Endoscopic submucosal dissection for nonpedunculated submucosal invasive colorectal cancer: is it feasible?

Long-term outcomes of endoscopic submucosal dissection for T1b colorectal cancer

BACKGROUND

Endoscopic submucosal dissection (ESD) is a standardized procedure for intramucosal and slightly invasive submucosal colorectal cancers (CRC). However, the role of ESD for T1b (depth of submucosal invasion: ≥1,000 μm) CRC remains unclear. This study aimed to investigate the long-term efficacy and safety of ESD for T1b CRC.

METHODS

This study involved 50 patients with T1b CRC who underwent ESD, including 31 who received subsequent surgery (ESD + surgery group) and 19 who reported comorbidities or refused subsequent surgery (ESD-alone group). The clinical outcomes, lymph node metastasis (LNM) rate, and recurrence and survival rates were determined.

RESULTS

All the patients achieved en-bloc resection, and 41 patients achieved R0 resection. The mean tumor diameter was 31.2 ± 11.9 mm. LNM was detected in 3 (6%) cases, demonstrating high-grade tumor budding (Bd 2/3) and invasion depth of >1,500 um. LNM was significantly correlated with tumor budding (P = 0.030). The overall median follow-up period was 41.00 ± 27.69 months and 33.16 ± 19.05 months in the ESD-alone and ESD + surgery groups, respectively (P = 0.241). Two patients in the ESD group had local recurrence and two patients died. Patients in the ESD + surgery group reported no local recurrence, distant metastasis, or disease-related death. Recurrence (P = 0.074) and survival rates (P = 0.072) were not significantly different between the two groups.

CONCLUSIONS

The LNM rate was exceedingly low in patients with T1b. ESD is an effective and safe method for these patients. The necessity of additional surgical treatment after ESD should be comprehensively determined following the patient's characteristics.

Endoscopic submucosal dissection versus endoscopic mucosal resection for the treatment of rectal lesions involving the dentate line

BACKGROUND

The ideal treatment of epithelial neoplastic rectal lesions involving the dentate line is a controversial issue. Piecemeal endoscopic mucosal resection (EMR) is the most commonly used resection technique, but it is associated with high recurrence rates. Endoscopic submucosal dissection (ESD) has been shown to be safe and effective for the treatment of rectal lesions, but evidence is lacking concerning its application close to the dentate line. The aim of our study is to compare ESD and EMR for the treatment of epithelial rectal lesions involving the dentate line.

METHODS

We identified all cases of endoscopic resections of rectal lesions involving the dentate line performed in two German high-volume centers between 2010 and 2022. Periinterventional and follow-up data were collected and retrospectively analyzed.

RESULTS

We identified 68 ESDs and 62 EMRs meeting our inclusion criteria. ESD showed a significant advantage in en bloc resection rates (89.7% vs. 9.7%; P = 0.001) and complete resection rates (72.1% vs. 9.7%; P = 0.001). The overall curative resection rate was similar between both groups (ESD: 92.6%, EMR: 83.9%; P = 0.324), whereas in the subgroup of low-risk adenocarcinomas ESD was curative in 100% of the cases vs. 14% in the EMR group (P = 0.002). There was one local recurrence after ESD (1,5%) vs. 16 (25.8%) after EMR (P < 0.0001), and the EMR patients required an average of three further interventions.

CONCLUSION

ESD is superior to EMR for the treatment of epithelial rectal lesions involving the dentate line and should be considered the treatment of choice.

Completion Surgery after Non-Curative Local Resection of Early Rectal Cancer

Background

The expanding indications of local - endoscopic and transanal surgical - resection of early rectal cancer has led to their increased popularity and inclusion in the treatment guidelines. The accuracy of the current diagnostic tools in identifying the low-risk T1 tumors that can be curatively treated with a local resection is low, and thus several patients require additional oncologic surgery with total mesorectal excision (TME). An efficient clinical strategy which avoids overtreatment and obstacle surgical procedures is under debate between different disciplines.

Summary

Completion surgery has comparable outcomes to primary surgery regarding perioperative morbidity and mortality but also recurrence rates and overall survival. However, local scarring in the mesorectum can make mesorectal excision technically challenging, especially after full-thickness resections, and has been associated with increased rates of permanent ostomy and worse quality of the TME specimen. This risk seems to be lower after muscle-sparing procedures like endoscopic submucosal dissection, which seem to show a benefit in comparison to full-thickness resections.

Key Messages

Completion surgery after non-curative local resection of gastrointestinal malignancies is safe and feasible. Full-thickness resection techniques can cause scarring of the mesorectum; therefore, muscle-sparing procedures should be preferred.

Additional staining for lymphovascular invasion is associated with increased estimation of lymph node metastasis in patients with T1 colorectal cancer: Systematic review and meta-analysis

OBJECTIVES

Lymphovascular invasion (LVI) is a critical risk factor for lymph node metastasis (LNM), which requires additional surgery after endoscopic resection of T1 colorectal cancer (CRC). However, the impact of additional staining on estimating LNM is unclear. This systematic review aimed to evaluate the impact of additional staining on determining LNM in T1 CRC.

METHODS

We searched five electronic databases. Outcomes were diagnostic odds ratio (DOR), assessed using hierarchical summary receiver operating characteristic curves, and interobserver agreement among pathologists for positive LVI, assessed using Kappa coefficients (κ). We performed a subgroup analysis of studies that simultaneously included a multivariable analysis for other risk factors (deep submucosal invasion, poor differentiation, and tumor budding).

RESULTS

Among the 64 studies (18,097 patients) identified, hematoxylin-eosin (HE) and additional staining for LVI had pooled sensitivities of 0.45 (95% confidence interval [CI] 0.32-0.58) and 0.68 (95% CI 0.44-0.86), specificities of 0.88 (95% CI 0.78-0.94) and 0.76 (95% CI 0.62-0.86), and DORs of 6.26 (95% CI 3.73-10.53) and 6.47 (95% CI 3.40-12.32) for determining LNM, respectively. In multivariable analysis, the DOR of additional staining for LNM (DOR 5.95; 95% CI 2.87-12.33) was higher than that of HE staining (DOR 1.89; 95% CI 1.13-3.16) (P = 0.01). Pooled κ values were 0.37 (95% CI 0.22-0.52) and 0.62 (95% CI 0.04-0.99) for HE and additional staining for LVI, respectively.

CONCLUSION

Additional staining for LVI may increase the DOR for LNM and interobserver agreement for positive LVI among pathologists.

Colon cancer: the 2023 Korean clinical practice guidelines for diagnosis and treatment

Colorectal cancer is the third most common cancer in Korea and the third leading cause of death from cancer. Treatment outcomes for colon cancer are steadily improving due to national health screening programs with advances in diagnostic methods, surgical techniques, and therapeutic agents.. The Korea Colon Cancer Multidisciplinary (KCCM) Committee intends to provide professionals who treat colon cancer with the most up-to-date, evidence-based practice guidelines to improve outcomes and help them make decisions that reflect their patients' values and preferences. These guidelines have been established by consensus reached by the KCCM Guideline Committee based on a systematic literature review and evidence synthesis and by considering the national health insurance system in real clinical practice settings. Each recommendation is presented with a recommendation strength and level of evidence based on the consensus of the committee.

Diagnostic Accuracy of Highest-Grade or Predominant Histological Differentiation of T1 Colorectal Cancer in Predicting Lymph Node Metastasis: A Systematic Review and Meta-Analysis

INTRODUCTION

Treatment guidelines for colorectal cancer (CRC) suggest 2 classifications for histological differentiation-highest grade and predominant. However, the optimal predictor of lymph node metastasis (LNM) in T1 CRC remains unknown. This systematic review aimed to evaluate the impact of the use of highest-grade or predominant differentiation on LNM determination in T1 CRC.

METHODS

The study protocol is registered in the International Prospective Register of Systematic Reviews (PROSPERO, registration number: CRD42023416971) and was published in OSF ( https://osf.io/TMAUN/ ) on April 13, 2023. We searched 5 electronic databases for studies assessing the diagnostic accuracy of highest-grade or predominant differentiation to determine LNM in T1 CRC. The outcomes were sensitivity and specificity. We simulated 100 cases with T1 CRC, with an LNM incidence of 11.2%, to calculate the differences in false positives and negatives between the highest-grade and predominant differentiations using a bootstrap method.

RESULTS

In 42 studies involving 41,290 patients, the differentiation classification had a pooled sensitivity of 0.18 (95% confidence interval [CI] 0.13-0.24) and 0.06 (95% CI 0.04-0.09) ( P < 0.0001) and specificity of 0.95 (95% CI 0.93-0.96) and 0.98 (95% CI 0.97-0.99) ( P < 0.0001) for the highest-grade and predominant differentiations, respectively. In the simulation, the differences in false positives and negatives between the highest-grade and predominant differentiations were 3.0% (range 1.6-4.4) and -1.3% (range -2.0 to -0.7), respectively.

DISCUSSION

Highest-grade differentiation may reduce the risk of misclassifying cases with LNM as negative, whereas predominant differentiation may prevent unnecessary surgeries. Further studies should examine differentiation classification using other predictive factors.

A proposal for grading the risk of lymph node metastasis after endoscopic resection of T1 colorectal cancer

PURPOSE

At present, for patients with early colorectal cancer as long as having any one risk factor of lymph node metastasis (LNM) after endoscopic resection (ER), additional surgery will be considered, regardless of the degree of LNM risk; however, most patients are free of LNM. This study aimed to further grade these patients according to LNM risk.

METHODS

We assessed 271 patients with T1 colorectal cancers treated initially with ER to analyze the correlation between LNM-associated risk factors and LNM rate. Differences in this rate between groups were estimated using the χ2 test or Fisher's exact test.

RESULTS

Poorly differentiated adenocarcinoma (Por) (3.4% vs. 40%, p < 0.001) and lymphovascular infiltration (LV) (1.6% vs. 29.0%, p < 0.001) were the only parameters correlated with LNM. When we divided the cases into LV-negative (LV(-)) and LV-positive (LV(+)) groups, we found a significantly higher LNM rate in the LV(+) group (29.0% vs. 1.6%, p < 0.001). Additionally, the rate of LNM in those positive for each parameter did not differ from the control rate in the same group, except in the Por subgroup. When the cases were divided into four groups based on the presence of LV infiltration and Por, the LNM rate in each group was 2/233 cases (0.8%) in the LV(-)Por(-) group, 2/7 cases (28.5%) in the LV(-)Por(+) group, 7/28 cases (25.0%) in the LV(+)Por(-) group, and 2/3 cases (66.6%) in the LV(+)Por(+) group.

CONCLUSIONS

Based on LV and histological differentiation, patients were classified into three LNM risk grades: low (LNM, 0.8%), moderate (LNM, 25.0-28.5%), and high (LNM, 66.6%).

Current problems and perspectives of pathological risk factors for lymph node metastasis in T1 colorectal cancer: Systematic review

With the prevalence of endoscopic submucosal dissection and endoscopic full thickness resection, which enable complete resection of T1 colorectal cancer with a negative margin, the treatment strategy following endoscopic resection has become more important. The necessity of secondary surgical resection is determined on the basis of the risk of lymph node metastasis according to the histopathological findings of resected specimens because ~10% of T1 colorectal cancer cases have lymph node metastasis. The current Japanese treatment guidelines state four risk factors for lymph node metastasis: lymphovascular invasion, histological differentiation, depth of submucosal invasion, and tumor budding. These guidelines have succeeded in stratifying the low-risk group for lymph node metastasis, in which endoscopic resection alone is acceptable for cure. On the other hand, there are some problems: there is variation in diagnosis methods and low interobserver agreement for each pathological factor and 90% of surgical resections are unnecessary, with lymph node metastasis negativity. To ensure patients with T1 colorectal cancer receive more appropriate treatment, these problems should be addressed. In this systematic review, we gave some suggestions to these practical issues of four pathological factors as predictors.

Deep Submucosal Invasion Is Not an Independent Risk Factor for Lymph Node Metastasis in T1 Colorectal Cancer: A Meta-Analysis

BACKGROUND & AIMS

Deep submucosal invasion (DSI) is considered a key risk factor for lymph node metastasis (LNM) and important criterion to recommend surgery in T1 colorectal cancer. However, metastatic risk for DSI is shown to be low in the absence of other histologic risk factors. This meta-analysis determines the independent risk of DSI for LNM.

METHODS

Suitable studies were included to establish LNM risk for DSI in univariable analysis. To assess DSI as independent risk factor, studies were eligible if risk factors (eg, DSI, poor differentiation, lymphovascular invasion, and high-grade tumor budding) were simultaneously included in multivariable analysis or LNM rate of DSI was described in absence of poor differentiation, lymphovascular invasion, and high-grade tumor budding. Odds ratios (OR) and 95% CIs were calculated.

RESULTS

Sixty-seven studies (21,238 patients) were included. Overall LNM rate was 11.2% and significantly higher for DSI-positive cancers (OR, 2.58; 95% CI, 2.10-3.18). Eight studies (3621 patients) were included in multivariable meta-analysis and did not weigh DSI as a significant predictor for LNM (OR, 1.73; 95% CI, 0.96-3.12). As opposed to a significant association between LNM and poor differentiation (OR, 2.14; 95% CI, 1.39-3.28), high-grade tumor budding (OR, 2.83; 95% CI, 2.06-3.88), and lymphovascular invasion (OR, 3.16; 95% CI, 1.88-5.33). Eight studies (1146 patients) analyzed DSI as solitary risk factor; absolute risk of LNM was 2.6% and pooled incidence rate was 2.83 (95% CI, 1.66-4.78).

CONCLUSIONS

DSI is not a strong independent predictor for LNM and should be reconsidered as a sole indicator for oncologic surgery. The expanding armamentarium for local excision as first-line treatment prompts serious consideration in amenable cases to tailor T1 colorectal cancer management.

Risk and Time Pattern of Recurrences After Local Endoscopic Resection of T1 Colorectal Cancer: A Meta-analysis

BACKGROUND & AIMS

Growing numbers of patients with T1 CRC are being treated with local endoscopic resection only and as a result, the need for optimization of surveillance strategies for these patients also increases. We aimed to estimate the cumulative incidence and time pattern of CRC recurrences for endoscopically treated patients with T1 CRC.

METHODS

Using a systematic literature search in PubMed, EMBASE, Web of Science and Cochrane Library (from inception till 15 May 2020), we identified and extracted data from studies describing the cumulative incidence of local or distant CRC recurrence for patients with T1 CRC treated with local endoscopic resection only. Pooled estimates were calculated using mixed-effect logistic regression models.

RESULTS

Seventy-one studies with 5167 unique, endoscopically treated patients with T1 CRC were included. The pooled cumulative incidence of any CRC recurrence was 3.3% (209 events; 95% CI, 2.6%-4.3%; I² = 54.9%), with local and distant recurrences being found at comparable rates (pooled incidences 1.9% and 1.6%, respectively). CRC-related mortality was observed in 42 out of 2519 patients (35 studies; pooled incidence 1.7%, 95% CI, 1.2%-2.2%; I² = 0%), and the CRC-related mortality rate among patients with recurrence was 40.8% (42/103 patients). The vast majority of recurrences (95.6%) occurred within 72 months of follow-up. Pooled incidences of any CRC recurrence were 7.0% for high-risk T1 CRCs (28 studies; 95% CI, 4.9%-9.9%; I² = 48.1%) and 0.7% (36 studies; 95% CI, 0.4%-1.2%; I² = 0%) for low-risk T1 CRCs.

CONCLUSIONS

Our meta-analysis provides quantitative outcome measures which are relevant to guidelines on surveillance after local endoscopic resection of T1 CRC.

Endoscopic Management of Complex Colorectal Polyps: Current Insights and Future Trends

Most colorectal cancers arise from adenomatous polyps and sessile serrated lesions. Screening colonoscopy and therapeutic polypectomy can potentially reduce colorectal cancer burden by early detection and removal of these polyps, thus decreasing colorectal cancer incidence and mortality. Most endoscopists are skilled in detecting and removing the vast majority of polyps endoscopically during a routine colonoscopy. Polyps can be considered “complex” based on size, location, morphology, underlying scar tissue, which are not amenable to removal by conventional endoscopic polypectomy techniques. They are technically more challenging to resect and carry an increased risk of complications. Most of these polyps were used to be managed by surgical intervention in the past. Rapid advancement in endoscopic resection techniques has led to a decreasing role of surgery in managing these complex polyps. These endoscopic resection techniques do require an expert in the field and advanced equipment to perform the procedure. In this review, we discuss various advanced endoscopic techniques for the management of complex polyps.

Transanal endoscopic microsurgical submucosal dissection (TEM-ESD): A novel approach to the local treatment of early rectal cancer

BACKGROUND

Complete local resection is currently the treatment of choice for low-risk early rectal cancer; however, the ideal resection technique for such tumours is still debated. Transanal endoscopic microsurgical submucosal dissection (TEM-ESD) is a new technique which combines the ergonomic advantages of transanal endoscopic microsurgery (TEM) with the minimally invasive approach of endoscopic submucosal dissection (ESD). The aim of our study was to assess the feasibility, safety, and long-term outcomes of TEM-ESD in treating early rectal cancer.

MATERIALS AND METHODS

We retrospectively analysed all cases of rectal adenocarcinomas treated with TEM-ESD in Karlsruhe Municipal Hospital between 2012 and 2019, as well as the perioperative and follow-up data of the patients.

RESULTS

We identified 40 cases (19 low-risk and 21 high-risk carcinomas) matching our criteria. The median size of the lesions was 3.8 cm and the median operating time 48.5 min. En bloc resection was possible in all cases, while histologically complete resection was confirmed in 18 of 19 low-risk tumours and in 30 out of all lesions. The resection was curative in 19 cases. No scarring of the mesorectum was reported during the completion of total mesorectal excision for high-risk tumours. There was only 1 case of local recurrence among patients treated with curative intent, with an overall survival rate of 100% and a disease-free survival rate of 96% at both 2 and 5 years for these patients.

CONCLUSION

TEM-ESD is a safe and feasible therapeutic option for resecting early rectal cancer, offering very good long-term outcomes.

Safety of simultaneous endoscopic submucosal dissection for two large colorectal neoplasias in the same patient

BACKGROUND/AIMS

Multiple large colorectal lesions requiring endoscopic submucosal dissection (ESD) are sometimes diagnosed during colonoscopy. We evaluated the feasibility and safety of ESD of two colorectal lesions in one session.

MATERIALS AND METHODS

The lesions of 16 patients who underwent two ESD procedures in a single session (double ESD group) from November 2009 to July 2014 were matched with those of 64 patients who underwent a single ESD procedure (single ESD group) based on the size and location of the lesion and presence of submucosal fibrosis.

RESULTS

The net ESD time per patient was longer in double ESD group than in single ESD group (104.0±36.2 vs. 59.1±39.2 min, p<0.001). The net ESD time per lesion tended to be shorter in double ESD group than in single ESD group (49.6±30.0 vs. 59.1±39.2 min, p=0.077). The en bloc resection and curative resection rates did not differ between double ESD and single ESD groups (93.8 % vs. 98.4%, p=0.262; 90.6 % vs. 84.4 %, p=0.534, respectively). The intra- and postprocedural bleeding rates were 12.5% and 0% in double ESD group and 15.6% and 3.1% in single ESD group, respectively. Perforation occurred in two (6.3%) in double ESD group and in six (9.4%) in single ESD group (p=0.715).

CONCLUSION

Compared with the single ESD, two simultaneous colorectal ESD procedures in a patient did not increase complications; the en bloc and curative resection rates were similar when performed a single ESD procedure and two simultaneous ESD procedures.

Clinical outcomes after endoscopic submucosal dissection for colorectal neoplasia: a systematic review and meta-analysis

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) is an endoscopic resection technique for lesions suspicious of superficial malignancy. It is performed using an ESD knife on its own (standard technique) or by the sequential use of a knife and a snare (hybrid technique). The experience with these techniques is different in Asian and non-Asian countries. We performed a systematic review and meta-analysis of available evidence on colorectal ESD.

METHODS

Electronic databases were searched up to August 2016 for studies evaluating R0, en bloc resection, and adverse event rates of both techniques for the treatment of colorectal lesions. Proportions were pooled by a random effects model.

RESULTS

Ninety-seven studies (71 performed in Asia) evaluated the standard technique and 12 studies (7 in Asia) the hybrid technique. The R0 resection rate of the standard technique was 82.9%, and it was significantly lower in non-Asian versus Asian countries: 71.3% versus 85.6%. The en bloc resection rate was 91% and was significantly lower in non-Asian versus Asian countries (81.2% vs 93%, respectively). Surgery was needed in 1.1% of the ESD-related adverse events, with a significant difference between non-Asian and Asian countries (3.1% vs 0.8%). The R0 and en bloc resection rates with the hybrid technique were significantly lower than those achieved with the standard technique: 60.6% and 68.4%, respectively, with similar adverse event rates.

CONCLUSIONS

In non-Asian countries the standard ESD technique is still failing to achieve acceptable levels of performance. The hybrid technique showed low R0 resection rates and should not be considered as an adequate alternative to the standard technique.

Tumor budding as a risk factor for nodal metastasis in pT1 colorectal cancers: a meta-analysis

Worldwide, colorectal cancer (CRC) screening programs have significantly increased the detection of submucosal (pT1) adenocarcinoma. Completion surgery may be indicated after endoscopic excision of these potentially metastasizing early cancers. However, the postsurgical prevalence of nodal implants does not exceed 15%, leading to questions concerning the clinical appropriateness of any post-endoscopy surgery. Eastern scientific societies (Japanese Society for Cancer of the Colon-Rectum, in particular) include tumor budding (TB), defined as the presence of isolated single cancer cells or clusters of fewer than 5 cancer cells at the tumor invasive front, among the variables that must be included in histologic reports. In Western countries, however, no authoritative endorsements recommend the inclusion of TB in the histology report because of the heterogeneity of definitions and measurement methods as well as its apparent poor reproducibility. To assess the prognostic value of TB in pT1 CRCs, this meta-analysis evaluated 41 studies involving a total of 10137 patients. We observed a strong association between the presence of TB and risk of nodal metastasis in pT1 CRC. In comparing TB-positive (684/2401; 28.5%) versus TB-negative (557/7736; 7.2%) patients, the prevalence of nodal disease resulted in an odds ratio value of 6.44 (95% confidence interval, 5.26-7.87; P<.0001; I2 = 30%). This increased risk of regional nodal metastasis was further confirmed after accounting for potential confounders. These results support the priority of histologically reporting TB in any endoscopically removed pT1 CRC to direct more appropriate patient management.

Endoscopic Approach for Superficial Colorectal Neoplasms

BACKGROUND

Colorectal cancer (CRC) is the third most commonly diagnosed cancer in males and the second in females, with an estimated 1.4 million cases and 693,900 deaths in 2012. Colonoscopy is the cornerstone for the detection and prevention of CRC. In addition, endoscopic treatment for CRC at an early stage can effectively improve patients' quality of life and cure rate.

SUMMARY

This review focuses on endoscopic approaches, including white light endoscopy, chromoendoscopy, magnifying endoscopy and therapeutic endoscopy, for the evaluation and treatment of superficial colorectal neoplasms.

KEY MESSAGE

Understanding the preoperative evaluation, indications and techniques of endoscopic mucosal resection/endoscopic submucosal dissection as well as postoperative surveillance for superficial colorectal neoplasms is critical for providing appropriate management to the patients.

PRACTICAL IMPLICATIONS

Endoscopic therapy, a method preserving organ function and improving quality of life, is a widely applied microinvasive treatment for superficial colorectal neoplasms. This review describes the basics and developments of endoscopic approaches and may facilitate daily practice for superficial colorectal neoplasms.

The Feasibility of Performing Colorectal Endoscopic Submucosal Dissection Without Previous Experience in Performing Gastric Endoscopic Submucosal Dissection

BACKGROUND

Experience in gastric endoscopic submucosal dissection (ESD) has been suggested as a prerequisite for performing colorectal ESD by some experts.

AIMS

To evaluate the feasibility of performing colorectal ESD without experience in gastric ESD.

METHODS

Between November 2009 and December 2013, ESD was attempted for 250 colorectal lesions by an endoscopist having extensive colonoscopy experience but no prior experience of gastric ESD. All attempts were categorized according to the chronological order of procedures: group 1, attempts 1-50; group 2, attempts 51-100; group 3, attempts 101-150; group 4, attempts 151-200; and group 5, attempts 201-250. Procedure-related outcomes were analyzed.

RESULTS

En bloc resection rate ≥80% was achieved after initial ten ESD attempts. The ESD success rate (72, 80, 90, 90, and 94% in group 1-5, respectively; p for trend = 0.001), perforation rate (14, 14, 6, 6, and 0% in group 1-5, respectively; p for trend = 0.003), and macroperforation rate (6, 6, 2, 2, and 0% in group 1-5, respectively; p for trend = 0.042) improved as experience accumulated. Performing >100 ESDs, rectal location, and absence of submucosal fibrosis were independent predictors of successful procedure.

CONCLUSION

Colorectal ESD can be safely and effectively performed by an endoscopist having extensive experience in colonoscopy-related procedures even without previous experience of gastric ESD. Meticulous case selection for ESD novice and active supervision by expert endoscopists during the initial learning period may minimize the risk of perforation.

Tumor budding in colorectal cancer--ready for diagnostic practice?

Tumor budding is an important additional prognostic factor for patients with colorectal cancer (CRC). Defined as the presence of single tumor cells or small clusters of up to 5 cells in the tumor stroma, tumor budding has been likened to an epithelial-mesenchymal transition. Based on well-designed retrospective studies, tumor budding is linked to adverse outcome of CRC patients in 3 clinical scenarios: (1) in malignant polyps, detection of tumor buds is a risk factor for lymph node metastasis indicating the need for colorectal surgery; (2) tumor budding in stage II CRC is a highly adverse prognostic indicator and may aid patient selection for adjuvant therapy; (3) in the preoperative setting, presence of tumor budding in biopsy material may help to identify high-risk rectal cancer patients for neoadjuvant therapy. However, lack of consensus guidelines for standardized assessment still limits reporting in daily diagnostic practice. This article provides a practical and comprehensive overview on tumor budding aimed at the practicing pathologist. First, we review the prognostic value of tumor budding for the management of colon and rectal cancer patients. Second, we outline a practical, evidence-based proposal for the assessment of tumor budding in the daily sign-out. Last, we summarize the current knowledge of the molecular characteristics of high-grade budding tumors in the context of personalized treatment approaches and biomarker discovery.