Diminutive polyps of large bowel should be an early target for endoscopic treatment

Comparative systematic review and meta-analysis of 1- to 5-mm versus 6- to 9-mm adenomas on the risk of metachronous advanced colorectal neoplasia

BACKGROUND AND AIMS

The current guidelines recommend the same surveillance interval for ≥3 nonadvanced adenomas (NAAs), without discriminating between diminutive (1-5 mm) and small (6-9 mm) adenomas. Additionally, the same surveillance interval is recommended for patients with ≤2 diminutive NAAs and those with ≤2 small NAAs. However, it is questionable whether these recommendations are appropriate.

METHODS

We searched all relevant studies published through September 2019 that examined the risk of metachronous advanced colorectal neoplasia (ACRN) according to the size (diminutive vs small) and the number of adenomas found during an index colonoscopy. Low-risk adenomas (LRAs) were subclassified into 2 categories (LRA-1, ≤2 diminutive NAAs; and LRA-2, ≤2 small NAAs), and high-risk adenomas (HRAs) were subclassified into 3 categories (HRA-1, ≥3 diminutive NAAs; HRA-2, ≥3 small NAAs; and HRA-3, advanced adenoma).

RESULTS

Eight studies involving 36,142 patients were evaluated. The LRA-2 group had a higher risk of metachronous ACRN than the LRA-1 group (risk ratio, 1.49; 95% confidence interval [CI], 1.23-1.81). Additionally, the HRA-2 and HRA-3 groups had a higher risk of metachronous ACRN than the HRA-1 group (hazard ratios [HRs], 1.51 [95% CI, 1.002-2.28] and 1.92 [95% CI, 1.11-3.33], respectively). However, there was no significant difference between the HRA-1 versus LRA-2 groups (HR, 1.23; 95% CI, .78-1.94).

CONCLUSIONS

Among the HRA and LRA groups, those with diminutive NAAs had a lower risk of metachronous ACRN than those with small NAAs. We believe that clinical guidelines should consider extending the surveillance intervals in patients with diminutive NAAs only.

Risk of Developing Metachronous Advanced Colorectal Neoplasia After Polypectomy in Patients With Multiple Diminutive or Small Adenomas

INTRODUCTION

Current post-polypectomy guidelines recommend a 3-year surveillance interval for ≥3 nonadvanced adenomas (NAAs) without discrimination between diminutive (1-5 mm) and small (6-9 mm) adenomas. We compared the risk of metachronous advanced colorectal neoplasia (ACRN) among these groups.

METHODS

We studied 9,733 patients who underwent ≥1 adenoma removal and follow-up colonoscopic surveillance. Patients were classified based on baseline adenoma characteristics: group 1, 1-2 NAAs (n = 8,051); group 2, ≥3 diminutive NAAs (n = 293); group 3, ≥3 small NAAs (n = 258); and group 4, advanced adenomas (AAs) (n = 1,131).

RESULTS

The mean age of the study population was 45.8 ± 8.2 years. In group 4, most patients (94.5%) had 1 AA. The 3- and 5-year cumulative incidence rates of metachronous ACRN in groups 1, 2, 3, and 4 were 0.9%, 2.8%, 3.5%, and 4.0% and 3.1%, 10.7%, 15.1%, and 8.5%, respectively. Groups 2, 3, and 4 had a higher risk of metachronous ACRN than group 1. Compared with those for group 1, adjusted hazard ratios (95% confidence interval) for metachronous ACRN were 2.07 (1.16-3.68), 3.29 (1.94-5.56), and 2.73 (2.00-3.72) for groups 2, 3, and 4, respectively. However, this relationship was statistically insignificant between groups 2, 3, and 4. Compared with those for group 2, adjusted hazard ratios (95% confidence intervals) for groups 3 and 4 were 1.59 (0.76-3.30) and 1.32 (0.72-2.42), respectively, and 0.83 (0.47-1.46) for group 4 compared with group 3. The results of patients aged ≥50 years were identical to those of all patients.

DISCUSSION

Risk of metachronous ACRN was not different between patients aged ≥50 years who underwent polypectomy of ≥3 diminutive NAAs, ≥3 small NAAs, and AA, thus supporting current guidelines that recommend a uniform surveillance interval for these lesions.

Jumbo biopsy forceps versus cold snares for removing diminutive colorectal polyps: a prospective randomized controlled trial

BACKGROUND AND AIMS

Cold snare polypectomy (CSP) and jumbo forceps polypectomy (JFP) have been shown to be effective for removing diminutive colorectal polyps (DCPs) (≤5 mm). However, no study has compared complete resection rates between CSP and JFP for DCPs. The aim of this study was to compare the efficacy and safety of JFP with CSP for the removal of DCPs.

METHODS

This was a prospective randomized controlled trial from 2 tertiary-care referral centers. A total of 1003 patients were screened, and 169 patients with 196 DCPs were enrolled. The main outcome was complete polyp resection rate.

RESULTS

Of 196 diminutive polyps, 177 (90.3%) were adenomatous polyps. The overall complete resection rate was 92.1% (163/177). The complete resection rate was not significantly different between JFP and CSP groups (92.0% vs 92.2%; P = .947). JFP achieved complete resection rates comparable with CSP for polyps >3 mm (90.3% vs 89.8%; P = .928). Polypectomy procedure time, tissue retrieval rate, and rate of postpolypectomy adverse events were not significantly different between the 2 groups.

CONCLUSIONS

Both JFP and CSP achieved complete resection rates of >90% for DCPs. Thus, JFP may be considered for polypectomy of DCPs. (International clinical trial registry number: KCT0002805.).

Comparative efficacy of cold polypectomy techniques for diminutive colorectal polyps: a systematic review and network meta-analysis

BACKGROUND

Although cold polypectomy techniques are preferred over polypectomy with electrocautery in the management of diminutive polyps, comprehensive comparisons among various cold polypectomy techniques have not yet been fully performed.

METHODS

We searched for all relevant randomized controlled trials published up until October 2016 examining the efficacy of cold polypectomy techniques for diminutive polyps. Cold polypectomy techniques were classified as cold forceps polypectomy (CFP), jumbo forceps polypectomy (JFP), traditional cold snare polypectomy (CSP), and dedicated CSP, according to the type of device. A network meta-analysis was performed to calculate the direct and indirect estimates of efficacy among the cold polypectomy techniques.

RESULTS

Seven studies with 703 patients and 968 polyps were included in the meta-analysis. Regarding comparative efficacy for complete histological eradication, there was no inconsistency in the network (Cochran's Q test, df = 4, P = 0.22; I ² = 30%). In terms of complete histological eradication, both dedicated and traditional CSP were superior to CFP (odds ratio [OR] [95% confidence interval [CI]] 4.31 [1.92-9.66] and 2.45 [1.30-4.63], respectively); dedicated CSP was superior to traditional CSP (OR [95% CI] 1.76 [1.07-2.89]); and there was no difference between JFP versus CFP (OR [95% CI] 1.36 [0.40-4.61]). Regarding tissue retrieval rate, there was no difference between dedicated versus traditional CSP (OR [95% CI] 1.03 [0.44-2.38]). The procedure time for CSP was comparable to that of CFP.

CONCLUSIONS

Dedicated CSP was shown to be superior to other cold polypectomy techniques in terms of complete histological eradication. Cold polypectomy using a dedicated snare can be recommended for the removal of diminutive colorectal polyps.

Risk of cancer in small and diminutive colorectal polyps

The prevalence of cancer in small and diminutive polyps is relevant to "resect and discard" and CT colonography reporting recommendations. We evaluated a prospectively collected colonoscopy polyp database to identify polyps <10mm and those with cancer or advanced histology (high-grade dysplasia or villous elements). Of 32,790 colonoscopies, 15,558 colonoscopies detected 42,630 polyps <10mm in size. A total of 4790 lesions were excluded as they were not conventional adenomas or serrated class lesions. There were 23,524 conventional adenomas <10mm of which 22,952 were tubular adenomas. There were 14,316 serrated class lesions of which 13,589 were hyperplastic polyps and the remainder were sessile serrated polyps. Of all conventional adenomas, 96 had high-grade dysplasia including 0.3% of adenomas ≤5mm in size and 0.8% of adenomas 6-9mm in size. Of all conventional adenomas, 2.1% of those ≤5mm in size and 5.6% of those 6-9mm in size were advanced. Among 36,107 polyps ≤5mm in size and 6523 polyps 6-9mm in size, there were no cancers. These results support the safety of resect and discard as well as current CT colonography reporting recommendations for small and diminutive polyps.

A prospective randomized comparative study of cold forceps polypectomy by using narrow-band imaging endoscopy versus cold snare polypectomy in patients with diminutive colorectal polyps

BACKGROUND AND AIMS

A previous study reported that cold snare polypectomy (CSP) was superior to cold forceps polypectomy (CFP) for the removal of diminutive colorectal polyps (DCPs) (≤5 mm) when the techniques were assessed for completeness of resection. However, completeness is expected to be greater with CFP when strict investigation of the remnant polyp is performed. The aim of this study was to assess the efficacy of CFP with narrow-band imaging (NBI) evaluation of polypectomy sites for removal of DCPs, compared with CSP.

METHODS

This was a randomized, controlled, noninferiority trial at a tertiary-care referral hospital. Of the 380 patients screened, 146 patients with 231 DCPs were enrolled. CFP was used to resect DCPs until no remnant polyp was visible by NBI endoscopy. The primary noninferiority endpoint was histologic eradication of polyps, with a noninferiority margin of -10%.

RESULTS

A size of >3 mm was seen in 129 polyps (55.8%). The overall rates of histologic eradication were 90.5% in the CFP group and 93.0% in the CSP group (difference, 2.5%; 95% confidence interval [CI], -9.67 to 4.62). However, when confined to the polyps >3 mm, the histologic eradication rate was 86.8% and 93.4% (95% CI, -17.2 to 3.6), respectively. Polyp size, histology, location, and time taken for polypectomy did not differ between the groups. The failure rate of tissue retrieval was higher in the CSP than in the CFP group (7.8% vs 0.0%, respectively; P =.001).

CONCLUSIONS

In this study, >90% of all DCPs were completely resected by using CFP with NBI evaluation of polypectomy sites, showing noninferiority compared with CSP. However, in polyps measuring >3 mm, CFP failed to show noninferiority versus CSP. CFP appears to be the proper method for resection of DCPs 1 to 3 mm in size if no remnant polyp is visible by NBI endoscopy, but CFP is likely to be insufficient for larger polyps. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT02201147.).

Endoscopic appearance of proximal colorectal neoplasms and potential implications for colonoscopy in cancer prevention

BACKGROUND

In everyday practice, the use of colonoscopy for the prevention of colorectal cancer (CRC) is less effective in the proximal than the distal colon. A potential explanation for this is that proximal neoplasms have a more subtle endoscopic appearance, making them more likely to be overlooked.

OBJECTIVE

To investigate the differences in endoscopic appearance, ie, diminutive size and nonpolypoid shape, of proximal compared with distal colorectal neoplasms.

DESIGN

Cross-sectional, single-center study.

SETTING

Endoscopists at the Maastricht University Medical Center in the Netherlands who were previously trained in the detection and classification of nonpolypoid colorectal lesions.

PATIENTS

Consecutive patients undergoing elective colonoscopy.

MAIN OUTCOME MEASUREMENTS

Endoscopic appearance, ie, diminutive size (<6 mm) or nonpolypoid shape (height less than half of the diameter) of colorectal adenomas and serrated polyps (SPs), with a focus on adenomas with advanced histology, ie, high-grade dysplasia or early CRC and SPs with dysplasia or large size.

RESULTS

We included 3720 consecutive patients with 2106 adenomas and 941 SPs. We found that in both men and women, proximal adenomas with high-grade dysplasia/early CRC (n = 181) were more likely to be diminutive or nonpolypoid than distal ones (76.3% vs 26.2%; odds ratio [OR] 9.24; 95% CI, 4.45-19.2; P < .001). Of the proximal adenomas, 84.4% were diminutive or nonpolypoid compared with 68.0% of the distal ones (OR 2.66; 95% CI, 2.14-3.29; P < .001). Likewise, large/dysplastic SPs in the proximal colon were more often nonpolypoid than distal ones (66.2% vs 27.8%; OR 5.51; 95% CI, 2.79-10.9; P < .001).

LIMITATIONS

Inclusion of both symptomatic and asymptomatic patients.

CONCLUSIONS

Proximal colorectal neoplasms with advanced histology frequently are small or have a nonpolypoid appearance. These findings support careful inspection of the proximal colon, if quality of cancer prevention with the use of colonoscopy is to be optimized.

The Miss Rate for Colorectal Adenoma Determined by Quality-Adjusted, Back-to-Back Colonoscopies

BACKGROUND/AIMS

Colonoscopy is considered to be the gold standard for detecting adenomatous polyps. Polyps are missed during colonoscopic examination at a rate that varies from 6% to 27%. The adenoma miss rate affects colonoscopic surveillance intervals and procedural quality. We aimed to assess the adenoma miss rate and the variables affecting the rate using same-day, quality-adjusted, back-to-back colonoscopies.

METHODS

This prospective study was performed at a single institution and included 149 patients. Two consecutive same-day colonoscopies were performed by two experienced endoscopists. The adenoma miss rates and variables affecting the missed adenomas, including polyp characteristics and procedure times, were evaluated.

RESULTS

The miss rates of polyps, adenomas, and advanced adenomas were 16.8%, 17%, and 5.4%, respectively. The smaller polyps and increased number of polyps detected during the first colonoscopy were more likely to be missed. A longer insertion time during the colonoscopy was correlated with an increased adenoma detection rate.

CONCLUSIONS

There was a significant miss rate in the detection of colonic adenomas even in quality-adjusted, back-to-back colonoscopies. The adenoma miss rate can be reduced with a sufficient observation time during colonoscopic insertion. The development of specific technological methods to reduce the adenoma miss rate is necessary.

Aspectos epidemiológicos dos pólipos e lesões plano-elevadas colorretais

INTRODUÇÃO: Os pólipos e as lesões plano-elevadas colorretais são importantes na prevenção do câncer colorretal pelo risco de malignização dos adenomas. OBJETIVO: traçar o perfil demográfico dos pacientes com diagnóstico endoscópico de pólipos e/ou lesões plano-elevadas colorretais no Hospital Universitário da Universidade Federal de Sergipe e Torres Centro Médico. MÉTODOS: Foram avaliados 6.919 prontuários de 2002 a 2007, enfatizando-se as variáveis: idade, gênero, procedência e indicação; número, tamanho, morfologia, histologia, grau de displasia, topografia, lesões sincrônicas e metacrônicas, e diagnósticos associados. RESULTADOS: Foram encontradas 1.031 (13,51%) lesões em 935 exames, correspondendo a 826 pacientes, 46% masculino e 54% feminino. A idade variou de 3 a 96 anos, com média de 53,64. A distribuição topográfica mais frequente das lesões polipoides foi em reto e sigmoide (58,40%). As lesões eram sésseis em 52,80%, pediculadas em 27,90% e plano-elevadas em 19,30% dos casos. Ocorreram lesões sincrônicas em 23,48% e metacrônicas em 30,10% dos pacientes. Histologicamente, 43,36% eram adenomas, sendo 85,70% tubulares, 9,60% tubulo-vilosos e 4,70% vilosos; 30,64% eram pólipos hiperplásicos, 15,80% inflamatórios e 10,20% possuíam outros tipos histológicos. Os adenomas apresentavam displasia de baixo grau em 83,40% dos casos e alto grau em 16,60%. Sete eram adenocarcinomas, um carcinoide e um tumor gastrointestinal estromal. CONCLUSÕES: A colonoscopia e a polipectomia são importantes no diagnóstico e prevenção do câncer colorretal.

Detection of colonic polyps according to insertion/withdrawal phases of colonoscopy

BACKGROUND AND AIMS

Issues on colonoscopy quality are crucial to reduce the advanced neoplasia miss rate of colonoscopy. Recently, a >6-min withdrawal time has been recommended. However, the relative prevalence of polyp detected during insertion and withdrawal phases of colonoscopy is unknown. Therefore, we designed this prospective, endoscopic study.

MATERIALS AND METHODS

Three hundred and sixty-eight patients with 396 adenomas were selected from a consecutive colonoscopic series of 1,205 cases. Detection rates of adenomas, advanced adenomas, and cancer according to withdrawal and insertion phases of colonoscopy, also subgrouping polyps for size and location, were compared.

RESULTS

Thirty-two (74%) advanced adenomas and 21 (95%) cancers were detected during the insertion, being only 11 (26%) and one (5%) identified during withdrawal, respectively. This was mainly due to a higher detection of >10 mm polyps during insertion than during withdrawal (75% versus 25%).

CONCLUSIONS

Most advanced neoplasia are detected during the insertion. Although withdrawal time has been shown to be important, the scope insertion phase related to polyp detection should be specifically addressed.

Perspective on the practical indications of endoscopic submucosal dissection of gastrointestinal neoplasms

Endoscopic submucosal dissection (ESD) is a new endoluminal therapeutic technique involving the use of cutting devices to permit a larger resection of the tissue over the muscularis propria. The major advantages of the technique in comparison with polypectomy and endoscopic mucosal resection are controllable resection size and shape and en bloc resection of a large lesion or a lesion with ulcerative findings. This technique is applied for the endoscopic treatment of epithelial neoplasms in the gastrointestinal tract from the pharynx to the rectum. Furthermore, some carcinoids and submucosal tumors in the gastrointestinal tract are treated by ESD. To determine the indication, two aspects should be considered. The first is a little likelihood of lymph node metastasis and the second is the technical resectability. In this review, practical guidelines of ESD for the gastrointestinal neoplasms are discussed based on the evidence found in the literature.

Risk factors for high-grade dysplasia or carcinoma in colorectal adenoma cases treated with endoscopic polypectomy

OBJECTIVE

Our aim is to establish the risk factors for carrying high-grade dysplasia or carcinoma by analyzing endoscopically treated adenoma cases.

METHODS

Patients who underwent endoscopic polypectomy at our hospitals between January 2003 and August 2004 were analyzed.

RESULTS

A total of 889 patients (mean age: 63+/-11 years), and 1486 adenomas resected from these patients, were included in the analysis. Seventy-five adenomas (5%) from 72 patients (8%) were found to have high-grade dysplasia or carcinoma. Among patient factors, female sex [odds ratio (OR) 2.25, 95% confidence intervals (CI)=1.34-3.76], presence of multiple adenomas (OR=2.15, 95% CI=1.15-4.00), older age (OR=1.02, 95% CI=1.00-1.04), and rectal bleeding as the indication for colonoscopy (OR=2.57, 95% CI=1.34-4.92) were identified as the significant risk factors for carrying high-grade dysplasia or carcinoma using the multivariate analysis. In addition, a size of > or = 10 mm (OR=10.83, 95% CI=5.86-20.0), flat appearance (OR=3.91, 95% CI=2.20-6.95), and location on the left side of the colon (OR=1.80, 95% CI=1.03-3.13) were identified as tumor risk factors.

CONCLUSION

Distinct factors were proved to be associated with high-grade dysplasia or carcinoma. These results are useful to select lesions that require immediate treatment. Moreover, female sex as a risk factor raises an interesting problem regarding the progression from adenoma to carcinoma.

The colorectal malignant polyp: scoping a dilemma

Colorectal adenomas containing invasive carcinoma represent the majority of early colorectal cancers. The malignant polyp carries a significant risk of lympho-haematic metastasis and mortality due to the penetration of cancerous cells into the submucosal layer. The therapeutic dilemma is whether to perform endoscopic or surgical resection. A thorough assessment of the endoscopic, histological and clinical variables is needed to unravel the best treatment for each patient. In particular, a unique staging of such lesions, based on certain histopathological features, has been deeply implicated in the therapeutic choice. Aim of this article is to review the main endoscopic, histological and clinical features of the malignant polyp in order to propose a systematic management of this lesion.

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