Does Magnifying Narrow-Band Imaging or Magnifying Chromoendoscopy Help Experienced Endoscopists Assess Invasion Depth of Large Sessile and Flat Polyps?

Background

Distinguishing deep submucosa (SM) from superficial SM cancer in large sessile and flat colorectal polyps (>2 cm) is crucial in making the most appropriate therapeutic decision. We evaluated the additional role of magnifying narrow-band imaging (NBI) and magnifying chromoendoscopy (MCE) in assessing the depth of invasion in large sessile and flat polyps in comparison to morphological evaluation performed by experienced endoscopists.

Methods

From May 2011 to December 2011, a total of 85 large sessile and flat polyps were analyzed. Endoscopic features of the polyps were independently evaluated by experienced endoscopists. Subsequently, the polyps were observed using magnifying NBI and MCE.

Results

A total of 58 intramucosal lesions and 27 SM cancers (five superficial and 22 deep) were identified. The diagnostic accuracy of the experienced endoscopists, NBI, and MCE were 92.9, 90.6, and 89.4 %, respectively, for deep SM cancer. In combination with NBI or MCE, the diagnostic accuracy of the experienced endoscopists did not change significantly for deep SM cancer, with an accuracy of 95.3 % for both NBI and MCE.

Conclusions

Conventional colonoscopy can differentiate superficial from deep SM cancers with an accuracy of as high as 92.9 % in large sessile and flat polyps. Further diagnostic strategies are required in order to precisely assess the depth of invasion, especially in large colorectal polyps.     

White Opaque Substance Visualized Using Magnifying Endoscopy with Narrow-Band Imaging in Colorectal Epithelial Neoplasms

Background

The presence of a white opaque substance (WOS) on magnifying endoscopy (ME) with narrow-band imaging (NBI) has been reported for gastric epithelial neoplasms, but the presence of WOS in colorectal epithelial neoplasms has not been investigated.

Aims

The purpose of this study was to determine whether WOS is present in colorectal epithelial neoplasms and to clarify its clinical significance.

Methods

A total of 590 colorectal epithelial neoplasms from 368 consecutive patients were retrospectively analyzed using prospectively collected data. Presence or absence of WOS in colorectal epithelial neoplasms was recorded based on the findings of ME with NBI.

Results

White opaque substance was present in 236 of the 590 (40 %) colorectal epithelial neoplasms. Compared with WOS-negative patients, WOS-positive patients showed significantly larger tumors (p < 0.0001) and significantly more tumors in the proximal colon (p = 0.0003). WOS was more frequently present in carcinomas (66.0 %) than in adenomas (31.8 %; p < 0.0001). WOS was also more frequent in submucosal carcinomas (75.9 %) than in intramucosal carcinomas (59.0 %; p = 0.0380).

Conclusions

This study confirmed the presence of WOS in colorectal epithelial neoplasms, and prevalence increased with the progression of cancer, from adenoma to carcinoma and from intramucosal carcinoma to submucosal carcinoma.     

Efficacy of magnifying endoscopy with flexible spectral imaging color enhancement in the diagnosis of colorectal tumors

Background

Magnifying endoscopy with flexible spectral imaging color enhancement (FICE) is an image-enhanced endoscopy that captures the surface and vascular patterns of colorectal tumors. We evaluated and compared FICE magnification to narrow-band imaging (NBI) magnification.

Methods

Flexible spectral imaging color enhancement or NBI magnification was performed to the visualize surface and vascular patterns of colorectal tumors, classified into 4 types: Type A, Type B, Type C1/C2, and Type C3, as previously reported. A total of 235 colorectal tumors were examined. The correlations between classifications found by FICE or NBI magnification and histopathological diagnoses were examined. Image evaluation was validated by assessing inter-observer and intra-observer agreements on examinations.

Results

Twenty-eight hyperplastic polyps (HPs), 115 tubular adenomas (TAs), 72 mucosal and slightly invaded submucosal cancers (M-sSM), and 20 massively invaded submucosal cancers (mSM) were diagnosed. By FICE magnification, HP and TA were observed in 93.3 and 6.7% of Type A (15 lesions), respectively. TA, M-sSM, and HP were observed in 82.6, 15.4, and 2.0% of Type B (52 lesions), respectively. M-sSM, TA, and mSM were observed in 50.0, 46.0, and 4.0% of Type C1/2 (50 lesions), respectively. mSMs were observed in all 7 Type C3 lesions. In diagnosing mSM in Type C3, the sensitivity and specificity of FICE magnification were 77.7 and 100%, respectively, compared to those of NBI, at 63.6 and 99.0%, respectively. Imaging evaluation was validated accurately by intra- and intra-observer measurements showing consistent results.

Conclusions

The classification of colorectal tumors by FICE magnification correlated well with the histopathological diagnoses, similar to findings for NBI magnification. FICE magnification can be evaluated accurately with the same diagnostic classifications as those used for NBI magnification.     

Differential diagnosis of colorectal polyps with respect to similar capabilities of white light colonoscopy and narrow-band imaging

Purpose

The responses of polyps to light essentially determine the diagnostic capability of an endoscopy system in differentiating adenomas from hyperplastic polyps. Compared with white light colonoscopy (WLC), narrow-band imaging (NBI) is expected to improve the diagnostic capability. The diagnostic capabilities of WLC and NBI are evaluated and compared based on the polyp responses.

Methods

The following WLC and NBI images were retrospectively reviewed and categorized: 195 images and polyps (89 WLC, 106 NBI) with the best visual quality were categorized in the best image group (BG), and 484 images of 242 polyps (both WLC and NBI) were categorized in the paired image group (PG). For each reflection of light used for WLC or NBI, the polyp responses were objectively expressed as reflection features. The reflection features were then used to establish a classification model for identifying adenomas. The diagnostic capability of reflection feature or classification model was measured by the area under the receiver operating characteristic curve (AUC).

Results

In both image groups, the diverse and heterogeneous features of the polyp responses enabled accurate identification of adenomas, regardless of the light source used for WLC and NBI. For differential diagnosis of adenomas and hyperplastic polyps, the WLC and NBI did not significantly differ in BG (AUC, 0.905 and 0.922, respectively; P?=?0.690) or in PG (AUC, 0.782 and 0. 769, respectively; P?=?0.755).

Conclusions

Using WLC and NBI as classification models is effective in differential diagnosis of colorectal polyps and exhibited similar capabilities.     

Endoscopic Tri-Modal Imaging Improves Detection of Gastric Intestinal Metaplasia Among a High-Risk Patient Population in Singapore

Background

Detection of pre-neoplastic gastric mucosal changes and early gastric cancer (EGC) by white-light endoscopy (WLE) is often difficult. In this study we investigated whether combined autofluorescence imaging (AFI) and narrow band imaging (NBI) can improve detection of pre-neoplastic lesions and early gastric cancer in high-risk patients.

Patients and Methods

Chinese patients who were 50-years-old or above with dyspepsia were examined by both high-resolution WLE and combined AFI followed by NBI (AFI–NBI), consecutively in a prospective randomized cross-over setting, by two experienced endoscopists. The primary outcome was diagnostic ability of the two methods for patients with pre-neoplastic lesions such as intestinal metaplasia (IM) and mucosal atrophy.

Results

Sixty-five patients were recruited. One patient with large advanced gastric cancer was found and excluded from the analysis. Among the remaining 64 patients, 38 (59 %) had IM; of these, 26 (68 %) were correctly identified by AFI–NBI (sensitivity 68 %, specificity 23 %) and only 13 (34 %) by WLE (sensitivity 34 %, specificity 65 %). AFI–NBI detected more patients with IM than did WLE (p = 0.011). Thirty-one patients (48 %) had mucosal atrophy. Ten patients (32 %) were identified by AFI–NBI (sensitivity 32 %, specificity 79 %) and four patients (13 %) by WLE (sensitivity 13 %, specificity 88 %) (p = 0.100). No dysplasia or EGC was found.

Conclusion

AFI–NBI identified significantly more patients with IM than did WLE. Our result warrants further studies to define the role of combined AFI–NBI endoscopy for detection of precancerous conditions.     

Characteristic magnifying narrow-band imaging features of colorectal tumors in each growth type

Purpose

We investigated the surface characteristics and vascular patterns of colorectal tumors according to growth type by means of magnifying narrow-band imaging (NBI).

Methods

Four hundred ninety-seven colorectal tumors larger than 10 mm (204 tubular adenomas [TAs], 199 frankly invasive intramucosal carcinomas to shallow invasive submucosal [M/SM-s] carcinomas, and 94 deeply invasive submucosal [SM-d] carcinomas) were analyzed. These colorectal tumors were classified according to growth type as follows: polypoid type, n?=?224; laterally spreading tumor-granular (LST-G) type, n?=?133; and LST-non-granular (LST-NG) type, n?=?140. Surface and vascular patterns were evaluated in relation to histology and growth type.

Results

The absent and irregular surface patterns were observed in approximately 40 % of the SM-d carcinomas of the polypoid and LST-G type. The unclear surface pattern was more frequent in tumors of the LST-NG type than in those of other growth types, regardless of histology. Among TAs and M/SM-s carcinomas, the dense vascular pattern was most frequent in polypoid type, the dense and corkscrew vascular patterns were most frequent in the LST-G type, and the honeycomb and avascular and/or fragmentary patterns were most frequent in the LST-NG type. The avascular and/or fragmentary vessel pattern was more frequent in SM-d carcinomas than in TA and M/SM-s carcinomas, regardless of growth type.

Conclusions

A part of LST-NG was difficult to identify the NBI magnifying surface pattern. Although NBI magnifying findings were almost same in each type lesion in SM-d lesion, those of LST-NG were different from those of LST-G and polypoid type in M/SM-s lesion.     

Effect of Pronase Premedication on Narrow-Band Imaging Endoscopy in Patients with Precancerous Conditions of Stomach

Background

Narrow-band imaging (NBI) endoscopy improves the detection of intestinal metaplasia. However, strategies to improve the visibility and diagnostic performance of NBI should be sought, as endoscopic views are often obscured by the presence of mucus.

Aim

To compare the visibility and diagnostic performance of NBI endoscopy according to pronase premedication in patients with precancerous conditions of the stomach.

Methods

Consecutive outpatients with a previous diagnosis of precancerous condition of the stomach were invited to undergo a surveillance NBI endoscopy between June and December 2012. Enrolled subjects were randomly assigned to pronase or control groups before NBI endoscopy. The visibility score and diagnostic performance of NBI endoscopy were compared between the two groups.

Results

Patients’ endoscopic and histopathological characteristics were similar between the two groups. Visibility score in the proximal part of the stomach and satisfaction score of the endoscopist were significantly higher in the pronase group than in the control group (p = 0.014 and p = 0.034, respectively). The diagnostic performance of NBI endoscopy to detect intestinal metaplasia was not different in either group (both p > 0.1). However, the negative predictive value of NBI endoscopy was much improved over that of white light endoscopy only in the pronase group (p = 0.013).

Conclusion

Pronase premedication increased the visibility of the proximal part of the stomach and the satisfaction score during NBI endoscopy. Furthermore, negative predictive value of NBI endoscopy was much improved compared with that of white light endoscopy after pronase premedication.     

Narrow band imaging versus white light gastroscopy in detecting potentially premalignant gastric lesions: a randomized prospective crossover study

Background and Aims

Narrow band imaging (NBI) detects mucosal surface details (pit pattern) as well as the microvasculature pattern of mucosa. In premalignant conditions the pattern and regularity of pits and microvasculature are altered. We aimed to assess whether NBI is superior to conventional white light gastroscopy (WLG) in detecting potentially premalignant gastric lesions.

Patients and Methods

We conducted a randomized prospective crossover study from January 2009 to July 2009. Patients above 45 years of age with dyspepsia in absence of alarm symptoms underwent gastric mucosal examination using WLG and NBI in the same session by different endoscopists who were blinded to each other’s endoscopy findings. Biopsy was taken if required at the end of the second gastroscopy after a third observer reviewed reports of both scopists. The yield of gastric potentially premalignant lesions (atrophic gastritis, intestinal metaplasia, dysplasia, adenomatous polyp) was compared for both procedures.

Results

Two hundred [mean age 52.3 (6.4) years, males-66 %] patients participated in the study. Thirty-two patients were diagnosed to have potentially premalignant lesions using both modalities. No patient had early gastric cancer. WLG detected lesions in 17 patients (atrophic gastritis in 12, atrophic gastritis with intestinal metaplasia in 5) and NBI in 31 patients (atrophic gastritis in 22, atrophic gastritis with intestinal metaplasia in 9). The sensitivity of lesion detection by NBI was significantly higher than WLG (p?=?0.001).

Conclusions

NBI was superior to WLG for detection of atrophic gastritis and intestinal metaplasia.     

Screening for Gastric Premalignant Lesions with Narrow Band Imaging, White Light and Updated Sydney Protocol or Both?

Background

Narrow band imaging (NBI) can accurately discriminate gastritis but premalignant lesions (PMLs) are difficult to detect.

Aims

The purpose of this study was to compare white light endoscopy (WLE) and histopathologic findings using the updated Sydney protocol (USP) with NBI and targeted biopsies (TB).

Methods

One hundred nineteen symptomatic patients referred for upper GI endoscopy were included in this prospective open study. All patients were assessed for gastritis and PMLs using WLE and NBI by two endoscopists selected in a random manner. Biopsies were taken according to USP and targeted from any area suspicious for PML. Imaging and histological findings between protocols were compared.

Results

In total 45 patients (38 %) had atrophy of whom 39 (32.7 %) were detected with WLE-USP and 28 (23.5 %) with NBI-TB (p = 0.03), 25 (21 %) had intestinal metaplasia (IM) of whom 19 (16 %) were detected with WLE-USP and 18 (15.1 %) with NBI-TB (p = 0.7) and 14 (12 %) had dysplasia of whom 12 (10 %) were detected with WLE-USP and 7 (7 %) with NBI-TB (p = 0.5), and 1 (0.8 %) case of gastric cancer only detected with WLE-USP. Accuracies for atrophy and IM were 93 and 90 % for the WLE-USP and 80 and 82 % for NBI-TB. The NBI-TB detected six cases of atrophy (13 %), 5 (20 %) of IM, and 2 (14 %) of dysplasia missed by WLE-USP as agreement was moderate. Accuracies of the NBI patterns for body and antral gastritis were 80 and 84 %.

Conclusions

In a non high-risk population NBI-TB has less accuracy in detecting premalignant lesions compared to WLE-USP. However, it may be used as an important and easy-to-use complementary method which increases overall detectability for gastric premalignant lesions.     

A randomized crossover open trial of the adenoma miss rate for narrow band imaging (NBI) versus flexible spectral imaging color enhancement (FICE)

Purpose

Narrow band imaging (NBI) and flexible spectral imaging color enhancement (FICE) allow improved contrasted evaluation of the mucosal surface. However, no study has compared the utility of these two modalities. Therefore, the aim of this study was to compare the adenoma miss rate (AMR) between NBI and FICE.

Methods

A total of 55 patients (38 men, 17 women) were enrolled in this study. Patients were randomly assigned to the NBI–FICE group (NBI followed by FICE) or the FICE–NBI group (FICE followed by NBI). NBI and FICE total colonic observations were tandemly performed for each patient during the scope withdrawal with white light following cecal intubation. All detected polyps with the NBI or FICE observation were categorized into three groups according to the size and number of polyps missed.

Results

Twenty-nine patients were assigned to the NBI–FICE group, and 26 patients were assigned to the FICE–NBI group. There was no significant difference in the overall AMR when comparing the image-enhanced endoscopy technologies (17.9 % for NBI, 26 % for FICE, p?=?0.159). AMR was lower for NBI than for FICE for adenomas <5 mm in diameter (5.7 % for NBI, 12.6 % for FICE, p?=?0.036). AMR was not significantly different when comparing NBI and FICE for lesions 5 to 10 mm (p?=?0.967) or for lesions ≥10 mm (p?=?0.269).

Conclusions

This study demonstrated that overall AMR was not different when comparing NBI and FICE.     

Factors associated with technical difficulties and adverse events of colorectal endoscopic submucosal dissection: retrospective exploratory factor analysis of a multicenter prospective cohort

Background

Colorectal endoscopic submucosal dissection (C-ESD) is a promising but challenging procedure. We aimed to evaluate the factors associated with technical difficulties (failure of en bloc resection and procedure time, ≥2 h) and adverse events (perforation and bleeding) of C-ESD.

Methods

We conducted a retrospective exploratory factor analysis of a prospectively collected cohort in 15 institutions. Eight-hundred sixteen colorectal neoplasms larger than 20 mm from patients who underwent C-ESD were included. We assessed the outcomes of C-ESD and risk factors for technical difficulties and adverse events.

Results

Of the 816 lesions, 767 (94 %) were resected en bloc, with a median procedure time of 78 min. Perforation occurred in 2.1 % and bleeding in 2.2 %. Independent factors associated with failure of en bloc resection were low-volume center (<30 neoplasms), snare use, and poor lifting after submucosal injection. Factors significantly associated with long procedure time (≥2 h) were large tumor size (≥4 cm), low-volume center, less-experienced endoscopist, CO₂ insufflation, and use of two or more endoknives. Poor lifting was the only factor significantly associated with perforation, whereas rectal lesion and lack of a thin-type endoscope were factors significantly associated with bleeding. Poor lifting after submucosal injection occurred more frequently for nongranular-type laterally spreading tumors (LST) and for protruding and recurrent lesions than for granular-type LST (LST-G).

Conclusions

Poor lifting after submucosal injection was the risk factor most frequently associated with technical difficulties and adverse events on C-ESD. Less experienced endoscopists should start by performing C-ESDs on LST-G lesions.     

Use of narrow band imaging in assessing duodenal villous atrophy

Background and Objective

Narrow band imaging endoscopy with magnification (NBI-ME) has already been established in Barrett’s esophagus, stomach, and colonic mucosa, but limited work has been done in the mucosal evaluation of duodenum. A study was done to determine the correlation between NBI and histology in grading villous architecture in varied etiology.

Method

A prospective observational study comprising 105 subjects with suspected malabsorption. The presence of a diagnosed celiac disease, severe life threatening comorbidity, or pregnancy was considered as exclusion criteria. Standard endoscopy (SE), NBI-ME, multiple duodenal biopsies with histopathological examination were done in all.

Results

Fifty-one patients had celiac disease while 54 patients comprised mainly functional dyspepsia, iron deficiency anemia, tropical malabsorption syndrome, and irritable bowel syndrome. Four NBI-ME image subtypes of villous morphology have been proposed (NBI type I/II/III/IV). NBI-ME had 95 % sensitivity, 90.2 % specificity, 91.2 % positive predictive value, and 94.2 % negative predictive value for diagnosing altered villous morphology. Intraobserver kappa agreement coefficient (κ) for NBI-ME was 0.83 while interobserver agreement was 0.89 (95 % CI 0.8–0.97).

Conclusion

NBI-ME has good performance characteristics and very good kappa intra/interobserver agreement coefficient for varied subtypes of villous morphology. NBI-ME is most useful for obtaining a targeted biopsy which can be missed by conventional white light endoscopy.     

Performance of the Fecal Immunochemical Test Is Not Decreased by High Ambient Temperature in the Rapid Return System

Background

Hemoglobin concentration of fecal immunochemical test may be decreased at high ambient temperature, and fecal samples in FIT may be exposed to high ambient temperature.

Aims

The aim of this study was to determine whether a high ambient temperature on the day of screening may decrease the performance of FITs in population-based screening.

Methods

We performed FITs for asymptomatic participants aged 50 years or older. Fecal hemoglobin concentration, the probability of a positive FIT and a detection rate of colorectal neoplasms were compared between low (<10.0 °C) and high (≥25.0 °C) temperature groups.

Results

The FIT results for 8,316 participants were analyzed. The mean log₁₀ Hb concentration in the low temperature group was significantly higher than those in the high temperature group (0.36 vs. 0.25 ng/ml, p = 0.000). Regression analysis showed that an increase in temperature of 1 °C reduced the probability of a positive FIT by 3.1 %. However, we found no differences between the two groups in the FIT positive rate and detection rate of colorectal neoplasms. In multivariate analysis, high ambient temperature was not a significant risk factor for either the positive FIT result or the detection of colorectal neoplasms.

Conclusions

Potential instability of fecal hemoglobin at high ambient temperatures should be considered; however, its influence on performance of FIT may be attenuated by the short exposure time of fecal samples to high ambient temperature (i.e., rapid return system).     

Inter-Observer Agreement in the Endoscopic Classification of Colorectal Laterally Spreading Tumors: A Multicenter Study Between Experts and Trainees

Background and Aim

The risk of cancer varies with the subtype of colorectal “laterally spreading tumors” (LSTs). However, visual interpretations vary among endoscopists. The aim of this study was to evaluate inter-observer agreement and accuracy in the endoscopic classification of LST subtypes among experts and trainees.

Methods

In total, 40 LST images were collected and reviewed independently by 14 gastroenterology experts and 10 trainees. All investigators recorded their findings as one of the following four categories: homogeneous, nodular mixed, flat-elevated, and pseudo-depressed. Agreement was assessed in terms of the kappa (κ) statistic and AC1 estimate. Accuracy is reported as percentage agreement with the gold standard, based on the gross morphology of the resected specimens.

Results

Of the possible 91 pair-wise κ estimates among experts, 41 (45.1 %) were >0.75, indicating excellent agreement, while only 2 (4.44 %) of the 45 pair-wise κ estimates among trainees were >0.75. Agreements for individual LST subtypes in the trainee group were significantly lower than those in the expert group. The κ and AC1 estimates showed similar values in individual subtypes of LSTs. The overall accuracy of LST was also significantly higher for the experts than the trainees (85.9 vs. 72.5 %, P < 0.001). Notably, the flat-elevated subtype showed the lowest agreement and accuracy and was frequently misclassified as the pseudo-depressed subtype by both groups.

Conclusions

Inter-observer agreement and accuracy for LST subtype classification differ significantly between experts and trainees. Implementation of an adequate training system for beginners is necessary to better identify colorectal LSTs.     

Can the Adenoma Detection Rate Reliably Identify Low-Performing Endoscopists? Results of a Modeling Study

Background

Experts have stated that adenoma detection rates (ADR) of individual endoscopists should be measured to assess colonoscopy quality.

Aim

The purpose of this study was to quantify the reliability of the ADR as a quality marker.

Methods

We simulated a population of endoscopists and patients using published data on adenoma prevalence and adenoma miss rates. For each endoscopist, the ADR was calculated. The proportion of ADR variance attributable to endoscopist and the area under the ROC (AUROC) curve for low-performing endoscopists (lowest quartile or decile) were also calculated.

Results

In the base-case analysis (200 patients per endoscopist, miss rate 22 %, adenoma prevalence 24 %), only 13 % of ADR variance was attributable to endoscopist performance (AUROC up to 0.73). An ADR cutoff of <16.5 % identified approximately half of endoscopists in the lowest performance decile (test sensitivity = 53 %), but most (79 %) of the endoscopists identified by this cutoff were NOT low performers (i.e., false positives). In sensitivity analysis, increasing the number of patients per endoscopist, reducing the variance of adenoma prevalence between endoscopists (i.e., performing case-mix adjustment), and increasing the variance in performance between endoscopists all improved ADR test characteristics (AUROC up to 0.88). However, regardless of assumptions, a substantial proportion of endoscopists would be misclassified if a simple ADR cutoff were utilized.

Conclusions

The ADR has limited reliability as a quality marker under real-world assumptions. Simple cutoffs are likely to either be insufficiently sensitive or have high false positive rates. Future studies should identify alternative means for assessing endoscopist performance.     

Acceptability, effectiveness, and cost-effectiveness of internet-based exposure treatment for irritable bowel syndrome in a clinical sample: a randomized controlled trial

Background

A colonoscopy may frequently miss polyps and cancers. A number of techniques have emerged to improve visualization and to reduce the rate of adenoma miss.

Methods

We conducted a randomized controlled trial (RCT) in two clinics of the Gastrointestinal Department of the Sanitas University Foundation in Bogota, Colombia. Eligible adult patients presenting for screening or diagnostic elective colonoscopy were randomlsy allocated to undergo conventional colonoscopy or narrow-band imaging (NBI) during instrument withdrawal by three experienced endoscopists. For the systematic review, studies were identified from the Cochrane Library, PUBMED and LILACS and assessed using the Cochrane risk of bias tool.

Results

We enrolled a total of 482 patients (62.5% female), with a mean age of 58.33 years (SD 12.91); 241 into the intervention (NBI) colonoscopy and 241 into the conventional colonoscopy group. Most patients presented for diagnostic colonoscopy (75.3%). The overall rate of polyp detection was significantly higher in the conventional group compared to the NBI group (RR 0.75, 95%CI 0.60 to 0.96). However, no significant differences were found in the mean number of polyps (MD -0.1; 95%CI -0.25 to 0.05), and the mean number of adenomas (MD 0.04 95%CI -0.09 to 0.17). Meta-analysis of studies (regardless of indication) did not find any significant differences in the mean number of polyps (5 RCT, 2479 participants; WMD -0.07 95% CI -0.21 to 0.07; I2 68%), the mean number of adenomas (8 RCT, 3517 participants; WMD -0.08 95% CI -0.17; 0.01 to I2 62%) and the rate of patients with at least one adenoma (8 RCT, 3512 participants, RR 0.96 95% CI 0.88 to 1,04;I2 0%).

Conclusion

NBI does not improve detection of colorectal polyps when compared to conventional colonoscopy (Australian New Zealand Clinical Trials Registry ACTRN12610000456055).     

Benefits and Limitations of Cap-Fitted Colonoscopy in Screening Colonoscopy

Background

Colonoscopy is widely used to detect colorectal cancer and to remove precancerous lesions to reduce the risk of colonic cancer.

Aims

To examine the benefits and limitations of cap-fitted colonoscopy compared to conventional colonoscopy in terms of technical performance and colorectal adenoma detection rate.

Methods

Screening colonoscopies performed from 2009 to 2010 with or without a transparent cap were retrospectively examined to compare the rate of successful intubation, cecal intubation time, and number, size, shape, and location of adenomas detected. An inclusion criterion was visualization of >95 % of the right colon.

Results

Data from 2,301 colonoscopies (1,165 with cap-fitted colonoscopy, 1,136 without the transparent cap) were retrospectively analyzed. Procedures were performed by four experienced endoscopists. The subjects’ demographic characteristics and technical performances were similar between the two methods. The only significant difference in the technical performance between the two techniques was a shorter cecal intubation time with cap-fitted colonoscopy (5.3 vs. 6.6 min; p = 0.045) by one endoscopist. The total number of adenomas detected was significantly higher with cap-fitted colonoscopy than without the cap (586 vs. 484, respectively; p < 0.0001). Adenoma detection with cap-fitted endoscopy was significantly higher in the right colon than in the left colon (19 vs. 12 %, respectively; p = 0.0001).

Conclusion

Cap-fitted colonoscopy did not improve the technical aspects of colonoscopy but significantly increased adenoma detection, especially in the right colon. It did not increase the detection rate of flat or depressed adenomas.     

Anatomic distribution of cancers and colorectal adenomas according to age and sex and relationship between proximal and distal neoplasms in an i-FOBT-positive average-risk Italian screening cohort

Background and aims

Subsite-specific incidence rates of colorectal cancer (CRC) and adenomas may vary considerably by race, sex and age as well as due to different screening strategies. We assessed variations in the anatomical distribution of adenomas according to age and sex in an average-risk screening cohort testing positive at immunological faecal occult blood test (i-FOBT) in northern Italy.

Methods

Data from 2,281 consecutive asymptomatic i-FOBT-positive subjects ageing 50–70 years undergone colonoscopy were reviewed. Size, number, macroscopic and histological features of all adenomas found as well as their proximal or distal location in relation to the splenic flexure were examined. Odds ratios (OR) of proximal neoplasms, according to the presence of distal neoplasms and other selected covariates were assessed by multiple logistic regression analysis.

Results

A total of 2,599 neoplasms were found in 1,396 patients. Of these, 116 (5 %) were colorectal cancers, diagnosed in 106 patients. Out of 2,483 adenomas found, 1,564 (63 %) were sessile, 795 (32 %) were peduncolated and 124 (5 %) were flat-type; 54 % of all adenomas were tubular, 36 % were tubulovillous or villous, and 10 % were serrated adenomas. The majority of neoplasms (66 %) were located in the distal colon. Tumour subsite distribution was consistent in both sexes, whereas significant proximal migration of neoplasms occurred in the older age cohort. Indeed, the rate of proximal neoplasms in patients aged ≥60 years was 37 % as compared with 29 % in those ageing 50–59 years. Male gender (OR 1.84), age of 60 years or older (OR 1.44), having a family history of colorectal neoplasms (OR 1.47) and presence of at least 1 distal advanced adenoma (OR 1.63) were all significant predictors of advanced proximal neoplasms.

Conclusions

A left to right shift of colorectal adenomas with increasing age is evident in northern Italian asymptomatic i-FOBT-positive population. Advanced proximal neoplasms are not uncommon in subjects with or without distal adenomas, especially after 60 years of age. This should be carefully considered when implementing public screening strategies for CRC since the use of flexible sigmoidoscopy as a screening tool, particularly in older age groups, appears to be less effective.     

Comparison of Clinical Outcomes Among Different Endoscopic Resection Methods for Treating Colorectal Neoplasia

Background/Aim

Endoscopic treatments of colorectal neoplasms have yet to be standardized. This study aimed to compare efficacy and tolerability of different endoscopic resection methods for colorectal epithelial tumors.

Methods

Patients with non-pedunculated colorectal tumors undergoing endoscopic treatments were consecutively enrolled, and their medical records were reviewed retrospectively. The resection methods were classified into three groups: endoscopic mucosal resection with circumferential precutting (EMR-P), endoscopic submucosal dissection with snaring (ESD-S), and endoscopic submucosal dissection alone (ESD). We compared en bloc resection, pathological complete resection, and complications associated with these methods.

Results

Overall, 206 lesions from 203 patients were included in the study (mean size 25.2 ± 10.1 mm). The number of lesions treated with EMR-P, ESD-S, and ESD was 91 (44.2 %), 57 (27.7 %), and 58 (28.2 %), respectively. There was a significant difference in both the en bloc resection rates (EMR-P, 61.5 %; ESD-S, 64.9 %; ESD, 96.6 %; p = 0.001) and complete resection rates (EMR-P, 51.6 %; ESD–S, 54.4 %; ESD, 75.9 %; p = 0.009). Bleeding and perforation were less frequently observed in the EMR-P group. In the subgroup-analysis of lesions less than 20 mm, however, these differences were not observed.

Conclusions

All endoscopic resection methods, including EMR-P, ESD-S, and ESD, were effective and safe for the treatment of colorectal neoplasms. Technically demanding ESD with high en bloc and complete resection rate should be reserved for the suspicious cancer lesion, which requires the precise histological evaluation. EMR-P with good feasibility can be considered an alternative to ESD for the lesions less than 20 mm.     

Comparison of metastatic lymph node ratio staging system with the 7th AJCC system for colorectal cancer

Purpose

To evaluate the prognostic value and staging accuracy of the metastatic lymph node ratio (rN) staging system for colorectal cancer.

Methods

A total of 1,127 patients with colorectal cancer who underwent curative surgery between 2000 and 2011 at our institute were analyzed. Lymph nodes status was assigned according to American Joint Committee on Cancer (AJCC) pN system and rN system. Patients with colon cancer (group 1, n = 652) and rectal cancer (group 2, n = 475) were analyzed separately.

Results

The rN staging system was generated using 0.2 and 0.6 as the cutoff values of lymph node ratio and then compared with AJCC pN stages. Linear regression model revealed that the number of retrieved lymph node was related to number of metastatic lymph nodes. After a median follow-up of 46 months, the 5-year survival rates of patients with more than 12 lymph nodes (LNs) retrieved were better than cases with fewer than 12 LNs, while the differences were not obvious in rN classification.

Conclusions

The rN category is a better prognostic tool than the AJCC pN category for colorectal cancer patients after curative surgery.