5-year outcome after complete mesocolic excision for right-sided colon cancer: a population-based cohort study

Clinical characteristics and risk factors of post-operative intestinal flora disorder following laparoscopic colonic surgery: A propensity-score-matching analysis

BACKGROUND

Intestinal flora disorder (IFD) poses a significant challenge after laparoscopic colonic surgery, and no standard criteria exists for its diagnosis and treatment.

AIM

To analyze the clinical features and risk factors of IFD.

METHODS

Patients with colon cancer receiving laparoscopic surgery were included using propensity-score-matching (PSM) methods. Based on the occurrence of IFD, patients were categorized into IFD and non-IFD groups. The clinical characteristics and treatment approaches for patients with IFD were analyzed. Multivariate regression analysis was performed to identify the risk factors of IFD.

RESULTS

The IFD incidence after laparoscopic surgery was 9.0% (97 of 1073 patients). After PSM, 97 and 194 patients were identified in the IFD and non-IFD groups, respectively. The most common symptoms of IFD were diarrhea and abdominal, typically occurring on post-operative days 3 and 4. All patients were managed conservatively, including modulation of the intestinal flora (90.7%), oral/intravenous application of vancomycin (74.2%), and insertion of a gastric/ileus tube for decompression (23.7%). Multivariate regression analysis identified that pre-operative intestinal obstruction [odds ratio (OR) = 2.79, 95%CI: 1.04-7.47, P = 0.041] and post-operative antibiotics (OR = 8.57, 95%CI: 3.31-23.49, P < 0.001) were independent risk factors for IFD, whereas pre-operative parenteral nutrition (OR = 0.12, 95%CI: 0.06-0.26, P < 0.001) emerged as a protective factor.

CONCLUSION

A stepwise approach of probiotics, vancomycin, and decompression could be an alternative treatment for IFD. Special attention is warranted post-operatively for patients with pre-operative obstruction or early use of antibiotics.

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.

Lymph node harvesting after laparoscopic complete mesocolic excision colectomy in colon cancer with practical application of glacial acid, absolute ethanol, water, and formaldehyde solution: A prospective cohort study

Objectives

Quality of surgery has recently become an essential topic in the prognosis of colon cancer. Complete mesocolic excision for colon cancer has recently gained popularity with high-quality surgery. Patient specimens after complete mesocolic excision with central vessel ligation procedures have an integrity of the mesocolon and the yield of three fields of lymph node harvest. We apply the glacial acid, absolute ethanol, water, and formaldehyde solution to each specimen based on the Japanese classification of lymph node groups and station numbers. We aim to identify the distribution and status of lymph node metastasis according to each tumor site and some pathological characteristics related to this disease.

Methods

A prospective cohort study was performed on 45 laparoscopic complete mesocolic excision surgery patients.

Results

2791 lymph nodes were harvested after complete mesocolic excision surgery. The average number was 62.0 ± 22.3 nodes. The mean tumor size (in the largest dimension) was 4.2 ± 1.8 cm. The average length of the resected bowel segments was 29.1 ± 7.7 cm. There are 63 (2.3%) node metastases in 2791 lymph nodes, in which 17/45 (37.8%) patients had pN(+). The minimum positive node size was 1 mm. The positive pericolic lymph nodes (station 1) accounted for the highest rate, with 53 nodes (1.9%). The number of lymph nodes in young age ⩽60 is more significant than in older. The results were similar, with a more significant node retrieval in the group with a tumor size >4.5 cm and specimen length >25 cm. The number of lymph nodes in lower tumor invasive (pT1,3) was smaller than pT4. Our research shows that the cecum, ascending, and descending colon had greater nodes than others, with a mean number of 78.6, 74.2, and 71.3, respectively.

Conclusions

The metastasis and harvested lymph nodes accounted for the highest rate of colon cancer in station 1 and the lowest rate in station 3. The number of retrieved lymph nodes was significantly associated with tumor location, size, specimen length, and patient age.

Effect of complete mesocolic excision (cme) on long-term survival after right colectomy for cancer: multivariate meta-analysis and restricted mean survival time estimation

INTRODUCTION

Debate exists concerning the impact of complete mesocolic excision (CME) on long-term oncological outcomes. The aim of this review was to condense the updated literature and assess the effect of CME on long-term survival after right colectomy for cancer.

METHODS

PubMed, MEDLINE, Scopus, and Web of Science were searched through July 2023. The included studies evaluated the effect of CME on survival. The primary outcome was long-term overall survival. Restricted mean survival time difference (RMSTD), hazard ratio (HR), and 95% confidence intervals (CI) were used as pooled effect size measures. GRADE methodology was used to summarize the certainty of evidence.

RESULTS

Ten studies (3665 patients) were included. Overall, 1443 (39.4%) underwent CME. The RMSTD analysis shows that at 60-month follow-up, stage I-III CME patients lived 2.5 months (95% CI 1.1-4.1) more on average compared with noCME patients. Similarly, stage III patients that underwent CME lived longer compared to noCME patients at 55-month follow-up (6.1 months; 95% CI 3.4-8.5). The time-dependent HRs analysis for CME vs. noCME (stage I-III disease) shows a higher mortality hazard in patients with noCME at 6 months (HR 0.46, 95% CI 0.29-0.71), 12 months (HR 0.57, 95% CI 0.43-0.73), and 24 months (HR 0.73, 95% CI 0.57-0.92) up to 27 months.

CONCLUSIONS

This study suggests that CME is associated with unclear OS benefit in stage I-III disease. Caution is recommended to avoid overestimation of the effect of CME in stage III disease since the marginal benefit of a more extended resection may have been influenced by tumor biology/molecular profile and multimodal adjuvant treatments.

Complete mesocolic excision for colon cancer: current status and controversies

According to Hohenberger's original description, complete mesocolic excision for colon cancer involves precise dissection of the avascular embryonic plane between the parietal retroperitoneum and visceral peritoneum of the mesocolon. This ensures mesocolic integrity, access to high ligation of the supplying vessels at their origin and an associated extended lymphadenectomy. Results from centres which have adopted this approach routinely have demonstrated that oncological outcomes can be improved by the rigorous implementation of established principles of cancer surgery. Meticulous anatomical dissection along embryonic planes is a well-established principle of precision cancer surgery used routinely by the specialist colorectal surgeon. Therefore, the real question concerns the need for true central vascular ligation and associated extended (D3) lymphadenectomy or otherwise, particularly along the superior mesenteric vessels when performing a right colectomy. Whether this approach results in improved overall or disease-free survival remains unclear and its role remains controversial particularly given the potential for significant morbidity associated with a more extensive central vascular dissection. Current literature is limited by considerable bias, as well as inconsistent and variable terminology, and the results of established randomized trials are awaited. As a result of the current state of equipoise, various national guidelines have disparate recommendations as to when complete mesocolic excision should be performed if at all. This article aims to review the rationale for and technical aspects of complete mesocolic excision, summarize available short and long term outcome data and address current controversies.

Management of Surgically Accessible Lymph Nodes Beyond Normal Resection Planes

This article discusses the management of isolated metastatic lymph nodes for colon and rectal cancer. There are traditionally significant differences in how certain regions of lymph nodes for colon and rectal cancer are managed in the East and West. This has led to the development of the lateral lymph node dissection for rectal cancer and extended lymphadenectomy techniques for colon cancer. This article will evaluate the literature on these techniques and what the surgical and oncological outcomes are at this time. In addition, colon and rectal cancers can occasionally have isolated distant lymph node metastases. These would traditionally be treated as systemic disease with chemotherapy. There is consideration though that these could be treated as similar to isolated liver or lung metastases which have been shown to be able to be treated surgically with good oncological results. The literature for these isolated distant lymph node metastases will be reviewed and treatment options available will be discussed.

Developing a phantom for simulating robotic-assisted complete mesocolic excision using 3D printing and medical imaging

BACKGROUND

Robotic-assisted complete mesocolic excision is an advanced procedure mainly because of the great variability in anatomy. Phantoms can be used for simulation-based training and assessment of competency when learning new surgical procedures. However, no phantoms for robotic complete mesocolic excision have previously been described. This study aimed to develop an anatomically true-to-life phantom, which can be used for training with a robotic system situated in the clinical setting and can be used for the assessment of surgical competency.

METHODS

Established pathology and surgical assessment tools for complete mesocolic excision and specimens were used for the phantom development. Each assessment item was translated into an engineering development task and evaluated for relevance. Anatomical realism was obtained by extracting relevant organs from preoperative patient scans and 3D printing casting moulds for each organ. Each element of the phantom was evaluated by two experienced complete mesocolic excision surgeons without influencing each other's answers and their feedback was used in an iterative process of prototype development and testing.

RESULTS

It was possible to integrate 35 out of 48 procedure-specific items from the surgical assessment tool and all elements from the pathological evaluation tool. By adding fluorophores to the mesocolic tissue, we developed an easy way to assess the integrity of the mesocolon using ultraviolet light. The phantom was built using silicone, is easy to store, and can be used in robotic systems designated for patient procedures as it does not contain animal-derived parts.

CONCLUSIONS

The newly developed phantom could be used for training and competency assessment for robotic-assisted complete mesocolic excision surgery in a simulated setting.

Complete mesocolic excision and extended lymphadenectomy: Where should we stand?

Debate regarding the risks and merits of complete mesocolic excision and extended lymphadenectomy is ongoing, particularly for right-sided colon cancers. In this article, we hope to provide a succinct yet encompassing review of the relevant literature. We posit that complete mesocolic excision with D3 dissection is indicated in select patients with colon cancers, particularly those distal to the cecum.

Nationwide standardization of minimally invasive right hemicolectomy for colon cancer and development and validation of a video-based competency assessment tool (the Right study)

BACKGROUND

Substantial variation exists when performing a minimally invasive right hemicolectomy (MIRH) due to disparities in training, expertise and differences in implementation of innovations. This study aimed to achieve national consensus on an optimal and standardized MIRH technique for colon cancer and to develop and validate a video-based competency assessment tool (CAT) for MIRH.

METHOD

Statements covering all elements of MIRH were formulated. Subsequently, the Delphi technique was used to reach consensus on a standardized MIRH among 76 colorectal surgeons from 43 different centres. A CAT was developed based on the Delphi results. Nine surgeons assessed the same 12 unedited full-length videos using the CAT, allowing evaluation of the intraclass correlation coefficient (ICC).

RESULTS

After three Delphi rounds, consensus (≥80% agreement) was achieved on 23 of the 24 statements. Consensus statements included the use of low intra-abdominal pressure, detailed anatomical outline how to perform complete mesocolic excision with central vascular ligation, the creation of an intracorporeal anastomosis, and specimen extraction through a Pfannenstiel incision using a wound protector. The CAT included seven consecutive steps to measure competency of the MIRH and showed high consistency among surgeons with an overall ICC of 0.923.

CONCLUSION

Nationwide consensus on a standardized and optimized technique of MIRH was reached. The CAT developed showed excellent interrater reliability. These achievements are crucial steps to an ongoing nationwide quality improvement project (the Right study).

Challenging case of deficient mismatch repair right-sided locally advanced adenocarcinoma of the ascending colon with duodenal involvement: A case report including step-by-step video of operation

INTRODUCTION AND IMPORTANCE

Irresectable colon cancer presents a complex clinical challenge. Neoadjuvant immunotherapy has shown potential in improving resectability. Additionally, advancements in surgical techniques, including complete mesocolic excision (CME) with central vascular ligation (CVL), have contributed to better outcomes for right-sided colon cancer. This case report aims to demonstrate the successful laparoscopic resection of initial appearing irresectable colon cancer with suspected duodenal involvement.

CASE PRESENTATION

A 70-year-old female presented with an irresectable mismatch repair deficient (dMMR) adenocarcinoma of the ascending colon with suspected duodenal ingrowth. Neoadjuvant treatment with pembrolizumab and ataluren resulted in a significant response, allowing for surgical resection. A laparoscopic right hemicolectomy with CME, including CVL, intracorporeal anastomosis and extraction through a Pfannenstiel incision, was performed. Additionally, the serosal layer of the duodenum was shaved after observing the absence of intraluminal invasion. Postoperatively, transient gastroparesis occurred, but overall outcomes were favourable.

CLINICAL DISCUSSION

This case emphasizes the potential of immunotherapy in improving resectability for irresectable dMMR colon cancer with suspected involvement of surrounding organs. The combination of neoadjuvant therapy and advanced surgical techniques, such as CME with CVL, shows promise in achieving favourable clinical outcomes. However, further studies are needed to validate the effectiveness and safety of this combined approach in a larger cohort of patients.

CONCLUSION

The successful laparoscopic resection of initially irresectable dMMR colon cancer with duodenal involvement, following neoadjuvant immunotherapy, demonstrated promising outcomes. This case advocates for further exploration of neoadjuvant treatments' efficacy, coupled with advanced surgical techniques, in managing locally advanced right-sided colon cancer.

Complete mesocolic excision for right colon cancer: Is D3 lymphadenectomy necessary?

AIM

Although complete mesocolic excision (CME) for colon cancer is oncologically sound, to date, there has been no consensus on the extent of lymphadenectomy in radical right colectomy. This study essentially compared the perioperative and survival outcomes of CME with two templates of lymphadenectomy for right colon cancer.

METHOD

This was a propensity matched, retrospective analysis of a single centre, prospectively maintained database of all patients undergoing elective right colectomy for nonmetastatic, biopsy-proven adenocarcinoma from November 2013 to October 2018. CME + D3 was adopted selectively, documented prospectively, and compared with patients undergoing CME + central vascular ligation (CVL). The only technical difference between the groups was the excision of the surgical trunk of Gillot in the CME + D3 group. Postoperative, long-term outcomes and patterns of recurrence were compared between the groups.

RESULTS

Of the 244 eligible patients, 88 (36.1%) and 156 (63.9%) underwent CME + D3 and CME + CVL, respectively. Matched groups (72 [CME + D3] vs. 108 [CME + CVL]) showed no difference in histology, tumour grade, postoperative complications, mortality, and hospital stay. CME + D3 was preferentially performed laparoscopically (35.2% vs. 9%), was associated with lower blood loss (215 mL vs. 297 mL, p = 0.001), higher nodal yield (31 vs. 25 nodes, p = 0.003) and a higher incidence of chyle leak (4 vs. 0, p = 0.013). At a median follow-up of more than 57 months, there was no significant difference in local recurrence, disease-free or overall survival.

CONCLUSION

In this retrospective study, lymphadenectomy along the superior mesenteric vein, as a component of CME for right colon cancer, offered a higher nodal yield with no improvement in oncological outcome. Dissection of the SMV, over and above a D2 dissection, could therefore be restricted to specialized colorectal units until further studies establish the incremental oncological benefit of this extended lymphadenectomy or define a patient group in whom it is beneficial.

Tata Memorial Centre Evidence Based Management of Colorectal cancer

ABSTRACT

This review article examines the evidence-based management of colorectal cancers, focusing on topics characterized by ongoing debates and evolving evidence. To contribute to the scientific discourse, we intentionally exclude subjects with established guidelines, concentrating instead on areas where the current understanding is dynamic. Our analysis encompasses a thorough exploration of critical themes, including the evidence surrounding complete mesocolic excision and D3 lymphadenectomy in colon cancers. Additionally, we delve into the evolving landscape of perioperative chemotherapy in both colon and rectal cancers, considering its nuanced role in the context of contemporary treatment strategies. Advancements in surgical techniques are a pivotal aspect of our discussion, with an emphasis on the utilization of minimally invasive approaches such as laparoscopy and robotic surgery in both colon and rectal cancers, including advanced rectal cases. Moving beyond conventional radical procedures, we scrutinize the feasibility and implications of endoscopic resections for small tumors, explore the paradigm of organ preservation in locally advanced rectal cancers, and assess the utility of total neoadjuvant therapy in the current treatment landscape. Our final segment reviews pivotal trials that have significantly influenced the management of colorectal liver and peritoneal metastasis.

Association of hemicolectomy with survival in stage II colorectal cancer: a retrospective cohort study

To compare the oncological survival outcomes of partial colectomy (PC) and hemicolectomy (HC) in patients with stage II colon cancer. A total of 18,795 patients with stage II colon cancer who underwent hemicolectomy (n = 12,022) or partial colectomy (n = 6773) from 2010 to 2019 were included in the the Surveillance, Epidemiology, and End Results (SEER) database. Overall survival (OS) and cancer-specific survival (CSS) were compared between the two groups, and the threshold of harvested lymph nodes was determined. The results showed that age, gender, race, tumor site, scope of regional lymph nodes, postoperative chemotherapy, postoperative radiotherapy, harvested lymph nodes, and tumor size were significantly different between the PC and HC groups (all P < 0.05). The OS rate was slightly lower in hemicolectomy patients than in partial colectomy patients (69.9% vs. 74.5%, respectively, P < 0.001), but CSS was similar between the two groups (87.9% vs. 88.1%, respectively, P = 0.32). After propensity score matching (PSM) was performed, the OS and CSS rates in the two groups were significantly different (CSS 84.3% vs. 88.0%, P < 0.001; OS 62.2% vs. 72.5%, P < 0.001). The survminer R package determined that the optimum threshold for the harvested lymph node count in stage II colon cancer patients was 16. CSS was significantly different between patients with ≥ 12 lymph nodes harvested and patients with ≥ 16 lymph nodes harvested (P = 0.043). Univariate and multivariate Cox regression and survival analyses of stage II colon cancer patients showed that the survival benefit of stage II colon cancer patients receiving partial colectomy was superior to that of patients receiving hemicolectomy. Partial colectomy has significant oncological benefits over hemicolectomy in the treatment of stage II colon cancer patients, even in the case of pT4b or tumor deposits. Removal of 16 lymph nodes during colectomy for stage II colon cancer correlated with improved survival, and this threshold was more effective than the standard threshold of 12 lymph nodes in distinguishing between patients with good and poor prognoses.

Best Evidence for Each Surgical Step in Minimally Invasive Right Hemicolectomy: A Systematic Review

Objective

The aim of this study was to systematically review the literature for each surgical step of the minimally invasive right hemicolectomy (MIRH) for non-locally advanced colon cancer, to define the most optimal procedure with the highest level of evidence.

Background

High variability exists in the way MIRH is performed between surgeons and hospitals, which could affect patients' postoperative and oncological outcomes.

Methods

A systematic search using PubMed was performed to first identify systematic reviews and meta-analyses, and if there were none then landmark papers and consensus statements were systematically searched for each key step of MIRH. Systematic reviews were assessed using the AMSTAR-2 tool, and selection was based on highest quality followed by year of publication.

Results

Low (less than 12 mmHg) intra-abdominal pressure (IAP) gives higher mean quality of recovery compared to standard IAP. Complete mesocolic excision (CME) is associated with lowest recurrence and highest 5-year overall survival rates, without worsening short-term outcomes. Routine D3 versus D2 lymphadenectomy showed higher LN yield, but more vascular injuries, and no difference in overall and disease-free survival. Intracorporeal anastomosis is associated with better intra- and postoperative outcomes. The Pfannenstiel incision gives the lowest chance of incisional hernias compared to all other extraction sites.

Conclusion

According to the best available evidence, the most optimal MIRH for colon cancer without clinically involved D3 nodes entails at least low IAP, CME with D2 lymphadenectomy, an intracorporeal anastomosis and specimen extraction through a Pfannenstiel incision.

Complete mesocolic excision for right hemicolectomy: an updated systematic review and meta-analysis

PURPOSE

Complete mesocolic excision improves lymphadenectomy for right hemicolectomy and respects the embryological planes. However, its effect on cancer-free and overall survival is questioned. Therefore, we aimed to determine the potential benefits of the technique by performing a systematic review of the literature and meta-analysis of the available evidence.

METHODS

Web of Science, PubMed/Medline, and Embase were searched on February 22, 2023. Original studies on short- and long-term oncological outcomes of adult patients undergoing right hemicolectomy with complete mesocolic excision as a treatment for primary colon cancer were considered for inclusion. Outcomes were extracted and pooled using a model with random effects.

RESULTS

A total of 586 publications were identified through database searching, and 18 from citation searching. Exclusion of 552 articles left 24 articles for inclusion. Meta-analysis showed that complete mesocolic excision increased the lymph node harvest (5 studies, 1479 patients, MD 9.62, 95% CI 5.83-13.41, p > 0.0001, I2 84%), 5-year overall survival (5 studies, 2381 patients, OR 1.88, 95% CI 1.14-3.09, p = 0.01, I2 66%), 5-year disease-free survival (4 studies, 1376 patients, OR 2.21, 95% CI 1.51-3.23, p < 0.0001, I2 0%) and decreased the incidence of local recurrence (4 studies, 818 patients, OR 0.27, 95% CI 0.09-0.79, p = 0.02, I2 0%) when compared to standard right hemicolectomy. Perioperative morbidity was similar between the techniques (8 studies, 3899 patients, OR 1.04, 95% CI 0.89-1.22, p = 0.97, I2 0%).

CONCLUSION

Meta-analysis of observational and randomised studies showed that right hemicolectomy with complete mesocolic excision for primary right colon cancer improves oncologic results without increasing morbidity/mortality. These results need to be confirmed by high-quality evidence and randomised trials in selected patients to assess who may benefit from the procedure.

Feasibility and safety of hybrid transvaginal natural orifice transluminal endoscopic surgery for colon cancer: Protocol for a multicenter, single-arm, phase II trial (vNOTESCA)

Introduction

It has been a decade since the first patient with colon cancer underwent colectomy by hybrid transvaginal natural orifice transluminal endoscopic surgery (hvNOTES). However, the efficacy and safety of this procedure is not well established.

Methods

This study is an open-label, multicenter, single-arm, phase 2 trial undertaken at six centers in China. Female patients aged over 18 years and below 80 years old with an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, with pathologically proven, resectable, cT1-3N0-2M0 disease who have previously untreated colon cancer are eligible for inclusion. The primary endpoint is a composite of major intraoperative and postoperative complications (greater than grade III, the Common Terminology Criteria for Adverse Events [CTCAE], version 5.0). Secondary endpoints include conversion to laparoscopic or open surgery, postoperative concentration of C-Reactive Protein and procalcitonine, complete pathological assessment of complete mesocolic excision specimens, postoperative pain, amount of narcotic pain medication administered, time to first flatus after surgery, number of harvested lymph nodes, R0 resection rate, length of hospital stay, sexual function assessment, quality of recovery, satisfaction with surgical scars, quality of life, postoperative recurrence patterns, relapse-free survival, and overall survival.

Ethics and dissemination

The study was approved by the Research Ethics Committee, Renmin Hospital of Wuhan University, China, number: WDRY2022-K053. All patients will receive written information of the trial and provide informed consent before enrollment. The results of this trial will be disseminated in academic conferences and peer-reviewed medical journals.Trial registration number NCT04048421.

Prospective evaluation of bowel function and quality of life after colon cancer surgery - is it time for routine screening for late sequelae?

AIM

Bowel dysfunction after colon cancer (CC) surgery is widely neglected in current follow up programmes. This study explored changes in bowel function and quality of life (QoL) from three (3 m) to twelve months (12 m) after surgery in CC patients undergoing right- or left-sided colon resection (RightSCR/LeftSCR) and investigated differences between the two groups 12 m after surgery.

METHOD

CC patients undergoing surgical resection in 2018-2020 at five surgical departments were included in this population-based prospective cohort study. Included patients completed electronic surveys consisting of a collection of validated scores 3 m and 12 m after surgery.

RESULTS

A total of 708 CC patients (423 RightSCR, 285 LeftSCR) were included. In RightSCR, no improvement was observed from 3 m to 12 m in most scores/items, on the contrary, symptom worsening in flatus- and faecal incontinence and urgency was observed (p < 0.05). Also, the proportion of patients rating their bowel function as very good/good decreased (p < 0.05) in this group. In LeftSCR improvement was found in flatus and faecal incontinence, urgency and night-time defaecation (p < 0.02), while no improvement was observed in the remaining scores/items. At 12 m, higher proportions of RightSCR than LeftSCR reported loose stools, incontinence and urgency (all p < 0.001), whereas LeftSCR more often reported hard stools and flatus incontinence (p < 0.05). Among all CC patients 18.3% reported bowel-related impairment of QoL at 12 m with no differences between the two groups.

CONCLUSION

From 3 m to 12 m no significant change was observed in the majority of bowel function and QoL scores/items, however, some symptoms worsened in RightSCR, while a few improved in LeftSCR. Bowel dysfunction and impaired QoL were still common in both groups at 12 m, although the symptom pattern differed between the groups. These findings call for a systematic screening for bowel dysfunction to ensure early treatment of symptoms.

Extended Right-Sided Colon Resection Does Not Reduce the Risk of Colon Cancer Local-Regional Recurrence: Nationwide Population-Based Study From Danish Colorectal Cancer Group Database

BACKGROUND

It is controversial whether extensive resection of right-sided colon cancer confers oncological benefits.

OBJECTIVE

The aim of this study was to evaluate short- and long-term outcomes of extended surgical removal of the mesocolon compared to the conventional approach.

DESIGN

This was a retrospective population-based study.

SETTING

Study is based on a prospectively maintained Danish Colorectal Cancer Group database.

MAIN OUTCOME MEASURES

Primary outcome measures included local-regional recurrence in patients who underwent curative resection for right-sided colon cancer and 30-day postoperative complications. Distant metastasis, unplanned intraoperative adverse events, and 30- and 90-day postoperative mortality were also investigated. Patients who had palliative or compromised resection, emergency surgery, or neoadjuvant chemotherapy were excluded.

RESULTS

Of the 12,855 patients with resection of right-sided colon cancer retrieved, 1151 underwent extended right hemicolectomy. Patients who had extended right hemicolectomy were younger males with lower ASA scores, were operated on by colorectal surgeons using a laparoscopic approach, and had a significantly higher number of harvested lymph nodes. The rate of local-regional recurrence was 1.1% (136/12,855), with no difference between conventional right hemicolectomy and extended right hemicolectomy (OR, 1.7; 95% CI, 0.63-2.18). Postoperative medical complications were significantly higher in extended right hemicolectomy even after adjusting for age, comorbidity, access to the abdomen, and other covariates (OR, 1.26; 95% CI, 1.01-1.58). No significant difference was noticed between conventional right hemicolectomy and extended right hemicolectomy in the rates of distant metastasis, unplanned intraoperative adverse events, and mortality.

LIMITATIONS

Because it is a register-based study, underreporting cannot be excluded. Extended right hemicolectomy, as defined in this study, does not reflect the extent of lymphatic dissection performed during the surgery.

CONCLUSIONS

This large population-based register study showed no difference in local-regional recurrence of right-sided colon cancer between conventional and extended right hemicolectomy with mesenteric resection and ligation of the middle colic vessels. Extended resection was associated with higher rates of postoperative complications. See Video Abstract at http://links.lww.com/DCR/B907 .

LA RESECCIN AMPLIADA DEL COLON DERECHO NO REDUCE EL RIESGO DE RECURRENCIA LOCALREGIONAL DEL CNCER DE COLON ESTUDIO POBLACIONAL A NIVEL NACIONAL DE LA BASE DE DATOS DEL GRUPO DANS DE CNCER COLORRECTAL

ANTECEDENTES:Es aun un tema controversial si la resección ampliada del cáncer de colon del lado derecho confiere beneficios oncológicos.OBJETIVOS:El objetivo de este estudio fue examinar los resultados a corto y largo plazo de la resección quirúrgica ampliada del mesocolon en comparación con el enfoque convencional.DISEÑO:Este fue un estudio poblacional de tipo retrospectivo basado en una base de datos del Grupo Danés de Cáncer Colorrectal mantenida de manera prospectiva.AJUSTES:La medida de resultado primaria fue la recurrencia local-regional en pacientes sometidos a resección curativa por cáncer de colon del lado derecho y las medidas de resultado secundarias fueron las complicaciones posoperatorias a los 30 días. También fueron investigadas las metástasis a distancia, los eventos adversos intraoperatorios no planificados y la mortalidad posoperatoria a los 30 y 90 días. Se excluyeron los pacientes sometidos a resección paliativa o comprometida, cirugía de urgencia y quimioterapia neoadyuvante.RESULTADOS:De los 12.855 pacientes recuperados y sometidos a resección de cáncer de colon del lado derecho, 1151 fueron sometidos a hemicolectomía derecha ampliada. Los pacientes sometidos a hemicolectomía derecha ampliada fueron varones más jóvenes con puntuaciones ASA más bajas, operados por cirujanos colorrectales, utilizando la vía laparoscópica, y tuvieron un número significativamente mayor de ganglios linfáticos extraídos. La tasa de recidiva local-regional fue del 1,1% (136 / 12.855) sin diferencia entre la hemicolectomía derecha convencional y la hemicolectomía derecha ampliada (OR 1,7 IC 95% 0,63-2,18). Las complicaciones médicas post operatorias fueron significativamente mayores en la hemicolectomía derecha ampliada incluso después del ajuste por edad, comorbilidad, acceso al abdomen y otras covariables (OR 1,26; IC 95% 1,01-1,58). No se observaron diferencias significativas entre la hemicolectomía derecha convencional y la hemicolectomía derecha ampliada con respecto a las tasas de metástasis a distancia, eventos adversos intraoperatorios no planificados y mortalidad.LIMITACIONES:Es un estudio basado en registros, por lo tanto, no se puede excluir la sub notificación. La hemicolectomía derecha ampliada como se define en este estudio no refleja la extensión de la disección linfática realizada durante la cirugía.CONCLUSIONES:Este gran estudio basado en el registro poblacional no mostró diferencias en la recurrencia local-regional del cáncer de colon del lado derecho entre la hemicolectomía derecha convencional y ampliada con resección mesentérica y ligadura de los vasos cólicos medios. La resección ampliada se asoció con tasas más altas de complicaciones posoperatorias. Consulte Video Resumen en http://links.lww.com/DCR/B907 . (Traducción-Dr. Osvaldo Gauto ).

Low anterior resection syndrome (LARS) and quality of life after colectomy

PURPOSE

Clinical experience shows complaints similar to LARS not only after rectal surgery, but even after other types of colorectal surgery. Our aim was to investigate the occurrence of LARS after several types of colorectal surgery and its impact on quality of life.

METHODS

We included adult patients who underwent colorectal surgery at our centre from January 2016 until March 2019, regardless of indication. A questionnaire was sent evaluating LARS and quality of life.

RESULTS

The questionnaire was answered by 119 patients. We noticed highest LARS-score after rectum surgery (26.1), but also surprisingly higher LARS-score after right-sided colectomy (21.0) compared to left-sided colectomy (16.4). We report lowest quality of life after rectal surgery, but higher quality of life in left colectomy compared to right colectomy.

CONCLUSION

LARS-score did not significantly correlate with type of procedure; however, higher LARS-scores were noted after right-sided colectomy compared to left-sided colectomy with similar impact on quality of life. We suggest CORS (colorectal resection syndrome) as a more suiting conceptual name instead of LARS to describe functional bowel complaints after colorectal surgery.

The concept of developmental anatomy: the greater omentum should be resected in right-sided colon cancer?

BACKGROUND

The greater omentum is derived from the foregut, and the right hemicolon is derived from the midgut based on developmental anatomy. This study aimed to investigate whether the greater omentum should be resected in laparoscopic complete mesocolic excision based on developmental anatomy for right-sided colon cancer.

METHODS

A total of 183 consecutive patients with right-sided colon cancer were recruited in this study between February 2020 and July 2022. Ninety-eight patients underwent standard laparoscopic complete mesocolic excision surgery (CME group). The presence of isolated tumor cells and micrometastases was detected in resected greater omentum by the HE staining and immunohistochemistry analysis. Based on developmental anatomy, laparoscopic CME surgery with greater omentum preservation (DACME group) was proposed and performed on 85 right-sided colon cancer patients. To overcome selection bias, we performed a 1:1 match between two groups using four variables: age, sex, BMI, and ASA scores.

RESULTS

No isolated tumor cells and micrometastases were found in the resected greater omentum specimen in the CME group. After the propensity score, 81 pairs were balanced and analyzed. Patients in the DACME group showed shorter operative time (194.9 ± 16.4 min vs.201.5 ± 11.5 min, p = 0.002), less blood loss (23.5 ± 24.7 ml vs.33.6 ± 26.3 ml, p = 0.013), and the shorter hospital stays (9.6 ± 1.7 days vs.10.3 ± 2.0 days, p = 0.010) compared with patients in the CME group. In addition, patients in the DACME group had a lower incidence of postoperative complications (4.9% vs.14.8%, p = 0.035) than patients in the CME group.

CONCLUSION

The greater omentum should be preserved during right-sided colon cancer surgery, laparoscopic CME surgery based on developmental anatomy is technically safe and feasible for right-sided colon cancer.

Current Controversies in the Management of Locally Advanced Colon Cancer

n/a.

Bach Mai Procedure for complete mesocolic excision, central vascular ligation, and D3 lymphadenectomy in total laparoscopic right hemicolectomy: a prospective study

PURPOSE

Total laparoscopic right hemicolectomy with complete mesocolic excision (CME), central vascular ligation (CVL), and D3 lymphadenectomy is still the most challenging colon procedures for gastrointestinal surgeons. We herein report the technical details and our preliminary experience of Bach Mai Procedure - a novel-combining (cranial, medial to lateral, and caudal) approach with early resection of the terminal ileum.

METHODS

The dissection stage was central vascular isolation and ligation by a combined multiple approaches in the following four steps: cranial approach, dissecting along the inferior aspect of pancreatic isthmus to reveal the middle colic vessels and the anterior aspect of the superior mesentery vein and then exposed the right gastroepiploic vein and the trunk of Henle; medial-to-lateral approach, exposing the surgical axis - the superior mesenteric vascular axis and then early resection of the terminal ileum to open the dissection from the bottom up; and caudal approach, radical ligation of the ileocecal artery and right colic artery (central vascular ligation), lymph node dissection (D3 lymphadenectomy), and resecting the Toldt fascia of the colon to release the entire right colon from the abdominal wall.

RESULTS

In 12 months, there were 32 cases of primary right-sided colon malignancies that have undergone tLRH_{D3, CME/CVL} based on the Bach Mai Procedure. In 3 cases (9.4%), the tumor site was hepatic flexure. The median of lymph node number (LNN) was 38, with the maximum number which was 101. No serious postoperative complications (grade 3 or higher) neither inhospital mortality was detected.

CONCLUSION

This Bach Mai procedure, a novel-combining approach with early resection of the terminal ileum, is technically feasible and safe for tLRH_{D3, CME/CVL}. Further investigations and follow-up must be proceeded to evaluate the long-term outcomes of our technique.

Effect of intra-operative chemotherapy with 5-fluorouracil and leucovorin on the survival of patients with colorectal cancer after radical surgery: a retrospective cohort study

BACKGROUND

The effect of intra-operative chemotherapy (IOC) on the long-term survival of patients with colorectal cancer (CRC) remains unclear. In this study, we evaluated the independent effect of intra-operative infusion of 5-fluorouracil in combination with calcium folinate on the survival of CRC patients following radical resection.

METHODS

1820 patients were recruited, and 1263 received IOC and 557 did not. Clinical and demographic data were collected, including overall survival (OS), clinicopathological features, and treatment strategies. Risk factors for IOC-related deaths were identified using multivariate Cox proportional hazards models. A regression model was developed to analyze the independent effects of IOC.

RESULTS

Proportional hazard regression analysis showed that IOC (hazard ratio [HR]=0.53, 95% confidence intervals [CI] [0.43, 0.65], P  < 0.001) was a protective factor for the survival of patients. The mean overall survival time in IOC group was 82.50 (95% CI [80.52, 84.49]) months, and 71.21 (95% CI [67.92, 74.50]) months in non-IOC group. The OS in IOC-treated patients were significantly higher than non-IOC-treated patients ( P  < 0.001, log-rank test). Further analysis revealed that IOC decreased the risk of death in patients with CRC in a non-adjusted model (HR=0.53, 95% CI [0.43, 0.65], P  < 0.001), model 2 (adjusted for age and gender, HR=0.52, 95% CI [0.43, 0.64], P  < 0.001), and model 3 (adjusted for all factors, 95% CI 0.71 [0.55, 0.90], P  = 0.006). The subgroup analysis showed that the HR for the effect of IOC on survival was lower in patients with stage II (HR = 0.46, 95% CI [0.31, 0.67]) or III disease (HR=0.59, 95% CI [0.45, 0.76]), regardless of pre-operative radiotherapy (HR=0.55, 95% CI [0.45, 0.68]) or pre-operative chemotherapy (HR=0.54, 95% CI [0.44, 0.66]).

CONCLUSIONS

IOC is an independent factor that influences the survival of CRC patients. It improved the OS of patients with stages II and III CRC after radical surgery.

TRIAL REGISTRATION

chictr.org.cn, ChiCTR 2100043775.

Surgical efficacy and learning curves of laparoscopic complete mesocolic excision with intracorporeal anastomosis for right-sided colon cancer: A retrospective two-center cohort study

BACKGROUND

There is a potential benefit on long-term outcomes following complete mesocolic excision (CME) for right-sided colon cancer when compared to conventional colectomy. This study aims to analyze the learning curve and short-term outcomes of laparoscopic CME with intracorporeal anastomosis (ICA) for right-sided colon cancer in the hands of experienced colorectal surgeons.

METHODS

A two-center cohort study of consecutive patients undergoing right-sided colectomy from September 2021 to May 2022 at two tertiary colorectal centers in Denmark. Learning curves of surgical time were estimated using a cumulative sum analysis (CUSUM).

RESULTS

A total of 61 patients were included. According to the CUSUM analysis, 32 cases were needed to obtain a peak in operative time, resulting in a decrease in time consumption (group 1/learning phase: 217.2 min [SD 53.6] and group 2/plateau phase 191.6 min [SD 45.1], p = 0.05). There was a nonsignificant reduction in the rates of severe surgical complications (Clavien-Dindo > 3) (13% vs. 7%, p = 0.67) between the two groups, while the length of hospital stay remained constant (median 3.0 days, interquartile range, IQR [2.0; 4.0]).

CONCLUSION

The learning curve of laparoscopic CME with ICA for right-sided colon cancer demonstrated that 32 cases were needed to obtain a plateau phase expressed by operative time.

Robot-assisted versus laparoscopic short- and long-term outcomes in complete mesocolic excision for right-sided colonic cancer: a systematic review and meta-analysis

BACKGROUND

Complete mesocolic excision (CME) surgery is increasingly implemented for the resection of right-sided colonic cancer, possibly resulting in improved 5-year overall and disease-free survival compared to non-CME surgery. However, it is not clear what surgical platform should be used. The aim of this study was to compare the following outcomes between robot-assisted and laparoscopic CME-surgery for right-sided colonic cancer: (i) short-term clinical outcomes, (ii) pathological specimen quality, and (iii) long-term oncological outcomes.

METHODS

Medline, Embase, and Cochrane Database of Systematic Reviews were searched from inception until August 2021. Pooled proportions were calculated by applying the inverse variance method. Heterogeneity was explored by I-square and supplemented by sensitivity- and meta-regression analyses. The risk of bias was evaluated by either MINORS or Cochrane's risk-of-bias tool (RoB 2).

RESULTS

Fifty-five studies with 5.357 patients (740 robot-assisted and 4617 laparoscopic) were included in the meta-analysis. Overall postoperative morbidity was 17% [95% CI (14-20%)] in the robot-assisted group and 13% [95%CI (12-13%)] in the laparoscopic group. Robot-assisted CME was associated with a shorter hospital stay, lower intraoperative blood loss, a higher amount of harvested lymph nodes, and better 3-year oerall and disease-free survival. MINORS and RoB2 indicated a serious risk of bias across studies included.

CONCLUSIONS

This review which includes predominantly non-randomized studies suggests a possible advantage of the robot-assisted CME compared with a laparoscopic technique for several short-term outcomes.

Do differences in surgical quality account for the higher rate of R1 margins to lymph node metastases in right- versus left-sided Stage III colon cancer: A retrospective cohort study

AIM

Microscopically positive (R1) margins to lymph node metastases (R1LNM) are associated with poorer oncological outcomes in patients with Stage III colon cancer. R1LNM margins are more common in right-sided cancer, although the cause of this phenomenon is unknown. We sought to investigate whether differences in surgical quality account for the higher rate of R1LNM in right-sided cancers.

METHOD

Patients treated for Stage III colon cancer from 1 January 2016 to 31 December 2018 were identified using the Danish national cancer registry. Indicators of surgical quality (mesocolic resection grade, median lymph node yield, and length to the distal colonic margin) were compared according to tumour site and margin status.

RESULTS

In all, 1765 patients were included, 981 (55.6%) with right-sided cancers. R1LNM margins were more common in right-sided cancers (14.4% vs. 6.1%, P < 0.001). All three surgical quality indicators were higher in patients with right-sided cancers (mesocolic resection planes 81.7% vs. 69.5%, P < 0.001; median lymph node yield 28 vs. 25, P < 0.001; ≥5 cm to the distal colon margin 81.2% vs. 53.6%, P < 0.001). When stratified according to margin status, no differences in mesocolic resection planes or resectate length were noted, whilst median lymph node yield was higher in patients with R1LNM margins (29 vs. 27, P = 0.009).

CONCLUSION

Surgical quality does not appear to be poorer in patients undergoing surgery for right-sided versus left-sided colon cancers in Denmark. Suboptimal surgery does not appear to be responsible for R1LNM margins, implying that these margins may be a surrogate for more aggressive biology.

Complete mesocolic excision for right colonic cancer: prospective multicentre study

BACKGROUND

Complete mesocolic excision (CME) for right colonic cancer is a more complex operation than standard right hemicolectomy but evidence to support its routine use is still limited. This prospective multicentre study evaluated the effect of CME on long-term survival in colorectal cancer centres in Germany (RESECTAT trial). The primary hypothesis was that 5-year disease-free survival would be higher after CME than non-CME surgery. A secondary hypothesis was that there would be improved survival of patients with a mesenteric area greater than 15 000 mm2.

METHODS

Centres were asked to continue their current surgical practices. The surgery was classified as CME if the superior mesenteric vein was dissected; otherwise it was assumed that no CME had been performed. All specimens were shipped to one institution for pathological analysis and documentation. Clinical data were recorded in an established registry for quality assurance. The primary endpoint was 5-year overall survival for stages I-III. Multivariable adjustment for group allocation was planned. Using a primary hypothesis of an increase in disease-free survival from 60 to 70 per cent, a sample size of 662 patients was calculated with a 50 per cent anticipated drop-out rate.

RESULTS

A total of 1004 patients from 53 centres were recruited for the final analysis (496 CME, 508 no CME). Most operations (88.4 per cent) were done by an open approach. Anastomotic leak occurred in 3.4 per cent in the CME and 1.8 per cent in the non-CME group. There were slightly more lymph nodes found in CME than non-CME specimens (mean 55.6 and 50.4 respectively). Positive central mesenteric nodes were detected more in non-CME than CME specimens (5.9 versus 4.0 per cent). One-fifth of patients had died at the time of study with recorded recurrences (63, 6.3 per cent), too few to calculate disease-free survival (the original primary outcome), so overall survival (not disease-specific) results are presented. Short-term and overall survival were similar in the CME and non-CME groups. Adjusted Cox regression indicated a possible benefit for overall survival with CME in stage III disease (HR 0.52, 95 per cent c.i. 0.31 to 0.85; P = 0.010) but less so for disease-free survival (HR 0.66; P = 0.068). The secondary outcome (15 000 mm2 mesenteric size) did not influence survival at any stage (removal of more mesentery did not alter survival).

CONCLUSION

No general benefit of CME could be established. The observation of better overall survival in stage III on unplanned exploratory analysis is of uncertain significance.

Is it possible to adopt the same oncological approach in urgent surgery for colon cancer?

BACKGROUND

Locoregional complications may occur in up to 30% of patients with colon cancer. As they are frequent events in the natural history of this disease, there should be a concern in offering an oncologically adequate surgical treatment to these patients.

AIM

To compare the oncological radicality of surgery for colon cancer between urgent and elective cases.

METHODS

One-hundred and eighty-nine consecutive patients with non-metastatic colon adenocarcinoma were studied over two years in a single institution, who underwent surgical resection as the first therapeutic approach, with 123 elective and 66 urgent cases. The assessment of oncological radicality was performed by analyzing the extension of the longitudinal margins of resection, the number of resected lymph nodes, and the percentage of surgeries with 12 or more resected lymph nodes. Other clinicopathological variables were compared between the two groups in terms of sex, age, tumor location, type of urgency, surgical access, staging, compromised lymph nodes rate, differentiation grade, angiolymphatic and perineural invasion, and early mortality.

RESULTS

There was no difference between the elective and urgency group concerning the longitudinal margin of resection (average of 6.1 in elective vs 7.3 cm in urgency, P = 0.144), number of resected lymph nodes (average of 17.7 in elective vs 16.6 in urgency, P = 0.355) and percentage of surgeries with 12 or more resected lymph nodes (75.6% in elective vs 77.3% in urgency, P = 0.798). It was observed that the percentage of patients aged 80 and over was higher in the urgency group (13.0% in elective vs 25.8% in urgency, P = 0.028), and the early mortality was 4.9% in elective vs 15.2% in urgency (P = 0.016, OR: 3.48, 95%CI: 1.21–10.06). Tumor location (P = 0.004), surgery performed (P = 0.016) and surgical access (P < 0.001) were also different between the two groups. There was no difference in other clinicopathological variables studied.

CONCLUSION

Oncological radicality of colon cancer surgery may be achieved in both emergency and elective procedures.

Computer-Assisted Differentiation between Colon-Mesocolon and Retroperitoneum Using Hyperspectral Imaging (HSI) Technology

Complete mesocolic excision (CME), which involves the adequate resection of the tumor-bearing colonic segment with “en bloc” removal of its mesocolon along embryological fascial planes is associated with superior oncological outcomes. However, CME presents a higher complication rate compared to non-CME resections due to a higher risk of vascular injury. Hyperspectral imaging (HSI) is a contrast-free optical imaging technology, which facilitates the quantitative imaging of physiological tissue parameters and the visualization of anatomical structures. This study evaluates the accuracy of HSI combined with deep learning (DL) to differentiate the colon and its mesenteric tissue from retroperitoneal tissue. In an animal study including 20 pig models, intraoperative hyperspectral images of the sigmoid colon, sigmoid mesentery, and retroperitoneum were recorded. A convolutional neural network (CNN) was trained to distinguish the two tissue classes using HSI data, validated with a leave-one-out cross-validation process. The overall recognition sensitivity of the tissues to be preserved (retroperitoneum) and the tissues to be resected (colon and mesentery) was 79.0 ± 21.0% and 86.0 ± 16.0%, respectively. Automatic classification based on HSI and CNNs is a promising tool to automatically, non-invasively, and objectively differentiate the colon and its mesentery from retroperitoneal tissue.

Risk of Local Recurrence After Complete Mesocolic Excision for Right-Sided Colon Cancer: Post-Hoc Sensitivity Analysis of a Population-Based Study

BACKGROUND

A causal treatment effect of complete mesocolic excision for right-sided colon cancer on the risk of recurrence has been shown, but it is still unclear whether this is caused solely by a risk reduction of local recurrence.

OBJECTIVE

The goal of this study was to assess to what extent complete mesocolic excision contributes to the risk of local recurrence.

DESIGN

This study was a posthoc analyses of data from a population-based cohort. Inverse probability of treatment weighting and competing risk analyses were used to estimate the possible causal effects of complete mesocolic excision.

SETTING

Data were collected from the 4 public colorectal cancer centers in the Capital Region of Denmark.

PATIENTS

Patients undergoing elective colon resections for right-sided colon cancer without distant metastases during the period 2010-2013 were included. One center performed complete mesocolic excision and the remaining 3 centers performed conventional resections.

MAIN OUTCOME MEASURES

The primary outcome was the cumulative incidence of solely local recurrence 5.2 years after surgery. Secondary outcomes were solely distant recurrence and both local and distant recurrence diagnosed within 180 days.

RESULTS

A total of 807 patients were included with 186 undergoing complete mesocolic excision and 621 conventional resections. The 5.2-year cumulative incidence of a solely local recurrence was 3.7% (95% CI, 0.5-6.1) after complete mesocolic excision compared with 7.0% (5.0-8.9) in the control group, and the absolute risk reduction of complete mesocolic excision was 3.7% (2.5-7.1; p = 0.035). The absolute risk reduction on local and distant recurrence was 3.4% (1.3-5.6; p = 0.002) and on solely distant recurrence was 3.1% (0.0-6.2; p = 0.052).

LIMITATIONS

The recurrence risk after conventional resection might be underestimated by the use of inappropriate modalities to diagnose local recurrence for some patients and the shorter duration in this group.

CONCLUSION

This study shows a causal treatment effect of complete mesocolic excision on the risk of a solely local recurrence and of distant recurrence with or without local recurrence. See Video Abstract at http://links.lww.com/DCR/B832 .RIESGO DE RECURRENCIA LOCAL DESPUÉS DE LA ESCISIÓN MESOCÓLICA COMPLETA PARA EL CÁNCER DE COLON DEL LADO DERECHO: ANÁLISIS DE SENSIBILIDAD POST-HOC DE UN ESTUDIO POBLACIONALANTECEDENTES:Se ha demostrado un efecto del tratamiento causal de la escisión mesocólica completa para el cáncer de colon del lado derecho sobre el riesgo de recurrencia, pero aún no está claro si esto se debe únicamente a una reducción del riesgo de recurrencia local.OBJETIVO:Evaluar en qué medida la escisión mesocólica completa se atribuye al riesgo de recurrencia local.DISEÑO:Análisis posthoc de datos de una cohorte poblacional. Se utilizaron análisis de probabilidad inversa de ponderación del tratamiento y de riesgo competitivo para estimar los posibles efectos causales de la escisión mesocólica completa.AJUSTE:Datos de los cuatro centros públicos de cáncer colorrectal en la Región Capital de Dinamarca.PACIENTES:Pacientes sometidos a resecciones de colon electivas por cáncer de colon derecho sin metástasis a distancia durante el período 2010-2013. Un centro realizó escisión mesocólica completa, el resto resecciones convencionales.PRINCIPALES MEDIDAS DE RESULTADO:El resultado primario fue la incidencia acumulada de la recidiva local únicamente, 5,2 años después de la cirugía. Los resultados secundarios fueron únicamente la recidiva a distancia y ambas,la recidiva local y a distancia diagnosticada dentro de los 180 días.RESULTADOS:Se incluyeron un total de 807 pacientes, 186 sometidos a escisión mesocólica completa y 621 resecciones convencionales. La incidencia acumulada de 5,2 años de una recidiva únicamente local fue del 3,7% (IC del 95%: 0,5 a 6,1) después de la escisión mesocólica completa en comparación con el 7,0% (5,0 a 8,9) en el grupo de control, y la reducción del riesgo absoluto de la escisión mesocólica completa fue del 3,7% (2,5-7,1; p = 0,035). La reducción del riesgo absoluto de recidiva local y distante fue del 3,4% (1,3-5,6; p = 0,0019) y de recidiva únicamente a distancia 3,1% (0,0-6,2; p = 0,052).LIMITANTES:El riesgo de recurrencia después de la resección convencional podría subestimarse por el uso de modalidades inapropiadas para el diagnostico de la recurrencia local en algunos pacientes y la duración más corta en este grupo.CONCLUSIÓN:Este estudio muestra un efecto del tratamiento causal de la escisión mesocólica completa sobre el riesgo de una recidiva únicamente local y de recidiva a distancia con o sin recidiva local. Consulte Video Resumen en http://links.lww.com/DCR/B832 . (Traducción-Dr. Mauricio Santamaria ).

Mid-term oncological outcomes after complete versus conventional mesocolic excision for right-sided colon cancer: a propensity score matching analysis

BACKGROUND

The correct extent of mesocolic dissection for right-sided colon cancer (RCC) is still under debate. Complete mesocolic excision (CME) has not gained wide diffusion, mainly due to its technical complexity and unclear oncological superiority. This study aims to evaluate oncological outcomes of CME compared with non-complete mesocolic excision (NCME) during resection for I-III stage RCC.

METHOD

Prospectively collected data of patients who underwent surgery between 2010 and 2018 were retrospectively analysed. 1:1 Propensity score matching (PSM) was used to balance baseline characteristics of CME and NCME patients. The primary endpoint of the study was local recurrence-free survival (LRFS). The two groups were also compared in terms of short-term outcomes, distant recurrence-free survival, disease-free survival, and overall survival.

RESULTS

Of the 444 patients included in the study, 292 were correctly matched after PSM, 146 in each group. The median follow-up was 45 months (IQR 33-63). Conversion rate, complications, and 90-day mortality were comparable in both groups. The median number of lymph nodes harvested was higher in CME patients (23 vs 19, p = 0.034). 3-year LRFS rates for CME patients was 100% and 95.6% for NCME (log-rank p = 0.028). At 3 years, there were no differences between the groups in terms of overall survival, distant recurrence-free survival, and disease-free survival.

CONCLUSION

Our PSM cohort study shows that CME is safe, provides a higher number of lymph nodes harvested, and is associated with better local recurrence-free survival.

Improving on-treatment risk stratification of cancer patients with refined response classification and integration of circulating tumor DNA kinetics

BACKGROUND

Significant intertumoral heterogeneity exists as antitumor treatment is introduced. Heterogeneous therapeutic responses are conventionally evaluated by imaging examinations based on Response Evaluation Criteria in Solid Tumors (RECIST); nevertheless, there are increasing recognitions that they do not fully capture patient clinical benefits. Currently, there is a paucity of data regarding the clinical implication of biological responses assessed by liquid biopsy of on-treatment circulating tumor DNA (ctDNA). Here, we investigated whether biological response evaluated by ctDNA kinetics added critical information to the RECIST, and whether integrating on-treatment biological response information refined risk stratification of cancer patients.

METHODS

In this population-based cohort study, we included 821 patients with Epstein-Barr virus (EBV)-associated nasopharynx of head and neck cancer (NPC) receiving sequential neoadjuvant chemotherapy (NAC) and chemoradiotherapy (CRT), who had pretreatment and on-treatment cfEBV DNA and magnetic resonance imaging (MRI) surveillance. Biological responses evaluated by cfEBV DNA were profiled and compared with conventional MRI-based RECIST evaluation. The inverse probability weighting (IPW)-adjusted survival analysis was performed for major survival endpoints. The Cox proportional hazard regression [CpH]-based model was developed to predict the on-treatment ctDNA-based individualized survival.

RESULTS

Of 821 patients, 71.4% achieved complete biological response (cBR) upon NAC completion. RECIST-based response evaluations had 25.3% discordance with ctDNA-based evaluations. IPW-adjusted survival analysis revealed that cfEBV DNA_post-NAC was a preferential prognosticator for all endpoints, especially for distant metastasis. In contrast, radiological response was more preferentially associated with locoregional recurrence. Intriguingly, cfEBV DNA_post-NAC further stratified RECIST-responsive and non-responsive patients; RECIST-based non-responsive patients with cBR still derived substantial clinical benefits. Moreover, detectable cfEBV DNA_post-NAC had 83.6% prediction sensitivity for detectable post-treatment ctDNA, which conferred early determination of treatment benefits. Finally, we established individualized risk prediction models and demonstrated that introducing on-treatment ctDNA significantly refined risk stratification.

CONCLUSIONS

Our study helps advance the implementation of ctDNA-based testing in therapeutic response evaluation for a refined risk stratification. The dynamic and refined risk profiling would tailor future liquid biopsy-based risk-adapted personalized therapy.

Propensity-score-matched analysis of D2 and D3 right hemicolectomy for colon cancer

BACKGROUND

Complete mesocolic excision with D3 lymph node dissection in right-sided colon cancer is associated with improved oncological outcomes, but can potentially be associated with higher rates of complications compared to conventional D2 right hemicolectomy. This study aims to evaluate the oncological and perioperative outcomes of patients who underwent D3 right hemicolectomy, comparing to conventional right hemicolectomy.

METHODS

From 2015 to 2020, 360 patients underwent right hemicolectomy for colonic malignancies. Data was retrospectively analysed from a prospectively collected database. A propensity-score-matched analysis was performed between the two groups to evaluate their outcomes.

RESULTS

About 88(24.4%) patients underwent D3 right hemicolectomy, with the rest undergoing D2 right hemicolectomy. After propensity-matched analysis, D3 right hemicolectomy had a higher lymph node yield (median of 26 versus 23, p = 0.005), lower overall recurrence rate (11.7% versus 25.7%, p = 0.03), and lower overall mortality rate (14.5% versus 30.1%, p = 0.02) There were no significant differences in the complication rates. There were no anastomotic leaks. D3 right hemicolectomy was associated with an improved 3-year disease-free survival (DFS) with a hazard ratio of 0.63 (P = 0.21), and also an improved 3-year overall survival (OS) with a hazard ratio of 0.68 (P = 0.31).

CONCLUSION

D3 right hemicolectomy is associated with a higher lymph node yield, without increasing morbidity or mortality. It is also associated with significantly lower recurrence and overall mortality rates in this study. Short term 3-year DFS and OS also trend towards favouring D3 right hemicolectomy. However, this study is limited by the small sample size and retrospective nature.

Consensus statements on complete mesocolic excision for right-sided colon cancer-technical steps and training implications

Background

CME is a radical resection for colon cancer, but the procedure is technically demanding with significant variation in its practice. A standardised approach to the optimal technique and training is, therefore, desirable to minimise technical hazards and facilitate safe dissemination. The aim is to develop an expert consensus on the optimal technique for Complete Mesocolic Excision (CME) for right-sided and transverse colon cancer to guide safe implementation and training pathways.

Methods

Guidance was developed following a modified Delphi process to draw consensus from 55 international experts in CME and surgical education representing 18 countries. Domain topics were formulated and subdivided into questions pertinent to different aspects of CME practice. A three-round Delphi voting on 25 statements based on the specific questions and 70% agreement was considered as consensus.

Results

Twenty-three recommendations for CME procedure were agreed on, describing the technique and optimal training pathway. CME is recommended as the standard of care resection for locally advanced colon cancer. The essential components are central vascular ligation, exposure of the superior mesenteric vein and excision of an intact mesocolon. Key anatomical landmarks to perform a safe CME dissection include identification of the ileocolic pedicle, superior mesenteric vein and root of the mesocolon. A proficiency-based multimodal training curriculum for CME was proposed including a formal proctorship programme.

Conclusions

Consensus on standardisation of technique and training framework for complete mesocolic excision was agreed upon by a panel of experts to guide current practice and provide a quality control framework for future studies.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00464-021-08395-0.

The Mesentery in Complete Mesocolic Excision

The following article summarizes technical aspects of how to operate in the mesentery during complete mesocolic excision (CME). Increasingly, CME is being adopted and as such it is important to establish the anatomical basis of the techniques involved. This review thus serves to provide that foundation and explains the surgical techniques built on it.

Pattern of recurrence and survival after D2 right colectomy for cancer: is there place for a routine more extended lymphadenectomy?

BACKGROUND

Conventional Right Colectomy with D2 lymphadenectomy (RC-D2) currently represent the most common surgical treatment of right-sided colon cancer (RCC). However, whether it should be still considered a standard of care, or replaced by a routine more extended D3 lymphadenectomy remains unclear. In the present study, we aim to critically review the patterns of relapse and the survival outcomes obtained from our 11-year experience of RC-D2.

METHODS

Clinical data of 489 patients who underwent RC-D2 for RCC at two centres, from January 2009 to January 2020, were retrospectively reviewed. Patients with synchronous distant metastases and/or widespread nodal involvement at diagnosis were excluded. Post-operative clinical-pathological characteristics and survival outcomes were evaluated including the pattern of disease relapse.

RESULTS

We enrolled a total of 400 patients with information follow-up. Postoperative morbidity was 14%. The median follow-up was 62 months. Cancer recurrence was observed in 55 patients (13.8%). Among them, 40 patients (72.7%) developed systemic metastases, and lymph-node involvement was found in 7 cases (12.8%). None developed isolated central lymph-node metastasis (CLM), in the D3 site. The estimated 3- and 5-year relapse-free survival were 86.1% and 84.4%, respectively. The estimated 3- and 5-year cancer-specific OS were 94.5% and 92.2%, respectively.

CONCLUSIONS

The absence of isolated CLM, as well as the cancer-specific OS reported in our series, support the routine use of RC-D2 for RCC. However, D3 lymphadenectomy may be recommended in selected patients, such as those with pre-operatively known CLM, or with lymph-node metastases close to the origin of the ileocolic vessels.

Nonmicroradical Resection Margin as a Predictor of Recurrence in Patients With Stage III Colon Cancer Undergoing Complete Mesocolic Excision: A Prospective Cohort Study

BACKGROUND

The prognostic value of the present definition of microradicality in colon cancer is poorly understood, especially considering the vast influence it has in rectal cancer prognosis.

OBJECTIVE

This study aimed to investigate whether the risk of recurrence after complete mesocolic excision for stage III colon cancer is associated with the distance from tumor tissue to resection margin and whether the location of the involved margin is of any significance.

DESIGN

A prospective cohort of patients was stratified into 2 groups to distinguish between direct margin invasion (0-mm resection margin) and a ≤1-mm resection margin without direct invasion or 3 groups to distinguish between the location of margin involvement (lateral tumor resection margin, central vascular ligation margin, and nonperitonealized mesocolic resection margin). Patients with microradical resections were used as a control group.

SETTINGS

We included all patients undergoing elective complete mesocolic excision for International Union Against Cancer stage III colon cancer at Nordsjællands Hospital between January 1, 2008, and December 31, 2016.

PATIENTS

A total of 276 patients met all inclusion criteria and none of the exclusion criteria.

MAIN OUTCOME MEASURES

Primary outcome was risk of recurrence after 3.2 years.

RESULTS

A total of 41 patients (15%) had a nonmicroradical resection. The 3.2-year cumulative incidence of recurrence for a 0-mm margin was 43% and 24% for a ≤1-mm margin without direct invasion, corresponding with an HR of 4.3 (p = 0.0146) and 1.3 (p = 0.474). The location of the involved margin showed no significant differences.

LIMITATIONS

This was a single-center study containing a limited number of patients with a nonmicroradical resection with a risk of type II error.

CONCLUSIONS

We found no increased risk of recurrence for a ≤1-mm margin without direct invasion, indicating that the present classification of microradicality might not be justified if an intact posterior mesocolic fascia without invasion of tumor tissue is present. See Video Abstract at http://links.lww.com/DCR/B625.

MARGEN DE RESECCIN NO MICRORRADICAL COMO PREDICTOR DE RECURRENCIA EN PACIENTES CON CNCER DE COLON EN ESTADIO III SOMETIDOS A ESCISIN MESOCLICA COMPLETA UN ESTUDIO DE COHORTE PROSPECTIVO

ANTECEDENTES:El valor pronóstico de la definición actual de microrradicalidad en el cáncer de colon es poco conocido, especialmente considerando la gran influencia que tiene en el pronóstico del cáncer de recto.OBJETIVO:Este estudio tiene como objetivo investigar si el riesgo de recurrencia después de la escisión mesocólica completa (CME) para el cáncer de colon en estadio III está asociado con la distancia desde el tejido tumoral hasta el margen de resección y si la localización del margen afectado tiene alguna importancia.DISEÑO:Una cohorte prospectiva de pacientes se estratificó en dos grupos para distinguir entre la invasión del margen directo (margen de resección de 0 mm) y un margen de resección ≤1 mm sin invasión directa, o tres grupos para distinguir entre la localización de la afectación del margen (resección lateral del margen del tumor, margen de ligadura vascular central y margen de resección mesocólica no peritonizada). Los pacientes con resecciones microrradicales se utilizaron como grupo control.ENTORNO CLÍNICO:Incluimos a todos los pacientes sometidos a CME electiva por cáncer de colon en estadio III de la UICC en el Hospital Nordsjællands, Dinamarca, entre el 1 de enero de 2008 y el 31 de diciembre de 2016.PACIENTES:Un total de 276 pacientes cumplieron todos los criterios de inclusión y ninguno de los criterios de exclusión.PRINCIPALES MEDIDAS DE RESULTADO:El resultado primario fue el riesgo de recurrencia después de 3 · 2 años.RESULTADOS:Un total de 41 (15%) pacientes tuvieron una resección no microrradical. La incidencia acumulada de recurrencia a los 3,2 años para un margen de 0 mm fue del 43% y del 24% para un margen ≤1 mm sin invasión directa, lo que corresponde a un cociente de riesgo de 4,3 (p = 0,0146) y 1,3 (p = 0,474) respectivamente. La localización del margen afectado no mostró diferencias significativas.LIMITACIONES:Estudio unicéntrico con un número limitado de pacientes con resección no microrradical con riesgo de error tipo II.CONCLUSIONES:No encontramos un mayor riesgo de recurrencia para un margen ≤1 mm sin invasión directa, lo que indica que la clasificación actual de microrradicalidad podría no estar justificada si está presente una fascia mesocólica posterior intacta sin invasión del tejido tumoral. Consulte Video Resumen en http://links.lww.com/DCR/B625. (Traducción-Dr Yazmin Berrones-Medina).

Is increasing nodal count associated with improved recurrence-free and overall survival following standard right hemicolectomy for cancer?

Background and Objectives

Increasing lymph node harvest for right‐sided colon cancer is associated with improved overall survival (OS), but most relevant studies failed to report the extent of resection. We examined the association between increasing lymph node count with standard right hemicolectomy according to nodal status and prognostic outcomes in right‐sided tumors.

Methods

Retrospective analysis of prospectively collected clinical data from patients with proximal colonic adenocarcinomas (n = 1390) following right hemicolectomy. Associations between lymph node counts (0–12 vs. 13–15, 16–20, and >20) and recurrence‐free survival (RFS) and OS were examined using multivariate Cox modeling adjusted for confounders.

Results

We found no association between increasing nodal count and RFS, regardless of nodal status. In the absence of nodal metastases, increasing nodal count (16–20 and >20 vs. 0–12 nodes) was associated with 57% (95% confidence interval [CI]: 0.21–0.89) and 52% (95% CI: 0.24–0.95) improved OS, respectively. In the presence of nodal metastases, increasing nodal count was not associated with OS. Adjuvant chemotherapy did not modify this effect.

Conclusion

Increasing nodal count (>15 nodes) with right hemicolectomy was not associated with improved RFS. Improved OS was only found for node‐negative tumors, casting some doubt on the benefits of resecting more lymph nodes in the presence of nodal metastases.

Intriguing Role of the Mesentery in Ileocolic Crohn's Disease

Crohn's disease (CD) is a chronic relapsing inflammatory bowel disease with unknown etiology. Up to 80% of patients will eventually require surgery throughout their lifetime, and often repeated resections are required for disease recurrence. Observations of “creeping fat” surrounding the diseased intestine renewed interest in the mesentery, recently defined as an organ with endocrine and immune functions. According to the inside-out model, the mesentery may be primarily affected in CD and subsequent cause alterations in the mucosa. Recently, lower surgical recurrence rates have been reported with en-bloc excision of the mesentery adjoining the diseased intestine. Results of ongoing randomized controlled trials may clarify the role of the mesentery in CD and possibly lead to its adoption as standard during surgery for Crohn's disease.

Does cranial-medial mixed dominant approach have a unique advantage for laparoscopic right hemicolectomy with complete mesocolic excision?

BACKGROUND

Complete mesocolic excision (CME) with central vascular ligation (CVL) was proposed by Hohenberger in 2009. The CME principle has gradually become the technical standard for colon cancer surgery. How to achieve CME with CVL in laparoscopic right hemicolectomy (LRH) is controversial, and a unified standard approach is not yet available. In recent years, the authors’ team has integrated the theory of membrane anatomy, tried to combine the cephalic approach with the classic medial approach (MA) for technical optimization, and proposed a cranial-medial mixed dominant approach (CMA).

AIM

To explore the feasibility of operational approaches for LRH with CME.

METHODS

In this retrospective cohort study, the clinical data of 57 patients with right-sided colon cancer (TNM stage I, II, or III) who underwent LRH with CME from January 2016 to June 2020 were collected and summarized. There were 31 patients in the traditional MA group and 26 in the CMA group.

RESULTS

There were no significant differences in baseline data between the two groups. The operation was shorter and the number of lymph nodes dissected was higher in the CMA group than in the MA group, but there was no significant difference in the number of positive lymph nodes, intraoperative blood loss, postoperative exhaust time, feeding time, postoperative hospital stay or postoperative complication incidence.

CONCLUSION

Our study shows that the CMA is a safe and feasible procedure for LRH with CME and has a unique advantage.