On the Incidence of Proximal Colorectal Carcinomas in a General Hospital

Risk Analyses for Sigmoidoscopy As a Screening Tool Based On the Incidence of Proximal Colorectal Carcinomas in a General Hospital Sanna Mulder, Rob J. Ouwendijk, Monique E. Van Leerdam, Ernst J. Kuipers Introduction: Sigmoidoscopy screening for colorectal cancer (CRC) has been suggested. Colonoscopy may be more effective in CRC prevention, however colonoscopy requires more endoscopy facilities, has a higher risk of complications and is more expensive. Aim: To determine the risk for advanced proximal neoplasia and to identify subgroups in which screening sigmoidoscopy might suffice using retrospective colonoscopy data from a single general hospital. Methods: A database search using the Endobase datasystem was performed on all patients who underwent lower endoscopy between 1997 and October 2005 in a single general hospital. All patients diagnosed with CRC were included. Demographical data were collected as well as data concerning tumor characteristics, i.e. location, stage. Variables including age (!65 or O65 years of age), sex, and distal findings were used for risk analyses. Results: In total, 794 patients were diagnosed with CRC (M/F 416/378, mean age 70 yrs, range 27-95 yr). The CRC was localized in 67% of the patients in the distal colon and in 33% proximal of the descending colon. In 7 patients the location of the CRC was not further specified.In the group under 65 years of age, in total 258 patients were diagnosed with CRC (149 M, 109 F). In 65/ 258 (25%) patients the CRC was localized in the proximal colon, without significant difference between men and women. A synchronous distal neoplasia was found in 21 of these 65 patients (12 M, 9 F). In 17% (44/258) only a proximal CRC was found, which would have been missed by screening sigmoidoscopy. In the group over 65 years of age, 536 patients were diagnosed with CRC (267 M, 269 F). In 198/536 (37%) patients the CRC was localized in the proximal colon, significantly more women had a proximal CRC (75 M, 123 F, p ! 0.01). A synchronous distal neoplasia was found in 44 of these 198 patients (22 M, 22 F). In 29% (154/536) only a proximal CRC was found, which is significantly more compared to those under 65 yrs of age (p ! 0.01). There was a significant difference regarding the overall prevalence of proximal neoplasia between the age-group under and over 65 years (p ! 0.01). Conclusions: The proportion of CRC that is located in the proximal colon changes with age. In elderly, proximal CRC is proportionally more common, and more often occurs without distal marker lesions. In patients above 65 yrs of age significantly more proximally localized CRC would have been missed by screening sigmoidoscopy. When considering CRC screening sigmoidoscopy screening will suffice in the age-group below 65 yrs of age. Given these data, in men and women above 65 yrs of age colonoscopy might be the preferred screening method.

Colon pathology detected after a positive screening flexible sigmoidoscopy: a prospective study in an ethnically diverse cohort.

Although the association between distal neoplasia on sigmoidoscopy and proximal colonic pathology on follow-up colonoscopy has been well-described, it is not known if these findings are consistent across ethnic groups. The aim of this study was to evaluate ethnic variations in the prevalence of proximal neoplasia on follow-up colonoscopy after a neoplastic lesion is found on sigmoidoscopy. Consecutive asymptomatic patients at average-risk for colorectal cancer who were referred for screening flexible sigmoidoscopy were prospectively enrolled. Colonoscopy was recommended for all patients with a polyp on flexible sigmoidoscopy, regardless of size. Advanced neoplasms were defined as adenomas > or = 10 mm in diameter or any adenoma, regardless of size, with villous histology, high-grade dysplasia, or cancer. Among the 2,207 patients who had sigmoidoscopy, 970 were Caucasian, 765 were African American, 395 were Hispanic, and 77 were Asian. The prevalence of neoplasia in the distal colon was 12.6% in Caucasians, 11.2% in African Americans, 15.9% in Hispanics, and 24.7% in Asians (p = 0.002). Of the 290 patients with neoplastic lesions on sigmoidoscopy, follow-up colonoscopy identified neoplasms in the proximal colon in 63.9% of Caucasians, 59.3% of African Americans, 66.7% of Hispanics, and 26.3% of Asians (p = 0.01). Advanced neoplasms in the proximal colon were highest in African Americans (34.9%) and lowest in Asians (10.5%). In our study population, Asians demonstrated a higher prevalence of distal colonic neoplasia and a lower prevalence of proximal colonic neoplasia compared to non-Asians. Future studies should explore ethnic variation in colonic neoplasia prevalence and location since ethnic variation could lead to tailored colorectal cancer screening strategies.

Risk of proximal colorectal neoplasia among asymptomatic patients with distal hyperplastic polyps

Purpose Many guidelines on colorectal cancer screening do not consider distal hyperplastic polyps to be a marker for proximal neoplasia. However, 11 of 17 published studies have shown an increased risk of proximal neoplasia in patients with distal hyperplastic polyps. Our goal is to assess the risk of proximal neoplasia in asymptomatic patients with distal hyperplastic polyps, compared to those with distal tubular adenomas or no distal polyps. Methods We assessed proximal (cecum, ascending, transverse colon and splenic flexure) and distal polyps in patients undergoing screening colonoscopy, classifying them into 3 groups: distal hyperplastic polyps only; distal adenomas with or without hyperplastic polyps; no distal polyps. The prevalence of proximal neoplasia and advanced neoplasia (polyps ≥1 cm, villous adenomas, or cancer) was compared among these groups. Results Of 2357 patients, 427 (18%) had neoplasia, including 103 (4%) with advanced neoplasia. Proximal neoplasia occurred in 175 (9%) of 1896 patients with no distal polyps, compared with 28 (12%) of 237 with distal hyperplastic polyps ( P = 0.20) and 64 (29%) of 224 with distal adenomas ( P <0.0001). Proximal advanced neoplasia occurred in 39 (2%) patients with no distal polyps, compared with 4 (2%) with distal hyperplastic polyps ( P = 0.70) and 9 (4%) with distal adenomas ( P = 0.13). Conclusions Patients with distal hyperplastic polyps, unlike those with distal adenomas, do not exhibit an increased risk for proximal neoplasia or proximal advanced neoplasia compared to those with no distal polyps. The discovery of hyperplastic polyps on screening sigmoidoscopy should not prompt colonoscopy.

Risk of Proximal Colon Neoplasia With Distal Hyperplastic Polyps

Most guidelines for colorectal cancer screening do not consider distal hyperplastic polyps (HPs) to be markers for proximal colon neoplasia. However, many studies have shown an increased risk of proximal neoplasia (PN) in patients with distal HPs. We performed a systematic review to assess the association between distal HPs and PN. We identified studies that compared the prevalence of PN and proximal advanced neoplasia in patients with distal HPs vs controls. Two masked investigators extracted data on individuals with distal HPs, distal adenomas, or no distal polyps. Using the DerSimonian and Laird method, we calculated summary risk ratios. Extensive subgroup analysis was performed. The prevalence of PN and proximal advanced neoplasia in persons with distal HPs was 26.0% and 4.4%, respectively. In studies comparing the risk of PN in patients with distal HPs vs those with no distal polyps, the summary risk ratio was 1.81 (95% confidence interval, 1.20-2.73). However, this increased risk disappeared if only high-quality studies on screening patients were considered. The risk ratio was 0.69 (95% confidence interval, 0.60-0.80) when comparing the risk of PN in those with distal HPs vs those with distal adenomas. Overall, patients with distal HPs have an intermediate risk of PN compared with those with distal adenomas or no distal polyps; however, in asymptomatic screening individuals, there is no increased risk of PN or proximal advanced neoplasia. The discovery of HPs on screening flexible sigmoidoscopy should not automatically prompt follow-up colonoscopy.

The yield of colonoscopy in average-risk patients with non-specific colonic symptoms.

The need for full colonoscopies in average-risk patients with non-specific colonic symptoms is controversial. We aimed to evaluate: (1) the yield of full colonoscopy; (2) the prevalence of proximal neoplasia in these patients; (3) the yield if any of doing full colonoscopies to diagnose proximal lesions in patients in whom the distal colon was clear; (4) the significance of this yield with respect to age. This is a retrospective analysis to assess the value of open access colonoscopy. All patients who underwent a colonoscopy in our Endoscopy Unit during January 1996 to December 1999 were assessed (n = 3357). We analysed 945 patients with average risk and non-specific colonic symptoms (significant risk factors excluded). The overall yield of adenomas was 5.8%. The yield of distal adenomas in patients > or= 50 years of age was 8.2% (37 out of 450) versus 0.2% in the 50 years group (one out of 495; = 0.0001). The proximal adenoma yield in > or= 50 year olds was 3.8% (17 out of 495) versus 0.2% in < 50 year olds (one out of 495) (P = 0.0001). In a cohort of average-risk patients with non-specific colonic symptoms attending an "open access" colonoscopy clinic, the yield for proximal adenomas is small in the < 50 years group. In patients aged < 50 years, distal colonic examination is all that is required, whereas a full colonoscopy may be justified in patients > or = 50 years old.