The efficacy of full-thickness endoscopic resection of subepithelial tumors in the gastric cardia

BACKGROUND

Gastric subepithelial tumors (SETs) may harbor potential malignancy. Although it is well recognized that large SETs should be resected, the precise treatment strategy remains controversial. Compared to surgical resection, endoscopic resection (ER) has many advantages; however, ER of SETs in the cardia is challenging.

AIM

To evaluate the safety and efficacy of endoscopic full-thickness resection (EFTR) for the treatment of gastric cardia SETs.

METHODS

We retrospectively reviewed data from all patients with SETs originating from the muscularis propria layer in the gastric cardia that were treated by EFTR or submucosal tunneling ER (STER) at Zhongshan Hospital Fudan University between November 2014 and May 2022. Baseline characteristics and clinical outcomes, including procedure times and complications rates, were compared between groups of patients receiving EFTR and STER.

RESULTS

A total of 171 tumors were successfully removed [71 (41.5%) tumors in the EFTR and 100 (58.5%) tumors in the STER group]. Gastrointestinal stromal tumors (GISTs) were the most common SET. The en bloc resection rate was 100% in the EFTR group vs 97.0% in STER group (P > 0.05). Overall, the EFTR group had a higher complete resection rate than the STER group (98.6% vs 91.0%, P < 0.05). The procedure time was also shorter in the EFTR group (44.63 ± 28.66 min vs 53.36 ± 27.34, P < 0.05). The most common major complication in both groups was electrocoagulation syndrome. There was no significant difference in total complications between the two groups (21.1% vs 22.0%, P = 0.89).

CONCLUSION

EFTR of gastric cardia SETs is a very promising method to facilitate complete resection with similar complications and reduced operative times compared to STER. In cases of suspected GISTs or an unclear diagnosis, EFTR should be recommended to ensure complete resection.

Efficacy of image-enhanced endoscopy for colorectal adenoma detection: A multicenter, randomized trial

BACKGROUND

Improved adenoma detection at colonoscopy has decreased the risk of developing colorectal cancer. However, whether image-enhanced endoscopy (IEE) further improves the adenoma detection rate (ADR) is controversial.

AIM

To compare IEE with white-light imaging (WLI) endoscopy for the detection and identification of colorectal adenoma.

METHODS

This was a multicenter, randomized, controlled trial. Participants were enrolled between September 2019 to April 2021 from 4 hospital in China. Patients were randomly assigned to an IEE group with WLI on entry and IEE on withdrawal (n = 2113) or a WLI group with WLI on both entry and withdrawal (n = 2098). The primary outcome was the ADR. The secondary endpoints were the polyp detection rate (PDR), adenomas per colonoscopy, adenomas per positive colonoscopy, and factors related to adenoma detection.

RESULTS

A total of 4211 patients (966 adenomas) were included in the analysis (mean age, 56.7 years, 47.1% male). There were 2113 patients (508 adenomas) in the IEE group and 2098 patients (458 adenomas) in the WLI group. The ADR in two group were not significantly different [24.0% vs 21.8%, 1.10, 95% confidence interval (CI): 0.99-1.23, P = 0.09]. The PDR was higher with IEE group (41.7%) than with WLI group (36.1%, 1.16, 95%CI: 1.07-1.25, P = 0.01). Differences in mean withdrawal time (7.90 ± 3.42 min vs 7.85 ± 3.47 min, P = 0.30) and adenomas per colonoscopy (0.33 ± 0.68 vs 0.28 ± 0.62, P = 0.06) were not significant. Subgroup analysis found that with narrow-band imaging (NBI), between-group differences in the ADR, were not significant (23.7% vs 21.8%, 1.09, 95%CI: 0.97-1.22, P = 0.15), but were greater with linked color imaging (30.9% vs 21.8%, 1.42, 95%CI: 1.04-1.93, P = 0.04). the second-generation NBI (2G-NBI) had an advantage of ADR than both WLI and the first-generation NBI (27.0% vs 21.8%, P = 0.01; 27.0% vs 21.2.0%, P = 0.01).

CONCLUSION

This prospective study confirmed that, among Chinese, IEE didn’t increase the ADR compared with WLI, but 2G-NBI increase the ADR.

Research development and potential therapeutic value of m6A modification in occurrence and progression of colorectal tumors

In recent years, significant breakthroughs have been made in the study of genomics and proteomics, as vital compoments in epigenetic modifications, in the development of malignant tumors. Thereby, researchers have focused on the modification of RNA. N6-methyladenosine (m6A) is the major internal epigenetic modification in eukaryotic mRNA, and it is dynamic, reversible, and regulated by methylation enzymes (writers), demethylases (erasers), and recognition proteins (readers) that preferentially recognize m6A modifications. Thus, m6A regulates RNA transport, localization, translation, and decay, and plays a tumor promoting or anti-cancer role. M6A provides potential therapeutic targets for a variety of malignancies. In this review, we will summarize the biological characteristics and regulatory mechanisms of m6A RNA modification, and discuss the role of m6A modification in colorectal carcinogenesis and development. Moreover, related target therapies are discussed, aiming to provide a basis for novel biomarkers and therapeutic targets in the future.

Prediction of technically difficult endoscopic submucosal dissection for large superficial colorectal tumors: a novel clinical score model

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) is a promising technique for removing superficial GI tumors, but ESD is technically difficult. The aim of this study was to establish a clinical score model for grading technically difficult colorectal ESD.

METHODS

Data on patients, lesions, and outcomes of colorectal ESD at 2 centers were analyzed. The objective parameter of successful ESD within 60 minutes was set as an endpoint to evaluate the difficulty. Independent predictors of difficulty in the derivation cohort were identified by multiple logistic regression analysis and used to develop a clinical score. We validated the score model in the validation cohort.

RESULTS

The clinical score comprised tumor size of 30 to 50 mm (1 point) or ≥50 mm (2 points), at least two-thirds circumference of the lesion (2 points), location in the cecum (1 point), flexure (2 points) or dentate line (1 point), and laterally spreading tumor nongranular lesions (1 point). Areas under the receiver operator characteristic curves for the score model were comparable (derivation [.70] vs internal validation [.69] vs external validation [.69]). The probability of successful ESD within 60 minutes in easy (score = 0), intermediate (score = 1), difficult (score = 2-3), and very difficult (score ≥4) categories were 75.0%, 51.3%, 35.6%, and 3.4% in the derivation cohort; 73.3%, 47.9%, 31.8%, and 16.7% in the internal validation cohort; and 79.5%, 66.7%, 43.3%, and 20.0% in the external validation cohort, respectively.

CONCLUSIONS

This clinical score model accurately predicts the probability of successful ESD within 60 minutes and can be applied to grade the technical difficulty before the procedure.

NLRP7 deubiquitination by USP10 promotes tumor progression and tumor-associated macrophage polarization in colorectal cancer

Background

NOD-like receptors affect multiple stages of cancer progression in many malignancies. NACHT, LRR, and PYD domain-containing protein 7 (NLRP7) is a member of the NOD-like receptor family, although its role in tumorigenesis remains unclear. By analyzing clinical samples, we found that NLRP7 protein levels were upregulated in colorectal cancer (CRC). We proposed the hypothesis that a high level of NLRP7 in CRC may promote tumor progression. Here, we further investigated the role of NLRP7 in CRC and the underlying mechanism.

Methods

NLRP7 expression in human CRC and adjacent non-tumorous tissues was examined by quantitative real-time polymerase chain reaction (qRT-PCR), western blotting, and immunohistochemistry. The effect of NLRP7 in CRC progression was investigated in vitro and in vivo. Proteins interacting with NLRP7 were identified by immunoprecipitation and mass spectrometry analysis while immunofluorescence staining revealed the cellular location of the proteins. Cellular ubiquitination and protein stability assays were applied to demonstrate the ubiquitination effect on NLRP7. Cloning and mutagenesis were used to identify a lysine acceptor site that mediates NLRP7 ubiquitination. Cytokines/chemokines affected by NLRP7 were identified by RNA sequencing, qRT-PCR, and enzyme-linked immunosorbent assay. Macrophage phenotypes were determined using qRT-PCR, flow cytometry, and immunohistochemistry.

Results

NLRP7 protein levels, but not mRNA levels, were upregulated in CRC, and increased NLRP7 protein expression was associated with poor survival. NLRP7 promoted tumor cell proliferation and metastasis in vivo and in vitro and interacted with ubiquitin-specific protease 10, which catalyzed its deubiquitination in CRC cells. NLRP7 stability and protein levels in CRC cells were modulated by ubiquitination and deubiquitination, and NLRP7 was involved in the ubiquitin-specific protease 10 promotion of tumor progression and metastasis in CRC. K379 was an important lysine acceptor site that mediates NLRP7 ubiquitination in CRC cells. In CRC, NLRP7 promoted the polarization of pro-tumor M2-like macrophages by inducing the secretion of C-C motif chemokine ligand 2. Furthermore, NLRP7 promoted NF-κB nuclear translocation and activation of C-C motif chemokine ligand 2 transcription.

Conclusions

We showed that NLRP7 promotes CRC progression and revealed an as-yet-unidentified mechanism by which NLRP7 induces the polarization of pro-tumor M2-like macrophages. These results suggest that NLRP7 could serve as a biomarker and novel therapeutic target for the treatment of CRC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-01920-y.

Self-expandable metallic stenting as a bridge to elective surgery versus emergency surgery for acute malignant right-sided colorectal obstruction

Background

The use of a self-expandable metallic stent (SEMS) as a bridge to surgery has increased for patients with obstructing colorectal cancer. However, relatively few reports have compared SEMS as a bridge to elective surgery for acute malignant obstruction of the right-sided colon (MORC) vs. emergency surgery (ES). This study aimed to evaluate the benefits of elective surgery after SEMS placement vs. ES for patients (including stage IV cases) with acute MORC.

Methods

Patients with acute MORC who underwent radical resection for a primary tumour from July 2008 to November 2016 at Zhongshan Hospital of Fudan University were retrospectively enrolled. Postoperative short-term outcomes, progression-free survival (PFS), and overall survival (OS) were compared between the SEMS and ES groups.

Results

In total, 107 patients with acute MORC (35 in the SEMS group and 72 in the ES group) were included for analysis. The Intensive Care Unit admission rate was lower (11.4% vs. 34.7%, P = 0.011), the incidence of complications was reduced (11.4% vs. 29.2%, P = 0.042), and the postoperative length of hospitalisation was significantly shorter (8.23 ± 6.50 vs. 11.18 ± 6.71 days, P = 0.033) for the SEMS group. Survival curves showed no significant difference in PFS (P = 0.506) or OS (P = 0.989) between groups. Also, there was no significant difference in PFS and OS rates between patients with stage II and III colon cancer. After colectomy for synchronous liver metastases among stage IV patients, the hepatectomy rates for the SEMS and ES groups were 85.7% and 14.3%, respectively (P = 0.029). The hazard ratio for colectomy alone vs. combined resection was 3.258 (95% CI 0.858–12.370; P = 0.041).

Conclusion

Stent placement offers significant advantages in terms of short-term outcomes and comparable prognoses for acute MORC patients. For synchronous liver metastases, SEMS placement better prepares the patient for resection of the primary tumour and liver metastasis, which contribute to improved survival.