Short-term outcomes of a multicentre randomized clinical trial comparing D2 versus D3 lymph node dissection for colonic cancer (COLD trial)

Short- and long-term outcome differences between patients undergoing left and right colon cancer surgery: cohort study

PURPOSE

Since the literature currently provides controversial data on the postoperative outcomes following right and left hemicolectomies, we carried out this study to examine the short- and long-term treatment outcomes.

METHODS

This study included consecutive patients who underwent right or left-sided colonic resections from year 2014 to 2018 and then they were followed up. The short-term outcomes such as postoperative morbidity and mortality according to Clavien-Dindo score, duration of hospital stay, and 90-day readmission rate were evaluated as well as long-term outcomes of overall survival and disease-free survival. Multivariable Cox regression analysis was performed of overall and progression-free survival.

RESULTS

In total, 1107 patients with colon tumors were included in the study, 525 patients with right-sided tumors (RCC) and 582 cases with tumors in the left part of the colon (LCC). RCC group patients were older (P < 0.001), with a higher ASA score (P < 0.001), and with more cardiovascular comorbidities (P < 0.001). No differences were observed between groups in terms of postoperative outcomes such as morbidity and mortality, except 90-day readmission which was more frequent in the RCC group. Upon histopathological analysis, the RCC group's patients had more removed lymph nodes (29 ± 14 vs 20 ± 11, P = 0.001) and more locally progressed (pT3-4) tumors (85.4% versus 73.4%, P = 0.001). Significantly greater 5-year overall survival and disease-free survival (P = 0.001) were observed for patients in the LCC group, according to univariate Kaplan-Meier analysis.

CONCLUSIONS

Patients with right-sided colon cancer were older and had more advanced disease. Short-term surgical outcomes were similar, but patients in the LCC group resulted in better long-term outcomes.

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.

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.

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.

Surgical outcomes of a prospective, phase 2 trial of robotic surgery for resectable right-sided colon cancer (the ROBOCOLO trial)

Aim

We evaluated the safety of robotic surgery for right-sided colon cancer in Japan.

Methods

This was a prospective, open-label, single-arm phase II trial conducted at two institutions. Patients ≥20 years old with stage I-III right-sided colon cancer and scheduled for radical resection with ≥D2 lymph node dissection were eligible. The criterion for surgeons was experience performing robot-assisted rectal resection in ≥40 cases. The primary endpoint was the postoperative complication rate ≤30 days after surgery.

Results

From August 2021 to February 2023, 42 patients were enrolled; three were excluded, with 39 analyzed as the full analysis set. The median age was 72 years, and the median body mass index was 23.2. The tumor was located in the cecum in 13 cases (33.3%), ascending colon in 20 cases (51.3%), and transverse colon in six cases (15.4%). Ileocolic resection was performed in 17 cases (43.5%) and right hemicolectomy in 22 cases (56.5%), both with D3 lymph node dissection. The median console time was 109 min, and the operative time was 170 min. The mean blood loss was 7.7 mL. Intracorporeal anastomosis was performed in 28 patients (71.8%). There were no conversions and no intraoperative adverse events. The median postoperative stay was 5 days. Postoperative complications occurred in four patients (10.2%; paralytic ileus [n = 3] and pneumonia [n = 1]). All postoperative complications were grade 1 or 2, with no mortalities noted. R0 resection was achieved in all patients.

Conclusions

This study demonstrated the safety and feasibility of robotic surgery for 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.

Weighing the benefits of lymphadenectomy in early-stage colorectal cancer

Recent advancements in endoscopic procedures have resulted in a growing diagnosis of early colorectal cancer (CRC) cases, where classical en bloc lymph node (LN) dissection is not performed and treatment is terminated with the removal of the main cancer lesion by endoscopy without pathologic LN staging. Although many studies report noninferior outcomes of endoscopic resection in comparison to surgical resection, a cautious approach to completing treatment with endoscopic resection alone is recommended because LN metastases may be present even in early-stage CRC. In most countries, including the United States, Europe, and South Korea, the guidelines for additional surgery after endoscopic resection are very similar. If LN metastasis is suspected, even in T1 stage or lower lesions, further surgery is an essential treatment modality, but confirmation of the presence of LN metastasis is perhaps the most difficult part of this process. Another paradoxical recent trend is the expansion of more extensive and complete surgical lymphadenectomy for CRC. The success rate of surgery has improved dramatically over the past decade with the introduction of surgical devices and minimally invasive surgery, and the associated risks have been significantly reduced. While the burden of surgery on patients is understandable, the indications for surgery in early colon cancer need to be carefully reviewed to improve cure rates. In this process, we believe that an integrated decision-making process with surgeons, radiologists, and pathologists, in addition to the opinions of endoscopists, will be an important process to improve the cure rate.

Complete mesocolic excision versus standard resection for colon cancer: a systematic review and meta-analysis of perioperative safety and an evaluation of the use of a robotic approach

PURPOSE

Complete mesocolic excision (CME) has been associated with improved oncological outcomes in treatment of colon cancer. However, widespread adoption is limited partly because of the technical complexity and perceived risks of the approach. The aim of out study was to evaluate the safety of CME compared to standard resection and to compare robotic versus laparoscopic approaches.

METHODS

Two parallel searches were undertaken in MEDLINE, Embase and Web of Science databases 12 December 2021. The first was to evaluate IDEAL stage 3 evidence to compare complication rates as a surrogate marker of perioperative safety between CME and standard resection. The second independent search compared lymph node yield and survival outcomes between minimally invasive approaches.

RESULTS

There were four randomized control trials (n = 1422) comparing CME to standard resection, and three studies comparing laparoscopic (n = 164) to robotic (n = 161) approaches. Compared to standard resection, CME was associated with a reduction in Clavien-Dindo grade 3 or higher complication rates (3.56% vs. 7.24%, p = 0.002), reduced blood loss (113.1 ml vs. 137.6 ml, p < 0.0001) and greater mean lymph node harvest (25.6 vs. 20.9 nodes, p = 0.001). Between the robotic and laparoscopic groups, there were no significant differences in complication rates, blood loss, lymph node yield, 5-year disease-free survival (OR 1.05, p = 0.87) and overall survival (OR 0.83, p = 0.54).

CONCLUSIONS

Our study demonstrated improved safety with CME. There was no difference in safety or survival outcomes between robotic and laparoscopic CME. The advantage of a robotic approach may lie in the reduced learning curve and an increased penetration of minimally invasive approach to CME. Further studies are required to explore this.

PROSPERO ID

CRD42021287065.

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.

Lymph node metastasis in cancer progression: molecular mechanisms, clinical significance and therapeutic interventions

Lymph nodes (LNs) are important hubs for metastatic cell arrest and growth, immune modulation, and secondary dissemination to distant sites through a series of mechanisms, and it has been proved that lymph node metastasis (LNM) is an essential prognostic indicator in many different types of cancer. Therefore, it is important for oncologists to understand the mechanisms of tumor cells to metastasize to LNs, as well as how LNM affects the prognosis and therapy of patients with cancer in order to provide patients with accurate disease assessment and effective treatment strategies. In recent years, with the updates in both basic and clinical studies on LNM and the application of advanced medical technologies, much progress has been made in the understanding of the mechanisms of LNM and the strategies for diagnosis and treatment of LNM. In this review, current knowledge of the anatomical and physiological characteristics of LNs, as well as the molecular mechanisms of LNM, are described. The clinical significance of LNM in different anatomical sites is summarized, including the roles of LNM playing in staging, prognostic prediction, and treatment selection for patients with various types of cancers. And the novel exploration and academic disputes of strategies for recognition, diagnosis, and therapeutic interventions of metastatic LNs are also discussed.

Drainage pattern of the splenic flexure vein and its accompanying arteries using three-dimensional computed tomography angiography: a single-centre study of 600 patients

AIM

The splenic flexure has variable vascular anatomy, and the details of the venous forms are not known. In this study, we report the flow pattern of the splenic flexure vein (SFV) and the positional relationship between the SFV and arteries such as the accessory middle colic artery (AMCA).

METHODS

This was a single-centre study using preoperative enhanced CT colonography images of 600 colorectal surgery patients. CT images were reconstructed into 3D angiography. SFV was defined as a vein flowing centrally from the marginal vein of the splenic flexure visible on CT. AMCA was defined as the artery feeding the left side of the transverse colon, separate from the left branch of the middle colic artery.

RESULTS

The SFV returned to the inferior mesenteric vein (IMV) in 494 cases (82.3%), the superior mesenteric vein in 51 cases (8.5%) and the splenic vein in seven cases (1.2%). The AMCA was present in 244 cases (40.7%). The AMCA branched from the superior mesenteric artery or its branches in 227 cases (93.0% of cases with existing AMCA). In the 552 cases in which the SFV returned to the IMV, superior mesenteric vein or splenic vein, the left colic artery was the most frequent artery accompanying the SFV (42.2%), followed by the AMCA (38.1%) and the left branch of the middle colic artery (14.3%).

CONCLUSIONS

The most common flow pattern of the vein in the splenic flexure is from the SFV to IMV. The SFV is frequently accompanied by the left colic artery or AMCA.

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.

Long-term oncologic outcome of D3 lymph node dissection for clinical stage 2/3 right-sided colon cancer

PURPOSE

To investigate oncologic outcomes including overall survival and disease-free survival depending on the extent of lymphadenectomy (D3 versus D2) by comparing D3 and D2 lymphadenectomy in patients with clinical stage 2/3 right colon cancer.

METHODS

Consecutive series of patients who underwent radical resection for right colon cancer at our three hospitals between January 2015 and June 2018 were retrospectively analyzed. Study cohorts were divided into two groups: D3 group and D2 group. Oncologic, pathologic, and perioperative outcomes of the two groups were compared.

RESULTS

A total of 295 patients (167 in the D2 group and 128 in the D3 group) were included in this study. Patients' characteristics showed no significant difference between the two groups. The median number of harvested lymph nodes was significantly higher in the D3 group than in the D2 group. The rate of complications was not significantly different between the two groups except for chyle leakage, which was more frequent in the D3 group. Five-year disease-free survival was 90.2% (95% CI: 84.8-95.9%) in the D3 group, which was significantly (p = 0.028) higher than that (80.5%, 95% CI: 74-87.5%) in the D2 group. There was no significant difference in overall survival between the two groups.

CONCLUSION

Our results indicate that D3 lymphadenectomy is associated with more favorable 5-year disease-free survival than D2 lymphadenectomy for patients with stage 2/3 right-sided colon cancer. D3 lymphadenectomy might improve oncologic outcomes in consideration of the recurrence rate.

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.

Indocyanine green for radical lymph node dissection in patients with sigmoid and rectal cancer: randomized clinical trial

BACKGROUND

D3 lymph node dissection is recommended for patients with advanced sigmoid and rectal cancer in Japan. This trial aimed to investigate the feasibility of indocyanine green (ICG) as a tracer to increase the nodal harvest during D3 lymph node dissection in patients with sigmoid and rectal cancer.

METHODS

This prospective randomized clinical trial was performed between May 2021 and April 2022. The inclusion criteria were patients with stage I-III sigmoid or rectal cancer eligible for laparoscopic resection. Patients were 1: 1 randomized to either the ICG group (endoscopic ICG injection at the tumour site and intraoperative imaging to guide dissection) or the control group (routine laparoscopic white-light imaging). All patients were treated with D3 dissection, and the primary outcome was the number of harvested lymph nodes at the D3 level.

RESULTS

Out of 210 patients screened, a total of 66 patients were enrolled and randomized. Patients in the two groups presented similar ages and clinical stages (ICG group versus control group, median age of 58.0 versus 58.5 years; stage III 36.4 per cent versus 36.4 per cent, whereas the rate of rectal cancer was 27.3 per cent versus 48.5 per cent respectively). ICG imaging was helpful for completely dissecting D3 lymph nodes and could identify a median of more than 2 (range 1-6) D3 lymph nodes neglected by routine laparoscopic white-light imaging during surgery. The median number of D3 lymph nodes harvested in the ICG group was significantly higher than that in the control group (7.0 versus 5.0, P = 0.003); however, there was no significant difference in the median numbers of positive D1, D2, and D3 lymph nodes between the two groups.

CONCLUSION

ICG is safe and feasible to guide D3 lymph node dissection and can increase the number of harvested D3 lymph nodes in patients with sigmoid and rectal cancer. Registration number: NCT04848311 (http://www.clinicaltrials.gov).

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.

Long-term outcomes of D2 vs. D3 lymph node dissection for cT2N0M0 colorectal cancer: a multi‑institutional retrospective analysis

BACKGROUND

According to Japanese guidelines, D2 or D3 lymph node dissection (LND) is indicated for cT2N0M0 colorectal cancer (CRC). In this study, we retrospectively compared the long-term outcomes between D2 and D3 LND among patients with cT2N0M0 CRC.

METHODS

Our sample included 515 patients from the Japanese Study Group for Postoperative Follow-Up of Colorectal Cancer database, who underwent surgical resection for cT2N0M0 CRC between January 2009 and December 2012, 195 (37.9%) of whom underwent D2 LND and 320 (62.1%) D3 LND. The D2 and D3 groups were retrospectively compared in terms of long-term outcomes including overall survival (OS) and relapse-free survival (RFS). The prognostic factors for these outcomes were also evaluated.

RESULTS

The D2 group had significantly older patients and higher proportion of men than the D3 group. The rates of OS (5-year OS; 94.8% in the D3 group vs. 93.4% in the D2 group, p = 0.38) and RFS (5-year RFS; 89.3% in the D3 group vs. 89.1% in the D2 group, p = 0.91) were comparable for both groups. On multivariate analysis, age ≥ 80 years was significantly associated with poor OS. The extent of LND was not associated with either OS or RFS. Long-term outcomes were similar between the two groups, independent of tumor location.

CONCLUSION

The long-term outcomes did not differ between the D2 and D3 groups and the extent of LND was not associated with prognosis for cT2N0M0 CRC. Therefore, D2 LND may be sufficient for cT2N0N0 CRC treatment.

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.

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.

The impact of three-dimensional reconstruction and standardised CT interpretation (AMIGO) on the anatomical understanding of mesenteric vascular anatomy for planning complete mesocolic excision surgery: A randomised crossover study

BACKGROUND

Preoperative planning is a crucial aspect of safe complete mesocolic excision (CME) surgery. 3D models derived from imaging may help improve anatomical understanding of the complex vascular anatomy. Here, we assessed the effect of 3D models on surgeons' anatomical understanding in comparison to a systematic approach for CT scan interpretation (AMIGO).

METHOD

Fifteen cases were included in the study. Two GI radiology consultants reviewed each scan to ascertain the vascular anatomy. Virtual 3D models were produced and displayed on a web-based platform (https://skfb.ly/6OZUZ). A total of 13 surgical trainees were recruited. Candidates were assessed after baseline anatomical training and subsequently using the AMIGO method and 3D models. Five cases were randomly allocated in each round of testing for each participant. The primary outcome measure was an objective vascular anatomy knowledge score. The secondary outcome measure was subjective feedback from participants.

RESULTS

Both 3D and AMIGO significantly improved anatomical understanding in comparison to baseline testing. However, 3D was superior to AMIGO (3D [n = 65; median score 8/14] vs. AMIGO [n = 65; median score 6/14; p < 0.0001]. For 13/15 patient cases examined, 3D was superior to the AMIGO method. Eleven participants demonstrated better anatomical understanding using 3D models versus AMIGO. Ten participants preferred 3D models in comparison to standard CT imaging.

CONCLUSIONS

3D models improve anatomical understanding of mesenteric vascular anatomy in a group of colorectal surgical trainees in comparison to a formal CT interpretation method. 3D models may be a useful planning adjunct to 2D imaging for CME surgery.

Tumor Deposits and Perineural Invasion had Comparable Impacts on the Survival of Patients With Non-metastatic Colorectal Adenocarcinoma: A Population-Based Propensity Score Matching and Competing Risk Analysis

BACKGROUND

Both tumor deposits (TD) and perineural invasion (PNI) have been identified as risk factors for poor survival in patients with non-metastatic colorectal adenocarcinoma (CRC). However, the adverse impacts of TD and PNI on the survival of patients with non-metastatic CRC have not been compared.

METHOD

Patients with non-metastatic CRC with known TD and PNI status were selected from the Surveillance, Epidemiology, and End Results (SEER) database. First, bivariate logistic regression analysis was utilized to identify the factors associated with TD and PNI status. Then, patients were divided into four groups, according to TD and PNI status. Propensity score matching (PSM) was performed to balance the baseline covariates. The impact of TD and PNI on survival was assessed by analyzing overall survival (OS) and cancer-specific mortality (CSM) rates. OS was calculated by the Kaplan-Meier method with log-rank analysis. CSM was estimated by competing risk analysis using the Fine and Gray model.

RESULTS

A total of 70 689 patients with CRC met the inclusion and exclusion criteria. The positive rates of TD and PNI were 9.37% and 9.91%, respectively. For TD, the most important risk factor was N stage. With respect to PNI, the most significant factor was T stage. Tumor location, tumor size, differentiation grade, and serum CEA level were also correlated with TD and PNI status. After PSM, 1849 pairs were selected. Patients with TD⁺PNI⁺ status had the worst 5 year CSM and 5 year OS. In addition, the long-term survival outcomes of patients with TD⁺PNI^- and TD^-PNI⁺ status were comparable.

CONCLUSION

The adverse impacts of TD and PNI on the survival of patients with non-metastatic CRC were comparable. CRC patients with both TD and PNI positive had the worst survival outcome.

Extended Versus Standard Complete Mesocolon Excision in Sigmoid Colon Cancer: A Multicenter Randomized Controlled Trial

OBJECTIVE

The aim of this study was to evaluate whether extended complete mesocolic excision (e-CME) for sigmoid colon cancer improves oncological outcomes without compromising morbidity or functional results.

BACKGROUND

In surgery for cancer of the sigmoid colon and upper rectum, s-CME removes the lymphofatty tissue surrounding the inferior mesenteric artery (IMA), but not the lymphofatty tissue surrounding the portion of the inferior mesenteric vein that does not run parallel to the IMA. Evidence about the safety and efficacy of extending CME to include this tissue is lacking.

METHODS

This single-blind study randomized sigmoid cancer patients at 4 centers to undergo e-CME or s-CME. The primary outcome was the total number of lymph nodes harvested. Secondary outcomes included disease-free and overall survival at 2 years, morbidity, and bowel and genitourinary function. Clinicaltrials.gov: NCT03107650.

RESULTS

We analyzed 93 patients (46 e-CME and 47 s-CME). Perioperative outcomes were similar between groups. No differences between groups were found in the total number of lymph nodes harvested [21 (interquartile range, IQR, 14-29) in e-CME vs 20 (IQR, 15-27) in s-CME, P = 0.873], morbidity (P = 0.829), disease-free survival (P = 0.926), or overall survival (P = 0.564). The extended specimen yielded a median of 1 lymph node (range, 0-6), none of which were positive.Bowel function recovery was similar between arms at all timepoints. Males undergoing e-CME had worse recovery of urinary function (P = 0.026).

CONCLUSION

Extending lymphadenectomy to include the IMV territory did not increase the number of lymph nodes or improve local recurrence or survival rates.

Oncological and clinical outcomes after conventional right hemicolectomy

PURPOSE

Complete mesocolic excision (CME) has been proposed for better local control of colon cancer and to improve cancer-specific survival (CSS). However, CME may be associated with increased morbidity from bleeding during central vascular ligation. This study aimed to investigate the outcome of conventional right hemicolectomy, a traditional anatomical dissection along anatomical planes with radical excision of the central lymph nodes at the level of the origin of colic artery but without exposure of superior mesenteric vein and artery (SMV/SMA).

METHOD

This was a retrospective review of a cohort of all elective right hemicolectomies performed at a specialist tertiary unit during a five-year period (2011-2015).

RESULTS

Five-hundred-nineteen patients (271 female, a median age of 73.0 years (interquartile range (IQR) 65.0-80.0)) were included (Stage I disease: 2.7%, stage II: 53.2%, stage III: 33.3%, stage IV: 10.8%). At the latest follow-up (a median 47 months (IQR 29-67)), local recurrence occurred in 34 patients (6.6%). Three-year overall survival was 74.4% and 3-year CSS was 85.9%. Subgroup analysis for stage I-III showed local recurrence in 6.0%, sole distant recurrence in 7.6% while 19 patients (4.1%) suffered concomitant local and distant recurrence. The anastomotic leak rate was 1.0% and perioperative bleeding occurred in 1.2%.

CONCLUSIONS

Oncological outcomes comparable to those of CME can be achieved by conventional surgery but with low rates of bleeding complications and anastomotic leakage. The proposed advantages of CME should be carefully considered and balanced against patients' co-morbidities and potential complications.

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.

Cribriform carcinoma in the lymph nodes is associated with distant metastasis, recurrence, and survival among patients with node-positive colorectal cancer

Cribriform lymph node pattern is an independent risk factor for metachronous or synchronous distant metastasis in patients with stage III and IV node-positive colorectal cancer. Multivariable analysis in patients with stage III disease indicated that the cribriform pattern of carcinoma in the lymph nodes was an independent risk factor for recurrence and survival. Kaplan–Meier analysis demonstrated that the group with stage III cribriform-type lymph node carcinoma had shorter recurrence-free and overall survival times than the stage III group with the tubular type (P &lt; 0.001).

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.

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.

Upgraded nomograms for the prediction of complications and survival in patients with colorectal liver metastases treated with neoadjuvant chemotherapy followed by hepatic resection

Background

To establish upgraded nomograms incorporating neoadjuvant chemotherapy (NAC)-related factors and preoperative testing markers to predict postoperative complications, progression-free survival (PFS) and overall survival (OS) in patients with colorectal liver metastases (CRLM).

Methods

Multivariate regression analyses were used to reveal independent predictors for postoperative complications, PFS and OS. Nomograms incorporating independent predictors were constructed, and discrimination and calibration were evaluated. Survival was estimated by the Kaplan-Meier method and compared using the log-rank test.

Results

A nomogram predicting postoperative complications was constructed based on preoperative serum gamma-glutamyl transpeptidase (GGT) ≥36 U/L, major liver resection, intraoperative blood loss ≥300 mL, primary site located in the right hemicolon and primary lymph node metastasis, with an area under the receiver operating characteristic curve (AUROC) of 0.750. The calibration curves and Hosmer-Lemeshow test revealed desirable model calibration (chi-square: 4.47, P=0.88). Moreover, a nomogram for the prediction of PFS was constructed based on tumour regression grade (TRG), primary lymph node metastasis, R0 resection and NAC cycles ≥5, with good discrimination (C-index: 0.663±0.024) and calibration, and one for predicting OS was constructed based on preoperative GGT ≥36 U/L, NAC toxicity, NAC cycles ≥5, primary lymph node metastasis and R0 resection, with favourable discrimination (C-index: 0.684±0.030) and calibration. Significant differences in PFS and OS were observed among patients stratified into three different risk groups (P<0.001) according to total scores based on the nomograms.

Conclusions

This study is the first to establish novel predictive nomograms specifically incorporating TRG, NAC toxicity and serum GGT level for the prediction of postoperative complications, PFS and OS in CRLM patients. The nomograms exhibit favourable discrimination and calibration to guide personalized CRLM management and therapy.

Oncological reasons for performing a complete mesocolic excision: a systematic review and meta-analysis

BACKGROUND

While complete mesocolic excision (CME) has been shown to have an oncological benefit as compared to conventional colonic surgery for colon surgery, this benefit must be weighed up against the risk of major intra-abdominal complications. This paper aimed to assess the comparative oncological benefits of CME.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, a systematic review of the literature until May 2020 was performed. Comparative studies assessing CME versus conventional colonic surgery for colon cancer were compared, and outcomes were pooled.

RESULTS

A total of 700 publications were identified, of which 19 were found to meet the inclusion criteria. A total of 25 886 patients were compared, with 14 431 patients in the CME arm. CME was associated with a significantly higher rate of vascular injury (odds ratio 3, P < 0.001). Rates of local and distant recurrence were lower in the CME group (odds ratio 0.66 and 0.73, respectively, both P < 0.001). CME patients had a significantly higher lymph node yield (P < 0.001). While no significant differences were noted between the two groups in terms of pooled 3- or 5-year disease-free survival, pooled 5-year overall survival was significantly higher in the CME group (relative risk 0.82, P < 0.001).

CONCLUSION

Based on the available evidence, CME is associated with improved oncologic outcomes at the expense of higher complication rates, including vascular injury. The oncological benefits need to weighed up against a multitude of factors including the level of hospital support, surgeon experience, patient age, and associated comorbidities.

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.

Current status and trend of laparoscopic right hemicolectomy for colon cancer

Laparoscopic right hemicolectomy (LRH) is utilized worldwide as one of the standard surgical treatments for right-sided colon cancer. However, there have been issues concerning its applicability, techniques, and trend. The present study aimed to elucidate the current status and trend of LRH by reviewing literature focusing on important issues associated with this surgery. Based on previous studies, LRH most likely provides better short-term outcomes and similar oncological outcomes compared to open surgery. Despite the increasing use of robotic approach in this surgery, it seems to have always been associated with longer operative times and greater hospital cost with limited advantage. Intracorporeal anastomosis seems to improve short-term outcomes, such as quicker recovery of bowel function, compared to extracorporeal anastomosis. However, it does not contribute to shorter hospital stay. With regard to dissection technique, various approaches, and landmarks have been advocated to overcome the technical difficulty in LRH. This difficulty is likely to be caused by anatomical variation, especially in venous structures. The superiority of one approach or landmark over another is still argued about due to the lack of large-scale prospective studies. However, deep understanding both of anatomical variation and characteristics of each approach would be of extreme importance to minimize adverse effects and maximize patient benefit after LRH.

Optimal extent of central lymphadenectomy for right-sided colon cancers: is lymphadenectomy beyond the superior mesenteric vein meaningful?

PURPOSE

The objective of the current study was to assess the therapeutic benefit of lymphadenectomy according to the extent of lymphadenectomy.

METHODS

Patients undergoing colectomy for right-sided colon cancer were identified. Distribution of lymph node metastases (DLNM) of 1, 2 and 3 were defined as lymph node metastasis (LNM) in the pericolic nodes, the intermediate nodes and the front of the SMV near the origin of the major artery, respectively. The therapeutic index (TI) was calculated based on the frequency of LNM and the 5 year overall survival (OS) rate of patients with LNM.

RESULTS

Among 344 patients who met the inclusion criteria, roughly half had LNM (n = 150, 43.7%). While 107 (31.1%) and 30 (8.7%) patients had DLNM1 and DLNM2, respectively, only 13 patients (3.8%) were defined as DLNM3. However, there was no significant difference in 5 year OS by DLNM (DLNM1 71.1%, DLNM2 78.7%, DLNM3 50.4%, p = 0.61). Overall, the TI of lymphadenectomy for D3 area was approximately 1/10 of the TI for D1 (1.9 vs.22.1), given the low frequency of LNM (3.8%) and poor 5 year OS of patients with LNM (50.4%). This trend was consistent irrespective of primary tumor locations.

CONCLUSION

The survival benefit from central lymphadenectomy namely D3 was low among patients with right-sided colon cancers.