Estimation Of Polyp Size Research Articles

S1174 UC Patients With High Level Antibody Responses to CD-Associated Microbial Antigens Exhibit Aberrant IFNG DNA Methylation Patterns

AIM: Colonic polyps are causally related to the nearly 150,000 yearly incident cases of colon cancer in the USA. The study aim was to identify and quantitate variables that affect polyp size in a large sample of patients undergoing CS for indications of routine screening or family history of colorectal cancer. METHODS: 93,110 adult patients from 67 GI practices in 25 states undergoing CS who had colorectal polyps on exam were identified in the Clinical Outcomes Research Initiative (CORI) database. Polyp size of the largest polyp was the outcome variable; patient age, race, gender, type of practice, anatomic location, and indication for procedure were independent variables. Ten-year age bands were used to stratify patient age; the size of the largest polyp in each patient was stratified into four ordinal groups (05 mm, 5.1-9, 9.1-15, >15 mm). Ordinal logistic regression was used to obtain multivariateadjusted estimates of polyp size in relation to patient age. RESULTS: For patients 80 years. After multivariate adjustment, odds of having a larger polyp increased with each increasing age group, compared to those under 50 years (see Table). The odds ratio for polyp size in the oldest age group versus youngest age group was 1.61 (95% CI = 1.46-1.77, p = <0.0001). Other factors with multivariate-adjusted significant odds ratios were gender (males vs females 1.18, P = <0.0001), race (blacks versus whites 1.33, P = <0.0001), practice type (community vs academic 1.26, P = <0.0001), and polyp location (distal vs proximal colon 0.89, P = <0.0001). CONCLUSION: Size of the largest polyp detected at CS increases significantly with age, and among variables included in a multivariate model, age has the strongest association with polyp size.

S1172 Genetic Markers Associated With the Development of Denovo Crohn's Disease After Ileal Pouch-Anal Anastomosis

AIM: Colonic polyps are causally related to the nearly 150,000 yearly incident cases of colon cancer in the USA. The study aim was to identify and quantitate variables that affect polyp size in a large sample of patients undergoing CS for indications of routine screening or family history of colorectal cancer. METHODS: 93,110 adult patients from 67 GI practices in 25 states undergoing CS who had colorectal polyps on exam were identified in the Clinical Outcomes Research Initiative (CORI) database. Polyp size of the largest polyp was the outcome variable; patient age, race, gender, type of practice, anatomic location, and indication for procedure were independent variables. Ten-year age bands were used to stratify patient age; the size of the largest polyp in each patient was stratified into four ordinal groups (05 mm, 5.1-9, 9.1-15, >15 mm). Ordinal logistic regression was used to obtain multivariateadjusted estimates of polyp size in relation to patient age. RESULTS: For patients 80 years. After multivariate adjustment, odds of having a larger polyp increased with each increasing age group, compared to those under 50 years (see Table). The odds ratio for polyp size in the oldest age group versus youngest age group was 1.61 (95% CI = 1.46-1.77, p = <0.0001). Other factors with multivariate-adjusted significant odds ratios were gender (males vs females 1.18, P = <0.0001), race (blacks versus whites 1.33, P = <0.0001), practice type (community vs academic 1.26, P = <0.0001), and polyp location (distal vs proximal colon 0.89, P = <0.0001). CONCLUSION: Size of the largest polyp detected at CS increases significantly with age, and among variables included in a multivariate model, age has the strongest association with polyp size.

Reply

Reply

Protrusion Method for Automated Estimation of Polyp Size on CT Colonography

The purpose of this study was to assess the accuracy and measurement variability of automated lesion measurement on CT colonography in comparison with manual 2D and 3D techniques under varying scanning conditions. The study included phantoms (23 phantom objects) and patients (16 polyps). Measurement with sliding calipers served as the reference for the phantom data. The mean of two independent colonoscopic measurements was the reference for the polyps. The automated measurement was developed for a computer-aided detection scheme, and the size of any detected object was obtained from measurement of its largest diameter. The automated measurement was compared with manual 2D and 3D measurements by two experienced observers. For phantom data, the measurement variability of the automated method was significantly less than that of the two observers (p < 0.05), except for the 3D measurement by observer 1, as follows: automated, 0.86 mm; observer 1, 1.76 mm (2D), 0.96 (3D); observer 2, 1.34 mm (2D), 1.45 mm (3D). The variability of the automated method did not differ significantly from that of manual methods in measurement with patient data. The automated method had a systematic error for phantom data (1.9 mm). For phantoms, the automated method has less measurement variability than manual 2D and 3D techniques. For true polyps, the measurement variability of the automated method is comparable with that of manual methods. The automated method does not suffer from intraobserver variability. Because systematic error can be calibrated, automated size measurement may contribute to a practical evaluation strategy.

Do topical nasal decongestants affect polyps?

Conclusions. The hypothesis that decongestants reduce the size of nasal polyps could not be verified. Decongestion is therefore recommended prior to nasal endoscopy, especially in polyp diagnosis, as it does not artificially change the size of the polyps. Objective. The role of nasal decongestants in nasal stuffiness is well established and their action is well known. Decongestants are also used prior to nasal endoscopy to achieve a better view of the nasal cavity in order to diagnose polyps. The question is whether this decongestion invalidates the estimation of polyp size in clinical and scientific practice. The aim of this study was to evaluate possible effects of topical decongestants on polyp extension in patients with nasal polyposis. Material and methods. The effect of the decongestants nafazoline and epinephrine on nasal polyp size was assessed by means of a double-blind, placebo-controlled randomized study. A sensitive endoscopic scoring system, lateral imaging, was used to assess the size and extension of the nasal polyps. Results. No significant effect of decongestion on polyp size could be found for either treatment.

I Once Caught a Fish This Big: Endoscopists' Estimate of Polyp Size

Background: Polyp size ≥1cm has important implications for surveillance recommendations as well as risk for development of colon cancer. No study has looked at how accurately endoscopists estimate polyp size over an extended period of time while eliminating observation bias (the Hawthorne effect). Aim: To examine the accuracy with which endoscopists estimate polyp size, and determine how frequently an inaccurate estimate may lead to an inappropriate surveillance regimen. Methods: We performed a retrospective analysis linking our endoscopy database to pathology results over a 3-year period. The Hawthorne effect (bias created when the act of observation changes the outcome) was minimized due to the retrospective nature of this study. Only pedunculated polyps that were completely removed by snare and retrieved intact were included in this study. The estimate of the polyp size was recorded and compared to the pathologists' measurement (the gold standard). Patient age, the adequacy of preparation, the location of the polyp, the histopathology of the polyp, and whether a training fellow was involved were recorded. Linear regression was employed to examine predictors of accurate polyp size estimation. Results: 206 consecutive polyps were included in this study. The average age (±SD) of the subjects was 59.4 years (±12.2). 86% of the polyps were removed from the recto-sigmoid colon. The mean estimate of the largest dimension was 1.2cm (±0.6cm). The mean largest dimension measured by pathologists was 1.1cm (±0.7cm). In 61/206 polyps (29.6%), the estimate of polyp size was ≥1cm while the actual size was <1cm. The mean difference between estimated and actual size in this group was 0.4cm (±0.3cm). In 8/206 patients (3.8%), the estimate of polyp size was <1cm while actual size was ≥1cm. The mean difference in this group was 0.3cm (±0.1cm). As the polyp size increased, the difference between estimated and actual polyp size decreased (p<0.0001). No other variable predicted accuracy. Conclusions: Gastroenterologists often overestimate polyp size during routine colonoscopy. In over 30% of cases, this inaccuracy may have led to inappropriate surveillance recommendations. While larger polyps are more likely to be accurately sized, the age of the patient, the quality of the preparation, the location of the polyp, and whether a training fellow was assisting do not predict inaccuracy.

The pathologic measurement of polyp size is preferable to the endoscopic estimate

Background: There is no standardized technique to measure polyp size. Estimation of polyp size at endoscopy is difficult. Polyp size measurement by pathologists would seem to be an accurate alternative, but tissue fixation may alter polyp size. To evaluate methods of determining polyp size, we compared endoscopists' estimates and pathologists' measurements with measurements made by an independent examiner. Methods: Polyps were measured by an independent investigator before and after formalin fixation. The investigator's measurement before fixation (the “gold standard”) was compared with the endoscopists' estimates and the pathologists' measurements. Results: Ten endoscopists removed 61 polyps with a snare in 33 patients: 82% were adenomatous and 72% were pedunculated. Mean size was 0.85 ± 0.6 cm (SD) (range: 0.3 to 3.6 cm, 26% ≥ 1 cm). Polyps remained in formalin for a mean of 239 minutes (46 to 1164 minutes). Polyps neither consistently shrank nor enlarged in formalin (maximum change ± 0.2 cm, r = 0.99 [ p < 0.001]). Interobserver agreement between pathologists' and the investigator's post-formalin measurements showed that 55 of 57 polyps (97%) were within ± 0.3 cm. Endoscopists inaccurately estimated 11 of 56 polyps (20%) (> 0.3 cm difference from the independent examiner). Polyp size was underestimated in three instances (range 0.5 to 0.9 cm) and overestimated in eight (range 0.4 to 0.8 cm). In 5 of 11 instances (46%), this inaccuracy altered polyp size classification across the 1 cm threshold. Results were not dependent on endoscopist, histology, or polyp location. Conclusions: (1) Polyp size is not significantly affected by formalin fixation; 2) Endoscopists' estimates of polyp size are often unreliable; and, when possible, (3) Pathologists' measurements of polyp size should be used in clinical trials and in clinical practice. (Gastrointest Endosc 1997;46:492-6.)

Inaccurate polyp size estimation can affect patient management: endoscopic estimates of polyp size should be abandoned in favor of the pathologist's measurement

Inaccurate polyp size estimation can affect patient management: endoscopic estimates of polyp size should be abandoned in favor of the pathologist's measurement

The difference in colon polyp size before and after removal

Background: Accurate knowledge of polyp size is important in assessing cancer risk in both clinical studies and individual patients. We sought to determine if a difference exists between the endoscopic estimation of colon polyp size and the actual measurement after removal. Methods: We measured polyps in a systematic fashion. Using open biopsy forceps as a guide, the largest diameter of 31 pedunculated polyps was estimated endoscopically. The polyp was then removed by snare polypectomy and directly measured by a technician who was blinded to the endoscopic estimate. Each polyp was also measured after formalin fixation by a pathologist who was blinded to previous measurements. Results: There was a significant difference between the endoscopic estimates and the postpolypectomy measurements. Endoscopic estimates on average were 1.6 mm greater than the postpolypectomy measurements (p < 0.05), representing an 18% difference. Twenty-three of the 31 (74%) endoscopic estimates were larger than the postpolypectomy measurements. There was not a significant difference between the postpolypectomy and postfixation measurements. Conclusions: The size of polyps measured endoscopically is significantly larger on average than postpolypectomy measurements. This is most likely due to factors involved in the removal of the in vivo polyp. (Gastrointest Endosc 1996;43:25-8.)

The difference in colon polyp size before and after removal

Background: Accurate knowledge of polyp size is important in assessing cancer risk in both clinical studies and individual patients. We sought to determine if a difference exists between the endoscopic estimation of colon polyp size and the actual measurement after removal. Methods: We measured polyps in a systematic fashion. Using open biopsy forceps as a guide, the largest diameter of 31 pedunculated polyps was estimated endoscopically. The polyp was then removed by snare polypectomy and directly measured by a technician who was blinded to the endoscopic estimate. Each polyp was also measured after formalin fixation by a pathologist who was blinded to previous measurements. Results: There was a significant difference between the endoscopic estimates and the postpolypectomy measurements. Endoscopic estimates on average were 1.6 mm greater than the postpolypectomy measurements (p < 0.05), representing an 18% difference. Twenty-three of the 31 (74%) endoscopic estimates were larger than the postpolypectomy measurements. There was not a significant difference between the postpolypectomy and postfixation measurements. Conclusions: The size of polyps measured endoscopically is significantly larger on average than postpolypectomy measurements. This is most likely due to factors involved in the removal of the in vivo polyp. (Gastrointest Endosc 1996;43:25-8.)

How accurate are endoscopic estimates of size?

The accuracy of polyp size estimations in clinical studies is not known. This study was designed to evaluate how well endoscopists can estimate the size of objects at endoscopy. Observations were made by six attending gastroenterologists, six gastroenterology fellows, and seven untrained medical residents. Ball bearings ranging in size from 3 mm to 19 mm were randomly inserted into a latex colon model, and size was estimated while being viewed with a video colonoscope with and without the aid of an open biopsy forceps. Estimated size correlated well to actual size (R ranged from 0.78 to 0.93), although the mean estimates were consistently lower (13%to 29%) than the actual size for all groups, with and without forceps. The use of forceps did not improve the estimates. Exactly correct estimates occurred in 8%; errors of as much as 110%were recorded. The 12 mm bearing was estimated to be less than 10 mm half of the time. We conclude that endoscopists frequently underestimate the size of objects viewed at the time of endoscopy. There was no difference in the performance of experienced gastroenterologists, fellows in training, or untrained residents. This study indicates that better methods of training and for determining size are needed. Research that depends on endoscopic estimates of polyp size may be biased (Gastrointest Endosc 1994;40:174-7.)

Are endoscopic measurements of colonic polyps reliable?

Many clinical studies of colorectal adenomatous polyps rely on endoscopic estimation of polyp size. To examine the reliability of such measurements, we conducted a study using artificial polyps in an endoscopy teaching model. Eight experienced endoscopists estimated the size of 13 polyps in two separate sessions 2 wk apart. Endoscopic estimates of polyp size tended to be significantly lower than the true polyp size for all polyps and all endoscopists at both sessions. We also found a statistically significant difference in the magnitude of the underestimation between the first and second session (p < 0.0001). At the first session, polyps tended to be estimated at 64% of their true size, and at the second session, the estimates tended to be at 77% of the actual polyp size. We estimate the magnitude of the variation in polyp measurements due to individual polyps, endoscopist, and examination session, and discuss the impact these sources of variation have in planning of clinical trials.