Infrapyloric and gastroepiploic node dissection for hepatic flexure and transverse colon cancer: A systematic review

[Evidence for the extent and oncological benefits of lymphadenectomy in colon and rectal cancer : A narrative review based on meta-analyses]

BACKGROUND

Lymphadenectomy for rectal cancer is clearly defined by total mesorectal excision (TME). The analogous surgical strategy for the colon, the complete mesocolic excision (CME), follows the same principles of dissection in embryologically predefined planes.

METHOD

This narrative review initially identified key issues related to lymphadenectomy of rectal and colon cancer. The subsequent search was based on PubMed and focused on meta-analyses. The endpoints for rectal cancer were the benefit of high tie versus low tie and the indications for lateral pelvic lymphadenectomy. For colon cancer the evidence for CME, for the longitudinal extent of resection, for the dissection of infrapyloric and gastroepiploic lymph nodes, for the number of lymph nodes and for the sentinel lymph node technique were used as endpoints.

RESULTS

An oncological benefit of the high tie cannot be derived from the current data. Lateral pelvic lymphadenectomy should only be selectively performed after chemoradiotherapy (CRT) in cases of remaining lymph nodes with suspected metastases. In most studies CME proved to be oncologically superior, especially in stage III. The longitudinal extent of resection should be at least 10 cm in both directions if the principles of CME are observed. Infrapyloric and gastroepiploic lymph node involvement is to be expected in 0.7-22% of cases, depending on patient selection, which justifies dissection, particularly in carcinomas of both flexure and the transverse colon. The minimum number of lymph nodes to be removed cannot be clearly derived from the available studies. Precisely performed CME and an optimal pathological work-up are important. The sentinel lymph node technique cannot currently be used as a criterion for limiting the extent of resection.

CONCLUSION

Both TME and CME are reliable standards for the lymphadenectomy in colorectal carcinomas. A lymphadenectomy that goes beyond this is reserved for selected cases and is partly the subject of currently ongoing studies.

Standardization of the definition of the types of oncological colectomy. Delphi method for consensus of experts of the Spanish Association of Surgeons

There is no international consensus on the definition of the type of oncological resection that corresponds to each of the colectomies existing in the current literature. The objective is to define for each colectomy described in the literature: embryological dissection plane, vascular pedicles in which to perform central ligation, the extent of the colectomy, and the need for resection of the greater momentum. A consensus of experts is carried out through the Delphi methodology through two rounds from the Coloproctology Section of the Spanish Association of Surgeons. Study period: November 2021-January 2023. 120 experts were surveyed. Degrees of consensus: Very strong: >90%, Strong: 80%-90%, Moderate: 50%-80%, No consensus: <50%. The definition for each oncological colectomy was established by very strong, and strong recommendations. Each oncological colectomy was established as Right hemicolectomy (RHC), RHC with D3 lymphadenectomy, Extended-RHC, transverse colon segmental colectomy, splenic flexure segmental colectomy, subtotal colectomy, total colectomy, left hemicolectomy (LHC), extended-LHC, sigmoidectomy.

Surgical treatment of right colon cancer

The study aimed to perform a systematic review of the literature on surgical treatment for right colon cancer (RCC) with complete mesocolic excision (CME) and D2/D3 lymph node dissection (LND). Material and Methods. A literature review was performed for studies published between 2013 and 2023 by the online resources from the official Web sites of the societies/panels and PubMed database. Sources included guidelines, meta-analyses, randomized and nonrandomized clinical studies, guidelines by European Society of Medical Oncology, the Japanese Society for Cancer of the Colon and Rectum, and the National Comprehensive Cancer Network, Russian clinical guidelines. Results. CME significantly improved both immediate and long-term treatment results, which was confirmed by numerous meta-analyses. The extent of LND remains one of the most controversial issues in RCC. For many Asian surgeons, D3 LND is the standard procedure for the treatment of RCC, whereas the European approach is more conservative and apical lymph node dissection is not mandatory. There are also large differences in understanding the extent of D3 LND in RCC. Most surgeons understand this term as dissection of adipose tissue along the anterior and lateral surface of the superior mesenteric vein, however, there are authors who perform circular dissection along the superior mesenteric vessels, considering this extent of surgery to be the most radical. Conclusion. It is necessary to standardize methods and effective criteria for quality control of CME for RCC and LND. In this case, external independent assessment of the quality of surgical intervention is important. There is also currently a growing number of studies in which intraoperative fluorescence imaging makes it possible to better visualize the location of the apical lymph nodes and individualize LND.

N6-methyladenosine reader protein IGF2BP1 suppresses CD8 + T cells-mediated tumor cytotoxicity and apoptosis in colon cancer

Tumor immune escape is an important manner for colon cancer to escape effective killing by immune system. Currently, the immune checkpoint PD-1/PD-L1-targeted immunotherapy has emerged as a promising therapeutic strategy in colon cancer. Here, present work aims to investigate the biological function of N6-methyladenosine (m6A) reader insulin-like growth factor 2 mRNA binding protein 1 (IGF2BP1) in regulating colon cancer's immune escape and CD8 + T cells-mediated tumor cytotoxicity and apoptosis. Results illustrated that IGF2BP1 was closely correlated to the colon cancer patients' poor clinical outcome. Functionally, upregulation of IGF2BP1 suppressed the CD8+ T-cells mediated antitumor immunity through reducing their tumor cytotoxicity. Mechanistically, MeRIP-Seq revealed that programmed death ligand 1 (PD-L1) mRNA had a remarkable m6A modified site on 3'-UTR genomic. Moreover, PD-L1 acted as the target of IGF2BP1, which enhanced the stability of PD-L1 mRNA. Overall, these results indicated that IGF2BP1 targeted PD-L1 to accelerate the immune escape in colon cancer by reducing CD8 + T cells-mediated tumor cytotoxicity in m6A-dependent manner. The findings demonstrate the potential of m6A-targeted immune checkpoint blockade in colon cancer, providing a novel insight for colon cancer immune escape and antitumor immunity in further precise treatment.

Prevention of delayed gastric emptying after right colectomy with extended lymphadenectomy: A randomized controlled trial

BACKGROUND

Delayed gastric emptying sometimes occurs after right colectomy with extended lymphadenectomy. The aim of this randomized controlled trial is to evaluate the effect on delayed gastric emptying after performing a fixation of the stomach to the retrogastric tissue to return the stomach to a physiological position after right colectomy with lymphadenectomy, including gastrocolic lymph nodes dissection for proximal transverse colon cancer.

METHODS

From January 2015 to December 2020, patients undergoing right colectomy with extensive lymphadenectomy for proximal transverse colon cancer were randomly assigned to either the gastropexy group or the conventional group. In the gastropexy group, the posterior wall of the stomach, at the level of the antrum, was sutured to the retrogastric tissue to prevent the abnormal shape that the gastric antrum acquires together with the duodeno-pancreatic complex, the shape that leads to an obstruction of the antrum region and to the delay in emptying the gastric contents.

RESULTS

Mean age, sex, comorbidities, and right colectomy procedures were similar in the 2 groups. Delayed gastric emptying developed in twelve patients in the conventional group (38.7%) versus 4 patients (12.1%) in the gastropexy group (P = .014). The total number of complications was higher in the conventional group (14 complications) than in the gastropexy group (7 complications). According to univariate analysis, gastropexy significantly lowered the risk of delayed gastric emptying (P = .014). Overall morbidity was 9.7% in the conventional group versus none in the gastropexy group. Postoperative hospitalization was longer in the conventional group (7.61 ± 3.26 days) than in the gastropexy group (6.24 ± 1.3 days; P = .006).

CONCLUSION

Gastropexy decreases the occurrence of delayed gastric emptying after right colectomy with extended lymphadenectomy for proximal transverse colon cancer.

Infrapyloric (No. 206) and greater curvature (No. 204) lymph node metastasis in adenocarcinoma located in the right half of the transverse colon (InCLART Study): protocol for a multicentre prospective observational study

INTRODUCTION

In the case of right-sided transverse colon cancer (RTCC) and hepatic flexure colon cancer (HFCC), there is a potential connection of lymph drainage between mesentery and greater omentum. However, most previous reports have been limited case series with No. 206 and No. 204 lymph node (LN) dissection for RTCC and HFCC.

METHODS AND ANALYSIS

The InCLART Study is a prospective observational study aiming to enrol 427 patients with RTCC and HFCC treated at 21 high-volume institutions in China. The prevalence of infrapyloric (No. 206) and greater curvature (No. 204) LN metastasis and short-term outcomes will be investigated in a consecutive series of patients with T2 or deeper invasion RTCC or HFCC, following the principle of complete mesocolic excision with central vascular ligation. Primary endpoints were performed to identify the prevalence of No. 206 and No. 204 LN metastasis. Secondary analyses will be used to estimate prognostic outcomes, intraoperative and postoperative complications, the consistency of preoperative evaluation and postoperative pathological results of LN metastasis.

ETHICS AND DISSEMINATION

Ethical approval for the study has been granted by the Ruijin Hospital Ethics Committee (approval number: 2019-081) and has been or will be approved successively by each participating centre's Research Ethics Board. The findings will be disseminated in peer-reviewed publications.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT03936530; https://clinicaltrials.gov/ct2/show/NCT03936530).

Development and validation of a new stage-specific nomogram model for predicting cancer-specific survival in patients in different stages of colon cancer: A SEER population-based study and external validation

Background

The effects of laterality of the primary tumor on survival in patients in different stages of colon cancer are contradictory. We still lack a strictly evaluated and validated survival prediction tool, considering the different roles of tumor laterality in different stages.

Methods

A total of 101,277 and 809 colon cancer cases were reviewed using the Surveillance, Epidemiology, and End Results database and the First Affiliated Hospital of Xi 'an Jiaotong University database, respectively. We established training sets, internal validation sets and external validation sets. We developed and evaluated stage-specific prediction models and unified prediction models to predict cancer-specific survival and compared the prediction abilities of these models.

Results

Compared with right-sided colon cancers, the risk of cancer-specific death of left-sided colon cancer patients was significantly higher in stage I/II but was markedly lower in stage III patients. We established stage-specific prediction models for stage I/II and stage III separately and established a unified prediction model for all stages. By evaluating and validating the validation sets, we reported high prediction ability and generalizability of the models. Furthermore, the stage-specific prediction models had better predictive power and efficiency than the unified model.

Conclusions

Right-sided colon cancer patients have better cancer-specific survival than left-sided colon cancer patients in stage I/II and worse cancer-specific survival in stage III. Using stage-specific prediction models can further improve the prediction of cancer-specific survival in colon cancer patients and guide clinical decisions.

Extended Lymphadenectomy for Proximal Transverse Colon Cancer: Is There a Place for Standardization?

Background and Objectives: Complete mesocolon excision and high vascular ligation have become a standard procedure in the treatment of colon cancer. The transverse colon has certain embryological and anatomical particularities which require special attention in case of oncological surgeries. Proximal transverse colon cancer (TCC) can metastasize to the lymph nodes in the gastrocolic ligament. The aim of this study is to assess the tumor involvement of these lymph nodes and to determine the applicability of gastrocolic ligament lymph nodes dissection as the standard approach for proximal transverse colon cancer. Materials and Methods: this study analyzes the cases of patients admitted to the Surgery Department, diagnosed with proximal transverse colon cancer, with tumor invasion ≥ T2 and for which complete mesocolon excision with high vascular ligation and lymphadenectomy of the gastrocolic ligament (No. 204, 206, 214v) were performed. Results: A total of 43 cases operated during 2015−2020 were included in the study. The median total number of retrieved central lymph nodes was 23 (range, 12−38), that had tumor involvement in 22 cases (51.2%). Gastrocolic ligament tumor involvement was found in 5 cases (11.6%). The median operation time was 180 min, while the median blood loss was 115 mL (range 0−210). The median time of hospitalization was 6 days (range, 5−11). Grade IIIA in the Clavien-Dindo classification was noticed in 3 patients, with no mortality. Upon Kaplan−Meier analysis, tumors > T3 (p < 0.016) and lymph node ratio < 0.05 (p < 0.025) were statistically significant. Conclusions: lymph node dissection of the gastrocolic ligament in patients with advanced proximal transverse colon cancer may improve the oncological outcome in T3/T4 tumors, and therefore standardization could be feasible