Endoscopic resection of superficial gastrointestinal tumors

Mechanisms and clinical landscape of N6-methyladenosine (m6A) RNA modification in gastrointestinal tract cancers

Epigenetics encompasses reversible and heritable chemical modifications of non-nuclear DNA sequences, including DNA and RNA methylation, histone modifications, non-coding RNA modifications, and chromatin rearrangements. In addition to well-studied DNA and histone methylation, RNA methylation has emerged as a hot topic in biological sciences over the past decade. N6-methyladenosine (m6A) is the most common and abundant modification in eukaryotic mRNA, affecting all RNA stages, including transcription, translation, and degradation. Advances in high-throughput sequencing technologies made it feasible to identify the chemical basis and biological functions of m6A RNA. Dysregulation of m6A levels and associated modifying proteins can both inhibit and promote cancer, highlighting the importance of the tumor microenvironment in diverse biological processes. Gastrointestinal tract cancers, including gastric, colorectal, and pancreatic cancers, are among the most common and deadly malignancies in humans. Growing evidence suggests a close association between m6A levels and the progression of gastrointestinal tumors. Global m6A modification levels are substantially modified in gastrointestinal tumor tissues and cell lines compared to healthy tissues and cells, possibly influencing various biological behaviors such as tumor cell proliferation, invasion, metastasis, and drug resistance. Exploring the diagnostic and therapeutic potential of m6A-related proteins is critical from a clinical standpoint. Developing more specific and effective m6A modulators offers new options for treating these tumors and deeper insights into gastrointestinal tract cancers.

Efficacy of endoscopic submucosal tunnel dissection versus endoscopic submucosal dissection for superficial esophageal neoplastic lesions: a systematic review and meta-analysis

BACKGROUND

To evaluate the effectiveness of endoscopic submucosal tunnel dissection (ESTD) and endoscopic submucosal dissection (ESD) in superficial esophageal neoplastic lesions (SENL).

METHODS

A comprehensive search for studies investigating the efficacy of ESTD and ESD for SENL was conducted to search for relevant studies through PubMed, Web of Science, Cochrane Library, SinoMed, CNKI, and Wanfang. Weighted pooled rates were calculated for en bloc resection rate, R0 resection rate, operation time, dissection area, dissection speed, and adverse events. The 95% confidence intervals (95%CI) for effect size were used to calculate the pooled value using the fixed- or random-effects model.

RESULTS

A total of seventeen studies with 1161 patients were identified and included in the meta-analysis. The pooled analysis showed that ESTD had significantly higher en bloc resection (OR 3.98; 95% CI 1.74 to 9.12; p = 0.001) and R0 resection rates (OR 2.29; 95% CI 1.54 to 3.46; p < 0.001) than ESD. The operation time in the ESTD group was shorter than that in the ESD group (SMD = - 0.57; 95% CI - 0.95 to - 0.19; p = 0.003). The dissection area of the ESTD group was larger than that in the ESD group (SMD = 0.49; 95% CI 0.16 to 0.83; p = 0.004), and the dissection speed is faster than that in the ESD group (SMD = 1.52; 95%CI 1.09 to 0.83; p < 0.001). There were no significant differences in esophageal stenosis (p = 0.94) between the two techniques. However, ESTD was superior to ESD in other adverse events (p < 0.05).

CONCLUSION

ESTD has a significant advantage over ESD in the treatment of SENL. ESTD has significantly higher en bloc and R0 resection rates and reduced adverse events.

Efficacy and Safety of Multiband Mucosectomy Versus Cap-assisted Endoscopic Resection For Early Esophageal Cancer and Precancerous Lesions: A Systematic Review and Meta-Analysis

BACKGROUND

The effectiveness of multiband mucosectomy (MBM) for early esophageal cancer and precancerous lesions is still in uncertainty. We aimed to evaluate the efficacy and safety of this procedure and to compare it with cap-assisted endoscopic resection (EMR-cap).

METHODS

A systematic search of both English and Chinese databases was performed from inception to April 30, 2019. Complete resection rate, local recurrence rate, and procedure time were considered the primary outcome measures. Prevalence of complications was considered the secondary outcome measure. All data analyses were performed using Review Manager Software.

RESULTS

Two randomized controlled trials (RCTs) and 3 non-RCTs were included in the final meta-analysis. When compared with the EMR-cap technique, MBM had a similar complete resection rate [odds ratio (OR)=2.09, 95% confidence interval (CI): 0.78-5.60, P=0.14], a similar local recurrence rate (OR=0.50, 95% CI: 0.09-2.67, P=0.42), a shorter resection time (mean difference: -9.08, 95% CI: -13.86 to -4.30, P=0.0002), a shorter procedure time (mean difference: -13.36, 95% CI: -17.85 to -8.86, P<0.00001), a lower bleeding rate (OR=0.45, 95% CI: 0.24-0.83, P=0.01), a similar perforation rate (OR=0.55, 95% CI: 0.15-2.06, P=0.37), and a similar stricture rate (OR=0.77, 95% CI: 0.10-5.84, P=0.80). The results of non-RCTs were consistent with those of RCTs.

CONCLUSIONS

MBM is similar to EMR-cap in terms of efficacy and safety for endoscopic resection of early cancer and precancerous lesions of the esophagus. However, MBM is less time-consuming.

A multicenter retrospective study of endoscopic submucosal tunnel dissection for large lesser gastric curvature superficial neoplasms

BACKGROUND AND AIM

Endoscopic submucosal tunnel dissection (ESTD) has been used for dissection of esophageal and gastric lesions. However, outcomes of ESTD for large lesions in the lesser gastric curvature had not been acknowledged because previous reports had the limitations of being single-center studies. We aimed to clarify the outcomes of ESTD for large lesser gastric curvature superficial neoplasms and provide our experience to accelerate its application.

METHODS

Between July 2014 and July 2016, 87 patients with early cancer in the lesser gastric curvature treated at six Chinese institutions were enrolled. Our primary outcome was dissection speed. Moreover, both efficacy and safety clinical data were collected and analyzed retrospectively.

RESULTS

All of the 87 patients were found to successfully undergo ESTD or ESD. Of these, 32 underwent ESTD and 55 underwent endoscopic submucosal dissection (ESD). The ESTD group had a higher dissection speed (18.0 mm2/min vs. 7.8 mm2/min, p < 0.01) and was associated with higher en bloc resection rate (100% vs. 87.3%, p = 0.035) and curative resection rate (100% vs. 85.5%, p = 0.024) compared with the ESD group. No perforation or muscular injury occurred in the ESTD group and its intraprocedural bleeding rate was lower (59.4% vs. 100%, p < 0.01) than that of the ESD group.

CONCLUSIONS

In this multicenter retrospective study, outcomes of ESTD were excellent with a higher dissection speed and radical curative rate compared with ESD.

Large Colorectal Lesions: Evaluation and Management

In the last years, a distinctive interest has been raised on large polypoid and non-polypoid colorectal tumors, and specially on flat neoplastic lesions ≥20 mm tending to grow laterally, the so called laterally spreading tumors (LST). Real or virtual chromoendoscopy, endoscopic ultrasound or magnetic resonance should be considered for the estimation of submucosal invasion of these neoplasms. Lesions suitable for endoscopic resection are those confined to the mucosa or selected cases with submucosal invasion ≤1000 μm. Polypectomy or endoscopic mucosal resection remain a first-line therapy for large colorectal neoplasms, whereas endoscopic submucosal dissection in high-volume centers or surgery should be considered for large LSTs for which en bloc resection is mandatory.

Multiband mucosectomy for advanced dysplastic lesions in the upper digestive tract

Endoscopic resection (ER) is at present an accepted treatment for superficial gastrointestinal neoplasia. ER provides similar efficacy to surgery; however, it is minimally invasive and less expensive. Endoscopic mucosal resection (EMR) is superior to biopsy for diagnosing advanced dysplasia and can change the diagnostic grade and the management. Several EMR techniques have been described that are alternatively used dependent upon the endoscopist personal experience, the anatomic conditions and the endoscopic appearance of the lesion to be resected. The literature suggests that EMR offers comparable outcomes to surgery for selected indications. EMR techniques using a cap fitted endoscope and EMR using a ligation device [multiband mucosectomy (MBM)] are the most frequently use. MBM technique does not require submucosal injection as with the endoscopic resection-cap technique, multiple resections can be performed with the same snare, pre-looping the endoscopic resection-snare in the ridge of the cap is not necessary, MBM does not require withdrawal of the endoscope between resections and up to six consecutive resections can be performed. This reduces the time and cost required for the procedure, while also reducing patient discomfort. Despite the increasing popularity of MBM, data on the safety and efficacy of this technique in upper gastrointestinal lesions with advanced dysplasia, defined as those lesions that have high-grade dysplasia or early cancer, is limited.

Endoscopic mucosal resection in colorectal lesion: a safe and effective procedure even in lesions larger than 2 cm and in carcinomas

CONTEXT: Endoscopic mucosal resection is a minimally invasive technique used in the treatment of colorectal neoplasms, including early carcinomas of different size and morphology. OBJECTIVES: To evaluate procedure safety, efficacy, outcomes, and recurrence rate in endoscopic mucosal resection of colorectal lesions. METHODS: A total of 172 lesions in 156 patients were analyzed between May 2003 and May 2009. All lesions showed pit pattern suggestive of neoplasia (Kudo types III-V) at high-magnification chromocolonoscopy with indigo carmine. The lesions were evaluated for macroscopic classification, size, location, and histopathology. Lesions 20 mm or smaller were resected en bloc and lesions larger than 20 mm were removed using the piecemeal technique. Complications and recurrence were analyzed. Patients were followed up for 18 months. RESULTS: There were 83 (48.2%) superficial lesions, 57 (33.1%) depressed lesions, 44 (25.6%) laterally spreading tumors, and 45 (26.2%) protruding lesions. Mean lesion size was 11.5 mm ± 9.6 mm (2 mm-60 mm). Patients' mean age was 61.6 ± 12.5 years (34-93 years). Regarding lesion site, 24 (14.0%) lesions were located in the rectum, 68 (39.5%) in the left colon, and 80 (46.5%) in the right colon (transverse, ascending, and cecum). There were 167 (97.1%) neoplasms: 142 (82.5%) adenomatous lesions, 24 (14.0%) intramucosal carcinomas, and 1 (0.6%) invasive carcinoma. En bloc resection was performed in 158 (91.9%) cases and piecemeal resection in 14 (8.1%). Bleeding occurred in 5 (2.9%) cases. Recurrence was observed in 4.1% (5/122) of cases and was associated with lesions larger than 20 mm (P<0.01), piecemeal resection (P<0.01), advanced neoplasm (P = 0.01), and carcinoma compared to adenoma (P = 0.04). CONCLUSIONS: Endoscopic mucosal resection of colorectal lesions is a safe and effective procedure, with low complication and local recurrence rates. Recurrence is associated with lesions larger than 20 mm and carcinomas.