Comparison of Short-term Results after Laparoscopic Complete Mesocolic Excision and Standard Colectomy for Right-Sided Colon Cancer: Analysis of a Western Center Cohort

Complete mesocolic excision (CME) impacts survival only for Stage III right-sided colon cancer: a systematic review and meta-analysis

INTRODUCTION

Complete mesocolic excision (CME) is widely adopted for its assumed superior oncological outcome. However, it's unclear if all right-sided colon cancer patients benefit from CME. The aim of this systematic review is to investigate whether CME contributes to postoperative outcomes and to determine the surgical indications for CME.

MATERIAL AND METHODS

We searched eligible articles about CME versus non-CME procedures for right-sided colon cancer in the OVID Medline, Embase, and Cochrane CENTRAL databases, and a meta-analysis was conducted.

RESULTS

Twenty-two articles and seven abstracts involving 8088 patients were included in this study. Among them, 3803 underwent CME and 4285 non-CME procedures. The analysis showed that CME was favoured for three-year disease-free survival (DFS) and overall survival (OS), for local, systemic, and total recurrence, and for hospital stay durations. However, increased vascular injury and longer surgery time were observed in CME. Regarding the three-year OS, the superiority of CME was observed only in Stage III. Additionally, no significant differences were observed between CME and non-CME groups regarding overall complications, 30-day readmission rates, reoperation, or postoperative mortality rates.

CONCLUSIONS

CME for right-sided colon cancer should be considered, particularly in Stage III patients, to contribute to improved oncological outcomes. However, careful attention must be paid to the increased risk of vascular injury.

Uptake of robot-assisted colon cancer surgery in the Netherlands

BACKGROUND

The robot-assisted approach is now often used for rectal cancer surgery, but its use in colon cancer surgery is less well defined. This study aims to compare the outcomes of robotic-assisted colon cancer surgery to conventional laparoscopy in the Netherlands.

METHODS

Data on all patients who underwent surgery for colon cancer from 2018 to 2020 were collected from the Dutch Colorectal Audit. All complications, readmissions, and deaths within 90 days after surgery were recorded along with conversion rate, margin and harvested nodes. Groups were stratified according to the robot-assisted and laparoscopic approach.

RESULTS

In total, 18,886 patients were included in the analyses. The operative approach was open in 15.2%, laparoscopic in 78.9% and robot-assisted in 5.9%. The proportion of robot-assisted surgery increased from 4.7% in 2018 to 6.9% in 2020. There were no notable differences in outcomes between the robot-assisted and laparoscopic approach for Elective cT1-3M0 right, left, and sigmoid colectomy. Only conversion rate was consistently lower in the robotic group. (4.6% versus 8.8%, 4.6% versus 11.6%, and 1.6 versus 5.9%, respectively).

CONCLUSIONS

This nationwide study on surgery for colon cancer shows there is a gradual but slow adoption of robotic surgery for colon cancer up to 6.9% in 2020. When comparing the outcomes of right, left, and sigmoid colectomy, clinical outcomes were similar between the robotic and laparoscopic approach. However, conversion rate is consistently lower in the robotic procedures.

Do Laparoscopic Approaches Ensure Oncological Safety and Prognosis for Serosa-Exposed Colon Cancer? A Comparative Study against the Open Approach

The adoption of laparoscopic surgery in the management of serosa-exposed colorectal cancer has raised concerns. This study aimed to investigate whether laparoscopic surgery is associated with an increased risk of postoperative recurrence in patients undergoing resection for serosa-exposed colon cancer. A retrospective analysis was conducted on a cohort of 315 patients who underwent curative resection for pathologically confirmed T4a colon cancer without distant metastases at the Asan Medical Center between 2006 and 2015. Patients were categorized according to the surgical approach method: laparoscopic surgery (MIS group) versus open surgery (Open group). Multivariate analysis was employed to identify risk factors associated with overall survival (OS) and disease-free survival (DFS). The MIS group included 148 patients and the Open group had 167 patients. Of the total cohort, 106 patients (33.7%) experienced recurrence during the follow-up period. Rates, patterns, and time to recurrence were not different between groups. The MIS group (55.8%) showed more peritoneal metastasis compared to the Open group (44.4%) among recurrence sites, but it was not significant (p = 0.85). There was no significant difference in the five-year OS (73.5% vs. 78.4% p = 0.374) or DFS (62.0% vs. 64.6%; p = 0.61) between the Open and MIS groups. Age and the pathologic N stage were independently associated with OS, and the pathologic N stage was the only associated risk factor for DFS. The laparoscopic approach for serosa-exposed colon cancer did not compromise the DFS and OS. This study provides evidence that laparoscopic surgery does not compromise oncologic outcomes of patients with T4a colon cancer although peritoneal seeding is the most common type of disease failure of serosa-exposed colon cancer.

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.

Influence of colonic mesenteric area on the number of lymph node retrieval for colon cancer: a prospective cohort study

PURPOSE

The minimum harvested 12 lymph nodes (LNs) is regarded as the limit for accurate staging of nodal status in colorectal cancer patients. Besides the association of the lengths of resected intestinal segments and vascular pedicles, the mesocolic mesenteric area's impact on LN count has not been studied. We aimed to evaluate the associations between metric variables, including the mesocolic mesentery area on the nodal harvest.

METHODS

All consecutive patients who underwent elective colectomy with a curative intention for colon adenocarcinoma were prospectively included. The metric variables included the lengths of resected intestinal segments, vascular pedicle, and colonic mesenteric area. The variables influencing the LN count and the correlation between the total LN count and the specimens' relevant metric measurements were analyzed.

RESULTS

There were 46 patients with a median age of 64 years. The median count for total LNs was 22, and the LN positivity was 59.2%. There was an inadequate LN yield (<12) in 3 patients (6.1%). No significant associations were found between the adequacy of nodal harvest and the demographic, clinical, and tumoral features (P>0.05). There were significant positive correlations between total LN number and length of vascular pedicle and mesenteric area (r=0.576, P<0.001 and r=0.566, P<0.001).

CONCLUSION

The length of the vascular pedicle and mesenteric area were significantly correlated with total LN counts. Although there was no significant impact on the length of resected segments, the colonic mesenteric area can be used alone as a measure for the assessment of the nodal yield in colon cancer.

Multidisciplinary Treatment Strategy for Early Colon Cancer: A Review-An English Version

Treatment for early colon cancer has progressed rapidly, with endoscopic resection and minimally invasive surgery. It is important to select patients without risk of lymph node metastasis before deciding on endoscopic resection for early colon cancer treatment. Pathological risk factors include histologic grade of cancer cell differentiation, lymphovascular invasion, perineural invasion, tumor budding, and deep submucosal invasion. These risk factors for predicting lymph node metastasis are crucial for determining the treatment strategy of endoscopic excision and radical resection for early colon cancer. A multidisciplinary approach is emphasized to establish a treatment strategy for early colon cancer to minimize the risk of complications and obtain excellent oncologic outcomes by selecting an appropriate treatment optimized for the patient's stage and condition. Therefore, we aimed to review the optimal multidisciplinary treatment strategies, including endoscopy and surgery, for early colon cancer.

Direction of diagnosis and treatment improvement in colorectal cancer

Background: Cancer is a major public health problem and the leading cause of death in Korea since 2000. Colorectal cancer is the third leading cause of cancer-related death. Therefore, early detection through screening, surgical techniques improvement, anticancer drugs, adjuvant treatment, and medical resources advancement is important to reduce colorectal cancer-related mortality.Current Concepts: In Korea, the 5-year relative survival rate of patients with colorectal cancer is approximately mid-70%, which is superior to other developed countries, such as the United States, United Kingdom, and Japan, with 60% to 68% because of the well performed screening program and technical improvement. Efforts are underway to conduct active endoscopic treatment for early colorectal cancer and identify cases requiring surgery. Minimally invasive surgery has evolved beyond conventional applications into disease-specific methods, and the robotic system has an important role for evolvement. Performing metastatic colorectal cancer efforts is necessary to improve the survival rate through active surgical treatment and gene therapy.Discussion and Conclusion: Eventually, the role of the patient’s genetic information in diagnosing and treating colorectal cancer is expected to increase. In some cases, diagnosing colorectal cancer using a non-invasive method is already realized. Active surgical treatment based on personal characteristics contributes in improving the treatment outcomes for difficult-to-treat metastatic colorectal cancer. After the period of overall colorectal cancer treatment results improvement, we will undertake the precision treatment era.

Multidisciplinary treatment strategy for early colon cancer

Background: Treatment for early colon cancer has progressed rapidly with endoscopic resection and minimally invasive surgery. Selection of patients without risk of lymph node metastasis is necessary before deciding on endoscopic resection for early colon cancer treatment. We aimed to review the optimal multidisciplinary treatment strategies for early colon cancer, including endoscopy and surgery.Current Concepts: Pathological risk factors include histologic grade of cancer cell differentiation, lymphovascular invasion, perineural invasion, tumor budding, and deep submucosal invasion. These risk factors for predicting lymph node metastasis are crucial for determining the treatment strategy of endoscopic excision and radical resection for early colon cancer. Prediction of the depth of invasion in early colon cancer using endoscopic optical assessments is vital to determine the appropriate treatment method for endoscopic or surgical resection. Furthermore, optical assessment of pit and vascular patterns is useful for estimating the depth of submucosal invasion using magnifying chromoendoscopy and narrow-band imaging endoscopy. Performing an endoscopic and pathologic evaluation of the risk factors for lymph node metastasis is imperative when selecting endoscopic or surgical resection. Endoscopic treatments include cold snare polypectomy, endoscopic mucosal resection, and endoscopic submucosal dissection. In addition, appropriate surgical treatment should be recommended for patients with early colon cancer with a high risk of lymph node metastasis.Discussion and Conclusion: A multidisciplinary approach should be recommended to establish an optimized treatment strategy, minimize the risk of complications, and obtain excellent oncologic outcomes via patienttailored treatment in patients with early colon cancer.