Long-term results following an anatomically based surgical technique for resection of colon cancer: a comparison with results from complete mesocolic excision

Right vs. Left colorectal cancer - Where do we draw the line?

PURPOSE

No consensus on the definition of right and left colorectal cancer (CRC) exists, nor studies offering histological or molecular basis for such categorisation. This study investigated the regional variations in the histological and molecular characteristics of CRCs, with the objective of determining an optimal division point between right and left CRCs.

MATERIALS AND METHODS

An observational study of consecutive patients who underwent CRC resection (1995-2022) at Concord Hospital, Sydney was performed. Clinicopathological data were extracted from a prospective database and seven permutations of right-left divisions considered. Logistic regression tested association between the right-left divisions and pathological characteristics. Receiver operating characteristic and area under the curve (AUC) analyses determined the discriminative ability of each division to predict 18 pathology characteristics.

RESULTS

3753 patients underwent a CRC resection (2120 male; mean 69.5yrs [SD12.6]). There was regional variation in tumours with respect to tumour infiltrating lymphocytes (TILs), mismatch repair deficiency (dMMR), and mutant BRAF (mBRAF). Left-sided tumours were less likely to demonstrate TILs (P < 0.001), be dMMR (P < 0.001), and express mBRAF (P < 0.001). Division at the descending-sigmoid junction yielded highest discriminative abilities: TILs - AUC 0.66, dMMR - AUC 0.76, and mBRAF - AUC 0.73.

CONCLUSION

This is the first study to provide a pathological basis on which right- and left-sided cancers may be defined, and found the optimal division point between the right and left colorectum to be at the descending-sigmoid junction. Further research is needed to determine whether this can facilitate individualised patient management.

Tissue morphometric measurements do not predict survival following colorectal cancer surgery

BACKGROUND

Ex vivo tissue morphometric (TM) measurements have been proposed as a quality marker for colorectal cancer (CRC) surgery. However, their survival associations require clarification. This study aimed to evaluate the feasibility of capturing TM measurements based on ex vivo fresh specimen images and explore the association between these TM measurements and survival outcomes.

METHODS

A prospective cohort study at Concord Hospital, Sydney was conducted with Stage I to III CRC patients (2009-2019) who underwent an anterior resection (AR) or right hemicolectomy (RH). Using high-resolution digital photographs of fresh CRC specimens, ex vivo tissue morphometric (TM) measurements-resected mesentery area (TM A), distances from high vascular tie to tumour (TM B) and bowel wall (TM C), and bowel length (TM D)-were recorded using Image J. Overall survival (OS) and disease-free survival (DFS) estimates and their associations to clinicopathological variables were investigated with Kaplan-Meier and Cox regression analyses. Linear regression models tested association between TM measurements and lymph node (LN) yield.

RESULTS

Of the 1,425 patients who underwent CRC surgery, TM measurements were performed on 312 patients, with an average age of 69.4 years (SD 12.3), of whom 52.9% were male. The majority had an AR (57.8%). Among AR patients, a 5-year OS rate of 77.4% and a DFS rate of 70.1% were observed, with TM measurements bearing no relationship to survival outcomes. Similarly, RH patients exhibited a 5-year OS rate of 67.2% and a DFS rate of 63.1%, with TM measurements again showing no association with survival. Only TM D (P = 0.02) measurements were associated with the number of LNs examined.

CONCLUSION

This study successfully demonstrates the feasibility of measuring TM measurements on photographs of ex vivo fresh specimens following CRC surgery. The lack of association with survival outcomes questions the utility of TM measurements as a quality metric of CRC surgery.

A systematic review of population-based studies on metachronous metastases of colorectal cancer

BACKGROUND

The occurrence of metachronous metastases (MM) of colorectal (CRC), colon (CC), and rectal (RC) cancer of population-based studies has not been compiled in a systematic review previously.

METHODS

MEDLINE, Embase, and Cochrane Library were searched for primary studies of any design from inception until January 2021 and updated in August 2023 (CRD42021261648). The PRISMA guidelines were adopted, and the Newcastle-Ottawa Quality Assessment Scale used for risk of bias assessment. Outcomes on overall and organ-specific MM were extracted. A narrative analysis followed.

RESULTS

Out of 2143 unique hits, 162 publications were read in full-text and 37 population-based cohort studies published in 1981-2022 were included. Ten studies adopted time-dependent analyses; eight were registry-based and seven had a low risk of bias. Three studies reported 5-year recurrence rate of MM overall of stages I-III; for CRC, it was 20.5%, for CC, it was 18% and 25.6%, and for RC, it was 23%. Four studies reported 5-year recurrence rate of organ-specific MM of stages I-III-for CRC, it was 2.2% and 5.5% for peritoneal metastases and 5.8% for lung metastases and for CC 4.5% for peritoneal metastases. Twenty-seven studies reported proportions of patients diagnosed with MM, but data on the length of follow-up was incomplete and varied widely. Proportions of patients with CRC stages I-III that developed MM overall was 14.4%-26.1% in 10 studies. In relation to the enrollment period, a downward trend may be discernible.

CONCLUSION

Studies adopting a more appropriate analysis were highly heterogeneous, whereas uncertain data of partly inadequate studies may indicate that MM are overall declining.

Validation of the German classification system for quality assessment of right-sided colon cancer specimens

AIM

The German classification system of the completeness of mesocolic excision aims to assess the quality of right-sided colonic cancer surgery by review of photographs. We aimed to validate the reliability of the classification in a clinical context.

METHOD

The study was based on a cohort of patients undergoing resection for right-sided colon cancer in two university hospitals served by the same group of pathologists. Prospectively collected photographs of the specimens were assessed twice by six colorectal surgeons to determine the intra-rater and inter-rater accuracy of the German classification and a modification assessing extended right-sided resections.

RESULTS

Specimens from 613 resections for right-sided colon cancer were reviewed. Twenty-one specimens were found to be non-assessable, leaving 436 right hemicolectomies, 139 extended right hemicolectomies and 17 right-sided subtotal colectomies. Intra-rater reliability was 0.57-0.74 and weighted kappa coefficients 0.58-0.74, without differences between subgroups. The percentage of agreement between all six participants was 20.3% for all specimens, 21.1% for right hemicolectomy specimens and 18.1% for extended hemicolectomy and right-sided subtotal colectomy specimens. For the right hemicolectomy specimens, the model-based kappa coefficient for agreement was 0.27 (95% CI 0.24-0.30) and for association 0.45 (95% CI 0.41-0.49).

CONCLUSION

The German classification of right hemicolectomy specimens showed low intra-rater reliability and inter-rater agreement and association. The use of this classification for scientific purposes appeared not to be reliable.

Splenic flexure cancer survival: a 25-year experience and implications for complete mesocolic excision (CME) and central vascular ligation (CVL)

BACKGROUND

The management of splenic flexure cancers (SFCs) in the era of complete mesocolic excision (CME) and central vascular ligation (CVL) is challenging because of its variable lymphatic drainage. This study aimed to compare survival outcomes for SFCs and non-SFCs, and better understand the clinicopathological characteristics which may define a distinct SFC phenotype.

METHODS

An observational cohort study at Concord Hospital, Sydney was conducted with patients who underwent resection for colon adenocarcinoma (1995-2019). Clinicopathological data were extracted from a prospective database. Overall survival (OS) and disease-free survival (DFS) estimates and their associations to clinicopathological variables were investigated with Kaplan-Meier and Cox regression analyses.

RESULTS

Of 2149 patients with colon cancer, 129 (6%) had an SFC. The overall 5-year OS and DFS rates were 63.6% (95% CI 62.5-64.7) and 59.4% (95% CI 58.3-60.5), respectively. SFCs were not associated with OS (P = 0.6) or DFS (P = 0.5). SFCs were more likely to present urgently (P < 0.001) with obstruction (P < 0.001) or perforation (P = 0.03), and more likely to require an open operation (P < 0.001). These characteristics were associated with poorer survival outcomes. No differences were noted between SFCs and non-SFCs with respect to tumour stage (P = 0.3).

CONCLUSION

SFCs have a distinct phenotype, the individual characteristics of which are associated with poorer survival. However, the survivals of SFCs and non-SFCs are similar, possibly because the most important determinant of outcome, tumour stage, is no different between the groups. This may have implications for the surgical approach to SFCs with respect to standardization of CME and CVL surgery for these cancers.

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

BACKGROUND

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

OBJECTIVE

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

DESIGN

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

SETTING

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

PATIENTS

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

MAIN OUTCOME MEASURES

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

RESULTS

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

LIMITATIONS

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

CONCLUSION

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

Finding Waldo: The Evolving Paradigm of Circulating Tumor DNA (ctDNA)—Guided Minimal Residual Disease (MRD) Assessment in Colorectal Cancer (CRC)

Simple Summary

After the surgical removal of colorectal cancer (CRC), residual cancer cells undetectable by standard blood tests and imaging studies are responsible for cancer recurrence. Currently, chemotherapy is often administered after surgery to eradicate residual cancer cells, a decision guided by clinical and pathologic criteria, which are imprecise. Circulating tumor DNA (ctDNA) consists of DNA fragments in the bloodstream derived from cancer cells, and the presence of ctDNA likely indicates the presence of residual cancer cells. The current article discusses how ctDNA technology can help guide treatment in patients with CRC after curative surgery.

Abstract

Circulating tumor DNA (ctDNA), the tumor-derived cell-free DNA fragments in the bloodstream carrying tumor-specific genetic and epigenetic alterations, represents an emerging novel tool for minimal residual disease (MRD) assessment in patients with resected colorectal cancer (CRC). For many decades, precise risk-stratification following curative-intent colorectal surgery has remained an enduring challenge. The current risk stratification strategy relies on clinicopathologic characteristics of the tumors that lacks precision and results in over-and undertreatment in a significant proportion of patients. Consequently, a biomarker that can reliably identify patients harboring MRD would be of critical importance in refining patient selection for adjuvant therapy. Several prospective cohort studies have provided compelling data suggesting that ctDNA could be a robust biomarker for MRD that outperforms all existing clinicopathologic criteria. Numerous clinical trials are currently underway to validate the ctDNA-guided MRD assessment and adjuvant treatment strategies. Once validated, the ctDNA technology will likely transform the adjuvant therapy paradigm of colorectal cancer, supporting ctDNA-guided treatment escalation and de-escalation. The current article presents a comprehensive overview of the published studies supporting the utility of ctDNA for MRD assessment in patients with CRC. We also discuss ongoing ctDNA-guided adjuvant clinical trials that will likely shape future adjuvant therapy strategies for patients with CRC.

Surgeon's role in CT-based preoperative determination of inferior mesenteric artery anatomy in colorectal cancer treatment

BACKGROUND

The inferior mesenteric artery (IMA) is a blood vessel of great importance in left colon and rectal cancer surgery. We aimed to determine the role of surgeons in computed tomography (CT) based vascular anatomy interpretation.

METHOD

Patients with left colon and rectal cancer treated surgically with D3 lymph node dissection and selective vascular ligation were included in this study. All patients (n=250) underwent preoperative CT with intravenous contrast. The IMA anatomy was schematically depicted by surgeon based on CT interpretation. Intraoperatively anatomy was defined by skeletonisation of the IMA. All patients had segmental resection with selective vascular ligation. The concurrence of prospectively obtained results were evaluated by intraclass correlation and Kendall's tau-b test. Misinterpretation of IMA anatomy was analysed by CT-specialist.

RESULTS

The preoperative and intraoperative IMA anatomy features were correctly interpreted in 237 cases (in 94.8%) within skeletonisation extent, which is supported by high level of agreement and concordance of preoperative data regards to intraoperative findings (K=0.926; p<0.001; CC=0.912; p<0.001). As a result of the CT-based evaluation of the IMA, E, K, and H types of branching patterns were proposed. IMV position was mistakenly identified in 2.6% of cases.

CONCLUSION

Surgeons are able to evaluate the IMA anatomy accurately with CT and use it in routine preoperative planning. The E, K, and H branching types may be used when defining approach to skeletonisation and level of vascular ligation.

Neoadjuvant Treatment Lowers the Risk of Mesopancreatic Fat Infiltration and Local Recurrence in Patients with Pancreatic Cancer

Simple Summary

After the implementation of an in-depth histopathological pancreas protocol, curative resection rates for pancreatic head cancers have drastically dropped. Standardized extended resections using embryo-anatomic landmarks (MPE), have recently been prooved to increase margin-negative resection rates. The mesopancreatic fat, excised during these extended resections, was infiltrated in the majority of the patients. Neoadjuvant treatment is an emerging topic of interest for pancreatic cancer patients. It remains unclear if these extended resections are still warranted in patients after neoadjuvant treatment. Neoadjuvant treatment lowered the risk for mesopancreatic fat infiltration and patients were less prone to local recurrence and margin positive resections when compared to patients after upfront surgery. However, the majority of the patients are yet diagnosed with mesopancreatic fat infiltration, justifying this extended approach synergistically with the treatment strategies for colorectal cancer.

Abstract

Background: Survival following surgical treatment of ductal adenocarcinoma of the pancreas (PDAC) remains poor. The recent implementation of the circumferential resection margin (CRM) into standard histopathological evaluation lead to a significant reduction in R0 rates. Mesopancreatic fat infiltration is present in ~80% of PDAC patients at the time of primary surgery and recently, mesopancreatic excision (MPE) was correlated to complete resection. To attain an even higher rate of R0(CRM−) resections in the future, neoadjuvant therapy in patients with a progressive disease seems a promising tool. We analyzed radiographic and histopathological treatment response and mesopancreatic tumor infiltration in patients who received neoadjuvant therapy prior to MPE. The aim of our study was to evaluate the need for MPE following neoadjuvant therapy and if multi-detector computed tomographically (MDCT) evaluated treatment response correlates with mesopancreatic (MP) infiltration. Method: Radiographic, clinicopathological and survival parameters of 27 consecutive patients who underwent neoadjuvant therapy prior to MPE were evaluated. The mesopancreatic fat tissue was histopathologically analyzed and the 1 mm-rule (CRM) was applied. Results: In the study collective, both the rate of R0 resection R0(CRM−) and the rate of mesopancreatic fat infiltration was 62.9%. Patients with MP infiltration showed a lower tumor response. Surgical resection status was dependent on MP infiltration and tumor response status. Patients with MDCT-predicted tumor response were less prone to MP infiltration. When compared to patients after upfront surgery, MP infiltration and local recurrence rate was significantly lower after neoadjuvant treatment. Conclusion: MPE remains warranted after neoadjuvant therapy. Mesopancreatic fat invasion was still evident in the majority of our patients following neoadjuvant treatment. MDCT-predicted tumor response did not exclude mesopancreatic fat infiltration.

Accurate population-based model for individual prediction of colon cancer recurrence

BACKGROUND

Prediction models are useful tools in the clinical management of colon cancer patients, particularly when estimating the recurrence rate and, thus, the need for adjuvant treatment. However, the most used models (MSKCC, ACCENT) are based on several decades-old patient series from clinical trials, likely overestimating the current risk of recurrence, especially in low-risk groups, as outcomes have improved over time. The aim was to develop and validate an updated model for the prediction of recurrence within 5 years after surgery using routinely collected clinicopathologic variables.

MATERIAL AND METHODS

A population-based cohort from the Swedish Colorectal Cancer Registry of 16,134 stage I-III colon cancer cases was used. A multivariable model was constructed using Cox proportional hazards regression. Three-quarters of the cases were used for model development and one quarter for internal validation. External validation was performed using 12,769 stage II-III patients from the Norwegian Colorectal Cancer Registry. The model was compared to previous nomograms.

RESULTS

The nomogram consisted of eight variables: sex, sidedness, pT-substages, number of positive and found lymph nodes, emergency surgery, lymphovascular and perineural invasion. The area under the curve (AUC) was 0.78 in the model, 0.76 in internal validation, and 0.70 in external validation. The model calibrated well, especially in low-risk patients, and performed better than existing nomograms in the Swedish registry data. The new nomogram's AUC was equal to that of the MSKCC but the calibration was better.

CONCLUSION

The nomogram based on recently operated patients from a population registry predicts recurrence risk more accurately than previous nomograms. It performs best in the low-risk groups where the risk-benefit ratio of adjuvant treatment is debatable and the need for an accurate prediction model is the largest.

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.

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.

Routine CT evaluation of central vascular ligation in patients undergoing complete mesocolic excision for sigmoid colon cancer

AIM

Objective and reproducible quality measures of complete mesocolic excision (CME) for colon cancer are not currently available. This study aimed to measure the inferior mesenteric stump length following CME for sigmoid colon cancer and explore surgical, pathological and oncological outcomes in patients with a stump length of <10 mm vs. ≥10 mm.

METHOD

This was a single-centre, retrospective cohort study including patients undergoing minimally invasive surgery for sigmoid colon cancer between May 2013 and May 2015. Follow-up CT scans were reviewed, and a vascular stump cut-off of <10 mm for adequate central ligation of the inferior mesenteric artery was applied. Differences in perioperative, histopathological and oncological outcome parameters (overall, disease-free and recurrence-free survival) were explored between <10 mm vs. ≥10 mm groups.

RESULTS

A total of 127 patients (43% female) with a median age of 68 years were included. The median follow-up time was 68 months. CT measurements showed good interrater agreement (90% absolute agreement) and reliability among raters (kappa = 0.77, 95% CI 0.53-1.00, p < 0.001). A stump length ≥10 mm was associated with longer operating time (150 vs. 180 min, p = 0.021), intramesocolic resection (p = 0.008), and a shorter distance from the bowel wall to vascular tie (120 vs. 102 mm, p = 0.005).

CONCLUSION

An arterial stump length ≥10 mm in sigmoid resection for colon cancer was associated with key clinical quality measures. Measurement of arterial stump length using routine follow-up CT may serve as a quality indicator of vascular ligation in CME surgery.

Completeness and accuracy of the registration of recurrences in the Swedish Colorectal Cancer Registry (SCRCR) and an update of recurrence risk in colon cancer

BACKGROUND

The completeness and accuracy of the registration of synchronous metastases and recurrences in the Swedish Colorectal Cancer Registry has not been investigated. Knowing how accurate these parameters are in the registry is a prerequisite to adequately measure the current recurrence risk.

METHODS

All charts for patients diagnosed with stage I-III colorectal cancer (CRC) in two regions were reviewed. In one of the regions, all registrations of synchronous metastases were similarly investigated. After the database had been corrected, recurrence risk in colon cancer was calculated stratified by risk group as suggested by ESMO in 2020.

RESULTS

In patients operated upon more than five years ago (N = 1235), there were 20 (1.6%) recurrences not reported. In more recent patients, more recurrences were unreported (4.0%). Few synchronous metastases were wrongly registered (3.6%) and, likewise, few synchronous metastases were not registered (about 1%). The five-year recurrence risk in stage II was 6% for low-risk, 11% for intermediate risk, and 23% for high-risk colon cancer patients. In stage III, it was 25% in low- and 45% in high-risk patients. Incorporation of risk factors in stage III modified the risks substantially even if this is not considered by ESMO. Adjuvant chemotherapy lowered the risk in stage III but not to any relevant extent in stage II.

CONCLUSION

The registration of recurrences in the registry after 5 years is accurate to between 1 and 2% but less accurate earlier. A small number of unreported recurrences and falsely reported recurrences were discovered in the chart review. The recurrence risk in this validated and updated patient series matches what has been recently reported, except for the risk of recurrence in stage II low risk colon cancers which seem to be even a few percentage points lower (6 vs. 9%).

Oncological outcomes after complete mesocolic excision in right-sided colon cancer: a population-based study

AIM

Complete mesocolic excision (CME) has been proposed as the preferred surgical technique for resection of colon cancer. This prospective cohort study evaluates the effect of CME surgery on colon cancer mortality after right-sided hemicolectomy on a population level.

METHODS

Data from the Swedish Colorectal Cancer Registry and the Cause of Death Registry on all patients treated with elective right-sided hemicolectomy for colon cancer Stages I-III in the Stockholm County 2008-2012 were analysed. Adherence to principles of CME surgery was determined by structured analysis of anonymized surgical reports regarding the presence of five essential features. The exposure to CME was graded as group 0 (not exposed to CME), group 1 (intermediate) and group 2 (exposed to CME).

RESULTS

In total, 1171 patients were analysed with 234 (20.0%) patients in CME group 0, 453 (38.7%) patients in CME group 1 and 484 (41.3%) in CME group 2. The 5-year colon cancer mortality was 20.2% in CME group 0, 13.9% in CME group 1 and 13.1% in CME group 2 (P = 0.026). The adjusted hazard ratio for colon cancer mortality was 0.61 (95% CI 0.42-0.91; P = 0.014) for CME group 1 and 0.52 (95% CI 0.35-0.77; P = 0.001) for CME group 2.

DISCUSSION

The presence of predefined CME features in surgical reports was related to a graded benefit on cancer-specific mortality after right-sided hemicolectomy for colon cancer Stages I-III.

Has the increase in the regional nodes evaluated improved survival rates for patients with locoregional colon cancer?

Background: The guidelines for colon cancer surgery have been evolving over the past three decades. The advances in colectomy have focused mainly on the number of regional nodes evaluated (RNE).

Methods: Data in this retrospective analysis were extracted from the Surveillance, Epidemiology, and End Results (SEER) linked database.

Results: Rapid growth of RNE (the median rising from 10 (6-16) to 17 (13-23)) occurred from 2000 to 2009. The rate of colon cancer patients with positive lymph nodes following colectomy was greatly decreasing only in the group with RNE greater than 12 after 2000. Patients with T4 and/or N+ cannot obtain survival benefit from the increasing trend of RNE. The apparent survival benefit for T1-3N0 patients may result from augmented false negatives in patients from previous periods.

Conclusions: The golden period of surgical development in colon cancer, using RNE as an alternative indicator, occurred in the first decade of the 21st century. Although a more extensive lymph node evaluation is able to reduce the risk of underestimated staging, the increase of RNE does not provide survival benefits for locoregional colon cancer. A proper reduction in the scope of lymph node dissection may be reasonable in radical surgery for colon cancer.

Robotic Complete Mesocolic Excision (CME) is a safe and feasible option for right colonic cancers: short and midterm results from a single-centre experience

BACKGROUND

Complete mesocolic excision (CME) for right colon cancers has traditionally been an open procedure. Surgical adoption of minimal access CME remains limited due to the technical challenges, training gaps and lack of level-1 data for proven benefits. Currently there is limited published data regarding the clinical results with the use of robotic CME surgery. Aim To report our experience, results and techniques, highlighting a clinical and oncological results and midterm oncological outcomes for robotic CME.

AIM

To report our experience, results and techniques, highlighting a clinical and oncological results and midterm oncological outcomes for robotic CME.

METHODS

All patients undergoing standardised robotic CME technique with SMV first approach between January 2015 and September 2019 were included in this retrospective review of a prospectively collected database. Patient demographics, operative data and clinical and oncological outcomes were recorded.

RESULTS

Seventy-seven robotic CME resections for right colonic cancers were performed over a 4-year period. Median operative time was 180 (128-454) min and perioperative blood loss was 10 (10-50) ml. There were 25 patients who had previous abdominal surgery. Median postoperative hospital stay was 5 (3-18) days. There was no conversion to open surgery in this series. Median lymph node count was 30 (10-60). Three (4%) patients had R1 resection. There was one (1%) local recurrence in stage III disease and 4(5%) distal recurrence in stage II and stage III. There was no 30- or 90-day mortality. Three-year disease-free survival was 100%, 91.7% and 92% for stages I, II and III, respectively. Overall survival was 94%.

CONCLUSIONS

Robotic CME is feasible, effective and safe. Good oncological results and improved survival are seen in this cohort of patients with a standardised approach to robotic CME.

Recurrence Risk after Radical Colorectal Cancer Surgery-Less Than before, But How High Is It?

Simple Summary

Evidence indicates that recurrence risk after colon cancer today is less than it was when trials performed decades ago showed that adjuvant chemotherapy reduces the risk and prolong disease-free and overall survival. After rectal cancer surgery, local recurrence rates have decreased but it is unclear if systemic recurrences have. After a systematic review of available literature reporting recurrence risks after curative colorectal cancer surgery we report that the risks are lower today than they were in the past and that this risk reduction is not solely ascribed to the use of adjuvant therapy. Adjuvant therapy always means overtreatment of many patients, already cured by the surgery. Fewer recurrences mean that progress in the care of these patients has happened but also that the present guidelines giving recommendations based upon old data must be adjusted. The relative gains from adding chemotherapy are not altered, but the absolute number of patients gaining is less.

Abstract

Adjuvant chemotherapy aims at eradicating tumour cells sometimes present after radical surgery for a colorectal cancer (CRC) and thereby diminish the recurrence rate and prolong time to recurrence (TTR). Remaining tumour cells will lead to recurrent disease that is usually fatal. Adjuvant therapy is administered based upon the estimated recurrence risk, which in turn defines the need for this treatment. This systematic overview aims at describing whether the need has decreased since trials showing that adjuvant chemotherapy provides benefits in colon cancer were performed decades ago. Thanks to other improvements than the administration of adjuvant chemotherapy, such as better staging, improved surgery, the use of radiotherapy and more careful pathology, recurrence risks have decreased. Methodological difficulties including intertrial comparisons decades apart and the present selective use of adjuvant therapy prevent an accurate estimate of the magnitude of the decreased need. Furthermore, most trials do not report recurrence rates or TTR, only disease-free and overall survival (DFS/OS). Fewer colon cancer patients, particularly in stage II but also in stage III, today display a sufficient need for adjuvant treatment considering the burden of treatment, especially when oxaliplatin is added. In rectal cancer, neo-adjuvant treatment will be increasingly used, diminishing the need for adjuvant treatment.

Propensity-score-matched analysis of short- and long-term outcomes in patients with an ileocolic artery crossing anterior vs posterior to the superior mesenteric vein during curative resection for right-sided colon cancer

BACKGROUND

Colorectal cancer is one of the most common malignant diseases worldwide. However, laparoscopic lymph node dissection is technically demanding and time-consuming in right-sided colon cancer surgery because of variable vessel anatomy. We evaluated whether the ileocolic artery (ICA) crossing anterior to the superior mesenteric vein (SMV) was associated with better intraoperative parameters and survival compared with the ICA crossing posterior to the SMV, following laparoscopic curative resection for right-sided colon cancer.

METHODS

This was a propensity-score-matched retrospective study including data for 540 patients with right-sided colon cancer undergoing laparoscopic curative resection (299 with the ICA crossing anterior to the SMV (group A) and 241 with the ICA crossing posterior to the SMV (group B). We compared propensity-matched scores between the two groups to evaluate surgical and oncological outcomes.

RESULTS

We found no significant difference in 5-year overall survival rates between groups for any disease stage (0-III). However, 5-year disease-free survival (DFS) rates did differ significantly between groups (p = 0.011), especially in patients with stage III disease (p = 0.013). We then performed univariate and multivariate analyses to determine the associations between DFS and ICA location and tumor-node-metastasis (UICC) stage. ICA location and UICC stage had a poor association with DFS on univariate analysis: ICA hazard ratio (HR) 2.52, CI 1.19-5.78, p = 0.014 vs HR 3.18, CI 1.08-9.46, p = 0.03, and on multivariate analysis: HR 2.48, CI 1.17-5.69, p = 0.016 vs HR 3.86, CI 1.90-7.96, p = 0.0002.

CONCLUSION

Our results showed that an ICA crossing posterior to the SMV was associated with worse DFS compared with an ICA crossing anterior to the SMV. We recommend careful laparoscopic technique in patients with an ICA crossing posterior to the SMV, during lymph node resection in right-sided colon cancer surgery.

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

BACKGROUND

The benefits of extensive lymph node dissection as performed in complete mesocolic excision are still debated, although recent studies have shown an association with improved long-term outcomes. However, none of these studies had an intention-to-treat design or aimed to show a causal effect; therefore in this study, we aimed to estimate the causal oncological treatment effects of complete mesocolic excision on right-sided colon cancer.

METHODS

We did a population-based cohort study involving prospective data collected from four hospitals in Denmark. We compared the oncological outcome data of patients at one centre performing central lymph node dissection and vascular division after almost complete exposure of the proximal part of the superior mesenteric vein (ie, the complete mesocolic excision group) with three other centres performing conventional resections with unstandardised and limited lymph node dissection (ie, non-complete mesocolic excision; control group). We included data for all patients in the Capital Region of Denmark undergoing elective curative-intent right-sided colon resections for stages I-III colon cancer, as categorised by the Union for International Cancer Control (UICC; 5th edition), from June 1, 2008, to Dec 31, 2013. Patients were followed-up for 5·2 years after surgery. The primary outcome was the cumulative incidence of recurrence after 5·2 years of surgery. Inverse probability of treatment weighting and competing risk analyses were used to estimate the possible causal effects of complete mesocolic excision. This study is registered with ClinicalTrials.gov, number NCT03754075.

FINDINGS

1069 patients (813 in the control group and 256 in the complete mesocolic excision group) underwent curative-intent elective surgery for right-sided colon cancer during the study period. None of the patients were lost to follow-up regarding survival or recurrence status, and consequently no patient was censored in the analyses. The 5·2-year cumulative incidence of recurrence was 9·7% (95% CI 6·3-13·1) in the complete mesocolic excision group compared with 17·9% (15·3-20·5) in the control group, and the absolute risk reduction of complete mesocolic excision after 5·2 years was 8·2% (95% CI 4·0-12·4; p=0·00015). In the control group, 145 (18%) of 813 patients were diagnosed with a recurrence and 281 (35%) died during follow-up, whereas in the complete mesocolic excision group 25 (10%) of 256 patients were diagnosed with a recurrence and 75 (29%) died during follow-up.

INTERPRETATION

This study shows a causal treatment effect of central mesocolic lymph node excision on risk of recurrence after resection for right-sided colon adenocarcinoma. Complete mesocolic excision has the potential to reduce the risk of recurrence and improve long-term outcome after resection for all UICC stages I-III of right-sided colon adenocarcinomas.

FUNDING

The Tvergaard Fund, Helen Rude Fund, Krista and Viggo Petersen Fund, Olga Bryde Nielsen Fund, and Else and Mogens Wedell-Wedellsborg Fund.

Introduction of complete mesocolic excision with central vascular ligation as standardized surgical treatment for colon cancer in Greece. Results of a pilot study and bi-institutional cooperation

INTRODUCTION

Complete mesocolic excision (CME) is generally accepted as state of the art in colon cancer surgery. However, the long-term impact of CME has not been systematically examined. Therefore cohort studies might be a possible way to clarify any differences between conventional resections and CME. Following bilateral cooperation between the Department of Surgery/University Hospital of Erlangen and the 1st Surgical Department of the General Hospital of Nikaia/Piraeus, including teaching activities for introduction of CME, a cohort study was performed, considering surgical quality criteria and clinical outcome.

MATERIAL AND METHODS

All patients with colon carcinomas (CME group, n = 31) referred to the 1st Surgical Department of General Hospital, Nikaia/Piraeus, Greece for surgery from January 2012 to December 2013 were prospectively analyzed and compared with patients who underwent conventional surgery for colon cancer between January 2008 and December 2011 (non-CME group, n = 35). Patients' follow-up was at least 48 months.

RESULTS

There were significantly better results in terms of lymph node yield (CME group: 29.6 vs. non-CME group: 17.85; p < 0.001) and lymph node ratio (LNR) (CME group: 0.12 vs. non-CME group: 0.24; p < 0.001) and recurrence-free survival in favor of the CME group (CME group: n = 0 vs. non-CME group: n = 5) without any increase in surgical morbidity (CME group: n = 6 vs. non-CME group: n = 11; p = 0.10).

CONCLUSIONS

Complete mesocolic excision appears to offer a superior oncological result without any increase of postoperative morbidity and mortality. Furthermore, CME represents a surgical technique which can be established in a surgical department after previous teaching without increasing the postoperative complication rate.

Recurrence and cancer-specific death after adjuvant chemotherapy for Stage III colon cancer

AIM

The recommended standard of care for patients after resection of Stage III colon cancer is adjuvant 5-fluorouracil based chemotherapy - FOLFOX (fluorouracil, leucovorin with oxaliplatin) - or CAPOX (capecitabine, oxaliplatin). This may be modified in older patients or depending on comorbidity. This has been challenged recently as the apparent benefit of adjuvant chemotherapy may arise from improvements in surgery or preoperative imaging or pathology staging. This study compares recurrence and colon-cancer-specific death between patients who received postoperative adjuvant chemotherapy and those who did not.

METHOD

Prospectively recorded data from 363 consecutive patients who had a resection for Stage III colonic adenocarcinoma between 1995 and 2010 inclusive were analysed. Surviving patients were followed for at least 5 years. The suitability of patients for chemotherapy was discussed routinely at multidisciplinary team meetings. The incidence of recurrence and colon-cancer-specific death was evaluated by competing risk methods.

RESULTS

After adjustment for the competing risk of non-colorectal cancer death, there was no significant difference in recurrence between the 204 patients who received chemotherapy and the 159 who did not [hazard ratio (HR) 0.94, 95% CI 0.66-1.32, P = 0.700) and no significant difference in colon-cancer-specific death (HR 0.73, 95% CI 0.50-1.04, P = 0.084; HR 0.88, 95% CI 0.57-1.36, P = 0.577 after adjustment for relevant covariates).

CONCLUSION

These findings question the routine use of chemotherapy after complete mesocolic excision for Stage III colon cancer. Recurrence and cancer-specific death, assessed by competing risk methods, should be the standard outcomes for evaluating the effectiveness of adjuvant chemotherapy after potentially curative resection.

Laparoscopic Complete Mesocolic Excision for Right-Sided Colon Cancer: Analysis of Feasibility and Safety from a Single Western Center

BACKGROUND

Colectomies performed according to complete mesocolic excision (CME) principles have demonstrated an improvement in the quality of surgical specimen and a potential improvement of long-term results. Laparoscopic CME right hemicolectomy is considered a demanding procedure and adopted in few centers from the West. The main purpose of this paper is to present a video showing our technique for laparoscopic CME right hemicolectomy and to analyze our short-term results to prove its safety.

METHODS

Data from 38 patients operated on at the Division of General and Hepatobiliary Surgery, University of Verona Hospital Trust, between September 2014 and February 2017, were included in the study.

RESULTS

In the present series, 37% of patients were ≥75 years old, 32% of patients were ASA class 3, 46% of patients had ≥2 comorbidities, 30% of patients had BMI >28 and 17% of patients had ≥2 previous abdominal surgeries. Despite these unfavorable clinic characteristics, no mortality was observed, Clavien-Dindo ≥3 complications occurred in 13.1% and redo surgery in 5.3%. Good quality specimens were obtained with a mean (SD) length of 34.5±7.5 cm, a proximal margin of 16.8±9.2 cm and a distal margin of 14.3±6.4 cm. The mean (SD) number of harvested lymph nodes was 24.3 (8.3).

CONCLUSIONS

When implemented in a Western center, laparoscopic CME right hemicolectomy is feasible and safe and allows obtaining good quality specimens.

Recurrence Risk After Up-to-Date Colon Cancer Staging, Surgery, and Pathology: Analysis of the Entire Swedish Population

BACKGROUND

Developments in the quality of care of patients with colon cancer have improved surgical outcome and thus the need for adjuvant chemotherapy.

OBJECTIVE

To investigate the recurrence rate in a large population-based cohort after modern staging, surgery, and pathology have been implemented.

DESIGN

This was a retrospective registry study.

SETTINGS

Data from patients included in the Swedish Colorectal Cancer Registry covering 99% of all cases and undergoing surgery for colon cancer stages I to III between 2007 and 2012 were obtained.

PATIENTS

In total, 14,325 patients who did not receive any neoadjuvant treatment, underwent radical surgery, and were alive 30 days after surgery were included.

MAIN OUTCOME MEASURES

Tumor and node classification and National Comprehensive Cancer Network-defined risk factors for recurrence were used to assess overall and stage-specific 5-year recurrence rates.

RESULTS

The median follow-up of nonrecurrent cases was 77 months (range, 47-118 mo). The 5-year recurrence rate was 5% in stage I, 12% in stage II, and 33% in stage III patients. In patients classified as having pT3N0 cancer with no or 1 risk factor, the 5-year recurrence rates were 9% and 11%. Risk factors for shorter time to recurrence were male sex, more advanced pT and pN classification, vascular and perineural invasion, emergency surgery, lack of central ligature, short longitudinal resection margin, postoperative complications, and, in stage III, no adjuvant chemotherapy.

LIMITATIONS

The registry does not contain some recently identified factors of relevance for recurrence rates, and some late recurrences may be missing.

CONCLUSIONS

The recurrence rate is less than that previously observed in historical materials, but current, commonly used risk factors are still useful in evaluating recurrence risks. Stratification by pT and pN classification and the number of risk factors enables the identification of large patient groups characterized by such a low recurrence rate that it is questionable whether adjuvant treatment is motivated. See Video Abstract at http://links.lww.com/DCR/A663.

Complete mesocolic excision in right-sided colon cancer does not increase severe short-term postoperative adverse events

AIM

The aim was to assess whether complete mesocolic excision (CME) in patients with right-sided colon cancer is related to short-term mortality or postoperative adverse events requiring reoperation. The complete mobilization of an integral mesocolon and central ligation of blood vessels are essential steps in CME surgery. The resultant specimen, with an intact mesocolic fascia and a high number of harvested lymph nodes, is believed to be oncologically favourable. However, it has been suggested that CME surgery may increase the risk of intra-operative severe adverse events, due to exposure of vital retroperitoneal organs and large blood vessels.

METHOD

In a population-based, nested case-control study, all residents in the Stockholm County operated for right-sided colon cancer from 2004 until 2012 were identified from the Swedish Colorectal Cancer Registry. Patients who died within 90 days after surgery or were reoperated within 30 days after surgery, or during the index hospital stay, were defined as cases. Two controls per case were randomly sampled and individually matched for age, sex, TNM stage and emergency vs elective surgery. Exposure status (CME surgery) was assessed from original surgical reports.

RESULTS

The estimated proportion of CME surgery was 14.8% (35 of 236) for cases and 19.5% (92 of 473) for controls. The unadjusted OR for short-term mortality or reoperation after CME surgery was 0.72 (95% CI: 0.47-1.10; P = 0.15). The ORs were lower in the late part of the study (0.51; 95% CI: 0.26-1.01) and in high volume hospitals (0.61, 95% CI: 0.35-1.06).

CONCLUSIONS

The present study does not indicate that CME surgery is associated with an increased risk of severe adverse events such as 90-day mortality or reoperation.

Session 1: Colon cancer - 10 years behind the rectum

The improvements in surgical technique brought about by the widespread adoption of total mesorectal excision plane dissection in rectal cancer has substantially improved survival and recurrence rates from this disease. For the first time in 50 years, the outcomes in rectal cancer have overtaken those of colon cancer. Professor Madoff's overview lecture and the experts' round table discussion address whether applying the surgical principles already achieved in rectal cancer can meet with similar success in colon cancer, how this can be achieved and the challenges we face.

Laparoscopic modified mesocolic excision with central vascular ligation in right-sided colon cancer shows better short- and long-term outcomes compared with the open approach in propensity score analysis

Background

The introduction of complete mesocolic excision (CME) with central vessel ligation (CVL) for right-sided colon cancer has improved oncologic outcomes. However, there is controversy over the oncologic safety of laparoscopic CME with CVL. This study compared short-term and long-term oncologic outcomes between laparoscopic and open modified CME (mCME) with CVL in patients with right-sided colon cancer.

Methods

We enrolled 1239 patients who underwent open mCME with CVL and 1010 patients treated by a laparoscopic approach for right-side colon cancer between 2000 and 2013 and used 1:1 propensity score matching to adjust for potential baseline confounders between two groups.

Results

After propensity score matching, 683 patients who underwent open mCME with CVL were compared with 683 patients treated with a laparoscopic approach. There were no significant differences between these groups in age, sex, ASA score, TNM stage, tumor size, lymphovascular invasion, and perineural invasion. Comparison of open and laparoscopic mCME groups showed no significant difference in postoperative morbidity (21.4 vs. 18.3%, p = 0.175) and mortality (0.1 vs. 0%, p = 1.000). The laparoscopic mCME group showed shorter length of hospital stay. The 5-year overall survival rate was 83.7% in the open group and 94.7% in the laparoscopic group (p < 0.001). The laparoscopic group also showed a significantly better 5-year disease-free survival rate (82.7 vs. 88.7%, p = 0.009) and 5-year disease-specific survival rate (83.7 vs. 94.7%, p < 0.001).

Conclusion

Laparoscopic modified mesocolic excision with central vascular ligation is a safe and feasible approach with better short-term recovery profiles and potential oncologic benefits than the open approach for right-sided colon cancer.

Safety, quality and effect of complete mesocolic excision vs non-complete mesocolic excision in patients with colon cancer: a systemic review and meta-analysis

AIM

The application of complete mesocolic excision (CME) in colon cancer is controversial. We performed a meta-analysis to compare the safety, quality and effect of CME with non-complete mesocolic excision (NCME) in patients with colon cancer.

METHOD

We searched PubMed, ScienceDirect, the Cochrane Library and Scopus to identify studies comparing CME with NCME in colon cancer. We focused on three study outcome areas: safety (operation time, blood loss, complications, mortality); quality (large bowel length, distance from the tumour to the high vascular tie, area of mesentery, total lymph nodes); and effect (long-term survival).

RESULTS

A total of 8586 patients from 12 studies were included in the meta-analysis. CME was associated with greater intra-operative blood loss [weighted mean difference (WMD) 79.87, 95% CI: 65.88-93.86], more postoperative surgical complications (relative risk 1.23, 95% CI: 1.08-1.40), longer large bowel resection (WMD 47.06, 95% CI: 10.49-83.62), greater distance from the tumour to the high vascular tie (WMD 17.51, 95% CI: 15.16-19.87), larger area of mesentery (WMD 36.09, 95% CI: 18.06-54.13) and more lymph nodes (WMD 6.13, 95% CI: 1.97-10.28) than NCME. CME also had positive effects on 5-year survival [hazard ratio (HR) 0.33, 95% CI: 0.13-0.81], 3-year survival (HR 0.58, 95% CI: 0.39-0.86) and 3-year survival for Stage III disease (HR 0.69, 95% CI: 0.60-0.80) compared with NCME.

CONCLUSION

Limited evidence suggests that CME is a more effective strategy for improving specimen quality and survival but with a higher complication rate.

Laparoscopic complete mesocolic excision via mesofascial separation for left-sided colon cancer

PURPOSE

To evaluate the safety and feasibility of laparoscopic complete mesocolic excision (CME) via mesofascial separation for left-sided colon cancer.

METHODS

We evaluated prospectively collected data on 65 consecutive patients with stage I-III left-sided colon cancer, who underwent laparoscopic CME between October 2011 and September 2016. After the exclusion of 5 patients who had T4b or other active tumors, 60 patients were the subjects of this analysis. The completeness of CME, preservation of the hypogastric nerve, operative data, pathological findings, complications, and length of hospital stay were assessed.

RESULTS

CME completeness was graded as the mesocolic and intramesocolic plane in 54 and 6 patients, respectively. The hypogastric nerve was preserved in all patients. A total of 17, 12, 28, and 3 patients had T1, T2, T3, and T4a tumors, respectively. The mean number of lymph nodes retrieved was 16.2, and lymph node metastasis was identified in 22 patients. The mean operative time and intraoperative blood loss were 283 min and 38 ml, respectively. One patient had an intraoperative complication and six patients had postoperative complications. The hospital stay was 12 days.

CONCLUSION

Laparoscopic CME via mesofascial separation is a safe and feasible procedure for left-sided colon cancer.

Impact of Proximal Vascular Ligation on Survival of Patients with Colon Cancer

In an effort to optimize further the surgical management of colon cancer, many groups have advocated extended lymphadenectomy as a strategy to improve completeness of resection and lymph node harvest. This review evaluates lymphadenectomy according to the definitions for extent of lymph node dissection based on the guidelines provided by the Japanese Society of Cancer of the Colon and Rectum and the contemporary concepts of complete mesocolic excision and central vascular ligation. The proposed benefits of a D3 or central nodal dissection along root vessels in colon cancer is improving accuracy of lymph node evaluation and ensuring complete removal of lymph nodes that may harbor undetected tumor cells or other undefined immunologic processes important for metastases. Metastasis to central lymph nodes occurs in 1 to 8% of patients with colon cancer and is most commonly seen in T3 and T4 tumors. Although central lymph node metastasis is associated with decreased survival after resection, resection of the nodes, when present, may confer a survival benefit analogous to resection of metastasis at distant sites. Current data support a standardized anatomic approach to colonic resection with complete resection of the mesocolic envelope and ligation at least to the D2 level.