Risk factors associated with missed colorectal flat adenoma: A multicenter retrospective tandem colonoscopy study

One in three adenomas could be missed by white-light colonoscopy - findings from a systematic review and meta-analysis

BACKGROUND

White light (conventional) colonoscopy (WLC) is widely used for colorectal cancer screening, diagnosis and surveillance but endoscopists may fail to detect adenomas. Our goal was to assess and synthesize overall and subgroup-specific adenoma miss rates (AMR) of WLC in daily practice.

METHODS

We conducted a systematic review in MEDLINE, EMBASE, Cochrane Library, and grey literature on studies evaluating diagnostic WLC accuracy in tandem studies with novel-colonoscopic technologies (NCT) in subjects undergoing screening, diagnostic or surveillance colonoscopy. Information on study design, AMR overall and specific for adenoma size, histology, location, morphology and further outcomes were extracted and reported in standardized evidence tables. Study quality was assessed using the QUADAS-2 tool. Random-effects meta-analyses and meta-regression were performed to estimate pooled estimates for AMR with 95% confidence intervals (95% CI) and to explain heterogeneity.

RESULTS

Out of 5,963 identified studies, we included sixteen studies with 4,101 individuals in our meta-analysis. One in three adenomas (34%; 95% CI: 30-38%) was missed by WLC in daily practice individuals. Subgroup analyses showed significant AMR differences by size (36%, adenomas 1-5 mm; 27%, adenomas 6-9 mm; 12%, adenomas ≥ 10 mm), histology (non-advanced: 42%, advanced: 21%), morphology (flat: 50%, polypoid: 27%), but not by location (distal: 36%, proximal: 36%).

CONCLUSIONS

Based on our meta-analysis, one in three adenomas could be missed by WLC. This may significantly contribute to interval cancers. Our results should be considered in health technology assessment when interpreting sensitivity of fecal occult blood or other screening tests derived from studies using WLC as "gold standard".

Day before late regimen vs standard split dose of low-volume PEG-CS for early morning colonoscopy: Multicenter randomized controlled trial

Background and study aims

Despite lower patient adherence, the overnight split-dose (SD) intestinal preparation regimen is currently recommended for early morning colonoscopies. Using low-volume preparation, we compared performance of a "day before late" (DBL) regimen, with the whole preparation taken between 8.30 pm and midnight on the day before the endoscopic procedure vs the overnight SD regimen for colonoscopies scheduled between 8 am and 10 am.

Patients and methods

Patients were randomized to the DBL group (n = 162) or SD group (n = 158). The SD group took the second dose 5 hours before colonoscopy. Successful bowel cleansing, defined as an overall Boston Bowel Preparation Score ≥ 3, safety, compliance and tolerability were assessed in the two groups.

Results

The DBL regimen failed to demonstrate non-inferiority compared with the SD regimen in terms of successful bowel cleansing (DBL, 88.2 % vs SD, 98.1%, P < 0.001). Subgroup analysis on colonoscopies before 9 am showed BBPS ≥ 3 rates of 94.6% and 100% in the DBL and SD groups, respectively P = 0.126). The two regimens showed similar compliance and tolerability. Compared with SD patients (25.5%), a lower proportion of DBL patients (13.9%) reported fear of incontinence during the journey to the hospital ( P = 0.01).

Conclusions

Albeit more tolerable, the DBL regimen was less effective than the SD regimen with regard to successful bowel cleansing for colonoscopies between 8 am and 10 am. Subgroup analysis on colonoscopies scheduled before 9 am showed that the two regimens have similar efficacy, suggesting that the DBL regimen may be a valuable alternative to the SD regimen for very early morning colonoscopies.

Enhanced accuracy with Segmentation of Colorectal Polyp using NanoNetB, and Conditional Random Field Test-Time Augmentation

Colonoscopy is a reliable diagnostic method to detect colorectal polyps early on and prevent colorectal cancer. The current examination techniques face a significant challenge of high missed rates, resulting in numerous undetected polyps and irregularities. Automated and real-time segmentation methods can help endoscopists to segment the shape and location of polyps from colonoscopy images in order to facilitate clinician's timely diagnosis and interventions. Different parameters like shapes, small sizes of polyps, and their close resemblance to surrounding tissues make this task challenging. Furthermore, high-definition image quality and reliance on the operator make real-time and accurate endoscopic image segmentation more challenging. Deep learning models utilized for segmenting polyps, designed to capture diverse patterns, are becoming progressively complex. This complexity poses challenges for real-time medical operations. In clinical settings, utilizing automated methods requires the development of accurate, lightweight models with minimal latency, ensuring seamless integration with endoscopic hardware devices. To address these challenges, in this study a novel lightweight and more generalized Enhanced Nanonet model, an improved version of Nanonet using NanonetB for real-time and precise colonoscopy image segmentation, is proposed. The proposed model enhances the performance of Nanonet using Nanonet B on the overall prediction scheme by applying data augmentation, Conditional Random Field (CRF), and Test-Time Augmentation (TTA). Six publicly available datasets are utilized to perform thorough evaluations, assess generalizability, and validate the improvements: Kvasir-SEG, Endotect Challenge 2020, Kvasir-instrument, CVC-ClinicDB, CVC-ColonDB, and CVC-300. Through extensive experimentation, using the Kvasir-SEG dataset, our model achieves a mIoU score of 0.8188 and a Dice coefficient of 0.8060 with only 132,049 parameters and employing minimal computational resources. A thorough cross-dataset evaluation was performed to assess the generalization capability of the proposed Enhanced Nanonet model across various publicly available polyp datasets for potential real-world applications. The result of this study shows that using CRF (Conditional Random Fields) and TTA (Test-Time Augmentation) enhances performance within the same dataset and also across diverse datasets with a model size of just 132,049 parameters. Also, the proposed method indicates improved results in detecting smaller and sessile polyps (flats) that are significant contributors to the high miss rates.

Effect of Real-Time Computer-Aided Polyp Detection System (ENDO-AID) on Adenoma Detection in Endoscopists-in-Training: A Randomized Trial

BACKGROUND

The effect of computer-aided polyp detection (CADe) on adenoma detection rate (ADR) among endoscopists-in-training remains unknown.

METHODS

We performed a single-blind, parallel-group, randomized controlled trial in Hong Kong between April 2021 and July 2022 (NCT04838951). Eligible subjects undergoing screening/surveillance/diagnostic colonoscopies were randomized 1:1 to receive colonoscopies with CADe (ENDO-AID[OIP-1]) or not (control) during withdrawal. Procedures were performed by endoscopists-in-training with <500 procedures and <3 years' experience. Randomization was stratified by patient age, sex, and endoscopist experience (beginner vs intermediate level, <200 vs 200-500 procedures). Image enhancement and distal attachment devices were disallowed. Subjects with incomplete colonoscopies or inadequate bowel preparation were excluded. Treatment allocation was blinded to outcome assessors. The primary outcome was ADR. Secondary outcomes were ADR for different adenoma sizes and locations, mean number of adenomas, and non-neoplastic resection rate.

RESULTS

A total of 386 and 380 subjects were randomized to CADe and control groups, respectively. The overall ADR was significantly higher in the CADe group than in the control group (57.5% vs 44.5%; adjusted relative risk, 1.41; 95% CI, 1.17-1.72; P < .001). The ADRs for <5 mm (40.4% vs 25.0%) and 5- to 10-mm adenomas (36.8% vs 29.2%) were higher in the CADe group. The ADRs were higher in the CADe group in both the right colon (42.0% vs 30.8%) and left colon (34.5% vs 27.6%), but there was no significant difference in advanced ADR. The ADRs were higher in the CADe group among beginner (60.0% vs 41.9%) and intermediate-level (56.5% vs 45.5%) endoscopists. Mean number of adenomas (1.48 vs 0.86) and non-neoplastic resection rate (52.1% vs 35.0%) were higher in the CADe group.

CONCLUSIONS

Among endoscopists-in-training, the use of CADe during colonoscopies was associated with increased overall ADR. (ClinicalTrials.gov, Number: NCT04838951).

Individualized intervention based on a preparation-related prediction model improves adequacy of bowel preparation: A prospective, multi-center, randomized, controlled study

AIMS

An easy-to-use preparation-related model (PRM) predicting inadequate bowel preparation (BP) was developed and proved superior to traditional models in our previous study. Here we aimed to investigate whether PRM-based individualized intervention can improve BP adequacy.

METHODS

Patients undergoing morning colonoscopy were prospectively enrolled in 5 endoscopic centers in China. After standard BP of split-dose polyethylene glycol (PEG) was completed, patients were randomized (1:1) to the individualized group or standard group. High-risk patients predicted by PRM score ≥3 were instructed to drink an additional 1.5 L PEG in the individualized group while not in standard group. The primary endpoint was the rate of adequate BP, defined by segmental Boston bowel preparation scale ≥2. Secondary outcomes included adenoma detection rate (ADR) and adverse events.

RESULTS

900 patients were randomly allocated to the individualized group (n = 449) and the control (n = 451). Baseline characteristics were similar between the two groups. The rates of high-risk patients were 19.6 % in individualized group and 19.7 % in standard group. In intention-to-treat analysis, adequate BP was 91.8 % in individualized group and 84.7 % in the standard group (p = 0.001). Among high-risk patients, adequate BP rate was 94.3 % in individualized group and 49.3 % in standard group (p < 0.001), and ADR were 40.9 % vs 16.9 %, respectively (p < 0.001). No significant differences were found regarding the adverse events and willingness to repeat BP (all p >0.05).

CONCLUSIONS

The individualized intervention using an additional dose of PEG to high-risk patients predicted by PRM, significantly improved BP quality. The intervention significantly improved ADR in high-risk patients. (ClinicalTrials.gov number: NCT04434625).

Risk Factors Related to Polyp Miss Rate of Short-Term Repeated Colonoscopy

BACKGROUND

Colonoscopy is regarded as the gold standard for colorectal cancer screening and surveillance. However, previous studies have reported large numbers of polyps were missed during routine colonoscopy.

AIMS

To evaluate polyp miss rate in short-term repeated colonoscopy and explore the related risk factors.

METHODS

A total of 3695 patients and 12,412 polyps were included in our studies. We calculated the miss rate for polyps of different sizes, pathologies, morphologies and locations, and patients of different characteristics. Univariate and multivariate logistic regression analyses were performed to evaluate risk factors related to miss rate.

RESULTS

The polyp miss rate was 26.3% and the adenoma miss rate was 22.4% in our study. The advanced adenoma miss rate was 11.0% and the proportion of missed advanced adenomas in missed adenomas sized > 5 mm was up to 22.8%. Polyps sized < 5 mm had a significantly higher miss rate. The miss rate of pedunculated polyps was lower than that of flat or sessile polyps. Polyps in the right colon were prone to be missed than that in the left colon. For older men, current smokers, individuals with multiple polyps detected in the first colonoscopy, the risk of missing polyps was significantly higher.

CONCLUSION

Nearly a quarter of polyps were missed during routine colonoscopy. Diminutive, flat, sessile, and right-side colon polyps were at higher risk of missing. The risk of missing polyps was higher in older men, current smokers, and individuals with multiple polyps detected in the first colonoscopy than their counterparts.

Risk factor analysis of malignant adenomas detected during colonoscopy

Background

Several studies have shown that colorectal adenomas are the most important precancerous lesions. The colonoscopic identification of groups with the high risk of malignant colorectal adenomas remains a controversial issue for clinicians.

Aims

To evaluate the basic characteristics of colorectal adenomas with malignancy risk using high-grade dysplasia (HGD) as an alternative marker for malignant transformation.

Methods

Data from Shanghai General Hospital between January 2017 and December 2021 were retrospectively analyzed. The primary outcome was the incidence of HGD in adenomas, which was used as a surrogate marker for the risk of malignancy. Odds ratios (ORs) for the HGD rate in adenomas were analyzed in relation to adenoma-related factors.

Results

A total of 9,646 patients identified with polyps during 57,445 screening colonoscopies were included in the study. Patients with flat polyps, sessile polyps, and pedunculated polyps represented 27.3% (N = 2,638), 42.7% (N = 4,114), and 30.0% (N = 2,894) of the total number, respectively. HGD was found in 2.41% (N = 97), 0.92% (N = 24), and 3.51% (N = 98) of sessile adenomas, flat adenomas, and pedunculated adenomas, respectively (P < 0.001). Multivariable logistic regression showed that polyp size (P < 0.001) but not shape (P > 0.8), was an independent predictor of HGD. Contrast to the diameter ≤1 cm, the OR value for diameters 1-2, 2-3, and >3 cm was 13.9, 49.3, and 161.6, respectively. The HGD incidence also increased in multiple adenomas (>3 vs. >1, ORs 1.582) and distal adenomas (distal vs. proximal adenomas, OR 2.252). Adenoma morphology (pedunculated vs. flat) was statistically significant in univariate analysis but not when size was included in the multivariate analysis. Besides, the incidence of HGD was also significantly higher in older patients (>64 vs. <50 years old, OR = 2.129). Sex (P = 0.681) was not statistically significant. All these associations were statistically significant (P < 0.05).

Conclusion

The malignant potential of polyps is mostly affected by their size but not by their shape. In addition, distal location, multiple adenomas, and advanced age were also correlated with malignant transformation.

Anatomical Distribution of Colon Cancer: A Retrospective 10-year Study to Evaluate Rightward Shift in Two Referral Hospitals in Iran

Background: In Iran, the incidence of colorectal cancer has been increasing over the last 25 years. Although left-sided colon cancers are still more common, several studies in recent years have shown a shift toward right colon. This rightward shift could have important clinical and healthcare consequences, as right-sided tumors generally have poorer prognoses compared to left-sided tumors and besides, are more likely to be missed in screening colonoscopy. Objectives: This retrospective study aimed at describing the demographic and clinicopathologic characteristics of patients with colon cancer based on tumor sidedness in two referral hospitals in Tehran. Methods: Data of the patients with colon cancer who had been treated from 2010 to 2020 in two referral hospitals in Tehran, Iran were retrospectively reviewed. Collected data included patients’ demographics, tumor histology and differentiation, tumor location, stage, and disease-free survival (DFS). Results: A total of 1535 cases entered the study including 849 (55.3%) males and 686 (44.7%) females with a mean age of 58.22 years (range: 22 - 89). Regarding the sidedness, 800 (52.1%) had left-sided and 735 (47.9%) had right-sided tumors. Although there were more cases of left-sided tumors compared to right-sided ones on total, there existed a trend toward shifting to the right side, which was statistically significant. There existed more cases of poorly differentiated tumors in the right side and besides, right-sided tumors had poorer DFS compared to the left-sided tumors (68.3% vs 78.3%). Conclusions: Left and right colon tumors differ in molecular mechanisms involved in tumorigenesis. These differences in epidemiological, molecular and histological parameters can have clinical implications. Tumor-sidedness should be acknowledged as an important epidemiological parameter with significant impacts on screening, tumorgenesis, response to treatment, and prognosis.

Race, age, and sex differences on the influence of obesity on colorectal cancer sidedness and mortality: A national cross‐sectional study

BACKGROUND AND OBJECTIVES

Colorectal cancer (CRC) sidedness is recognized as a prognostic factor for survival; left-sided colorectal cancer is associated with better outcomes than right-sided colon cancer (RsCC). We aimed to evaluate the influence of obesity on CRC sidedness and determine how race, age, and sex affect mortality among overweight and obese individuals.

METHODS

A survey-weighted analysis was conducted using data obtained from the National Inpatient Sample between 2016 and 2019.

RESULTS

Of the 24 549 patients with a diagnosis of CRC and a reported body mass index (BMI), 13.6% were overweight and 49.9% were obese. The race distribution was predominantly non-Hispanic Whites (69.7%), followed by Black (15.6%), Hispanic (8.7%), and other race (6.1%). Overweight (BMI: 25-29.9) and obese (BMI: ≥30) individuals were more likely to have RsCC (adjusted OR [aOR] = 1.28; 95% CI: 1.17-1.39, p < 0.001 and aOR = 1.45; 95% CI: 1.37-1.54, p < 0.001, respectively). Obese Black individuals were more likely to have RsCC as compared to their White counterparts (aOR = 1.23; 95% CI: 1.09-1.38).

CONCLUSIONS

Obesity is associated with an increased risk of RsCC. In addition, racial disparities in CRC sidedness and outcomes are most pronounced among obese patients.

Retroflexed view for reexamination of the right colon after forward view examination: Systematic review and meta-analysis

BACKGROUND

The effect of retroflexed view (RV) for the reexamination of the right colon after forward view (FV) examination has not been fully understood.

METHODS

We searched multiple databases including PubMed, Embase, and the Cochrane Library for prospective studies exploring the role of RV for reexamination of the right colon. A meta-analysis was performed on outcomes including lesion detection rates, lesion miss rates, and withdrawal time.

RESULTS

Four randomized controlled trials aimed to compare the impact of the second withdrawal from the right colon in RV vs. FV following a standard colonoscopy. Both the additional adenoma detection rate (AADR) and additional polyp detection rate (APDR) of the right colon were lower in the RV group compared with the FV group (risk ratio [RR] 0.73 for AADR; RR 0.76 for APDR); similar results were noted in comparisons of the adenoma miss rate and polyp miss rate. Six prospective cohort studies aimed to describe the effect of the RV examination of the right colon after one or two rounds of FV examination. Both the adenoma detection rate (ADR) and polyp detection rate (PDR) of the right colon were slightly higher in combined examinations with RV examination than single FV examination (RR 1.11 for ADR; RR 1.16 for PDR) or two FV examinations (RR 1.21 for ADR; RR 1.22 for PDR).

CONCLUSIONS

FV may detect more adenomas and polyps than RV during the second withdrawal from the right colon. RV may detect additional adenomas and polyps in the right colon after two FV examinations.

Bowel cleansing efficacy for colonoscopy: prospective, randomized comparative study of same-day dosing with 1-L and 2-L PEG + ascorbate

Background and study aims  Polyethylene glycol (PEG) bowel preparations are effective but associated with high ingestion volume. In this study, 1-L PEG and 2-L PEG preparations were compared in a randomized, colonoscopist-blinded, single-center trial. Patients and methods  Patients were aged > 18 years, required colonoscopy, and provided informed consent. Randomization was 1:1 to 1-L PEG or 2-L PEG, based on hospital identification number (odd or even). Preparations were administered using same-day dosing adjusted for colonoscopy start time. The primary endpoint was successful bowel preparation on the Boston Bowel Preparation Scale (BBPS) (no segment scored < 2). Results  A total of 852 patients were randomized. In the intention-to-treat (ITT) population, significantly more patients had diabetes in the 2-L PEG arm, resulting in the creation of the modified-ITT population (mITT) that excluded diabetic patients to correct the imbalance (1-L PEG, n = 239; 2-L PEG, n = 238). In the mITT, there was no significant difference in successful cleansing between 1-L PEG and 2-L PEG (88.3 % vs. 82.4 %; P  = 0.067). Excellent cleansing (BBPS 7-9; no segment < 2) was significantly improved with 1-L PEG (60.7 % vs. 50.4 %; P  < 0.024), as were mean scores in the right and left colon (right: 2.47 vs. 2.30; P  < 0.008; left: 2.55 vs. 2.39; P  = 0.008). Adverse events were mild to moderate in intensity and none resulted in discontinuation. Rates of nausea and vomiting were significantly higher with 1-L PEG, but that did not affect successful cleansing. Conclusions  The lower-volume 1-L PEG was associated with higher levels of excellent bowel cleansing and greater mean segmental scores on the BBPS than 2-L PEG.

Comparing right colon adenoma detection rate during water exchange and air insufflation: a double-blind randomized controlled trial

BACKGROUND

Randomized controlled trials (RCTs) have reported that water exchange (WE) produced the highest adenoma detection rate (ADR) but did not evaluate right colon adenoma detection rate (rADR) as a primary outcome and only one of the trials employed blinded colonoscopists. The aim of our study was to determine whether, compared with air insufflation, WE significantly increases rADR and right colon serrated lesion detection rate (rSLDR) and decreases adenoma miss rate (rAMR).

METHODS

This prospective, double-blind RCT was conducted at a regional hospital in Taiwan between December 2015 and February 2020. Standard WE and air insufflation were performed. After cecal intubation, the second blinded endoscopist examined the right colon and obtained rADR (primary outcome) and rSLDR. Then, the primary colonoscopist reinserted the scope to the cecum with WE in both groups and performed a tandem examination of the right colon to obtain rAMR.

RESULTS

There were 284 patients (50.9% male, mean age 58.9 ± 9.4 years) who were randomized to WE (n = 144) or air insufflation (n = 140). The baseline characteristics were similar. The rADR (34.7% vs. 22.3%, p = 0.025), Boston Bowel Preparation Scale scores (mean, 2.6 ± 0.6vs. 2.2 ± 0.6, p < 0.001), rSLDR (18.1% vs. 7.1%, p = 0.007), and rAMR (31.5% vs. 45.2%, p = 0.038) were significantly different between WE and air insufflation.

CONCLUSIONS

The current study demonstrated a significantly higher rADR and rSLDR with the WE method performed by blinded colonoscopists. The impact of the significant findings in this report on the occurrence of interval cancers deserves to be studied.

[Post-colonoscopy Colorectal Cancer: Causes and Prevention of Interval Colorectal Cancer]

Colorectal cancer (CRC) is the third most commonly diagnosed cancer and the fourth leading cause of cancer death in the worldwide. Colonoscopy is the gold standard for screening and surveillance of CRC. Removing adenomas by colonoscopy has lowered the incidence and mortality of CRC. However, colonoscopy is imperfect for detection of colorectal neoplasia. After a colonoscopy that is negative for malignancy, CRC can be diagnosed. These are termed as post-colonoscopy CRC (PCCRC). The proportion of PCCRC, among all CRC was reported to be 1.8% to 9.0%. It occurred 2.4 times more in the right colon than in the left colon. The causes of PCCRC are missed lesions, incomplete resection, and new lesions. Among these causes, missed lesion and incomplete resection are procedural factors and preventable. Therefore, it is necessary to improve the quality of colonoscopy to minimize the occurrence of PCCRC.

Fecal DNA Testing of TWIST1 Methylation Identifies Patients With Advanced Colorectal Adenoma Missed by Fecal Immunochemical Test for Hemoglobin

INTRODUCTION

We have reported previously that fecal DNA testing of TWIST1 methylation in combination with the fecal immunochemical test for hemoglobin (FIT) (combination test) is useful for colorectal neoplasia screening. In this study, using larger sample sizes, we studied the clinical performance of the combination test for the detection of colorectal neoplasia and, especially, advanced colorectal adenoma.

METHODS

We performed a prospective study in which FIT, fecal DNA testing of TWIST1 methylation, and colonoscopy were performed on 372 patients with colorectal neoplasia and 71 subjects without colorectal neoplasia. We assessed the individual clinical performance of each of FIT and fecal DNA testing of TWIST1 methylation and of the combination test for the detection of colorectal neoplasia including advanced adenoma based on morphologic subtypes.

RESULTS

The FIT alone had a sensitivity of 7.5% (3/40) for nonadvanced adenoma, 32.3% (41/127) for advanced adenoma, and 93.7% (192/205) for colorectal cancer and a specificity of 87.3% (62/71). The combination test had a sensitivity of 35.0% (14/40) for nonadvanced adenoma, 68.5% (87/127) for advanced adenoma, and 95.6% (196/205) for colorectal cancer and a specificity of 80.3% (57/71). For morphological subtypes of advanced adenoma, the sensitivity of FIT was only 28.2% (20/71) for polypoid type and 16.1% (5/31) for nonpolypoid type, whereas the combination test increased the sensitivities to 64.8% (46/71) and 71.0% (22/31), respectively.

DISCUSSION

The combination of the fecal DNA test with FIT seemed to be useful to detect colorectal neoplasia and, especially, advanced adenoma of the nonpolypoid type.

Impact of Inadequate Bowel Cleansing on Colonoscopic Findings in Routine Screening Practice

INTRODUCTION

Colonoscopy is an imperfect gold standard for detecting colorectal neoplasms because some proportion of adenomas may be missed, mainly small lesions. This proportion is expected to be higher in case of inadequate bowel cleansing, which is frequently seen in routine practice. We estimated the proportions of neoplasms that are in principle detectable by colonoscopy but might be missed in case of incomplete bowel preparation.

METHODS

For 8,193 participants of screening colonoscopy in South-Western Germany, recruited between 2005 and 2016, the prevalence and numbers of different findings were extracted from colonoscopy reports and compared according to the reported bowel preparation quality.

RESULTS

Bowel preparation quality was reported as good, poor, or was unspecified in 30.3%, 11.1%, and 58.6% of colonoscopy records. Reported prevalences of nonadvanced adenomas (NAAs) were similar among participants with poor and unspecified bowel preparation quality but substantially lower than among participants with good bowel preparation (adjusted prevalence rate ratio [RR] 0.86, 95% confidence interval [CI]: 0.77-0.96). The differences were observed for proximal but not for distal NAAs (RRs 0.82, 95% CI: 0.71-0.95 and 0.95, 95% CI: 0.82-1.10).

DISCUSSION

Our study suggests that a significant proportion of NAAs located in the proximal colon might be missed during colonoscopy if bowel cleansing is not adequate. Major efforts should be made to further facilitate and enhance high-quality bowel preparation in routine screening practice.

Retroflexion, a costless endoscopic maneuver, increases adenoma detection rate in the ascending colon

Background

Missed polyps during colonoscopy are considered an important factor for interval cancer appearance, especially in the ascending colon (AC). We evaluated the contribution of retroflexion to polyp and adenoma detection in the AC.

Methods

This prospective observational study included consecutive patients who underwent a complete colonoscopy between 06/2017 and 06/2018. The AC was examined in 2 phases: the first included 2 forward views from the hepatic flexure to the cecum; the second involved a retroflexion in the cecum, inspection up to the hepatic flexure and reinsertion to the cecum.

Results

The study included 655 patients, 628 (95.88%) with successful retroflexion (mean age: 62.5±10.8 years, 332 male). Indications for colonoscopy were screening in 33.28%, follow up in 36.03%, and diagnostic assessment in 30.69%. In total, 286 polyps and 220 adenomas were detected in the AC. Phase 1 identified 119 adenomas, yielding an adenoma detection rate (ADR) in the AC of 14.2% (95% confidence interval [CI] 11.52-16.84%) while phase 2 identified 86 additional adenomas, improving the ADR in the AC to 22.75% (95%CI 19.54-25.96%; P<0.01). Adenoma miss rate was 39.1% (86/225) and per-patient adenoma miss rate was 11.15% (73/655). Retroflexion proved beneficial mainly in the upper third of the AC (odds ratio [OR] 4.29, 95%CI 1.84-11.56; P<0.01) and for small (<5 mm) adenomas (OR 1.61, 95%CI 1.02-2.56; P=0.04). Multivariate analysis showed that age >60 years, detection of adenomas in forward views and the indication “follow up” influenced ADR during retroflexion.

Conclusion

Retroflexion is a simple and safe maneuver that increases the ADR in the AC and should complete a second forward view.

Molecular heterogeneity of guanine nucleotide binding-protein γ subunit 4 in left- and right-sided colon cancer

Molecular heterogeneity determines the differences in the pathological features, prognosis and survival after relapse when comparing left-sided colon cancer (LCC) and right-sided colon cancer (RCC). At present, the discrepancy in the underlying molecular events between the two types of colon cancer has not been thoroughly investigated. The present study aimed to explore novel targets to predict the disease stage and prognosis of LCC and RCC. Expression analysis of guanine nucleotide binding-protein γ subunit 4 (GNG4) was performed using the Gene Expression Profiling Interactive Analysis (GEPIA) and Oncomine databases. Survival and association analyses were performed using GEPIA and the colon adenocarcinoma dataset from The Cancer Genome Atlas database. GNG4-positive cells in a tissue microarray were examined using immunohistochemistry. According to the GNG4 expression data from Caucasian patients included in the TCGA dataset, GNG4 was highly expressed and positively associated with pathological stage and overall survival (OS) rates in colon cancer. GNG4 expression was higher in LCC than in RCC. Patients with LCC with high GNG4 expression exhibited higher pathological stage and lower survival rates, whereas this was not observed in patients with RCC. In addition, the clinical tissues used in the microarray showed that GNG4 expression was increased in Chinese patients with LCC compared with that in patients with RCC. Consistently, GNG4 expression was negatively associated with OS in patients with LCC, but not in patients with RCC. However, no association was observed between GNG4 expression and the disease stage of colon cancer in both patients with LCC and RCC. Overall, the molecular heterogeneity of GNG4 in LCC and RCC suggests that GNG4 may be used as a diagnostic and prognostic biomarker in patients with LCC.

Relationship between the polyp detection rate and the post-colonoscopy colorectal cancer rate

AIM

the adenoma detection rate is the quality indicator of colonoscopy that is most closely related to the development of interval colorectal cancer or post-colonoscopy colorectal cancer. However, the recording of this indicator in different units of gastrointestinal endoscopy is obstructed due to the large consumption of resources required for its calculation. Several alternatives have been proposed, such as the polyp detection rate. The objective of this study was to evaluate the relationship between the polyp detection rate and its influence on post-colonoscopy colorectal cancer rate.

PATIENTS AND METHODS

in this study, 12,482 colonoscopies conducted by 14 endoscopists were analyzed. The polyp detection rate was calculated for each endoscopist. Endoscopists were grouped into quartiles (Q1, Q2, Q3, and Q4), from lowest to highest polyp detection rate, in order to evaluate whether there were any differences in the development of post-colonoscopy colorectal cancer.

RESULTS

the lowest polyp detection rate was 20.66% and the highest was 52.16%, with a median of 32.78 and a standard deviation of ± 8.54. A strong and positive association between polyp endoscopy diagnosis and adenoma histopathology result was observed and a linear regression was performed. A significantly higher post-colonoscopy colorectal cancer rate was observed in the group of endoscopists with a lower polyp detection rate (p < 0.02).

CONCLUSION

polyp detection rate is a valuable quality indicator of colonoscopy and its calculation is much simpler than that of the adenoma detection rate. In our study, the prevalence of post-colonoscopy colorectal cancer was inversely and significantly related to the endoscopists' polyp detection rate.

Multitarget Stool DNA for Average Risk Colorectal Cancer Screening: Major Achievements and Future Directions

After 2 screen-setting studies showing high sensitivity for colorectal cancer and advanced precancerous lesions, multitarget stool DNA testing was endorsed by the US Preventative Services Task Force as a first-line colorectal cancer screening test. Uptake has increased exponentially since approval by the US Food and Drug Administration and Centers for Medicare and Medicaid Services. Adherence to testing is approximately 70%. Patients with positive results have high diagnostic colonoscopy completion rates in single-center studies. The positive predictive value for colorectal neoplasia in postapproval studies is high. Next-generation test prototypes show promise to extend specificity gains while maintaining high sensitivity.

Proximal retroflexion versus second forward view of the right colon during screening colonoscopy: A multicentre randomized controlled trial

BACKGROUND

Colonoscopy is the gold standard investigation for the detection of colorectal cancer, but the right colon is more difficult to examine than the left colon. A second examination of the proximal colon has the potential to reduce rates of missed pathology.

OBJECTIVE

To determine whether proximal retroflexion improves the adenoma detection rate or other outcomes in the right colon compared with the forward view.

METHODS

We performed a multicentre randomized controlled trial of patients from the colorectal cancer screening programme with a positive faecal immunochemical test. Patients were randomized to a second right colon examination using proximal retroflexion or forward view.

RESULTS

A total of 692 patients were included. A second examination of the right colon, with an average additional procedure time of 1.62 min, increased the adenoma detection rate by 11%, regardless of the method used (9% proximal retroflexion vs. 12% second forward view, p = 0.21). The adenoma miss rate was 19% (17% proximal retroflexion vs. 20% forward view, p = 0.28) The success rate of retroflexion was 83%, without secondary complications. In the 15.6% of patients in whom lesions were detected during the second pass, endoscopic follow-up was modified by reducing the time of the next colonoscopy.

CONCLUSIONS

A second examination of the right colon, either from retroflexion or second forward view, can increase adenoma detection rate and shorten surveillance intervals in patients undergoing screening colonoscopy. This should be emphasized during colonoscopy training and integrated into diagnostic colonoscopy practice.

Multitarget Stool DNA Screening in Clinical Practice: High Positive Predictive Value for Colorectal Neoplasia Regardless of Exposure to Previous Colonoscopy

OBJECTIVES

Multitarget stool DNA (MT-sDNA) testing has grown as a noninvasive screening modality for colorectal cancer (CRC), but real-world clinical data are limited in the post-FDA approval setting. The effect of previous colonoscopy on MT-sDNA performance is not known. We aimed to evaluate findings of colorectal neoplasia (CRN) at diagnostic colonoscopy in patients with positive MT-sDNA testing, stratified by patient exposure to previous colonoscopy.

METHODS

We identified consecutive patients completing MT-sDNA testing over a 39-month period and reviewed the records of those with positive tests for neoplastic findings at diagnostic colonoscopy. MT-sDNA test positivity rate, adherence to diagnostic colonoscopy, and the positive predictive value (PPV) of MT-sDNA for any CRN and neoplastic subtypes were calculated.

RESULTS

Of 16,469 MT-sDNA tests completed, testing returned positive in 2,326 (14.1%) patients. After exclusion of patients at increased risk for CRC, 1,801 patients remained, 1,558 (87%) of whom underwent diagnostic colonoscopy; 918 of 1,558 (59%) of these patients had undergone previous colonoscopy, whereas 640 (41%) had not. Any CRN was found in 1,046 of 1,558 patients (PPV = 67%). More neoplastic lesions were found in patients without previous colonoscopy (73%); however, the rates remained high among those who had undergone previous colonoscopy (63%, P < 0.0001). The large majority (79%) of patients had right-sided neoplasia.

DISCUSSION

MT-sDNA has a high PPV for any CRN regardless of exposure to previous colonoscopy. Right-sided CRN was found at colonoscopy in most patients with positive MT-sDNA testing, representing a potential advantage over other currently available screening modalities for CRC.

Multi-Target Stool DNA Testing for Colorectal Cancer Screening: Emerging Learning on Real-world Performance

PURPOSE OF REVIEW

Multi-target stool DNA (MT-sDNA) was approved in 2014 for use in screening average-risk patients for colorectal cancer (CRC). Here, we highlight recent literature from post-market studies to provide an update on clinical use and utility not possible from pre-approval studies.

RECENT FINDINGS

MT-sDNA has been included in major society guidelines as an option for colorectal cancer screening, and has seen exponentially increasing use in clinical practice. MT-sDNA appears to be attracting new patients to CRC screening, and patient adherence to diagnostic colonoscopy after a positive MT-sDNA test is high. Approximately two-thirds of these patients are found to have colorectal neoplasia (CRN), 80% of whom have at least one right-sided lesion; 1 in 3 will have advanced CRN. High yield of CRN is due not only to post-screening increase in probability but also likely improved endoscopist attention. In those with a negative high-quality colonoscopy after positive MT-sDNA test ("false positive MT-sDNA"), further interventions do not appear to be necessary.

SUMMARY

MT-sDNA is a promising tool to improve rates and quality of CRC screening. Further investigation should examine MT-sDNA performance in populations at increased risk for CRC, and as an interval test after colonoscopy to detect potentially missed lesions.

Does the withdrawal time affect adenoma detection in non-screening colonoscopies?

AIMS

There are no studies looking at the relationship between colonoscopy withdrawal time (CWT) and adenoma detection rate (ADR) in non-screening patients. Our aim is to explore the relationship between CWT and ADR, particularly in the proximal colon where colonoscopy is shown to be less protective for the development of cancers.

METHODS

This is a retrospective study during November 2015 to December 2016 of non-screening colonoscopies done at a large teaching hospital. Incomplete and therapeutic procedures were excluded. The 39 endoscopists included were 15 gastroenterologists, 10 colorectal surgeons and 14 trainee colonoscopists. CWT was calculated by reviewing caecal intubation and rectal retroflexion images.

RESULTS

783 colonoscopies were included, with mean patient age of 58.51 years (SD 15.5). The mean ADR was 21.45% in the study. The CWT could be calculated for 62.83% of the cases (n=492). 80% (393) of colonoscopies had CWT of ≥6 min. Mean CWT was 9.15 min (SD 4.4). The ADR positively correlated with longer CWT (r=0.31, p=0.0001). The ADR was significantly higher when CWT was ≥8 min compared with CWT <6 min or CWT of 6-8 min (p=0.0001). More polyps were detected in the proximal colon when CWT ≥8 min (p=0.078). Mean CWT of gastroenterologists was 9.8 min (SD 4.5), similar to the trainee group (10.3 min, SD 3.8), while mean CWT for colorectal surgeons was 5.7 min (SD 3.2). The ADR for gastroenterologists was 25.9% versus 17.5% for colorectal surgeons and 17.8% for trainees.

CONCLUSIONS

There is a moderately strong positive correlation between longer CWT and ADR in non-screening colonoscopies. CWT can differ between different endoscopists. Meticulous colonoscopy withdrawal may improve polyp detection in the proximal colon.

Effect of fellow involvement on colonoscopy outcomes: A systematic review and meta-analysis

BACKGROUND AND AIMS

The effect of fellow involvement on colonoscopy outcomes is controversial. Thus, we evaluated this effect on adenoma detection rate (ADR) and on other colonoscopy quality indicators.

METHODS

MEDLINE and Cochrane central register of controlled trials were searched up to September 2018 for studies evaluating fellow-involved colonoscopies vs. attending physicians-only examinations in terms of colonoscopy outcomes. Primary outcome was ADR, while advanced ADR (AADR), mean number of adenomas per colonoscopy (MAC), cecum intubation rate (CIR) and adverse events rate comprised the secondary outcomes. The effect size on study outcomes was calculated using random-effects model and it is presented as Odds Ratio (OR) or Mean Difference (MD) with 95% confidence interval (CI).

RESULTS

Nineteen observational studies involving 34,059 patients (fellow-involved 16,875, attending physician-only 17,184) were included. Compared to the attending physician-only group, fellow involvement marginally increased ADR [OR (95%CI) = 1.12 (1.00-1.26); p = 0.06, I² = 76%]. Attending physicians with low-to-moderate ADR (<35%) benefited most from fellow's participation [OR (95%CI): 1.26 (1.13-1.40) vs. 1.12 (1.00-1.26); p = 0.03 when ADR < 35% and OR (95%CI): 1.29 (1.13-1.46) vs. 0.95 (0.78-1.16); p = 0.01 when ADR < 30%, respectively]. Moreover, fellow-involved group had higher MAC compared to attending-only group [MD (95%CI) = 0.12 (0.04-0.20); p = 0.002, I² = 53%]. No benefit from fellow involvement was detected either for AADR, CIR or adverse events rate.

CONCLUSIONS

Fellow involvement during colonoscopy is associated with more adenomas detected per procedure and with higher ADR when the attending physician-only group ADR is less than 35%.

The Efficacy of Split-Dose Bowel Preparations for Polyp Detection: A Systematic Review and Meta-Analysis

INTRODUCTION

Split-dose bowel preparation leads to superior colon cleansing for colonoscopy. However, the magnitude of benefit in detecting colonic polyps is uncertain. We performed a systematic review to synthesize the data on whether using a split-dose bowel preparation regimen improves the detection of polyps when compared with other dosing methods or regimen products.

METHODS

We searched MEDLINE, EMBASE, and CENTRAL databases (from the inception to June 2017) for randomized controlled trials that assessed the following: split-dose vs day-before, split-dose vs same-day (as colonoscopy), or different types of split-dose regimens for patients undergoing colonoscopy. We excluded studies limited to inpatients, children, or individuals with inflammatory bowel disease. We compared the number of patients undergoing colonoscopy with recorded detection of polyps, adenomas, advanced adenomas, sessile serrated polyps (SSPs), right colonic adenomas, right colonic polyps, or right colonic SSPs.

RESULTS

Twenty-eight trials fulfilled the inclusion criteria (8,842 participants). Of the seven trials comparing split-dose vs day-before bowel preparation regimens, there was an increased detection rate of adenomas (risk ratio (RR) 1.26, 95% confidence intervals (CIs): 1.10-1.44; 4 trials; 1,258 participants), advanced adenomas (RR 1.53, 95% CI: 1.22-1.92; 3 trials; 1,155 participants), and SSPs (RR 2.48, 95% CI: 1.21-5.09; 2 trials; 1,045 participants). Pooled estimates from 8 trials (1,587 participants) evaluating split-dose vs same-day bowel preparations yielded no evidence of statistical difference. For various split-dose vs split-dose trials, 14 fulfilled the criteria (5,496 participants) and no superior split-regimen was identified.

CONCLUSIONS

Compared with day-before bowel preparation regimens, split-dose bowel preparations regimens increase the detection of adenomas, advanced adenomas, and have the greatest benefit in SSP detection.

Increasing adenoma detection rates in the right side of the colon comparing retroflexion with a second forward view: a systematic review

BACKGROUND AND AIMS

Right-sided lesions are often missed during standard colonoscopy (SC). A second forward-view examination or retroflexion in the right side of the colon have both been proposed as techniques to improve adenoma detection rate (ADR) in the right side of the colon. Comparative data on examining the right side of the colon with a second forward view or retroflexion is not known in a pooled analysis. We performed a systematic review of the literature to assess the yield of a second forward view compared with retroflexion examination for the detection of right-sided adenomas.

METHODS

A systematic literature search was performed using the following databases: PubMed, Embase, Web of Science, and Cochrane. Only full-length published articles that provided information on adenoma detection and miss rates during either a second forward view or retroflexed view of the right side of the colon after the initial standard forward withdrawal (SC) were included. The following outcomes were assessed: comparison of adenoma miss rate (AMR) for second forward view versus retroflexion after SC, AMR of SC compared with second forward view, AMR of SC compared with retroflexion, and right-sided adenoma detection with second forward view and retroflexion. Pooled rates were reported as risk difference or odds ratios (OR) with 95% confidence intervals (CI) with a P value <.05 indicating statistical significance. Statistical analysis was performed with Review Manager v5.3.

RESULTS

We identified 4 studies with 1882 patients who underwent a second forward view of the right side of the colon after an initial SC. The average age of the patients was 58.3 years. Data on right-sided ADR were available from all 4 studies for the second forward view; however, only 2 of the studies provided information on right-sided ADR with retroflexion. The pooled estimate of AMR of a single SC was 13.3% (95% CI, 6.6%-20%) compared with a second forward-view examination (n = 4), whereas it was 8.1% (3.7%-12.5%) compared with a retroflexion examination (n = 3). However, when the second forward view was compared with retroflexion in terms of AMR from an analysis of 3 eligible studies, there was no statistically significant difference (7.3% vs 6.3%; pooled OR, 1.2; 95% CI, 0.9-1.61; P = .21). Second forward view of the right side of the colon increased the right-sided ADR by 10% (n = 4; second forward view vs SC, 33.6% vs 26.7%) with a pooled risk difference of 0.09 (95% CI, 0.03-0.15; P < .01). Retroflexion increased the right-sided ADR by 6% (n = 3; retroflexion vs SC, 28.4% vs 22.7%) with a pooled risk difference of 0.06 (95% CI, 0.03-0.09; P < 01).

CONCLUSION

After SC withdrawal, a second forward view and retroflexed view of the right side of the colon are both associated with improvement in ADR. One of these techniques should be considered during SC to increase ADR and to improve the quality of colonoscopy.

Changing from two- to one-operator colonoscopy insertion technique is feasible with similar quality outcomes

Background and Aim

Colonoscopy can be performed with two-operator (2OP) or one-operator (1OP) methods. This study aimed to investigate the feasibility and colonoscopy quality outcomes for the two different colonoscopy insertion techniques.

Methods

One colonoscopist from Changhua Christian Hospital learned and changed the colonoscopy insertion technique from 2OP to 1OP during 2013. Real-life results of screening colonoscopies performed by this colonoscopist between these two insertion techniques (year 2012: 2OP vs year 2014: 1OP) were retrospectively reviewed and compared.

Results

In total, 219 screening colonoscopies were reviewed (2OP group, n = 103 vs 1OP group, n = 116). No differences were noted between both groups in terms of patient age, gender, weight, and height. The overall cecum intubation was 98.2%, adenoma detection rate (ADR) was 29.7%, and colonoscopy withdrawal time was 518.58 ± 972.04 s. On comparing colonoscopy quality outcomes between both methods, no differences were observed in cecal intubation rates (2OP vs 1OP: 100 vs 96.6%, P = 0.1626), ADR (28 vs 31%, P = 0.7401), and colonoscopy withdrawal time (454.88 ± 178.21 vs 576.92 ± 1325.01 s, P = 0.355). However, the 1OP group demonstrated significantly shorter colonoscopy insertion time (2OP vs 1OP: 298.28 ± 202.95 vs 216.21 ± 121.99 s, P = 0.003).

Conclusion

Colonoscopy quality outcomes were not impaired when one endoscopist changed the colonoscopy practice pattern from 2OP to 1OP. However, 1OP significantly shortened the colonoscopy insertion time.

Colonoscopy attachments for the detection of precancerous lesions during colonoscopy: A review of the literature

Although colonoscopy has been proven effective in reducing the incidence of colorectal cancer through the detection and removal of precancerous lesions, it remains an imperfect examination, as it can fail in detecting up to almost one fourth of existing adenomas. Among reasons accounting for such failures, is the inability to meticulously visualize the colonic mucosa located either proximal to haustral folds or anatomic curves, including the hepatic and splenic flexures. In order to overcome these limitations, various colonoscope attachments aiming to improve mucosal visualization have been developed. All of them - transparent cap, Endocuff, Endocuff Vision and Endorings - are simply mounted onto the distal tip of the scope. In this review article, we introduce the rationale of their development, present their mode of action and discuss in detail the effect of their implementation in the detection of lesions during colonoscopy.

Characteristics of right-sided colonic neoplasia and colonoscopy barriers limiting their early detection and prognosis: a review of the literature

Colonoscopy provides less protection from colorectal cancer in the right colon than the left. Areas covered: This review examines patient outcomes and colonoscopy success rates to identify factors that limit the protective effect of colonoscopy in the right colon. The MEDLINE and Embase databases were searched for literature from 2000 onwards, on the long-term outcomes and differences in screening practice between the right and left colon. In total, 12 systematic reviews (including nine meta-analyses) and 44 primary data records were included. Differences in patient outcomes and colonoscopy practice were identified between the right and left colon, suggesting that several factors, many of which disproportionally affect the right colon, impact lesion detection rates. Shorter withdrawal times reduce detection rates, while longer times significantly increase detection; mostly of adenomas in the right colon. Colonoscope attachments often only show a significant improvement in detection rates in the right colon, suggesting detection is more challenging due to visibility of the right colonic mucosa. Higher bowel cleansing grades significantly improve detection rates in the right colon compared to the left. Expert commentary: These findings confirm the need for continued improvement of colonoscopy effectiveness, and obligatory quality assessment, overall and especially in the right colon.

Predictive factors for missed adenoma on repeat colonoscopy in patients with suboptimal bowel preparation on initial colonoscopy: A KASID multicenter study

Suboptimal bowel preparation can result in missed colorectal adenoma that can evolve into interval colorectal cancer. This study aims to identify the predictive factors associated with missed adenoma on repeat colonoscopy in patients with suboptimal bowel preparation at initial colonoscopy. A total of 441 patients with suboptimal bowel preparation on initial colonoscopy and who had repeat colonoscopy within two years were included from 2007 to 2014 in six tertiary hospitals. Suboptimal bowel preparation was defined as 'poor' according to the Aronchick scale or a score ≤ 1 in at least one segment or total score < 6 according to the Boston bowel preparation scale. Of 441 patients, mean age at initial colonoscopy was 59.1 years, and 69.2% patients were male. The mean interval from initial to repeat colonoscopy was 14.1 months. The per-patient adenoma miss rate (AMR) was 42.4% for any adenoma and 5.4% for advanced adenoma. When the association between baseline clinical characteristics and missed lesions on repeat colonoscopy was analyzed, dyslipidemia (odds ratio [OR], 5.19; 95% confidence interval [CI], 1.14-23.66; P = 0.034), and high-risk adenoma (OR, 4.45; 95% CI, 1.12-17.68; P = 0.034) on initial colonoscopy were independent risk factors for missed advanced adenoma. In patients with suboptimal bowel preparation, dyslipidemia and high-risk adenoma on initial colonoscopy were independently predictive of missed advanced adenoma on repeat colonoscopy.

Predictive factors for missed adenoma on repeat colonoscopy in patients with suboptimal bowel preparation on initial colonoscopy: A KASID multicenter study

Suboptimal bowel preparation can result in missed colorectal adenoma that can evolve into interval colorectal cancer. This study aims to identify the predictive factors associated with missed adenoma on repeat colonoscopy in patients with suboptimal bowel preparation at initial colonoscopy. A total of 441 patients with suboptimal bowel preparation on initial colonoscopy and who had repeat colonoscopy within two years were included from 2007 to 2014 in six tertiary hospitals. Suboptimal bowel preparation was defined as ‘poor’ according to the Aronchick scale or a score ≤ 1 in at least one segment or total score < 6 according to the Boston bowel preparation scale. Of 441 patients, mean age at initial colonoscopy was 59.1 years, and 69.2% patients were male. The mean interval from initial to repeat colonoscopy was 14.1 months. The per-patient adenoma miss rate (AMR) was 42.4% for any adenoma and 5.4% for advanced adenoma. When the association between baseline clinical characteristics and missed lesions on repeat colonoscopy was analyzed, dyslipidemia (odds ratio [OR], 5.19; 95% confidence interval [CI], 1.14–23.66; P = 0.034), and high-risk adenoma (OR, 4.45; 95% CI, 1.12–17.68; P = 0.034) on initial colonoscopy were independent risk factors for missed advanced adenoma. In patients with suboptimal bowel preparation, dyslipidemia and high-risk adenoma on initial colonoscopy were independently predictive of missed advanced adenoma on repeat colonoscopy.

Tumor location impact in stage II and III colon cancer: epidemiological and outcome evaluation

Background

We aimed to describe clinico-pathological characteristics and differences between right-sided (RCC) and left-sided colon cancer (LCC) in Tunisian population. We also analyzed outcome to determine whether location is of prognostic significance.

Methods

Clinico-pathological characteristics and Kaplan Meier survival were compared between two groups of LCC [150] and RCC [53] patients with stage II and III adenocarcinoma treated with curative intent between 2003-2014.

Results

RCC patients were significantly more likely to be female, (56.6% vs. 39.3%, P=0.029) and to have undifferentiated tumor (87.1% vs. 8.4%, P=0.014), then LCC. After a median follow up of 49 months, 5-year overall survival (OS) was significantly worse in RCC vs. LCC [42% vs. 78%; hazard ratio (HR) =2.07; 95% CI: 1.05-4.09; P=0.03], no difference in relapse free survival (RFS) was observed. Median time to relapse was significantly shorter in RCC (15 months) vs. LCC (24 months), P=0.005. Tumor location significantly impacted survival in stage III, 5-year OS was 45% in RCC, and 63% in LCC, (HR =2.28; 95% CI: 1.01-5.24; P=0.04), there was no impact of tumor location in stage II, (HR =1.94; 95% CI: 0.54-6.93; P=0.29).

Conclusions

Prognostic impact of tumor location should be considered as a stratification factor in the future clinical trials.

Multi-target stool DNA test in the surveillance of inflammatory bowel disease: a cross-sectional cohort study

BACKGROUND AND AIM

Colonoscopic surveillance is recommended in patients with longstanding inflammatory bowel disease (IBD) as they are at increased risk of colorectal cancer (CRC). Non-invasive surveillance may improve compliance and access. Multi-target stool DNA (MT-sDNA) has been validated for screening of sporadic CRC but has not been assessed in IBD. Our aim was to assess the performance of a MT-sDNA test in a real-life surveillance setting of patients with longstanding IBD.

MATERIAL AND METHODS

A total of 192 IBD patients enrolled from two prospective cohorts submitted an EDTA buffered stool sample and underwent chromo- or white light colonoscopy. Stools were assayed for methylated BMP3 & NDRG4, mutant KRAS and β-actin by a laboratory blinded to clinical data.

RESULTS

The multitarget-sDNA panel was positive in 2/2 CRC and 5/15 low-grade dysplasia (LGD) < 1 cm in diameter. Sensitivities were 100% (95% CI 16-100%) for CRC and 33% (95% CI 13-61%) for LGD lesions <1 cm, with specificities of 87% (95% CI 81-91%) and 93% (95% CI 88-96%), respectively. The estimated number of patients needed to screen to detect a single CRC was 96 (95% CI 93-99%) and was 28 (95% CI 22-34%) to detect any colorectal neoplasia (CRN).

CONCLUSION

The MT-sDNA panel detected CRC in IBD. Sensitivity for sub-centimeter colorectal neoplasms in IBD patients appears similar to that observed in the general population. The test may be a valuable tool for detection of malignancy during structured surveillance of long-term IBD in a first line hospital setting.

The effect of the primary tumor location on the survival of colorectal cancer patients after radical surgery

Background and Objectives: Colorectal cancer is one of the most common cancers and the leading cause of cancer-related death worldwide. The impact of the primary tumor location on the prognosis of patients with colorectal cancer has long been a concern, but studies have led to conflicting conclusions. Methods: In total, 465 colorectal cancer patients who received radical surgery were reviewed in this study. Enrolled patients were divided into two groups according to the tumor location. Disease-free survival (DFS) and overall survival (OS) were analyzed via the Kaplan-Meier method. A Cox regression model was employed to evaluate the independent prognostic factors for DFS and OS. Results: The right colorectal cancer (RCC) and left colorectal cancer (LCC) groups comprised 202 and 140 patients, respectively. Univariate and multivariate analyses revealed that the tumor location and TNM stage were independent predictors of DFS and OS. Subgroup analyses by stage demonstrated that there were significant differences in DFS and OS between patients with stage II and III RCC and LCC, but not for those with stage I colorectal cancer. Conclusions: Patients with stage II and III LCC had better survival than those with RCC. However, this improvement in DFS and OS was not observed in patients with stage I colorectal cancer.

Impact of cap-assisted colonoscopy on detection of proximal colon adenomas: systematic review and meta-analysis

BACKGROUND AND AIMS

Proximal colon adenomas can be missed during routine colonoscopy. Use of a cap or hood on the tip of the colonoscope has been shown to improve overall adenoma detection with variable rates. However, it has not been systematically evaluated for detection of proximal colon or right-sided adenomas where the cap may have maximum impact on adenoma detection rate (ADR). Our aim was to perform a systematic review and meta-analysis to evaluate the impact of cap-assisted colonoscopy (CC) on right-sided ADRs (r-ADRs) compared with standard colonoscopy (SC).

METHODS

PubMed, EMBASE, SCOPUS, and Cochrane databases as well as secondary sources (bibliographic review of selected articles and major GI proceedings) were searched through October 1, 2016. Primary outcome was the pooled rate of r-ADR. Detection of flat adenoma, sessile serrated adenoma/polyp (SSA/P), and number of right-sided adenomas per patient were also assessed. Pooled odds ratio (OR) and 95% confidence intervals (CIs) were calculated using random-effect models.

RESULTS

We screened 686 records and analyzed data from 4 studies (CC group, 2546 patients; SC group, 2547 patients) that met criteria for determination of r-ADRs, whereas 6 studies (CC group, 3159 patients; SC group, 3137 patients) were analyzed to estimate right-sided adenomas per patient. r-ADR was significantly higher with CC compared with SC (23% vs 17%; OR, 1.49; 95% CI, 1.08-2.05; I² = 79%; P = .01). CC also improved detection rates of flat adenoma (OR, 2.08; 95% CI, 1.35-3.20; P < .01) and SSA/P (OR, 1.33; 95% CI, 1.01-1.74; P = .04). The total number of right-sided adenomas (CC: 1428 [60%] vs SC: 1127 [58%]) and number of right-sided adenomas per patient (CC, .71 ± .5, vs SC, .65 ± .62 [mean ± standard deviation]) were numerically higher for CC but were not statistically significant (P = .43). Approximately 17 CCs would be required to detect an additional patient with right-sided adenoma.

CONCLUSIONS

Use of CC significantly improves the proximal colon ADR. In addition, flat adenoma and serrated colonic lesion detection rates are also significantly higher as compared with SC.

Missed adenomas with behind-folds visualizing colonoscopy technologies compared with standard colonoscopy: a pooled analysis of 3 randomized back-to-back tandem colonoscopy studies

BACKGROUND AND AIMS

The Third Eye Retroscope, Full Spectrum Endoscope (FUSE), and EndoRings devices have been shown to reduce overall adenoma miss rates. We evaluated the characteristics of adenomas and patient subgroups for which these behind-folds visualizing technologies mostly reduce adenoma miss rates.

METHODS

Data of 3 multicenter randomized trials (NCT01044732, NCT01549535, NCT01955122) were combined. Patients underwent same-day, back-to-back tandem examinations with standard colonoscopy and Third Eye Retroscope, FUSE, or EndoRings colonoscopy, respectively. Adenoma miss rates were stratified by adenoma characteristics and patient subgroups.

RESULTS

A total of 650 patients (60% male, mean age 57.5 years, standard deviation 9.7 years) were included; 330 patients underwent behind-folds visualizing colonoscopy first, and 320 patients underwent standard colonoscopy first. Regarding adenoma characteristics, adenoma miss rates were significantly (P < .001) lower with behind-folds visualizing technologies compared with standard colonoscopy for proximal (14% vs 38%) and distal (15% vs 35%), ≤5 mm (17% vs 38%), 6 to 9 mm (8% vs 44%), sessile (16% vs 37%), flat (9% vs 52%; P = .014), and tubular (15% vs 38%) adenomas and sessile serrated polyps (7% vs 50%; P = .039) but were not statistically significantly (P > .05) different for ≥10 mm, pedunculated, (tubulo-)villous, and advanced adenomas. Regarding patient subgroups, adenoma miss rates were significantly (P ≤ .020) lower with behind-folds visualizing technologies for patients ≥50 years, both sexes, and all indications.

CONCLUSIONS

Behind-folds visualizing colonoscopy reduces miss rates for 1 to 9 mm adenomas in the entire colon, whereas no advantage was found for ≥10 mm and advanced adenomas. Whether increased detection and removal of <10 mm adenomas also reduces colorectal cancer incidence and mortality remains to be determined. Future research is needed to determine which colonoscopy technology would be most beneficial for which patient or endoscopist.

Polyp missing rate and its associated risk factors of referring hospitals for endoscopic resection of advanced colorectal neoplasia

Missed polyps are frequently observed in surveillance colonoscopy or referral resection. We evaluated the polyp missing rate and its associated risk factors in patients who were referred to a tertiary hospital for endoscopic resection of advanced colorectal neoplasia.A total of 388 patients with advanced neoplasia who underwent colonoscopy in their referring hospitals and only endoscopic resection without total colonoscopy in Pusan National University Yangsan Hospital from 2009 to 2014 and who underwent surveillance colonoscopy within 6 to 12 months were retrospectively analyzed.The per-patient missing rate for polyps, adenomas, and advanced neoplasia in referring hospital were 58.2% (226 cases), 47.2% (183 cases), and 5.7% (22 cases), respectively. The advanced neoplasia in surveillance colonoscopy comprised the following: ≥1 cm lesions (11 cases, 50%), high-grade dysplasia (4 cases, 18.2%), villous adenoma (4 cases, 18.2%), and invasive cancer (3 cases, 13.6%). Risk factors for missed adenomas in multivariate analysis were ≥60 years (P = .004), male (P <.001), and no usage of the cap-assisted colonoscopy (P = .015). Missed polyps/adenomas were most frequent in the ascending colon (P <.001).The missing rate for polyps/adenomas of referring hospitals was higher than expected. Especially, patients with old age or male, or no usage of cap-assisted colonoscopy on initial colonoscopy were at increased risk of missed adenoma. Careful complete colonoscopy during referral resection or early surveillance colonoscopy is mandatory in the patients with advanced colorectal neoplasia and unknown-quality index colonoscopy.

Multiple, zonal and multi-zone adenoma detection rates according to quality of cleansing during colonoscopy

BACKGROUND

The safety and diagnostic accuracy of colonoscopy depend on the quality of colon cleansing. The adenoma detection rate is usually used as a quality measurement score.

OBJECTIVE

We aimed to introduce and evaluate three new parameters to determine polyps and adenomas segmental localization and their distribution in association with different bowel preparation levels during colonoscopy. We introduce the multiple adenoma detection rate (the percentage of patients with >2 adenomas diagnosed during colonoscopy), the zonal adenoma detection rate (the percentage of patients with >2 adenomas diagnosed during colonoscopy in different colon areas (rectum, sigmoid, descending, transverse, ascending and cecum colon)), and multi-zone adenoma detection rate (the percentage of patients with >2 adenomas diagnosed during colonoscopy in different colon areas with at least a segment between them with or without lesions (i.e. rectum and descending colon with or without lesions in the sigmoid)).

METHODS

We prospectively enrolled outpatients who underwent colonoscopy from January 2013 to October 2014. The bowel preparation quality, according to the Aronchick modified scale, number and location of lesions, Paris classification and histology, were recorded. The multiple adenoma/polyp detection rate, zonal adenoma/polyp detection rate, and multi-zone adenoma/polyp detection rate were determined.

RESULTS

In total, 519 consecutive patients (266/253 M/F; mean age 55.3 ± 12.8 years) were enrolled. The adenoma and polyp detection rates were 21% and 35%, respectively. Multiple adenomas were detected in 28 patients. Adenoma and polyp detection rate and new parameters were statistically significantly higher in the optimal as compared with the adequate bowel preparation.

CONCLUSIONS

An optimal level of bowel preparation was strongly associated not only with a higher adenoma detection rate, but also with a higher chance of detecting multiple clinically relevant lesions in adjacent or discrete segments of the colon.

Enhanced flat adenoma detection rate with high definition colonoscopy plus i-scan for average-risk colorectal cancer screening

BACKGROUND AND AIM

The usefulness of high definition colonoscopy plus i-scan (HD+i-SCAN) for average-risk colorectal cancer screening has not been fully assessed. The detection rate of adenomas and other measurements such as the number of adenomas per colonoscopy and the flat adenoma detection rate have been recognized as markers of colonoscopy quality. The aim of the present study was to compare the diagnostic performance of an HD+i-SCAN with that of standard resolution white-light colonoscope.

METHODS

This is a retrospective analysis of a prospectively collected screening colonoscopy database. A comparative analysis of the diagnostic yield of an HD+i-SCAN or standard resolution colonoscopy for average-risk colorectal screening was conducted.

RESULTS

During the period of study, 155/163 (95.1%) patients met the inclusion criteria. The mean age was 56.9 years. Sixty of 155 (39%) colonoscopies were performed using a HD+i-SCAN. Adenoma-detection-rates during the withdrawal of the standard resolution versus HD+i-SCAN colonoscopies were 29.5% and 30% (p = n.s.). Adenoma/colonoscopy values for standard resolution versus HD+i-SCAN colonoscopies were 0.46 (SD = 0.9) and 0.72 (SD = 1.3) (p = n.s.). A greater number of flat adenomas were detected in the HD+i-SCAN group (6/60 versus 2/95) (p < .05). Likewise, serrated adenomas/polyps per colonoscopy were also higher in the HD+i-SCAN group.

CONCLUSIONS

A HD+i-SCAN colonoscopy increases the flat adenoma detection rate and serrated adenomas/polyps per colonoscopy compared to a standard colonoscopy in average-risk screening population. HD+i-SCAN is a simple, available procedure that can be helpful, even for experienced providers. The performance of HD+i-SCAN and substantial prevalence of flat lesions in our average-risk screening cohort support its usefulness in improving the efficacy of screening colonoscopies.

The clinical effectiveness of different surveillance strategies to prevent colorectal cancer in people with intermediate-grade colorectal adenomas: a retrospective cohort analysis, and psychological and economic evaluations

BACKGROUND

The UK guideline recommends 3-yearly surveillance for patients with intermediate-risk (IR) adenomas. No study has examined whether or not this group has heterogeneity in surveillance needs.

OBJECTIVES

To examine the effect of surveillance on colorectal cancer (CRC) incidence; assess heterogeneity in risk; and identify the optimum frequency of surveillance, the psychological impact of surveillance, and the cost-effectiveness of alternative follow-up strategies.

DESIGN

Retrospective multicentre cohort study.

SETTING

Routine endoscopy and pathology data from 17 UK hospitals (n = 11,944), and a screening data set comprising three pooled cohorts (n = 2352), followed up using cancer registries.

SUBJECTS

Patients with IR adenoma(s) (three or four small adenomas or one or two large adenomas).

PRIMARY OUTCOMES

Advanced adenoma (AA) and CRC detected at follow-up visits, and CRC incidence after baseline and first follow-up.

METHODS

The effects of surveillance on long-term CRC incidence and of interval length on findings at follow-up were examined using proportional hazards and logistic regression, adjusting for patient, procedural and polyp characteristics. Lower-intermediate-risk (LIR) subgroups and higher-intermediate-risk (HIR) subgroups were defined, based on predictors of CRC risk. A model-based cost-utility analysis compared 13 surveillance strategies. Between-group analyses of variance were used to test for differences in bowel cancer worry between screening outcome groups (n = 35,700). A limitation of using routine hospital data is the potential for missed examinations and underestimation of the effect of interval and surveillance.

RESULTS

In the hospital data set, 168 CRCs occurred during 81,442 person-years (pys) of follow-up [206 per 100,000 pys, 95% confidence interval (CI) 177 to 240 pys]. One surveillance significantly lowered CRC incidence, both overall [hazard ratio (HR) 0.51, 95% CI 0.34 to 0.77] and in the HIR subgroup (n = 9265; HR 0.50, 95% CI 0.34 to 0.76). In the LIR subgroup (n = 2679) the benefit of surveillance was less clear (HR 0.62, 95% CI 0.16 to 2.43). Additional surveillance lowered CRC risk in the HIR subgroup by a further 15% (HR 0.36, 95% CI 0.20 to 0.62). The odds of detecting AA and CRC at first follow-up (FUV1) increased by 18% [odds ratio (OR) 1.18, 95% CI 1.12 to 1.24] and 32% (OR 1.32, 95% CI 1.20 to 1.46) per year increase in interval, respectively, and the odds of advanced neoplasia at second follow-up increased by 22% (OR 1.22, 95% CI 1.09 to 1.36), after adjustment. Detection rates of AA and CRC remained below 10% and 1%, respectively, with intervals to 3 years. In the screening data set, 32 CRCs occurred during 25,745 pys of follow-up (124 per 100,000 pys, 95% CI 88 to 176 pys). One follow-up conferred a significant 73% reduction in CRC incidence (HR 0.27, 95% CI 0.10 to 0.71). Owing to the small number of end points in this data set, no other outcome was significant. Although post-screening bowel cancer worry was higher in people who were offered surveillance, worry was due to polyp detection rather than surveillance. The economic evaluation, using data from the hospital data set, suggested that 3-yearly colonoscopic surveillance without an age cut-off would produce the greatest health gain.

CONCLUSIONS

A single surveillance benefited all IR patients by lowering their CRC risk. We identified a higher-risk subgroup that benefited from further surveillance, and a lower-risk subgroup that may require only one follow-up. A surveillance interval of 3 years seems suitable for most IR patients. These findings should be validated in other studies to confirm whether or not one surveillance visit provides adequate protection for the lower-risk subgroup of intermediate-risk patients.

STUDY REGISTRATION

Current Controlled Trials ISRCTN15213649.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Preliminary Experience Using Full-Spectrum Endoscopy for Colorectal Cancer Screening: Matched Case Controlled Study

Background/Aim. High-quality colonoscopy is needed to reduce the morbidity and mortality of colorectal cancer. Full-spectrum endoscopy (FUSE) has recently shown potential in improving adenoma detection during colonoscopy. This study aimed to evaluate the feasibility and utility of FUSE colonoscopy. Methods. From April 2015 to February 2016, 130 patients underwent FUSE colonoscopy for screening at a tertiary cancer center. Cecal intubation rate (CIR), procedure time, polyp/adenoma detection rate (PDR/ADR), and mean number of adenomas per colonoscopy (APC) were compared in matched-control patients (n = 260) who underwent standard colonoscopy (SC). Accordingly, endoscopists subjectively evaluated the utility of FUSE colonoscopy. Results. The CIR of FUSE colonoscopy was 94.6%. Cecal intubation time (8.8 min versus 5.1 min, P < 0.001) and total procedure time (21.6 min versus 17.3 min, P < 0.001) in the FUSE group were significantly longer than those in the SC group. PDR (68.3 versus 71.2%, P = 0.567), ADR (63.4% versus 58.5%, P = 0.355), and APC (1.4 versus 1.4, P = 0.917) were not significantly different between the two groups. The wide view of FUSE colonoscopy was superior to that of SC based on the questionnaires. Conclusions. FUSE colonoscopy did not demonstrate superiority to SC in a clinical setting.

Meta-Analysis of the Effect of Bowel Preparation on Adenoma Detection: Early Adenomas Affected Stronger than Advanced Adenomas

Background and Aims

Low-quality bowel preparation reduces efficacy of colonoscopy. We aimed to summarize effects of bowel preparation on detection of adenomas, advanced adenomas and colorectal cancer.

Methods

A systematic literature search was performed regarding detection of colonic lesions after normal and low-quality bowel preparation. Reported bowel preparation quality was transformed to the Aronchick scale with its qualities “excellent”, “good”, “fair”, “poor”, and “insufficient” or “optimal” (good/excellent), “suboptimal” (fair/poor/insufficient), “adequate” (good/excellent/fair) and “inadequate” (poor/insufficient). We identified two types of studies: i) Comparative studies, directly comparing lesion detection according to bowel preparation quality, and ii) repeat colonoscopy studies, reporting results of a second colonoscopy after previous low-quality preparation.

Results

The detection of early adenomas was reduced with inadequate vs. adequate bowel preparation (Odds Ratio (OR) 0.53, CI: 0.46–0.62, p<0.001). The advanced adenomas were affected less in comparison (0.74, CI: 0.62–0.87, p<0.001). The large number of subjects considered in the present meta-analysis resulted in smaller confidence intervals compared to earlier studies. Classifying the bowel-preparation quality as suboptimal vs. optimal led to the same qualitative conclusion (OR: 0.81, CI: 0.74–0.89, p<0.001 for early adenomas, OR: 0.94, CI: 0.87–1.01, n.s. for advanced adenomas). Bowel preparation was equally important for right-sided/ flat/ serrated vs. other lesions in most observational studies but more relevant in some repeat colonoscopy studies; data regarding carcinoma detection were insufficient.

Conclusion

Inadequate bowel preparation affects detection of early colonic lesions stronger than advanced lesions.

Interval Colorectal Cancer After Colonoscopy: Exploring Explanations and Solutions

There is good evidence that colorectal cancer (CRC) screening has been successful at reducing both CRC incidence and death. Colonoscopy, utilized as either a primary screening tool or a follow-up exam when other screening tests are positive, has significantly contributed to these encouraging trends. However, it is well recognized that colonoscopy is not perfectly sensitive for the detection of neoplasia and that CRC can be diagnosed within a short interval following a colonoscopy that did not detect one. The literature surrounding these cases has rapidly expanded over the last decade. Specifically, studies aimed at understanding the frequency of these events and the likely explanations for their occurrence have been performed. This review will highlight current knowledge around the epidemiology of interval post colonoscopy CRC (PCCRC). The common explanations for these cancers including missed lesions, new lesions, and incompletely resected lesions will be reviewed and their contribution to interval PCCRC estimated. Finally, the relationship of these putative explanations to potential opportunities to prevent interval PCCRC will be explored. Current approaches to prevention largely center on consistent adherence to quality colonoscopy standards. Future approaches include advances in technology to better visualize the colon and adequately resect detected neoplasia. Finally, improvement in training as well as development of a culture of continuous quality improvement will be essential to maximize the benefits of colonoscopy in daily clinical practice.

Computer vision and augmented reality in gastrointestinal endoscopy

Augmented reality (AR) is an environment-enhancing technology, widely applied in the computer sciences, which has only recently begun to permeate the medical field. Gastrointestinal endoscopy—which relies on the integration of high-definition video data with pathologic correlates—requires endoscopists to assimilate and process a tremendous amount of data in real time. We believe that AR is well positioned to provide computer-guided assistance with a wide variety of endoscopic applications, beginning with polyp detection. In this article, we review the principles of AR, describe its potential integration into an endoscopy set-up, and envisage a series of novel uses. With close collaboration between physicians and computer scientists, AR promises to contribute significant improvements to the field of endoscopy.

Different treatment strategies and molecular features between right-sided and left-sided colon cancers

The colon is derived from the embryological midgut and hindgut separately, with the right colon and left colon having different features with regards to both anatomical and physiological characteristics. Cancers located in the right and left colon are referred to as right colon cancer (RCC) and left colon cancer (LCC), respectively, based on their apparent anatomical positions. Increasing evidence supports the notion that not only are there differences in treatment strategies when dealing with RCC and LCC, but molecular features also vary between them, not to mention the distinguishing clinical manifestations. Disease-free survival after radical surgery of both RCC and LCC are similar. In the treatment of RCC, the benefit gained from adjuvant FOLFIRI chemotherapy is superior, or at least similar, to LCC, but inferior to LCC if FOLFOX regimen is applied. On the other hand, metastatic LCC exhibits longer survival than that of RCC in a palliative chemotherapy setting. For KRAS wild-type cancers, LCC benefits more from cetuximab treatment than RCC. Moreover, advanced LCC shows a higher sensitivity to bevacizumab treatment in comparison with advanced RCC. Significant varieties exist at the molecular level between RCC and LCC, which may serve as the cause of all apparent differences. With respect to carcinogenesis mechanisms, RCC is associated with known gene types, such as MMR, KRAS, BRAF, and miRNA-31, while LCC is associated with CIN, p53, NRAS, miRNA-146a, miRNA-147b, and miRNA-1288. Regarding protein expression, RCC is related to GNAS, NQO1, telomerase activity, P-PDH, and annexin A10, while LCC is related to Topo I, TS, and EGFR. In addition, separated pathways dominate progression to relapse in RCC and LCC. Therefore, RCC and LCC should be regarded as two heterogeneous entities, with this heterogeneity being used to stratify patients in order for them to have the optimal, current, and novel therapeutic strategies in clinical practice. Additional research is needed to uncover further differences between RCC and LCC.