Efficacy and Safety of Complete Mesocolic Excision in Patients With Colon Cancer: Three-year Results From a Prospective, Nonrandomized, Double-blind, Controlled Trial. Ann Surg. 2020;271:519-526. [PMID: 30148752 DOI: 10.1097/sla.0000000000003012]

Lymph Node Yield and Colorectal Cancer Survival: A Bowel Cancer Outcomes Registry Cohort Study

BACKGROUND

The current standard for lymph node (LN) sampling in colorectal cancer (CRC) surgery is a minimum of 12 LNs. Emerging evidence suggests higher LN yields may improve disease-free survival (DFS); however, an "optimal" number of LNs has yet to be definitively established. The aim of this study was to correlate LN yield with survival outcomes in patients undergoing surgery for nonmetastatic CRC.

METHODS

The Bowel Cancer Outcomes Registry (BCOR) is a clinical quality registry in Australia and New Zealand. Post-operative patients aged ≥ 18 years with histologically confirmed CRC, nonmetastatic disease at diagnosis and with follow-up status documented were included. Post-operative outcomes and survival were assessed with logistic regression. The primary endpoint was CRC-specific mortality. Secondary endpoints were CRC recurrence and all-cause mortality.

RESULTS

Of 91 271 patient episodes, 10 616 individual eligible patients were identified (45.4% male, n = 4828). The median number of LNs resected was 18 [quartiles 0-12, 13-17, 18-23 and > 23]. A significant difference in CRC-specific mortality was seen between quartiles (p = 0.023), with the primary significant difference demonstrated between the lowest quartile (≤ 12 LNs) and other groups. On long-term follow-up, CRC recurrence and CRC-specific mortality were higher in the group with ≤ 12 LNs resected (16.0% vs. 14.0%, adjusted p = 0.049 and 4.5% vs. 3.3%, adjusted p = 0.037 respectively).

CONCLUSION

This study supports the current consensus that > 12 LNs are required for adequate staging and oncological clearance in CRC surgery, and demonstrates yields ≤ 12 LNs are associated with higher CRC recurrence and mortality.

Complete mesocolic excision versus D2 lymphadenectomy in right hemicolectomy: a meta-analysis of propensity score matched studies and randomized controlled trials

Introduction

The complete mesocolic excision (CME) in right-sided hemicolectomy could result in higher lymph node yield and decreased local recurrence. However, this approach could increase intraoperative and postoperative complications. Therefore, our meta-analysis aims to demonstrate the outcomes of CME versus D2 conventional lymphadenectomy in right-side colon cancer.

Methods

We searched MEDLINE, Cochrane Central Register of Clinical Trials, and Scopus for studies published until April 2024. Odds ratios (OR) with 95% confidence intervals (CIs) were pooled using a random-effects model. Heterogeneity was assessed using the Cochran Q test and I 2 statistics, with P values <0.10 and I 2 >25% considered significant. Statistical analysis was performed using R Software, version 4.1.2.

Results

Three randomized controlled trials and four observational studies comprising 2296 patients were included, of whom 1138 (49.6%) were submitted to the CME and 1158 (50.4%) to the conventional D2 lymphadenectomy. CME was associated with decreased local recurrence rates (OR 0.07; 95% CI 0.001 to 0.36; P = 0.002). There were no significant differences between groups in overall complications, severe complications, intraoperative complications, blood loss, and 30-day mortality. No difference between groups was observed in distance metastasis and 3-year disease-free survival.

Conclusion

In this meta-analysis, CME significantly decreases local recurrence rates compared with D2 conventional lymphadenectomy in patients with right-side colon cancer. No significant difference was observed between groups in rates of overall complications, severe complications, intraoperative complications, blood loss, and 30-day mortality.

European multicentre analysis of the implementation of robotic complete mesocolic excision for right-sided colon tumours

AIM

Complete mesocolic excision (CME) is an oncologically driven technique for treating right colon cancer. While laparoscopic CME is technically demanding and has been associated with more complications, the robotic approach might reduce morbidity. The aim of this study was to assess the safety of stepwise implementation of robotic CME.

METHOD

A multicentre retrospective analysis of prospectively collected data on robotic right colectomy was performed at five European tertiary centres. Patients were classified for type of surgery: R-RHC (standard right colectomy), R-impCME (learning cases towards robotic CME defined as R-RHC with one but not all the hallmarks of CME) or R-CME (robotic CME). Primary outcomes were overall and severe 30-day complication rates before and after propensity score matching (PSM) analysis.

RESULTS

Five hundred and fifty-one consecutive patients undergoing robotic surgery for (pre)malignant lesions of the right colon between 2010 and 2020 were included: R-RHC (n = 101), R-impCME (n = 135) and R-CME (n = 315). Baseline characteristics differed for American Society of Anesthesiologists score (p = 0.0012) and preoperative diagnosis of adenocarcinoma (p < 0.001). Procedure time increased by surgical complexity (p < 0.001). Vascular event rates did not differ, with no superior mesenteric vein injuries. Conversion, complication and anastomotic leak rates, time to flatus/soft diet and length of stay (LOS) did not differ. While R-RHC was performed for a lower rate of malignancies (p < 0.001), lymph node yield was significantly higher in R-CME (p < 0.001). After PSM, analyses on 186 patients documented no differences in overall and severe 30-day complication rate, conversion rate, LOS or 30-day mortality.

CONCLUSION

R-CME can be implemented without increasing the overall or 30-day severe complication rate.

Extent of Lymphadenectomy for Surgical Management of Right-Sided Colon Cancer: The Randomized Phase III RELARC Trial

PURPOSE

Complete mesocolic excision (CME) is being increasingly used for the treatment of right-sided colon cancer, although there is still no strong evidence that CME provides better long-term oncological outcomes than D2 dissection. The controversy is mainly regarding the survival benefit from extended lymph node dissection emphasized by CME.

METHODS

This multicenter, open-label, randomized controlled trial (ClinicalTrials.gov identifier: NCT02619942) was performed across 17 hospitals in China. Patients diagnosed with stage T2-T4aNanyM0 or TanyN + M0 right-sided colon cancer were randomly assigned (1:1) to undergo either CME or D2 dissection during laparoscopic right colectomy. The primary outcome was the 3-year disease-free survival (DFS), and the main secondary outcome was the 3-year overall survival (OS).

RESULTS

Between January 11, 2016, and December 26, 2019, 1,072 patients were randomly assigned (536 patients to CME and 536 patients to D2 dissection). In total, 995 patients (median age 61 years, 59% male) were included in the primary analysis (CME [n = 495] v D2 dissection [n = 500]). No significant differences were found between the groups in 3-year DFS (hazard ratio [HR], 0.74 [95% CI, 0.54 to 1.02]; P = .06; 86.1% in the CME group v 81.9% in the D2 group) or in 3-year OS (HR, 0.70 [95% CI, 0.43 to 1.16]; P = .17; 94.7% in the CME group v 92.6% in the D2 group).

CONCLUSION

This trial failed to find evidence of superior DFS outcome for CME compared with standard D2 lymph node dissection in primary surgical excision of right-sided colon cancer. Standard D2 dissection should be the routine procedure for these patients. CME should only be considered in patients with obvious mesocolic lymph node involvement.

Sidedness and Molecular Pattern in Defining the Risk of Lymph Node Metastasis in Nonmetastatic Colorectal Cancer: Single-Center Retrospective Study

Background: Lymphadenectomy plays a central role in the treatment of localized colon cancer. While in left colon cancer the D3 lymphadenectomy/CME is considered the standard of care, lymphatic stations to be removed in right colon cancer are still a matter of discussion. The individuation of LNM risk factors could help in choosing the lymphadenectomy in right-sided tumors. This study aims to analyze the correlation of histopathological and molecular characteristics with lymph node metastasis, both in right- and left-sided colon cancer, and their impact on survival; Methods: We conducted a single-center observational retrospective study. The following data were collected and analyzed for each patient: demographics, histopathological and molecular data, and intraoperative and perioperative data. Statistical analyses were performed, including descriptive statistics, multivariate logistic regression and survival analysis; Results: An association between tumor size (pT, p < 0.001), grading (p = 0.013), budding (p < 0.001), LVI (79,4% p < 0.001) and LNM was observed. A multivariate analysis identified pT4 (OR 5.45, p < 0.001) and LVI+ (OR 10.7, p < 0.001) as significant predictors of LNM. Right-sided patients presented a worse OS when associated with LNM, while no significant difference was observed in N0 patients; Conclusions: histological and molecular analysis can help identify high risk patients, which could benefit from extended lymphadenectomies. These patients could be ideal candidates for the D3 lymphadenectomy/CME.

Learning curve and safety of the implementation of laparoscopic complete mesocolic excision with intracorporeal anastomosis for right-sided colon cancer: results from a propensity score-matched study

BACKGROUND

Retrospective studies and randomized controlled trials support the safety of laparoscopic complete mesocolic excision (CME) for the treatment of right-sided colon cancer (RSCC). Few studies, however, examine the learning curve of this operation and its impact on safety during an implementation period. We aim to evaluate the learning curve and safety of the implementation of laparoscopic CME with intracorporeal anastomosis for RSCC.

METHODS

Consecutive patients undergoing a laparoscopic right colectomy with intracorporeal anastomosis for RSCC between January 2016 and June 2023 were included. Clinical, perioperative, and histopathological variables were collected. Correlation and cumulative sum (CUSUM) analyses between the operating time and case number were performed. Breakpoints of the learning curve were estimated using the broken-line model. CME and conventional laparoscopic right colectomy outcomes were compared after propensity score matching (PSM).

RESULTS

Two hundred and ninety patients underwent laparoscopic right colectomy during study period. One hundred and eight met inclusion criteria. After PSM, 56 non-CME and 28 CME patients were compared. CME group had a non-statistically significant tendency to a longer operating time (201 versus 195 min; p = 0.657) and a shorter hospital stay (3 versus 4 days; p = 0.279). No significant differences were found in total complication rates or their profile. Correlation analysis identified a significant trend toward operating time reduction with increasing case numbers (Pearson correlation coefficient =  - 0.624; p = 0.001). According to the CUSUM analysis, an institutional learning curve was deemed completed after 13 cases and the broken-line model identified three phases: learning (1-6 cases), consolidation (7-13 cases), and mastery (after 13 cases).

CONCLUSION

The learning curve of laparoscopic CME for RSCC can be achieved after 13 cases in centers with experience in advanced laparoscopic surgery and surgeons with familiarity with this technique. Its implementation within this setting seems to be as safe as performing a conventional right colectomy.

The effect of ileal resection length on postoperative complications and prognosis in right colon cancer

BACKGROUND

There is a lack of literature on the length of the terminal ileum to be resected in right hemicolectomy for colon cancer. Therefore, we aimed to determine the mean ileal loop length and the effect of this variation on postoperative complications and long-term oncological outcomes in patients who underwent right hemicolectomy.

METHODS

Right hemicolectomy surgeries performed for colon cancer in a tertiary care hospital between January 2011 and December 2018 were retrospectively analyzed from a prospective database. Two patient groups were established based on the mean length of the resected ileum above and below 7 cm. The two groups were compared for clinicopathological data, postoperative complications, mortality, long-term overall survival (OS) and disease-free survival (DFS). The factors contributing to OS and DFS were analyzed.

RESULTS

The study included 217 patients. Body mass index (BMI) values were significantly higher in the ileum resection length > 7 cm group (p = 0.009). Pathological N stage, tumor diameter, and number of metastatic lymph nodes were significantly higher in the ileum resection length > 7 cm group (p = 0.001, p = 0.001, and p = 0.026, respectively). There was no significant difference for postoperative complication and mortality rates between the two groups. The mean follow-up period was 61.2 months (2-120) in all patients. The total number of deaths was 29 (11.7%) while the 60-month OS was 83.5% and 50-month DFS was 81.8%. There was no significant difference between the groups in terms of OS and DFS rates (p > 0.05).

CONCLUSIONS

Excessive resection of the distal ileum in right hemicolectomy does not provide any benefit in terms of prognosis and complications.The ileum resection length and values close to it in our study appear to be sufficient.

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.

Early recurrence after complete mesocolic excision for right-sided colon cancer with D3 lymphadenectomy: pattern, risk factors, prognostic impact, and individualized follow-up

The definition of early recurrence (ER) for right-sided colon cancer patients after complete mesocolic excision (CME) with D3 lymphadenectomy remains unclear. This study aimed to define the optimal time for ER and clarify risk factors for ER and post-recurrence survival (PRS). A total of 578 right-sided colon cancer patients who underwent CME with D3 lymphadenectomy were included. The minimum p value method was used to evaluate theme optimal time of recurrence-free survival to discriminate between ER and late recurrence (LR). Risk factors for ER were determined by a logistics regression model. The PRS was compared between ER and LR. The optimal time to define ER was 15 months (P = 1.8697E-7). 93 patients developed tumor recurrence, 46 patients had ER (≤15 months) and 47 patients had LR (>15 months). Preoperative serum CA19-9 > 37 U/mL (OR = 3.185, P = 0.001), pathological N+ stage (OR = 3.042, P = 0.027), and lymphovascular invasion (OR = 2.182, P = 0.027) were identified as independent risk factors associated with ER. Age > 75 years (HR = 1.828, P = 0.040), pathological N2 stage (HR = 1.850, P = 0.009), multiple sites of recurrence (HR = 1.680, P = 0.024), and time to recurrence ≤15 months (HR = 2.018, P = 0.043) were significantly associated with worse PRS in patients with recurrence. 15 months was the optimal time to distinguish ER and LR. ER was associated with a poor PRS. Elevated preoperative serum CA19-9 level, pathological N+ stage, and lymphovascular invasion were significantly predictive of ER.

Tata Memorial Centre Evidence Based Management of Colorectal cancer

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.

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.

Adaptive radiotherapy of locally advanced sigmoid colon cancer with intra‑fractional motion using the MRIdian system: A case report

Neoadjuvant chemotherapy, when combined with radiotherapy, serves as an optional treatment for patients with locally advanced sigmoid colon cancer and is usually performed in conjunction with complete mesocolic excision. The substantial movement of surrounding organs in cases of sigmoid colon cancer frequently leads to toxicity in normal tissues. The present report details the case of a 76-year-old man diagnosed with locally advanced sigmoid colon cancer. Initially, treatment using the Tomotherapy Hi-Art system was selected; however, during image guidance from the first to the sixth fractions, the tumor location underwent a marked change, exceeding the range of the planning target volume. Efforts to recapture the image were unsuccessful, leading to a decision to transition the patient to the MRIdian system for daily treatment with online adaptive radiotherapy. The positional variations in the tumor were evident in each treatment using the MRIdian system, with mean shifts of 2.58 cm in the right-left direction, 1.24 cm in the cranial-caudal direction and 0.40 cm in the anterior-posterior direction. The mean time from the entry of the patient to treatment completion was 41 min. Adaptive treatment plans were performed for all 19 fractions, with two treatments repeated due to the tumor moving out of tracking range. Following irradiation using the MRIdian system, the gross tumor volume decreased by 62%. Notably, the patient experienced no side effects during treatment. A CT scan conducted 3 months after radiotherapy revealed a marked reduction in the tumor size, consistent with a partial response, leading to the scheduling of surgery. Following surgery, a CT scan after 6 months revealed no local recurrence in the surgical bed region. The findings in the present case support the feasibility of implementing an adaptive treatment plan using the MRIdian system for locally advanced sigmoid colon cancer in the context of neoadjuvant chemoradiotherapy.

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.

Robotic versus laparoscopic left colectomy with complete mesocolic excision for left-sided colon cancer: a multicentre study with propensity score matching analysis

BACKGROUND

Robotic surgery for right-sided colon and rectal cancer has rapidly increased; however, there is limited evidence in the literature of advantages of robotic left colectomy (RLC) for left-sided colon cancer. The purpose of this study was to compare the outcomes of RLC versus laparoscopic left colectomy (LLC) with complete mesocolic excision (CME) for left-sided colon cancer.

METHODS

Patients who had RLC or LLC with CME for left-sided colon cancer at 5 hospitals in China between January 2014 and April 2022 were included. A one-to-one propensity score matched analysis was performed to decrease confounding. The primary outcome was postoperative complications occurring within 30 days of surgery. Secondary outcomes were disease-free survival, overall survival and the number of harvested lymph nodes.

RESULTS

A total of 292 patients (187 males; median age 61.0 [20.0-85.0] years) were eligible for this study, and propensity score matching yielded 102 patients in each group. The clinical-pathological characteristics were well-matched between groups. The two groups did not differ in estimated blood loss, conversion to open rate, time to first flatus, reoperation rate, or postoperative length of hospital stay (p > 0.05). RLC was associated with a longer operation time (192.9 ± 53.2 vs. 168.9 ± 52.8 minutes, p=0.001). The incidence of postoperative complications did not differ between the RLC and LLC groups (18.6% vs. 17.6%, p = 0.856). The total number of lymph nodes harvested in the RLC group was higher than that in the LLC group (15.7 ± 8.3 vs. 12.1 ± 5.9, p< 0.001). There were no significant differences in 3-year and 5-year overall survival or 3-year and 5-year disease-free survival.

CONCLUSIONS

Compared to laparoscopic surgery, RLC with CME for left-sided colon cancer was found to be associated with higher numbers of lymph nodes harvested and similar postoperative complications and long-term survival outcomes.

Recent advances in nanomedicine preparative methods and their therapeutic potential for colorectal cancer: a critical review

Colorectal cancer (CRC) is a prevalent malignancy that affects a large percentage of the global population. The conventional treatments for CRC have a number of limitations. Nanoparticles have emerged as a promising cancer treatment method due to their ability to directly target cancer cells and regulate drug release, thereby enhancing therapeutic efficacy and minimizing side effects. This compilation examines the use of nanoparticles as drug delivery systems for CRC treatment. Different nanomaterials can be used to administer anticancer drugs, including polymeric nanoparticles, gold nanoparticles, liposomes, and solid lipid nanoparticles. In addition, we discuss recent developments in nanoparticle preparation techniques, such as solvent evaporation, salting-out, ion gelation, and nanoprecipitation. These methods have demonstrated high efficacy in penetrating epithelial cells, a prerequisite for effective drug delivery. This article focuses on the various targeting mechanisms utilized by CRC-targeted nanoparticles and their recent advancements in this field. In addition, the review offers descriptive information regarding numerous nano-preparative procedures for colorectal cancer treatments. We also discuss the outlook for innovative therapeutic techniques in the management of CRC, including the potential application of nanoparticles for targeted drug delivery. The review concludes with a discussion of current nanotechnology patents and clinical studies used to target and diagnose CRC. The results of this investigation suggest that nanoparticles have great potential as a method of drug delivery for the treatment of colorectal cancer.

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.

Robotic versus laparoscopic left colectomy with complete mesocolic excision for left-sided colon cancer: a multicentre study with propensity score matching analysis

PURPOSE

Robotic surgery for right-sided colon and rectal cancer has rapidly increased; however, there is limited evidence in the literature of advantages of robotic left colectomy (RLC) for left-sided colon cancer. The purpose of this study was to compare the outcomes of RLC versus laparoscopic left colectomy (LLC) with complete mesocolic excision (CME) for left-sided colon cancer.

METHODS

Patients who had RLC or LLC with CME for left-sided colon cancer at five hospitals in China between January 2014 and April 2022 were included. A one-to-one propensity score matched analysis was performed to decrease confounding. The primary outcome was postoperative complications occurring within 30 days of surgery. Secondary outcomes were disease-free survival, overall survival and the number of harvested lymph nodes.

RESULTS

A total of 292 patients (187 male; median age 61.0 [20.0-85.0] years) were eligible for this study, and propensity score matching yielded 102 patients in each group. The clinicopathological characteristics were well-matched between groups. The two groups did not differ in estimated blood loss, conversion to open rate, time to first flatus, reoperation rate, or postoperative length of hospital stay (p > 0.05). RLC was associated with a longer operation time (192.9 ± 53.2 vs. 168.9 ± 52.8 min, p = 0.001). The incidence of postoperative complications did not differ between the RLC and LLC groups (18.6% vs. 17.6%, p = 0.856). The total number of lymph nodes harvested in the RLC group was higher than that in the LLC group (15.7 ± 8.3 vs. 12.1 ± 5.9, p < 0.001). There were no significant differences in 3-year and 5-year overall survival or 3-year and 5-year disease-free survival.

CONCLUSION

Compared to laparoscopic surgery, RLC with CME for left-sided colon cancer was found to be associated with higher numbers of lymph nodes harvested and similar postoperative complications and long-term survival outcomes.

Definition and reporting of lymphadenectomy and complete mesocolic excision for radical right colectomy: a systematic review

BACKGROUND

Several procedures have been proposed to reduce the rates of recurrence in patients with right-sided colon cancer. Different procedures for a radical right colectomy (RRC), including extended D3 lymphadenectomy, complete mesocolic excision and central vascular ligation have been associated with survival benefits by some authors, but results are inconsistent. The aim of this study was to assess the variability in definition and reporting of RRC, which might be responsible for significant differences in outcome evaluation.

METHODS

PRISMA-compliant systematic literature review to identify the definitions of RRC. Primary aims were to identify surgical steps and different nomenclature for RRC. Secondary aims were description of heterogeneity and overlap among different RRC techniques.

RESULTS

Ninety-nine articles satisfied inclusion criteria. Eight surgical steps were identified and recorded as specific to RRC: Central arterial ligation was described in 100% of the included studies; preservation of mesocolic integrity in 73% and dissection along the SMV plane in 67%. Other surgical steps were inconstantly reported. Six differently named techniques for RRC have been identified. There were 35 definitions for the 6 techniques and 40% of these were used to identify more than one technique.

CONCLUSIONS

The only universally adopted surgical step for RRC is central arterial ligation. There is great heterogeneity and consistent overlap among definitions of all RRC techniques. This is likely to jeopardise the interpretation of the outcomes of studies on the topic. Consistent use of definitions and reporting of procedures are needed to obtain reliable conclusions in future trials. PROSPERO CRD42021241650.

Relationship between prognostic impact of N3 lymph node metastasis at the root of the feeding artery and location of colon cancer

PURPOSE

To determine whether N3 nodal involvement predicts outcomes and whether its prognostic implications vary with tumor location in patients with Stage III colon cancer (CC).

METHODS

We defined N3 as lymph node metastases near the bases of the major feeding arteries. We retrospectively examined recurrence rates and patterns by tumor location and sites of lymph node metastases in 57 patients with N3 CC who had undergone curative resections between January 2000 and March 2019. Survival analysis was performed to compare the prognoses of patients with and without N3 lymph node metastasis.

RESULTS

Most N3 patients had large tumors (T ≥ 3); five had T2 disease. Recurrence occurred quickly in one patient with T2N3M0 disease. Multivariate survival analysis demonstrated that N3 lymph node metastasis is an independent predictor of poor prognosis in Stage III CC patients (P < 0.001). Categorizing N3 patients according to UICC-TNM staging system does not stratify risk of recurrence (P = 0.970). To investigate the impact of tumor location on recurrence risk, we classified N3 CC into two subtypes according to tumor location: metastasis at the base of the superior mesenteric artery in right-sided CC and inferior mesenteric artery in left-sided CC. The former was found to have a statistically significant poorer prognosis than the latter (P = 0.091).

CONCLUSION

N3 is a robust prognostic marker in CC patients. Recurrence risk varies by tumor location. N3 right-sided CCs with lymph node metastasis at the base of the superior mesenteric artery have poorer prognoses than do N3 left-sided CCs.

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.

Assessment of adjuvant chemotherapy benefits after complete mesocolic excision in patients with colon cancer: Reanalysis of data from the ESCME trial

AIM

The benefits of adjuvant chemotherapy (AC) in colon cancer after complete mesocolic excision (CME) have not been evaluated sufficiently. We reanalysed the ESCME trial data to investigate the survival benefits and establish AC stratified indications.

METHODS

The data of Stage II and III colon cancer patients who received CME in the ESCME trial were reanalysed. Patients were divided into AC and non-AC (NAC) groups. The primary outcomes measured were differences in 5-year cancer-specific survival and disease-free survival (DFS) between the groups.

RESULTS

Of the 206 patients enrolled in the study, 125 patients (AC, 49; NAC, 76) had Stage II cancer and 111 (AC, 86; NAC, 25) had Stage III cancer. There were no significant differences in the adjusted 5-year cancer-specific survival and DFS between the AC and NAC groups. Poor differentiation (hazard ratio [HR] 2.947; 95% CI 1.218-7.131) and RAS mutation (HR 3.140; 95% CI 1.363-7.234) affected the 5-year DFS significantly in multivariate Cox regression analysis for Stage II and III cancer, respectively. In subgroup analysis, AC significantly improved 5-year DFS (HR 0.369; 95% CI 0.140-0.978) for Stage III cancer with lymphovascular/perineural invasion compared to NAC.

CONCLUSION

The current indication and benefits of AC for colon cancer patients after CME should be re-evaluated. AC is more appropriate for Stage III cancer with lymphovascular/perineural invasion.

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.

Clinical implication of the advanced lung cancer inflammation index in patients with right-sided colon cancer after complete mesocolic excision: a propensity score-matched analysis

Background

This study aimed to assess the clinical implications of the advanced lung cancer inflammation index (ALI) in patients with right-sided colon cancer (RCC) after complete mesocolic excision (CME).

Methods

A total of 441 patients with RCC who underwent CME were included. The optimal cut-off value for the ALI was determined using the X-tile software. Logistic and Cox regression analyses were used to identify risk factors for postoperative complications and long-term outcomes. Predictive nomograms for overall survival (OS) and disease-free survival (DFS) were constructed after propensity score matching (PSM), and their performance was assessed using the net reclassification improvement index (NRI), integrated discrimination improvement index (IDI), and time-dependent receiver operating characteristic (time-ROC) curve analysis.

Results

The optimal preoperative ALI cut-off value was 36.3. After PSM, ASA classification 3/4, operative duration, and a low ALI were independently associated with postoperative complications in the multivariate analysis (all P<0.05). Cox regression analysis revealed that an age >60 years, a carbohydrate antigen 19-9 (CA19-9) level >37 U/mL, pathological N+ stage, and a low ALI were independently correlated with OS (all P<0.05). A CA19-9 level >37 U/mL, pathological N+ stage, lymphovascular invasion, and a low ALI were independent predictors of DFS (all P<0.05). Predictive nomograms for OS and DFS were constructed using PSM. Furthermore, a nomogram combined with the ALI was consistently superior to a non-ALI nomogram or the pathological tumor-node-metastasis classification based on the NRI, IDI, and time-ROC curve analysis after PSM (all P<0.05).

Conclusion

The ALI was an effective indicator for predicting short- and long-term outcomes in patients with RCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02712-0.

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.

Does adjuvant chemotherapy improve outcomes in elderly patients with colorectal cancer? A systematic review and meta-analysis of real-world studies

BACKGROUND

Elderly patients are frequently excluded from randomized trials. It is unclear if adjuvant chemotherapy improves outcomes of colorectal cancer in such patients. The current study aimed to review evidence on the impact of adjuvant chemotherapy on overall survival (OS) and disease-free survival (DFS) in elderly patients with stage II/III colorectal cancer by pooling data from real-world studies.

METHODS

PubMed, Embase, ScienceDirect, CENTRAL, and Google Scholar databases were searched for observational studies reporting adjusted data on OS and DFS in elderly (≥70 years) colorectal cancer patients based on receipt of adjuvant chemotherapy.

RESULTS

Thirteen studies included. The meta-analysis demonstrated statistically significant improved OS in elderly patients receiving adjuvant chemotherapy (p < 0.00001). Results were similar for sub-group analysis based on cancer stage and definition of elderly. Improvement in OS was noted in only Western population studies with no difference in Asian patients. The meta-analysis also revealed no statistically significant difference in DFS in elderly patients receiving adjuvant chemotherapy vs surgery alone (p = 0.14).

CONCLUSION

Real-world evidence indicates that adjuvant chemotherapy significantly improved OS but not DFS in elderly colorectal cancer patients. Scarce evidence suggests a limited role of adjuvant chemotherapy in Asian patients which needs confirmation by further studies.

Computer-based multimodal training module facilitates standardization of complete mesocolic excision technique for right-sided colon cancer: Long-term oncological outcomes

AIM

The aim of this study is to demonstrate our video training tool developed to teach and standardize complete mesocolic excision (CME) for right-sided colon cancer and also to present our long-term oncological outcomes.

METHOD

Educational narrative videos were produced to demonstrate the technical steps of CME. First, a three-dimensional animation video was prepared. Then cadaveric dissections were recorded in a step-by-step fashion, following the sequences of open and minimally invasive surgery. These were followed by videos of real-life demonstrations of surgical procedures, enhanced by superimposed animations of key anatomical structures. In order to demonstrate the impact of this training module on outcomes of patients undergoing CME, we retrospectively queried data from before (2005-2010) and after (2011-2019) implementation of standardized CME in our practice.

RESULTS

A total of 180 consecutive patients underwent right hemicolectomy between 2005 and 2019. Fifty-four patients underwent surgery before and 126 patients after CME principles were elaborated and standardized. Of those patients who had surgery after the training module, 58 (46%) underwent open surgery and 68 (54%) underwent laparoscopic colectomy. Demographics, perioperative parameters and morbidity were comparable between the groups. The 5-year overall and disease-free survival rates were significantly improved after implementation of CME training (p = 0.059 and p = 0.041, respectively). Also, 5-year overall and disease-free survival rates for all patients were considerably better than our reported national outcomes.

CONCLUSION

Our comprehensive step-by-step training video module for the CME technique demonstrates surgical anatomical planes and important vascular structures and variations. The video also helps standardization of the CME technique and should contribute to improved histopathological and oncological outcomes.

Disease recurrence after right hemicolectomy in Scotland: Is there rationale to adopt complete mesocolic excision (CME)?

AIMS

Complete mesocolic excision (CME) has been proposed as a way to improve the oncological outcomes in patients with colon cancer. To investigate whether there is rationale for adopting the technique in Scotland, our aim was to define the incidence of disease recurrence following standard right hemicolectomy and to compare this with published CME outcomes.

METHODS

Data was collected on consecutive patients undergoing right or extended right hemicolectomy for colonic adenocarcinoma (2012-2017) at three hospitals in Scotland (Raigmore Hospital, Aberdeen Royal Infirmary and Glasgow Royal Infirmary). Emergency or palliative surgery was excluded. Patients were followed up with CT scans and colonoscopy for a minimum of 3 years.

RESULTS

689 patients (M 340, F 349) were included. 30-day mortality was 1.6%. Final pathological stage was Stage I (14%), Stage II (49.8%) and Stage III (36.1%). During follow-up, 10.5% developed loco-regional recurrence and 12.2% developed distant metastases. The 1, 3 and 5-year disease-free survival (DFS) was 94%, 84% and 82% respectively. Primary determinants of recurrence were T stage (p < 0.001), N stage (p < 0.001), apical node involvement (p < 0.001) and EMVI (p < 0.001). When compared to the literature, 30-day mortality was lower than many published series and DFS rates were similar to the largest CME study to date (4 year DFS 85.8% versus 83%).

CONCLUSION

The outcomes of patients undergoing right hemicolectomy in Scotland compare favourably with many published CME studies. The technique demands further evaluation before it can be recommended for adoption into routine surgical practice.

Right-side colectomy with complete mesocolic excision vs conventional right-side colectomy in the treatment of colon cancer: a systematic review and meta-analysis

BACKGROUND

This meta-analysis aims to investigate the role of complete mesocolic excision (CME) in the treatment of right-side colon cancer when compared with standard right-side hemicolectomy, focusing on oncological outcomes, mortality and morbidity rates.

MATERIALS AND METHODS

A systematic literature search was performed on MEDLINE and EMBASE archives, including studies on CME in right-side colon cancer. Primary outcomes were five-year disease-free survival and five-year overall survival. Secondary outcomes investigated were mortality and morbidity rates, intraoperative blood loss, anastomotic leakage, postoperative ileus, day of postoperative flatus, pulmonary infection, duration of hospital stay and number of lymph nodes harvested.

RESULTS

Seventeen studies have been included in this meta-analysis for a total of 3918 patients. The five-year disease-free survival (DFS) and overall survival (OS) results improved in the CME group with respect to conventional right-side colectomy with an OR 1.88 (95% CI 1.02-3.45) and OR 2.77 (95% CI 1.33-5.74), respectively. The incidence of mortality and morbidity was comparable between the two groups. Moreover, conventional surgery time was faster than CME (MD 33.69 min, 95% CI 12.79-54.59), while no significant differences were reported in mean blood loss and hospital stay. Furthermore, the CME group showed a higher mean number of harvested lymph nodes (MD 7.08 lymph nodes 95% CI 4.90-9.27).

CONCLUSION

Complete mesocolic excision of the right-side colectomy improves oncological outcomes without increasing mortality and morbidity rates compared to standard right-side hemicolectomy. CME should therefore be routinely performed in the treatment of right-side colon cancer.

The Value of Sentinel Lymph Node Mapping for the Staging of Node-Negative Colon Cancer: Propensity Score and Mediation Analyses

Objectives

Mediation analysis to assess the protective impact of sentinel lymph node (SLN) mapping on prognosis and survival of patients with colon cancer through a more precise evaluation of the lymph node (LN) status.

Background

Up to 20% of patients with node-negative colon cancer develop disease recurrence. Conventional histopathological LN examination may be limited in describing the real metastatic burden of LN.

Methods

Data of 312 patients with stage I & II colon cancer was collected prospectively. Patients were either staged using intraoperative SLN mapping with multilevel sectioning and immunohistochemical staining of the SLN or conventional techniques. The value of the SLN mapping for the detection of truly node-negative patients was assessed using Cox regression and mediation analysis.

Results

SLN mapping was performed in 143 patients. Disease recurrence was observed in 13 (9.1%) patients staged with SLN mapping and in 27 (16%) staged conventionally. Five-year overall survival (OS) rate was 82.7% (95% confidence interval [CI], 76.5-89.4%) with SLN mapping compared with 65.8% (95% CI, 58.8-73.7%). Five-year cancer-specific survival (CSS) was 95.1% (95% CI, 91.3-99.0%) with SLN mapping compared with 92.5% (95% CI, 88.0-97.2%). Node-negative staging with SLN mapping was associated with significantly better OS (hazard ratio [HR], 0.64; 95% CI, 0.56-0.72; P < 0.001) and CSS (HR, 0.49; 95% CI, 0.39-0.61; P < 0.001) in multivariate analysis. Mediation analysis confirmed a direct protective effect of SLN mapping on OS (HR, 0.78; 95% CI, 0.52-0.96; P < 0.01) and disease-free survival (DFS) (HR, 0.75; 95% CI, 0.48-0.89; P < 0.01).

Conclusions

Staging performed by SLN mapping with multilevel sectioning provides more accurate results than conventional staging. The observed clinically relevant and statistically significant benefit in OS and DFS is explained by a more accurate detection of positive LN by SLN mapping.

Recurrence after complete mesocolic excision for right-sided colon cancer: post hoc sensitivity analyses-early recurrence, surgery by specialist and dissection in the mesocolic plane

AIM

The aim was to investigate whether the previously reported causal treatment effect of complete mesocolic excision on the risk of recurrence was biased by inclusion of patients with potentially undiagnosed disseminated disease at the time of surgery, by non-specialist surgery, or caused by mesocolic plane dissection.

METHOD

A population of 1069 patients, 813 undergoing conventional resection and 256 complete mesocolic excision for colon cancer during the period 2008-2013, was stepwise reduced in the following order by excluding patients with recurrence diagnosed within 6 months of the resection, having surgery performed by a non-specialist without supervision, and specimens assessed as not being mesocolic plane dissection. The primary outcome measure was risk of recurrence after 5.2 years using competing risk analyses.

RESULTS

The absolute risk reduction of complete mesocolic excision was 6.0% (95% CI 1.8-10.2; P = 0.0049) after excluding patients with recurrence within 6 months of resection, 6.1% (95% CI 1.9-10.4; P = 0.0045) after excluding non-specialist surgery, and 7.5% (95% CI 2.9-12.0; P = 0.0013) after the exclusion of patients whose specimens were assessed as dissections not being performed in the mesocolic plane.

CONCLUSION

The absolute risk reduction of recurrence after complete mesocolic excision for right-sided colon cancer in our previous study was not biased by potentially undiagnosed disseminated disease at the time of surgery or non-specialist surgery, and was not solely caused by dissection in the mesocolic plane. Central vascular dissection with central lymphadenectomy seems a major factor for better oncological results.

Complete mesocolic excision versus conventional surgery for colon cancer: A systematic review and meta-analysis

AIM

Complete mesocolic excision (CME) lacks consistent data advocating operative superiority compared to conventional surgery for colon cancer. We performed a systematic review and meta-analysis, analysing population characteristics and perioperative, pathological and oncological outcomes.

METHODS

D3 extended lymphadenectomy dissection was considered comparable to CME, and D2 and D1 dissection to be comparable to conventional surgery. Outcomes reviewed included lymph node yield, R1 resection, overall complications, overall survival and disease-free survival.

RESULTS

In all, 3039 citations were identified; 148 studies underwent full-text reviews and 31 matched inclusion criteria: total cohort 26 640 patients (13 830 CME/D3 vs. 12 810 conventional). Overall 3- and 5-year survival was higher in the CME/D3 group compared with conventional surgery: relative risk (RR) 0.69 (95% CI 0.51-0.93, P = 0.016) and RR 0.78 (95% CI 0.64-0.95, P = 0.011) respectively. Five-year disease-free survival also demonstrated CME/D3 superiority (RR 0.67, 95% CI 0.52-0.86, P < 0.001), with similar findings at 1 and 3 years. There were no statistically significant differences between the CME/D3 and conventional group in overall complications (RR 1.06, 95% CI 0.97-1.14, P = 0.483) or anastomotic leak (RR 1.02, 95% CI 0.81-1.29, P = 0.647).

CONCLUSIONS

Meta-analysis suggests CME/D3 may have a better overall and disease-free survival compared to conventional surgery, with no difference in perioperative complications. Quality of evidence regarding survival is low, and randomized control trials are required to strengthen the evidence base.

Predictive value of computed tomography with coronal reconstruction in right hemicolectomy with complete mesocolic excision for right colon cancers: a retrospective study

Background

Understanding the vascular anatomy is critical for performing central vascular ligation (CVL) in right hemicolectomy with complete mesocolic excision (CME). This study aimed to investigate the predictive value of multi-slice spiral computed tomography (MSCT) with coronal reconstruction in right hemicolectomy with CME.

Methods

This is a retrospective descriptive study. Eighty patients with right colon cancer who underwent right hemicolectomy from December 2015 to January 2020 were included. The intraoperative reports (including imaging data) and MSCT images with coronal reconstruction were analysed and compared. The detection rates of the ileocolic vein (ICV) and ileocolic artery (ICA) roots and the accuracy in predicting their anatomical relationship were analysed. The detection rate and accuracy in predicting the location of the gastrocolic trunk of Henle (GTH), middle colic artery (MCA) and middle colic vein (MCV) were analysed. The distance from the ICV root to the GTH root (ICV-GTH distance) was measured and analysed. The maximum distance from the left side of the superior mesenteric artery (SMA) to the right side of the superior mesenteric vein (SMV), named the ‘lsSMA-rsSMV distance’, was also measured and analysed.

Results

In seventy-four (92.5%) patients, both the ICV and ICA roots were located; their anatomical relationship was determined by MSCT, and the accuracy of the prediction was 97.2% (72/74). The GTH was located by MSCT in 75 (93.7%) patients, and the accuracy of the prediction was 97.33% (73/75). The MCA was located by MSCT in 47 (58.75%) patients, and the accuracy was 78.72% (37/47). The MCV was located by MSCT in 51 (63.75%) patients, and the accuracy of the prediction was 84.31% (43/51). The ICV-GTH distance was measured in 73 (91.2%) patients, and the mean distance was 4.28 ± 2.5 cm. The lsSMA-rsSMV distance was measured in 76 (95%) patients, and the mean distance was 2.21 ± 0.6 cm.

Conclusions

With its satisfactory accuracy in predicting and visualising the information of key anatomical sites, MSCT with coronary reconstruction has some predictive value in CME with CVL in right hemicolectomy.

2D vs 3D laparoscopic right colectomy: A propensity score-matching comparison of personal experience with systematic review and meta-analysis

BACKGROUND

The benefits of laparoscopic approach for right colectomy have been well established. However, the technical difficulty to construct the intra-corporeal anastomosis is still cumbersome.

AIM

To analyze the results of 3D and 2D laparoscopic right colectomy and to compare it to the published series through a systematic review and meta-analysis.

METHODS

A retrospective study with propensity score matching analysis of patients undergoing laparoscopic right colectomy at Umbria2 Hospitals from January 2014 to March 2020 was performed. A systematic review was accomplished comparing 2D and 3D right colectomy.

RESULTS

In the personal series 47 patients of the 2D group were matched to 47 patients of the 3D group. The 3D group showed a favorable trend in terms of mean operative time (170.7 ± 32.9 min vs 183.8 ± 35.4 min; P = 0.053) and a significant lower anastomotic time (16.9 ± 2.3 min vs 19.6 ± 2.9 min, P < 0.001). The complete mesocolic excision (CME) subgroups analysis showed a shorter anastomotic time (16.5 ± 1.8 min vs 19.9 ± 3.0 min; P < 0.001) and operative time (175.0 ± 38.5 min vs 193.7 ± 37.1 min; P = 0.063) in the 3D group. Six studies and our series were included in the meta-analysis with 551 patients (2D group: 291; 3D group: 260).The pooled analysis demonstrated a significant difference in favour of the 3D group regarding the operative time (P < 0.001) and the anastomotic time (P < 0.001) while no differences were identified between groups in terms of blood loss (P = 0.827), LNH yield (P = 0.243), time to first flatus (P = 0.333), postoperative complications (P = 0.718) and length of stay (P = 0.835).

CONCLUSION

The meta-analysis results showed that 3D laparoscopic right colectomy shortens operative and anastomotic time without affecting the standard lymphadenectomy. In our series, the advantage of the 3D system becomes evident when CME and/or more complex associated procedure are requested significantly reducing both the total operative and the anastomotic time.

Complete Mesocolic Excision and D3 Lymphadenectomy versus Conventional Colectomy for Colon Cancer: A Systematic Review and Meta-Analysis

BACKGROUNDS

Previous systematic reviews suggest that the implementation of 'complete mesocolon excision' (CME) for colon tumors entails better specimen quality but with limited long-term outcomes. We performed a meta-analysis to compare the pathological, perioperative, and oncological results of CME with conventional surgery (CS) in primary colon cancer.

METHODS

Embase, MEDLINE and CENTRAL databases were searched using Medical Subject Headings for CME and D3 lymphadenectomy. The systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

A total of 18,989 patients from 27 studies were included. Postoperative complications were higher in the CME group (relative risk [RR] 1.13, 95% confidence interval [CI] 1.04-1.22, I² = 0%), while no differences were observed in terms of anastomotic leak (I² = 0%) or perioperative mortality (I² = 49%). CME was associated with a higher number of lymph nodes harvested (I² = 95%), distance to high tie (I² = 65%), bowel length (I² = 0%), and mesentery area (I² = 95%). CME also had positive effects on 3- and 5-year overall survival (RR 1.09, 95% CI 1.04-1.15, I² = 88%; and RR 1.05, 95% CI 1.02-1.08, I² = 62%, respectively) and 3-year disease-free survival (RR 1.10, 95% CI 1.04-1.17, I² = 22%), as well as decreased local (RR 0.35, 95% CI 0.24-0.51, I² = 51%) and distant recurrences (RR 0.71, 95% CI 0.60-0.85, I² = 34%).

CONCLUSIONS

Limited evidence suggests that CME improves oncological outcomes with a higher postoperative adverse events rate but no increase in anastomotic leak rate or perioperative mortality, compared with CS.

Complete mesocolic excision versus conventional hemicolectomy in patients with right colon cancer: a systematic review and meta-analysis

PURPOSE

Complete mesocolic excision (CME) has introduced a promising surgical approach for treatment of right colon cancer. However, benefits of CME are still a matter of debate. We conducted a systematic review and meta-analysis to assess safety and long-term outcomes of CME versus conventional right hemicolectomy (CRH).

METHODS

We systematically searched MEDLINE, the Cochrane Database of Systematic Reviews, Scopus, Web of Science, and Embase for retrieving studies comparing CME with CRH in right colon cancer. After data extraction from the included studies, meta-analysis was performed to compare postoperative complications, anastomotic leakage, 30-day mortality, number of lymph node yield, disease-free survival (DFS), and overall survival (OS).

RESULTS

Eight studies met the inclusion criteria with a total of 1871 patients enrolled. No difference was observed in postoperative complications (OR 1.13, 95% CI 0.88-1.47, p = 0.34). CME was associated with significantly higher number of lymph nodes retrieved (MD 9.17, CI 4.67-13.68, p < 0.001). CME also improved 3-year OS (OR 1.57, 95% CI 1.17-2.11, p = 0.003), 5-year OS (OR 1.41, 95% CI 1.06-1.89, p = 0.02), and 5-year DFS (OR 1.99, 95% CI 1.29-3.07, p = 0.002). A sub-group analysis for patients with stage III colon cancer showed no significant impact of CME on 3-year and 5-year OS (OR 2.47, 95% CI 0.86-7.06, p = 0.09; OR 1.23, 95% CI 0.78-1.94, p = 0.38).

CONCLUSION

Although with limited evidence, CME shows similar postoperative complication rates and an improved survival outcome compared with CRH.

Comparing complete mesocolic excision versus conventional colectomy for colon cancer: A systematic review and meta-analysis

Conventional colectomy, and the Japanese Society for Cancer of the Colon and Rectum (JSCCR) D2 Lymphadenectomy (LND2), are currently considered standard of care for surgical management of colon cancer. Colectomy with complete mesocolic excision (CME) and JSCCR D3 Lymphadenectomy (LND3) are more radical alternative approaches and provide a greater degree of lymph nodal clearance. However, controversy exists over the long-term benefits of CME/LND3 over non-CME colectomies (NCME)/LND2. In this study, we performed a systematic review and meta-analysis to compare the surgical, pathological, and oncological outcomes of CME/LND3 with NCME/LND2. Embase, Medline and CENTRAL databases were searched from inception until May 15, 2020, in accordance with PRISMA guidelines. Studies were included if they compared curative intent CME/LND3 with NCME/LND2. Weighted mean differences (WMD) and odds ratios (OR) were estimated for continuous and dichotomous outcomes respectively. Out of 1310 unique citations, 106 underwent full-text review, and 30 were included for analysis. In total, 21,695 patients underwent resection for colon cancer. 11,625 received CME/LND3, and 10,070 underwent NCME/LND2. No significant differences were found in post-operative morbidity and mortality. Both overall and disease-free survival favored CME/LND3 (5-year OS: OR = 1.29; 95% CI 1.02 to 1.64, p = 0.03; 5-year DFS: OR = 1.61; 95% CI 1.14 to 2.28; p = 0.007). This is the first systematic review and meta-analysis to demonstrate that CME/LND3 has superior long-term survival outcomes compared to NCME/LND2.

Feasibility of robotic right colectomy with complete mesocolic excision and intracorporeal anastomosis: short-term outcomes of 161 consecutive patients

Technical and oncological aspects are still debated when dealing with minimally-invasive right colectomy. Main controversial issues still remain about whether the anastomosis should be performed intra- or extracorporeally and if a complete mesocolic excision (CME) should be carried out. We report the feasibility of robotic right colectomy with CME and intracorporeal anastomosis (IA) for right sided colon cancer. Data from patients who underwent robotic right colectomy with IA and CME from January 2015 to April 2020 were prospectively collected and retrospectively analyzed. Intraoperative outcomes and complications (minor I-II and major III-IV according to Clavien-Dindo classification), conversion rate, 30-day postoperative outcomes and pathological outcomes were the variables assessed. A total of 161 patients undergoing robotic right colectomy for cancer met the inclusion criteria. Mean operative time was 185 min, no intraoperative complications were observed, and the conversion rate was 3.7% (6 patients requiring elective conversions). Overall, mean postoperative stay was 4.9 days and the overall 30-day complication rate was 16.1%. 20 patients (12.4%) had minor complications, while major postoperative complications occurred in six patients (3.7%). Anastomotic leak was recorded in one patient (0.6%) and the 30-day re-admission rate was 0.6%. Mean number of harvested lymph nodes was 21.9. Patients requiring conversion experienced two minor complications, with a mean length of stay of 7 days. Robotic right colectomy with CME and IA is feasible and it is associated with good intraoperative and short-term postoperative clinical outcomes.

Establishment of deformable three-dimensional printed models for laparoscopic right hemicolectomy in transverse colon cancer

BACKGROUND

Applications of three-dimensional (3-D) printed solid organ models for navigation and simulation were previously reported for abdominal surgeries, and their usefulness was shown by subjective evaluation. However, thus far, no study has examined the effect of intraoperative movements for tissue handling. Novel, deformable 3-D printed models of the superior mesenteric artery (SMA) and superior mesenteric vein (SMV) were created to optimize laparoscopic right hemicolectomy. The aim of this study was to establish a method using these individualized models for use in surgical practice.

METHODS

Deformable 3-D models for laparoscopic right hemicolectomy were created using a 3-D printing flexible filamentous material (thermoplastic polyurethane). Five patients with transverse colon cancer who underwent laparoscopic right hemicolectomy with D3 lymphadenectomy between April 2017 and September 2019 were enrolled in this study. Then, the created patient-specific models were compared with the previously recorded intraoperative video views.

RESULTS

Transverse colon mobilization changed the spatial arrangement of the branches of the SMA and SMV. The 3-D models reproduced the intraoperative view, although approaches to the dominant vessels to complete D3 lymphadenectomy may vary.

CONCLUSIONS

Deformable 3-D models of the SMA and SMV with added branches may aid in optimizing laparoscopic right hemicolectomy operations.