Optimal margins and lymphadenectomy in colonic cancer surgery

Indocyanine green highlights the lymphatic drainage pathways, enhancing the effectiveness of radical surgery for mid-low rectal cancer: A non-randomized controlled prospective study

BACKGROUND

Fluorescence-guided lymphadenectomy (FLND) using indocyanine green (ICG) has emerged as a promising technique to enhance the accuracy of lymphadenectomy in rectal cancer surgery. Effective lymphadenectomy is crucial for improving prognosis in patients with advanced rectal cancer, but it remains technically challenging and controversial.

METHODS

This prospective nonrandomized controlled study was conducted involving 129 patients underwent laparoscopic surgery, and 64 patients assisted by FLND. Patients received submucosal ICG injections before surgery to facilitate FLND. Lymph nodes were categorized as station 251, station 252, or station 253 based on their anatomical locations. The effectiveness of FLND was evaluated by comparing the number of harvested and metastatic lymph nodes between the FLND and control groups.

RESULTS

The FLND group demonstrated a significantly higher median number of harvested station 253 lymph nodes compared to the control group (2.0 vs. 1.0, P = 0.007). The FLND cohort had a shorter postoperative hospital stay (6 days vs. 8 days, P < 0.001) and similar rates of postoperative complications compared to the control cohort. The study found no significant differences in the median number of harvested station 251 (10.0 vs. 11.0, P = 0.872) and station 252 (6.0 vs. 5.0, P = 0.369) lymph nodes between the groups. Univariate and multivariate analyses indicated that FLND significantly increased the harvested lymph node count.

CONCLUSION

Radical surgery assisted by FLND significantly improves the accuracy and yield of lymphadenectomy in mid-low rectal cancer, enhancing surgical outcomes and patient prognosis. Future advancements in fluorescence imaging and related technologies hold promise for further improving the clinical effectiveness of this technique.

Is surgical quality more important than radicality? Long-term outcomes of stage I-III colon cancer (SAKK 40/00)

BACKGROUND

To prospectively determine the influence of variations of surgical radicality and surgical quality on long-term outcome in patients with stage I-III colon cancer.

METHODS

From a prospective multicenter cohort study including 1040 patients undergoing surgery for colorectal cancer from 09/2001 to 06/2005 in nine Swiss and one German hospital, 423 patients with stage I-III colon cancer were selected and analyzed. Surgeons and pathologists filled in standardized forms prospectively assessing items of oncosurgical radicality and quality. Patients had standardized follow-up according to national guidelines.

RESULTS

Follow-up was median 6.2 years (range 0.3-10.4) showing a 5-year disease-free survival/overall survival of 83 %/87 % in stage I (n = 85), 69 %/77 % in stage II (n = 187), and 53 %/61 % in stage III (n = 151) colon cancer. Despite remarkable variations of oncosurgical radicality and quality, the multivariate model revealed that mainly quality items correlated significantly with disease-free survival (surgical tumor lesion HR 2.12, p = 0.036, perioperative blood transfusion HR 1.67, p = 0.018, emergency resection HR 1.74, p = 0.035) and overall survival (early venous ligation HR 0.66, p = 0.023, surgical tumor lesion HR 2.28, p = 0.027, perioperative blood transfusion HR1.79, p = 0.010, emergency resection HR 1.88, p = 0.026), while radicality parameters (length of specimen, distance of the tumor to nearest bowel resection site, number of lymph nodes, height of resected mesocolon and of central vascular dissection) did not.

CONCLUSION

Surgical quality seems to have a stronger impact on oncologic long-term outcome in stage I - III colon cancer than surgical radicality.

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

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

The topographical distribution of lymph node metastases in colon cancer resections

In accordance with international guidelines all lymph nodes in colon cancer specimens must be examined to obtain accurate staging. This study aimed to determine the topographical location of lymph node metastases and evaluate if a more limited sampling approach could be an alternative. Partial colectomies received at the Department of Pathology, Zealand University Hospital during a six-month period were included. At the macroscopic examination, each specimen was divided into three different segments: a segment containing the index tumor and the tumor-feeding artery, an oral and an anal segment. The number of lymph nodes and lymph node metastases were registered separately for each segment. Resections from 93 patients were included. Of 2466 lymph nodes, 1839 (74.6 %) were located in the tumor segment, 308 (12.5 %) in the oral, and 319 (12.9 %) in the anal segment, respectively. In 133 (5,4 %) lymph nodes a metastasis was present. Of these 129 (97.0 %) were located in the tumor segment, one (0.8 %) in the oral segment, and three (2.3 %) in the anal segment. No patients had metastasis in the oral or anal segments without metastases also being present in the tumor segment leading to consideration of the need for lymph node harvest of the complete specimen upon initial examination. As such, the segment containing the index tumor and tumor-feeding artery could be regarded as a sentinel segment indicating a potential need for lymph node dissection in the oral and anal segments.

Is 10 cm ileal resection sufficient in locally advanced caecal cancer surgery?

BACKGROUND

There is no consensus as to how much ileal resection is sufficient when performing a right hemicolectomy for right colon cancers. Locally advanced caecal cancer has the highest incidence of peri-ileal lymph node metastasis. Therefore, this study investigated whether the 10 cm ileum resection suggested by the Japanese Society for Cancer of the Colon and Rectum is oncologically safe in stage II and III caecal cancer.

METHODS

The prospectively collected medical records of stage II and III caecal cancer patients who underwent a right hemicolectomy with at least D2 lymph node dissection were reviewed retrospectively. The patients were divided into two groups according to the length of proximal ileal resected: group 1 (≤10 cm) and group 2 (>10 cm). Factors contributing to the 5-year overall survival (OS) were analysed.

RESULTS

The study enrolled 89 patients with pathological stage II or III caecal cancer. The >10 cm group tended to be younger (P = 0.0938) with higher pathological N stages (P = 0.0899) than the ≤10 cm group. The 5-year OS did not differ between the two groups. No significant difference was found between the two groups according to stage. Age (HR = 1.06, 95% CI = 1.02-1.10, P = 0.0069) and N2 stage (HR = 5.38, 95% CI = 1.90-15.28, P = 0.0016) were significantly associated with OS in both uni- and multivariate analyses.

CONCLUSIONS

There was no OS benefit to resecting >10 cm of ileum in either stage II or III caecal cancer patients. Hence, we suggest that the '10 cm rule' is sufficient for stage II and III caecal cancer patients.

Lymph node retrieval colon cancer: Are we making the grade?

BACKGROUND

Adequate lymph node (LN) excision is imperative for pathologic staging and determination of adjuvant treatment.

METHODS

he 2004-2017 National Cancer Database (NCDB) was queried for curative colon cancer resections. Tumors were categorized by location: left, right, and transverse colon cancers. Adequate (12-20 LNs) vs. inadequate (<12 LNs) lymphadenectomy was examined and sub-analysis of <12 LNs, 12-20 LNs or >20 LNs. Primary outcome was predictors of inadequate lymph node retrieval.

RESULTS

Of 101,551 patients, 11.2% (11,439) had inadequate lymphadenectomy. The inadequate lymphadenectomy rate steadily decreased. On multivariable analysis, inadequate LN retrieval was associated with transverse (OR 1.49, CI [1.30-1.71]) and left colon cancers (OR 2.66, CI [2.42-2.93], whereas income >$63,333 had decreased likelihood of inadequate LN retrieval (OR 0.68, CI[0.56-0.82].

CONCLUSION

We are making the grade as NCDB data demonstrates a steady decrease in inadequate lymphadenectomy (2004-2017). There remain socioeconomic risk factors for inadequate lymphadenectomy that need to be addressed.

Optimal bowel resection margin in colon cancer surgery: prospective multicentre cohort study with lymph node and feeding artery mapping

Background

There are no standardised criteria for the 'regional' pericolic node in colon cancer, which represents a major cause of the international uncertainty regarding the optimal bowel resection margin. This study aimed to determine 'regional' pericolic nodes based on prospective lymph node (LN) mapping.

Methods

According to preplanned in vivo measurements of the bowel, the anatomical distributions of the feeding artery and LNs were determined in 2996 stages I-III colon cancer patients who underwent colectomy with resection margin >10 cm at 25 institutions in Japan.

Findings

The mean number of retrieved pericolic nodes was 20.9 (standard deviation, 10.8) per patient. In all patients except seven (0.2%), the primary feeding artery was distributed within 10 cm of the primary tumour. The metastatic pericolic node most distant from the primary tumour was within 3 cm in 837 patients, 3-5 cm in 130 patients, 5-7 cm in 39 patients and 7-10 cm in 34 patients. Only four patients (0.1%) had pericolic lymphatic spread beyond 10 cm; all of whom had T3/4 tumours accompanying extensive mesenteric lymphatic spread. The location of metastatic pericolic node did not differ by the feeding artery's distribution. Postoperatively, none of the 2996 patients developed recurrence in the remaining pericolic nodes.

Interpretation

The pericolic nodes designated as 'regional' were those located within 10 cm of the primary tumours, which should be fully considered when determining the bowel resection margin, even in the era of complete mesocolic excision.

Funding

Japanese Society for Cancer of the Colon and Rectum.

A Clinicopathological Feature-Based Nomogram for Predicting the Likelihood of D3 Lymph Node Metastasis in Right-Sided Colon Cancer Patients

BACKGROUND

Despite advancements in treating right-sided colon cancer patients, the ideal scope of lymphadenectomy remains controversial.

OBJECTIVE

Our objective was to investigate the likelihood of D3 lymph node metastasis in right-sided colon cancer patients and develop a clinicopathological feature-based nomogram for D3 lymphadenectomy.

DESIGN

We retrospectively analyzed 286 right-sided colon cancer patients who underwent D3 lymphadenectomy. The patients were divided into 2 groups based on whether D3 lymph node metastasis was positive. Then, univariable and multivariable logistic regression analyses were performed to obtain independent risk factors for predicting D3 lymph node metastasis. Moreover, we performed receiver operating characteristic curve analyses to evaluate the predictive power of the model.

SETTING

This study was conducted at Nanfang Hospital of Southern Medical University in China.

PATIENTS

A total of 286 consecutive patients who underwent right hemicolectomy and D3 lymphadenectomy as a primary treatment for right-sided colon cancer between January 2016 and December 2019 were enrolled in this study.

MAIN OUTCOME MEASURES

The primary measures were independent risk factors for predicting D3 lymph node metastasis in right-sided colon cancer.

RESULTS

The D3 lymph node metastasis rate in right-sided colon cancer patients was 16.1% (46/286). D3 lymphadenectasis on CT, lymphatic invasion, and T4 tumors were filtered out as independent risk factors for D3 lymph node metastasis according to the multivariable logistic regression analysis. We established a nomogram that predicted D3 lymph node metastasis of right-sided colon cancer on the combination of the 3 factors with an area under the curve of 0.717 (95% CI, 0.629-0.806).

LIMITATIONS

This was a retrospective study from a single center.

CONCLUSIONS

We developed a valuable clinicopathological feature-based nomogram to predict the incidence of D3 lymph node metastasis in right-sided colon cancer patients. Patients with D3 lymphadenectasis on CT, preoperative T4 tumors, and lymphatic invasion should undergo D3 lymphadenectomy. See Video Abstract at http://links.lww.com/DCR/B852 .

UN NOMOGRAMA BASADO EN CARACTERSTICAS CLNICOPATOLGICAS PARA PREDECIR LA PROBABILIDAD DE METSTASIS EN GANGLIOS LINFTICOS D EN PACIENTES CON CNCER DE COLON DERECHO

ANTECEDENTES:A pesar de los avances en el tratamiento de pacientes con cáncer de colon derecho, el ámbito ideal de la linfadenectomía sigue siendo controvertido.OBJETIVO:Investigar la probabilidad de metástasis en los ganglios linfáticos D3 en pacientes con cáncer de colon derecho y desarrollar un nomograma basado en características clínico-patológicas basado para la linfadenectomía D3.DISEÑO:Analizamos retrospectivamente a 286 pacientes con cáncer de colon derecho que se sometieron a linfadenectomía D3. Los pacientes se dividieron en dos grupos en función de si eran positivos para metástasis en los ganglios linfáticos D3. Luego, se realizaron análisis de regresión logística univariable y multivariable para obtener factores de riesgo independientes para predecir metástasis en los ganglios linfáticos D3. Además, realizamos análisis de las curvas de características operatorias del receptor para evaluar el poder predictivo del modelo.SEDE:Este estudio se realizó en el Hospital Nanfang de la Universidad Médica del Sur en China.PACIENTES:Un total de 286 pacientes consecutivos que se sometieron a hemicolectomía derecha y linfadenectomía D3 como tratamiento primario para el cáncer de colon derecho entre enero de 2016 y diciembre de 2019 se inscribieron en este estudio.PRINCIPALES MEDIDAS DE RESULTADO:Las medidas primarias fueron factores de riesgo independientes para predecir las metástasis en ganglios linfáticos D3 en el cáncer de colon derecho.RESULTADOS:La tasa de metástasis en los ganglios linfáticos D3 en pacientes con cáncer de colon del lado derecho fue del 16,1% (46/286). El aumento de tamaño de ganglios D3 en la TC, la invasión linfática y los tumores T4 se filtraron como factores de riesgo independientes de metástasis en los ganglios linfáticos D3 de acuerdo con el análisis de regresión logística multivariable. Establecimos un nomograma que predijo metástasis en los ganglios linfáticos D3 del cáncer de colon derecho en la combinación de los tres factores con un área bajo la curva de 0,717 (IC del 95%, 0,629-0,806).LIMITACIONES:Este fue un estudio retrospectivo de un solo centro.CONCLUSIONES:Desarrollamos un valioso nomograma basado en características clínico-patológicas para predecir la incidencia de metástasis en los ganglios linfáticos D3 en pacientes con cáncer de colon derecho. Los pacientes con crecimiento de ganglios D3 en TC, tumores con clasificación preoperatoria T4 e invasión linfática, deben ser sometidos a linfadenectomía D3. Consulte Video Resumen en http://links.lww.com/DCR/B852 . (Traducción-Dr. Juan Carlos Reyes ).

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Robotic versus open pancreaticoduodenectomy, comparing therapeutic indexes; a systematic review

BACKGROUND

Pancreaticoduodenectomy (PD) is a challenging procedure with peri-operative complications. Robotic surgery offers improved dexterity, visibility, and accessibility. Recently, many centres have reported improved clinical outcomes for robotic PD. We reviewed the safety and efficacy of robotic PD in comparison to open PD using 'Therapeutic Index' (TI).

METHODS

A systematic review of the literature was conducted in various databases. Articles published between January 2010 and March 2021 reporting totally-robotic and open PD were included, according to the PRISMA and AMSTAR-2 guidelines. The Cochrane tool was used for risk of bias assessment. We compared 30-day mortality rates (MR₃₀), lymphadenectomy rates (LR), R0 resection rates (R₀RR) and therapeutic index (TI). STATA 16.1 was used for statistical analysis.

RESULTS

The four studies that met inclusion criteria included 5090 PDs, out of which 617 were totally-robotic (RPD) and 4473 were open (OPD). Variance ratio tests demonstrated a)Higher TI for RPD versus OPD (1807.42 vs 1723.37, p = 0.86), b)Significantly smaller MR₃₀ (2.50 vs 19.00, p = 0.0004), c)Significantly lower R₀RR (130.50 vs 939.25, p = 0.00) and d)No significant difference in LR between RPD and OPD (35.63 vs 38.25, p = 0.81). Meta-regression analysis showed a significantly higher TI coefficient of RPD than OPD (0.66 vs -0.40, p = 0.08, α = 0.1).

CONCLUSION

Our study suggests that robotic PD is safe and not inferior to open PD and our analysis RPD demonstrated a higher therapeutic index than OPD. Randomised controlled trials are required to establish the efficacy of robotic PD. Also, standardisation of reporting mortality, survival and oncological outcomes is needed for the effective calculation of TI.

Lymph Node Status and Long-Term Oncologic Outcomes After Colon Resection in Locally Advanced Colon Cancer

Locally advanced colon cancer is associated with poor prognosis. The aim of this report was to examine the association between the lymph node status and prognosis of locally advanced colon cancer. Perioperative and oncologic outcomes were studied in patients who had undergone colectomy for colon cancer between June 2004 and December 2018. Locally advanced colon cancer was defined as stage T4a/T4b cancer. The long-term oncologic results were investigated in patients with non-metastatic locally advanced colon cancer. Of 195 patients operated for locally advanced colon cancer, 83 (42.6%), 43 (22.1%), and 69 (35.3%) had pN0, pN1, and pN2 disease, respectively. Preoperative serum levels of CEA and CA 19-9, as well as incidence of distant metastases were significantly higher in patients with pN2 compared to those with pN0 and pN1. In non-metastatic setting, a trend towards higher incidence of recurrence was observed in node-positive patients. Nodal stage was a significant predictor for survival in the univariable analysis but non-significant after adjusting for confounders. Subgroup analyses among the patients with T4a and T4b cancer did not demonstrate any association between the nodal stage and survival. Preoperative CA 19-9 > 37 U/ml and adjuvant chemotherapy were the only prognostic factors in T4a and T4b colon cancer, respectively. Although a trend towards higher incidence of recurrence was observed in node-positive locally advanced colon cancer, nodal stage was not associated with survival. Adjuvant chemotherapy should be strongly considered in T4b stage colon cancer.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Hemicolectomy Does Not Provide Survival Benefit for Right-Sided Mucinous Colon Adenocarcinoma

BACKGROUND

The extent of bowel resection is widely debated in colon cancer surgery. Right hemicolectomy (RHC) and partial colectomy (PC) are the most common operation options for right-sided colon cancer (RCC). However, there are still no treatment guidelines or published studies to guide surgical options for mucinous adenocarcinoma (MAC) of RCC.

METHODS

Patients with MAC and non-specific adenocarcinoma (AC) of RCC who underwent RHC and PC from 2010 to 2015 in the Surveillance, Epidemiology, and End Results (SEER) database were retrieved. The general characteristics and survival were compared and analyzed.

RESULTS

A total of 27,910 RCC patients were enrolled in this study, among them 3,413 were MAC. The results showed that race, carcinoembryonic antigen (CEA) level, perineural invasion (PNI), tumor size, tumor location, TNM stage, liver metastasis, chemotherapy were significantly different between MAC and AC groups. The MAC group had similar dissected lymph nodes, but more positive lymph nodes than the AC group. The overall survival (OS) of the MAC group was poorer than that of the AC group, but cancer-specific survival (CSS) was similar between the two groups. The RHC subgroup of the MAC group had more patients of age ≤60 years, larger tumor size, cecum/ascending colon location and dissected lymph nodes than the PC subgroup, but similar positive lymph nodes, perioperative mortality, OS and CSS as the PC subgroup. Moreover, the univariate and multivariable analyses for the survival of RCC patients with MAC showed that RHC might not be a superior predictor for OS and CSS compared with PC.

CONCLUSIONS

RHC could not dissect more positive lymph nodes or provide long-term survival benefits for RCC patients with MAC compared with PC. This study could provide some evidence for surgery treatment selection for MAC of RCC, which has important clinical value in individual management of colon cancer patients.

Study protocol for an International Prospective Observational Cohort Study for Optimal Bowel Resection Extent and Central Radicality for Colon Cancer (T-REX study)

This is a prospective observational cohort study aiming to include 4000 patients with stages I to III colon cancer treated at 35 specialist institutions in Japan, South Korea, Germany, Russia, Lithuania and Taiwan. The anatomical distribution of lymph nodes and feeding arteries are investigated using surgical specimens according to pre-specified categorizing methods using intraoperative anatomical markings. Primary analyses are performed to identify the general principles of metastatic lymph node distribution in terms of its relation to the location of the primary tumor and feeding arteries. Secondary analyses will be used to estimate prognostic outcomes according to bowel resection length and central radicality and will be used to evaluate the quality of resected surgical specimens. Through in-depth lymph node mapping, standardized criteria for the definite area of ‘regional’ lymph node resection in routine surgical procedures can be identified, which is expected to contribute to international standardization in colon cancer surgery (ClinicalTrials.gov NCT02938481).

Proposal for a post-operative surveillance strategy for stage I colorectal cancer patients based on a novel recurrence risk stratification: a multicenter retrospective study

BACKGROUND

The recurrent risk of stage I colorectal cancer (CRC) is not clear, and the data regarding appropriate post-operative surveillance schedules in stage I CRC are scarce.

OBJECTIVES

We aimed to stratify stage I CRC based on the recurrence risk and evaluate optimal post-operative surveillance durations based on this stratification.

METHODS

We retrospectively analyzed the cases of 6607 stage I CRC patients from 24 institutions. To assess the patients' clinicopathological factors that impact recurrence-free survival (RFS), we performed univariate and multivariate analyses using Cox proportional hazards models. We divided the patients into classes based on their numbers of factors that were associated with poor RFI in the multivariate analysis.

RESULTS

Recurrence occurred in 3.9% patients. The multivariate analysis revealed the independent factors for poor RFS: rectal cancer, T2 depth, presence of lymphatic invasion, high level of pre-operative carcinoembryonic antigen, and absence of D2-3 lymphadenectomy. We also divided the patients into three classes based on their numbers of these risk factors; the 3-year and 5-year RFS rates were 99.3% and 99.1% in the no-risk patients, 97.4% and 96.5% in the patients with 1-2 risks, and 92.1% and 90.0% in the patients with 3-5 risks, respectively. In the patients with no risk and in the patients with 1-2 risks after 3 years post-surgery, ≤ 1% recurrence occurred. Thus, post-operative surveillance may be omitted in these populations.

CONCLUSIONS

Our new classification properly stratified the recurrence risks of stage I CRC patients, and may help reduce unnecessary post-operative surveillance.

Robotic Complete Mesocolic Excision with Central Vascular Ligation for Right Colon Cancer: Surgical Technique and Short-term Outcomes

BACKGROUND

Minimally invasive colorectal surgery has demonstrated to have the same oncological results as open surgery, with better clinical outcomes. Robotic assistance is an evolution of minimally invasive technique.

PURPOSE

The study aims to present technical details and short-term oncological outcomes of robotic-assisted complete mesocolic excision (CME) with central vascular ligation (CVL) for right colon cancer.

METHODOLOGY

Fifty-two consecutive patients affected by right colon cancer were operated between May 2016 and February 2020 with da Vinci Xi platform. Data regarding surgical and short-term oncological outcomes were systematically collected in a colorectal specific database for statistical analysis.

RESULTS

Thirty-seven (71.15%) and 15 (28.85%) patients underwent right and extended right hemicoletomy with an extracorporeal anastomosis. Median age was 55 years. Mean operative time was 182 ± 36 min. Mean blood loss was 110 ± 90 ml. Conversion rate was 3.84% (two cases). 78.84% (41 cases) were pT3 and mean number of harvested lymph nodes was 28 ± 4. 1/52 (1.92%) had a documented anastomotic leak requiring exploratory laparotomy and diversion proximal ileostomy. Surgery-related grade IIIa-IIIb Calvien Dindo morbidity were noted in 9.61% and 1.92%, respectively.

CONCLUSION

Robotic assistance allows performance of oncological adequate dissection of the right colon with radical lymphadenectomy as in open surgery, confirming the safety and oncological adequacy of this technique, with acceptable results and short-term outcomes.

The role of apical lymph node metastasis in right colon cancer

BACKGROUND

The role of apical lymph node (APN) metastasis in colorectal cancer remains controversial. The main purpose of this study is to explore the prognostic value of APN metastasis in patients with right colon cancer.

METHODS

This is a retrospective study of patients with stage III right colon cancer between April 2007 and December 2016. Patients who underwent resection of right colon cancers with D3 lymph node dissection were divided into APN-positive (APN+) and APN-negative (APN-) groups according to the postoperative pathological presence or absence of APN metastasis. Relapse-free survival (RFS) and overall survival (OS) between groups were compared after Cox regression analysis and 1:1 propensity score matching (PSM).

RESULTS

A total of 254 patients were included in this study: 28 (11.0%) were APN+ and 226 (89.0%) were APN-. Before matching, the rates of elevated carcinoembryonic antigen (CEA), T3-4 tumor invasion, and N2 lymph node metastasis were significantly higher in the APN+ group (CEA ≥ 5 ng/mL, 53.6% vs. 37.6%, p < 0.001; T3-4, 92.9% vs. 85.4%, p < 0.001; N2 metastasis, 57.1% vs. 20.4%, p < 0.001), and APN+ tumors were associated with significantly higher postoperative relapse rates (39.3% vs. 21.2%; p = 0.03), especially with lung metastases (14.3% vs. 4.0%; p = 0.019), which conferred worse RFS (p = 0.013), although OS was similar (p = 0.078). However, after PSM, there were no apparent between-group differences in RFS (p = 0.29) or overall survival rate (p = 0.637). The Cox regression analysis indicated that lymphatic vessel infiltration and depth of invasion were independent risk factors for OS, while APN+ status was not a significant predictor for RFS or OS.

CONCLUSIONS

APN metastasis was not a prognostic indicator for RFS or OS in right colon cancer. However, APN+ patients with elevated CEA levels and deeper tumor invasion should be closely monitored for lung metastasis during postoperative follow-up.

Laparoscopic complete mesocolic excision with D3 lymph node dissection for right colon cancer in elderly patients

Complete mesocolic excision (CME) with D3 lymph node dissection is considered an oncological surgery for right colon cancer. However, there is still controversy for extensive oncological surgery in elderly patients. The aim of this study is to evaluate the safety and oncological outcomes of laparoscopic CME with D3 lymph node dissection for right colon cancer in elderly patients. Patients who underwent laparoscopic right colectomy, from 2004 to 2014, were divided into Groups A (age ≥ 70 years, n = 80) or B (age < 70 years, n = 127). Short and long-term outcomes were analysed. Basic demographics and short-term surgical outcomes were similar between groups. Among pathological outcomes, the mean number of harvested lymph nodes was significantly less in Group A. Adjuvant chemotherapy refusal rate was significantly higher in Group A. Overall and recurrence-free survival were similar between groups. We found laparoscopic CME with D3 lymph node dissection is a safe and feasible surgical option for right colon cancer in elderly patients.

Minimally invasive complete mesocolic excision and central vascular ligation (CME/CVL) for right colon cancer

Total mesorectal excision (TME) is the standard of care in rectal cancer surgery. Complete mesocolic excision and central vascular ligation (CME and CVL) are surgical concepts that are extrapolated from the principles of TME. Increasingly adopted by surgical units worldwide, laparoscopic CME/CVL for right sided colon cancer is a challenging procedure that requires meticulous dissection by the surgeon and detailed knowledge of the colonic vascular anatomy. This review article addresses the main issues pertaining to this surgical technique and also discusses steps on how to perform this operation safely.

Which is more important in the management of splenic flexure colon cancer: strict central lymph node dissection or adequate bowel resection margin?

BACKGROUND

What qualifies as optimal lymph node (LN) dissection in the surgical management of splenic flexure colon cancer (SFCC) still remains controversial because few studies have evaluated the distribution of LN metastasis of SFCC. The aim of this study was to clarify detailed distribution of LN metastasis and long-term outcomes of SFCC.

METHODS

This retrospective study enrolled patients who had curative colectomy for primary transverse or descending colon cancer of pathological stage I, II, or III at a single high-volume cancer center between April 2002 and December 2018. The 538 eligible patients were divided into three groups: patients with SFCC (SFCC group, n = 168), patients with proximal transverse colon cancer (PTCC group, n = 290), and patients with distal descending colon cancer (DDCC group, n = 80). LNs were classified into horizontal (pericolic) and vertical (intermediate and main) nodes. Intermediate and main LN station numbers were defined according to the Japanese Society for Cancer of the Colon and Rectum classification. Distributions of LN metastasis and long-term outcomes were compared.

RESULTS

In the SFCC group, the mean age was 67.3 ± 10.5 years and 110 patients (65.5%) were male. The proportion of patients with LN metastasis in the intermediate or main region was significantly lower in the SFCC group (8%) than in the PTCC (37%) (p < 0.01) or DDCC group (29%) (p < 0.01) in pathological stage III patients. In the SFCC group, the incidence of pericolic LN metastasis on the oral side of tumor (43%) was significantly higher than in the PTCC group (21%) (p < 0.01) and was similar to that in the DDCC group (42%) (p = 0.51), while in the SFCC group, the incidence of pericolic LN metastasis on the anal side of tumor (17%) was lower than in the PTCC group (31%) and was also similar to that in the DDCC group (21%). There were no significant differences in disease-specific survival rates among all groups.

CONCLUSIONS

LN metastasis occurred mainly in the pericolic region, especially on the oral side of the tumor in SFCC. It may, therefore, be important to have an adequate bowel resection margin, especially on the oral side, for SFCC.

How does lymph node yield affect survival outcomes of stage I and II colon cancer?

Background

According to the American Joint Committee on Cancer staging for cancer of the colon, a minimum of 12 lymph nodes (LN) has to be sampled for accurate staging. This has bearing on the long-term prognosis and the need for adjuvant chemotherapy. The aim of this study was to revisit the association of lymph node yield and the long-term survival in patients with stages I and II, i.e. node-negative, colon cancer.

Method

Consecutive patients who underwent elective or emergency curative resections for cancer of colon between the years 2003 and 2012 were retrospectively reviewed. Only patients with stage I or II diseases (AJCC 8th edition) were included. They were analysed in three groups, LN<12, LN12-19 and LN≥20. Their clinic-pathological characteristics were compared. The disease-free (DFS) and overall survival (OS) were estimated with the Kaplan-Meier method and compared with the log-rank test.

Results

There was a total of 659 patients included in the analysis. Twelve or more LN were found in 65.6% of the specimens. The mean follow-up was 83.9 months. LN≥20 had significantly better DFS (p = 0.015) and OS (p = 0.036), whereas LN<12 had similar DFS and OS when compared to LN12-19. The advantage in DFS and OS were mainly seen in those with stage II diseases. A lymph node yield of greater than 20 was one of the predictors of favourable DFS, hazard ratio 0.358; 95% CI 0.170–.756, p = 0.007.

Conclusion

The lymph node yield had a significant association with survival outcomes. A lymph node yield of 20 or more was associated with better survival outcomes. On the other hand, lymph node yield less than 12 was not shown to have inferior survival outcomes when compared to those between 12 and 19.

Distribution of lymph node metastasis and the extent of lymph node dissection in descending colon cancer patients

BACKGROUND

The optimal extent of lymph node dissection in patients with descending colon cancer is still debatable. We designed this study to evaluate the distribution of lymph node metastasis and the appropriate extent of lymph node dissection in descending colon cancer patients.

METHODS

We retrospectively reviewed the medical records of 118 descending colon cancer patients without distant metastasis, who underwent curative resection between January 2004 and December 2014. The distribution of lymph node metastasis was evaluated, and prognostic factors were analysed.

RESULTS

The median follow-up period was 52 months (range 1-125 months). Twenty-six (22.0%) patients underwent high ligation of the inferior mesenteric artery (IMA), whereas 92 (78.0%) patients underwent ligation of the left colic artery, saving the IMA. Lymph nodes at the origin of the IMA showed no metastasis in any of the 26 patients who underwent high ligation of the IMA. After propensity score matching, 3-year disease-free survival (80.4% versus 92.9%, P = 0.471) and 5-year overall survival (81.8% versus 90.9%, P = 0.875) were not significantly different according to the type of IMA ligation.

CONCLUSION

In patients with descending colon cancer, there was no lymph node metastasis at the origin of the IMA, and ligation of the IMA showed no prognostic benefit.

[Lymphadenectomy in oncological visceral surgery-Part 2 : Cancer of the upper and lower intestinal tract]

In cancers of the upper and lower intestinal tract the risk of lymphatic metastases depends on the histological results, tumor grading, and depth of tumor infiltration (T-stage). Pretherapeutic staging is of particular importance for determining the surgical strategy (local excision vs. en bloc resection with regional lymphadenectomy) as well as for evaluating the necessity of neoadjuvant therapy. While the first part on "Lymphadenectomy in oncological visceral surgery" focused on hepatobiliary and pancreatic cancer, this second part contains an overview of anatomical conditions of lymphatic drainage of the esophagus, stomach, duodenum, small intestine, colon, rectum and anus. Based on this, the principles and techniques of lymphadenectomy for cancer in these organs and the requirements on systematic regional lymphadenectomy in the actual TNM classification (8th edition) are discussed.

The Impact of a Multivisceral Resection and Adjuvant Therapy in Locally Advanced Colon Cancer

BACKGROUND

Multivisceral resection for locally advanced colon cancer is mandatory to achieve complete tumor resection. We aimed to determine if local multivisceral resections (LMR) for pT4 and pT3 tumors impact perioperative and long-term oncological outcomes.

METHODS

All stage II or III colon cancer patients who had surgery between 2004 and 2014 were identified. We analyzed patients with non-multivisceral resections (NMR) for pT4 tumors vs. pT4-LMR. In addition, outcomes were compared to both NMR and LMR pT3 patients.

RESULTS

LMR was performed in 55 (29.7%) of all patients with pT4 tumors and in 48 (8.9%) of all patients with pT3 tumors. The most commonly involved areas of extension were the abdominal wall and the small intestine. Transverse colon cancer was correlated with LMR. Morbidity rates were comparable between NMR and LMR, with the exception of higher rates of blood transfusion and postoperative ileus. Over one third of all pT4-NMR patients developed recurrent disease, which was higher compared to all other groups. Subsequently, overall and disease-specific survival, as well as disease-free survival (DFS), was worse for pT4-NMR, even after adjustment for pTN-staging, adjuvant therapy, and R0 resection. Furthermore, when analyzing only curative resections, radial margin < 1 cm along with nodal disease was independent predictor for worse DFS. Long-term outcomes were comparable between pT4-LMR and pT3 patients.

CONCLUSIONS

Multivisceral resection for locally advanced colon cancer preserves long-term oncological outcomes without increased postoperative morbidity. Moreover, LMR in pT3 tumors does not contribute to postoperative morbidity. Our study underlines the feasibility and importance of performing LMR when locally advanced cancer is suspected.

Biology-Based Surgery: The Extent of Lymphadenectomy in Cancer of the Colon

The progression of colon cancer (CC) involves hematogenous and lymphatic spread to locoregional lymph nodes (LN), distant LN, and metastatic sites including the liver. The biological mechanisms that govern CC progression remain elusive. The Halsted model assumes an orderly, stepwise progression from the primary tumor to nearby nodes, henceforth to anatomically more distant nodes, and ultimately to distant organs. The Fisher model, on the other hand, regards the release of metastatic cells as early and essentially random events. The underlying biology has important implications for the ideal extent of surgery: when the Fisher model is correct, efforts to remove apical (central), extramesenteric, or para-aortic LN are unlikely to affect the oncological outcome. Recent data from phylogenetic studies suggest that cancer cell populations differ genetically among different LN stations and from distant metastases. Circulating tumor cells and other liquid biomarkers can be detected in the circulation of patients with early-stage disease. Local recurrence in CC is uncommon, and it is associated with a high risk of systemic progression and poor survival. Clinical studies comparing standard colectomy with extensive surgery (high ligation of the inferior mesenteric artery, complete mesocolic excision, D3 dissection, and para-aortic or extramesenteric node dissection) show that these techniques increase the LN count, while any beneficial effect on the risk of local recurrence or disease-free survival is at present uncertain due to the lack of controlled trials. Ongoing randomized trials comparing extensive vs. standard surgery for CC will generate important answers.

Laparoscopic right hemicolectomy oriented by superior mesenteric artery for right colon cancer: efficacy evaluation with a match-controlled analysis

Background

Laparoscopic right hemicolectomy (LRC) with a principle of D3 lymphadenectomy seems to be appropriate in treatment of right-sided colon cancer (RCC). This study aimed to evaluate clinical efficacy of superior mesenteric artery (SMA)-guided LRC (SLRC) for RCC patients.

Patients and methods

Data for RCC patients with radical resection were retrieved from our database and electronic medical records (January 2010 to December 2014). Patients undergoing SLRC procedure were compared with those undergoing conventional laparoscopic right hemi-colectomy (CLRC), with a match ratio of 1:2 for group balance. Perioperative and long-term outcomes were compared between two groups.

Results

In sum, 102 matched patients were selected, with a median follow-up of 32 (range, 3–68) months. The mean operative time was significantly reduced in the SLRC group compared to the CLRC group (206.9 vs 240.0 minutes, P=0.007), with increased incidence of postoperative complications observed (14.7% vs 8.8%, P=0.499). Average length of stay after surgery (7.4 vs 8.0 days), estimated blood loss (85.3 vs 105.4 mL), number of harvested (28.4 vs 28.2) and positive (0.6 vs 0.9) lymph nodes, and overall costs ($4826.9 vs $4874.6) were comparable between two groups (P>0.05). The 3-year disease-free survival rate (89.4% vs 92.1%, P=0.840) and overall survival rate (93.0% vs 83.1%, P=0.273) were similar in both groups. Older age (≥65 years, P=0.049) and advanced tumor stage (≥II, P=0.009) were independent risk factors of recurrence.

Conclusion

The perioperative and oncologic outcomes of SLRC were not superior, but comparable to CLRC. SMA-guided dissection was a feasible surgical approach in treatment of RCC.

Clinical Significance of Lymph Node Metastasis in the Mesentery of the Terminal Ileum in Patients With Right-sided Colon Tumors at Different Locations

BACKGROUND

There are limited reports on peri-ileal lymph node metastasis in patients with right-sided colon cancer, and little is known about their clinical significance.

OBJECTIVE

This study aimed to examine the role of tumor location in the prevalence and clinical significance of peri-ileal lymph node metastasis in patients with right-sided colon cancer.

DESIGN

This is a retrospective study from a prospective cohort database.

SETTINGS

The study was conducted at a tertiary referral hospital.

PATIENTS

Patients with right-sided colon cancer treated with radical surgery in a hospital between May 2006 and September 2016 were included.

MAIN OUTCOME MEASURES

The frequency of peri-ileal lymph node metastasis in the study cohort and the role of tumor location and the clinical characteristics of patients with peri-ileal lymph node metastasis were determined.

RESULTS

We examined 752 cases with right-sided colon cancer including 82 cecal, 554 ascending colon, and 116 hepatic flexure cancer. Twenty patients (2.7%) had peri-ileal lymph node metastasis. The incidence of metastasis to peri-ileal lymph nodes was 7.3% (6/82) in patients with cecal cancer, 2.2% (12/554) in patients with ascending colon cancer, and 1.7% (2/116) in patients with hepatic flexure cancer. Three patients had stage III cancer and 17 had stage IV. All 3 patients with positive peri-ileal lymph nodes and stage III cancer had cecal tumors. In contrast, all patients with ascending colon or hepatic flexure cancer and positive peri-ileal lymph nodes had stage IV cancer.

LIMITATIONS

The results were limited by the retrospective design of the study and the small number of patients with peri-ileal lymph node metastasis.

CONCLUSIONS

Peri-ileal lymph node metastasis was rare even in right-sided colon cancer and occurred mainly in stage IV. However, it occurred in some patients with locally advanced cecal cancer. These results suggest that optimal resection of the mesentery of the terminal ileum might have clinical benefit, especially in curative surgery for cecal cancer. See Video Abstract at http://links.lww.com/DCR/A556.

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.

The distribution of lymph node metastases and their size in colon cancer

PURPOSE

The purpose of this study is to clarify the optimal extent of lymph node dissection for colon cancer by evaluating the distributions of lymph node metastases and lymph node size according to tumor location and T stage.

METHODS

This study enrolled 662 patients who underwent curative resection for primary colon cancer between 2013 and 2015. Lymph node regions were classified into pericolic, intermediate, and main nodes. The short-axis diameter of each dissected lymph node was measured. The distributions of lymph node metastases and lymph node size were evaluated according to tumor location and T stage.

RESULTS

In the overall cohort, the incidence of metastases in pericolic nodes located more than 5 cm but no more than 10 cm from tumor and in pericolic nodes located more than 10 cm from tumor was 3.6 and 0.2%, respectively. More than 2% of patients with ≥ T2 tumor had metastases in main lymph nodes, and no patients with T1 tumor had metastases in main lymph nodes. Only 0.7% of patients with T1 tumor had lymph node metastases in pericolic nodes located more than 5 cm from the tumor. Both metastatic and non-metastatic lymph node sizes were significantly larger in right-sided colon cancer than in left-sided colon cancer, and both metastatic and non-metastatic lymph node sizes were significantly larger in ≥ T2 tumor than in T1 tumor.

CONCLUSION

It is necessary to resect 10 cm of normal bowel both proximal and distal to the tumor and to perform D3 lymph node dissection for ≥ T2 colon cancer.

The American Society of Colon and Rectal Surgeons Clinical Practice Guidelines for the Treatment of Colon Cancer

The American Society of Colon and Rectal Surgeons is dedicated to ensuring high-quality patient care by advancing the science, prevention, and management of disorders and diseases of the colon, rectum, and anus. The Clinical Practice Guidelines Committee is composed of society members who are chosen because they have demonstrated expertise in the specialty of colon and rectal surgery. This committee was created to lead international efforts in defining quality care for conditions related to the colon, rectum, and anus. This is accompanied by developing Clinical Practice Guidelines based on the best available evidence. These guidelines are inclusive and not prescriptive. Their purpose is to provide information on which decisions can be made, rather than to dictate a specific form of treatment. These guidelines are intended for the use of all practitioners, health care workers, and patients who desire information about the management of the conditions addressed by the topics covered in these guidelines. It should be recognized that these guidelines should not be deemed inclusive of all proper methods of care or exclusive of methods of care reasonably directed to obtaining the same results. The ultimate judgment regarding the propriety of any specific procedure must be made by the physician in light of all the circumstances presented by the individual patient.

Prognostic impact of the length of the longitudinal resection margin in colon cancer

AIM

Although several guidelines recommend a longitudinal resection margin (LRM) of at least 5 cm, the impact of the LRM on survival is still unknown. The study assessed the prognostic significance of the LRM in patients with colon cancer.

METHOD

We retrospectively reviewed 1343 primary colon cancer patients without distant metastasis who underwent curative resection between January 2004 and December 2012. Patients were classified into three groups: LRM < 3 cm (n = 186), LRM ≥ 3 and <5 cm (n = 376) and LRM ≥5 cm (n = 781). Clinicopathological characteristics and the oncological outcome in the three groups were compared.

RESULTS

The median LRM length was 5.0 cm (range 0.5-26.0 cm). With increasing LRM, the number of retrieved lymph nodes (LNs) tended to increase (19.5 ± 12.0, 22.1 ± 12.8 and 30.0 ± 16.2; P < 0.001). After a median follow-up period of 45 (1-128) months, 3-year disease-free survival (DFS) (89.2%, 89.0% and 87.0%; P = 0.629) and 5-year overall survival (OS) (89.0%, 92.1% and 91.8%; P = 0.679) were not significantly different between the three groups. When confounders were adjusted, LRM was not significantly associated with either DFS or OS, but the number of retrieved LNs (< 12) was an independent risk factor for both DFS (hazard ratio 1.748, 95% confidence interval 1.048-2.917) and OS (hazard ratio 1.929, 95% confidence interval 1.046-3.559).

CONCLUSION

LRM was not associated with oncological outcome, but care should be taken to obtain an adequate number of LNs for better survival.

Lymph node evaluation for colon cancer in routine clinical practice: a population-based study

BACKGROUND

Guidelines recommend that 12 or more lymph nodes (lns) be evaluated during surgical resection of colon cancer. Here, we report ln yield and its association with survival in routine practice.

METHODS

Electronic records of treatment were linked to the population-based Ontario Cancer Registry to identify all patients with colon cancer treated during 2002-2008. The study population (n = 5508) included a 25% random sample of patients with stage ii or iii disease. Modified Poisson regression was used to identify factors associated with ln yield; Cox models were used to explore the association between ln yield and overall (os) and cancer-specific survival (css).

RESULTS

During 2002-2008, median ln yield increased to 17 from 11 nodes (p < 0.001), and the proportion of patients with 12 or more nodes evaluated increased to 86% from 45% (p < 0.001). Lymph node positivity did not change over time (to 53% from 54%, p = 0.357). Greater ln yield was associated with younger age (p < 0.001), less comorbidity (p = 0.004), higher socioeconomic status (p = 0.001), right-sided tumours (p < 0.001), and higher hospital volume (p < 0.001). In adjusted analyses, a ln yield of less than 12 nodes was associated with inferior os and css for stages ii and iii disease [stage ii os hazard ratio (hr): 1.36; 95% confidence interval (ci): 1.19 to 1.56; stage ii css hr: 1.52; 95% ci: 1.26 to 1.83; and stage iii os hr: 1.45; 95% ci: 1.30 to 1.61; stage iii css hr: 1.54; 95% ci: 1.36 to 1.75].

CONCLUSIONS

Despite a temporal increase in ln yield, the proportion of cases with ln positivity has not changed. Lymph node yield is associated with survival in patients with stages ii and iii colon cancer. The association between ln yield and survival is unlikely to be a result of stage migration.

Pattern of Colon Cancer Lymph Node Metastases in Patients Undergoing Central Mesocolic Lymph Node Excision: A Systematic Review

BACKGROUND

Extended mesocolic lymph node dissection in colon cancer surgery seems to improve oncological outcome. A possible reason might be related to metastases in the central mesocolic lymph nodes.

OBJECTIVE

The purpose of this study was to describe the pattern of mesocolic lymph node metastases, particularly in central lymph nodes, and the risk of skip, aberrant, and gastrocolic ligament metastases as the argument for performing extended lymph node dissection.

DATA SOURCES

EMBASE and PubMed were searched using the terms colon or colorectal with sentinel node, lymph node mapping, or skip node; lymph node resection colon; and complete or total and mesocolic excision.

STUDY SELECTION

Studies describing the risk of metastases in central, skip, aberrant, and gastrocolic ligament lymph node metastases from colon adenocarcinomas in 10 or more patients were included. No languages were excluded.

MAIN OUTCOME MEASURES

The risk of metastases in the central mesocolic lymph nodes was measured.

RESULTS

A total of 2052 articles were screened, of which 277 underwent full-text review. The 47 studies fulfilling the inclusion criteria were very heterogeneous, and meta-analyses were not considered appropriate. The risk of central mesocolic lymph node metastases for right-sided cancers varies between 1% and 22%. In sigmoid cancer, the risk is reported in ≤12% of the patients and is associated with advanced T stage.

LIMITATIONS

The retrospective design and heterogeneity, in terms of definitions of lymph node location, tumor sites, stage, morphology, pathology assessment, and inclusion criteria (selection bias), of the included studies were limitations. Also, anatomic definitions were not uniform.

CONCLUSIONS

The present literature cannot give a theoretical explanation of a better oncological outcome after extended lymph node dissection. Consensus for a standardization of anatomical definitions and surgical and pathological assessments is warranted for future mapping studies.

Surgery along the embryological planes for colon cancer: a systematic review of complete mesocolic excision

BACKGROUND

Complete mesocolic excision (CME) for colonic cancer offers a surgical specimen of higher quality, with higher number of lymph nodes compared to conventional colectomy. However, evidence on oncological outcomes is limited. The aim of the present study is to review recent literature and provide more information regarding the effect of CME colectomy on short- and long-term outcomes.

METHOD

PubMed and MEDLINE databases were searched, and articles in English reporting data on CME were reviewed. Intraoperative events; postoperative morbidity and mortality; histopathological characteristics, including macroscopic assessment, number, and status of retrieved lymph nodes; and oncological outcomes were the end-points.

RESULTS

Thirty-two studies were analyzed. As regards the macroscopic assessment, a larger specimen (p = 0.02) that contains a higher number of lymph nodes (p < 0.00001) is acquired after CME. Two studies report a higher disease-free survival, in stage I and II and particularly in stage III disease after CME. CME by laparoscopy offers comparable outcomes, as regards intraoperative blood loss and immediate postoperative morbidity and mortality rates. Specimen quality is similar after either approach, for cancers located at the right and left colon, but not at the transverse colon.

CONCLUSION

There is strong evidence that CME offers a longer central pedicle that contains more lymph nodes than conventional surgery for colon cancer. CME represents the surgical background for the maximum lymph node harvest, an important quality marker for the surgical outcome. However, and according to present data, there is limited evidence that colectomy in terms of CME leads to improved long-term oncological outcomes.

Nomograms to predict survival after colorectal cancer resection without preoperative therapy

Background

The predictive accuracy of the American Joint Committee on Cancer (AJCC) stages of colorectal cancer (CRC) is mediocre. This study aimed to develop postoperative nomograms to predict cancer-specific survival (CSS) and overall survival (OS) after CRC resection without preoperative therapy.

Methods

Eligible patients with stage I to IV CRC (n = 56072) diagnosed from 2004 to 2010 were selected from the Surveillance, Epidemiology, and End Results (SEER) database. The patients were allocated into training (n = 27,700), contemporary (n = 3158), and prospective (n = 25,214) validation cohorts. Clinically important variables were incorporated and selected using the Akaike information criterion in multivariate Cox regressions to derive nomograms with the training cohort. The performance of the nomograms was assessed and externally testified using the concordance index (c-index), bootstrap validation, calibration, time-dependent receiver-operating characteristic curves, Kaplan–Meier curves, mosaic plots, and decision curve analysis (DCA). Performance of the conventional AJCC stages was also compared with the nomograms using similar statistics.

Results

The nomograms for CSS and OS shared common predictors: sex, age, race, marital status, preoperative carcinoembryonic antigen status, surgical extent, tumor size, location, histology, differentiation, infiltration depth, lymph node count, lymph node ratio, and metastasis. The c-indexes of the nomograms for CSS and OS were 0.816 (95 % CI 0.810–0.822) and 0.777 (95 % CI 0.772–0.782), respectively. Performance evaluations showed that the nomograms achieved considerable predictive accuracy, appreciable reliability, and significant clinical validity with wide practical threshold probabilities, while the results remained reproducible when applied to the validation cohorts. Additionally, model comparisons and DCA proved that the nomograms excelled in stratifying each AJCC stage into three significant prognostic subgroups, allowing for more robust risk classification with an improved net benefit.

Conclusions

We propose two prognostic nomograms that exhibit improved predictive accuracy and net benefit for patients who have undergone CRC resection. The established nomograms are intended for risk assessment and selection of suitable patients who may benefit from adjuvant therapy and intensified follow-up after surgery. Independent external validations may still be required.

No benefit of extended mesenteric resection with central vascular ligation in right-sided colon cancer

AIM

The optimal extent of mesenteric resection in colon cancer surgery is not known. We have previously shown an increased mortality associated with wider mesenteric resection in right hemicolectomy. This study compares the short- and long-term outcome in three variations of right hemicolectomy based on the position of the vascular ligature in the mesentery.

METHOD

In all, 2084 cases of cancer in the caecum or ascending colon were identified in the Swedish Colorectal Cancer Registry and categorized according to the position of the vascular ligature: central ligation of ileocolic vessels (ICVs) ± right colic vessels (n = 390), central ligation of ICVs + right branch of middle colic vessels (MCVs) (n = 1360) and central ligation of ICVs + central ligation of MCVs (n = 334).

RESULTS

Neither 3-year overall survival, 3-year disease-free survival nor local recurrence rate differed between the groups (P = 0.604; P = 0.247; P = 0.237). There was still no difference after multivariate analysis adjusted for age, sex, American Society of Anesthesiologists classification, TNM stage and adjuvant therapy. An increased peri-operative mortality, however, was observed in extended mesenteric resections, increasing from 0.8% in non-extended to 3.6% in more extended resection, P = 0.025.

CONCLUSION

The study showed no survival benefit by more extended mesenteric resection, indicating that there is no need to extend the mesenteric resection to involve the MCVs in cancer of the caecum or ascending colon. On the contrary, increased peri-operative mortality by more extensive mesenteric resection was noted suggesting that a more conservative approach may be favourable.

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

AIM

Complete mesocolic excision (CME) has been advocated as likely to improve the long-term oncological outcome of colon cancer resection, although there is a paucity of long-term results in the literature. The aim of this study was to supplement our previously published results on colon cancer resection based on a standardized technique of precise dissection along anatomical planes with high vascular ligation and to compare our long-term results with those of recent European studies of CME.

METHOD

Data were drawn from a prospective hospital registry of consecutive resections for colon cancer between 1996 and 2007, including follow-up to the end of 2012. The principal outcomes from potentially curative resections were 5-year Kaplan-Meier rates of local recurrence, systemic recurrence, overall survival and cancer-specific survival. Secondary outcomes for all resections were postoperative complications, number of lymph nodes retrieved and R0 status.

RESULTS

For 779 potentially curative resections the local recurrence rate was 2.1% (95% CI 1.3-3.4), the systemic recurrence rate was 10.2% (95% CI 8.1-12.7), the 5-year overall survival rate was 76.2% (95% CI 73.0-79.0) and the cancer-specific survival rate was 89.8% (95% CI 87.3-91.9). For all 905 resections, rates of 14 surgical complications were low and not dissimilar to those in a comparable study. The median lymph node count was 15 (range 0-113). R0 status was confirmed in 883/905 patients (97.6%; 95% CI 96.4-98.5).

CONCLUSION

For colon cancer, meticulous dissection along anatomical planes together with high vascular ligation results in few complications, a high R0 rate, low recurrence and high survival.

Complete mesocolic excision and central vascular ligation for colon cancer: Principle, anatomy, surgical technique, and outcomes

Classic colon cancer surgery refers to a wide resection of the tumor-bearing segment and the lymphatics draining along the named artery. The concept of TME has been applied to colon cancer and complete mesocolic excision (CME) in conjuction with central vascular ligation (CVL) has been introduced as the surgical treatment for colon cancer. Here, we discuss appropriate CME procedure with regard to the oncologic backgrounds, essential components, applied anatomy, laparoscopic technique, short-term, and oncologic outcomes. The introduction of CME has improved oncologic outcomes greatly in patients with colon cancer. The improved outcomes with CME can be attributed to underlying sound oncologic principles such as dissection through the proper plane of mesocolic excision, central vascular ligation, and sufficient length of proximal and distal margins. Thereby, CME technique can achieve en bloc removal of the diseased lesion with the increased amount of the colonic mesentery even though the length of for both bowel and mesentery resection remains a matter of debate. CME is a technically demanding operation thus, comprehensive understanding of the applied vascular anatomy is essential for successful CME. Favorable outcomes of open CME have been replicated with a laparoscopic approach. In future perspective, incorporating a structured education program on minimally invasive (laparoscopy or robot) CME would be beneficial.

Complete mesocolic excision and extended (D3) lymphadenectomy for colonic cancer: is it worth that extra effort? A review of the literature

PURPOSE

Recent interest in complete mesocolic excision (CME) with central vascular ligation (CVL) or extended (D3) lymphadenectomy (EL) for curative resection of colon cancer has been driven by published series from experienced practitioners showing excellent survival outcomes and low recurrence rates. In this article, we attempt to clarify the role of CME or EL in modern colorectal surgery.

METHODS

A narrative review of the evidence for CME and EL in the curative treatment of colon cancer.

RESULTS

The principal of CME surgery, similar to total mesorectal excision (TME) for rectal cancer, is the removal of all lymphatic, vascular, and neural tissue in the drainage area of the tumour in a complete mesocolic envelope with intact mesentery, peritoneum and encasing fascia. Extended (D3) lymphadenectomy (EL) is based on similar principles. Sound anatomical and oncological arguments are made to support the principles of removing the tumor contained within an intact mesocolic facial envelope together with an extended lymph node harvest. Excellent oncological outcomes with minimal morbidity and mortality have been reported. This has led to calls for the standardisation of surgery for colon cancer using CME. However, there is conflicting evidence regarding the prognostic benefit of greater lymph node harvests and the evidence for an oncological benefit of CME is limited by methodology flaws and several potential confounding factors.

CONCLUSIONS

Although there is a reasonable anatomical and oncological basis for these techniques, there are no randomised controlled trials from which to draw confident conclusions and there is insufficient consistent high quality evidence to recommend widespread adoption of CME.

Assessment of lymph node involvement in colorectal cancer

Lymph node metastasis informs prognosis and is a key factor in deciding further management, particularly adjuvant chemotherapy. It is core to all contemporary staging systems, including the widely used tumor node metastasis staging system. Patients with node-negative disease have 5-year survival rates of 70%-80%, implying a significant minority of patients with occult lymph node metastases will succumb to disease recurrence. Enhanced staging techniques may help to identify this subset of patients, who might benefit from further treatment. Obtaining adequate numbers of lymph nodes is essential for accurate staging. Lymph node yields are affected by numerous factors, many inherent to the patient and the tumour, but others related to surgical and histopathological practice. Good lymph node recovery relies on close collaboration between surgeon and pathologist. The optimal extent of surgical resection remains a subject of debate. Extended lymphadenectomy, extra-mesenteric lymph node dissection, high arterial ligation and complete mesocolic excision are amongst the surgical techniques with plausible oncological bases, but which are not supported by the highest levels of evidence. With further development and refinement, intra-operative lymphatic mapping and sentinel lymph node biopsy may provide a guide to the optimum extent of lymphadenectomy, but in its present form, it is beset by false negatives, skip lesions and failures to identify a sentinel node. Once resected, histopathological assessment of the surgical specimen can be improved by thorough dissection techniques, step-sectioning of tissue blocks and immunohistochemistry. More recently, molecular methods have been employed. In this review, we consider the numerous factors that affect lymph node yields, including the impact of the surgical and histopathological techniques. Potential future strategies, including the use of evolving technologies, are also discussed.

Complete mesocolic excision: Lessons from anatomy translating to better oncologic outcome

Since the introduction of complete mesocolic excision (CME) for colon cancer, the oncologic outcome of patients has been greatly improved, which has led to a longer survival and a lower recurrence, just like the total mesorectum excision for rectal cancer. Despite the fact that the exact anatomy of the organ is one of the most vital things for surgeons to conduct surgery, no team has really studied the exact structure of the mesocolon and related attachments for CME, until the mesocolonic anatomy was first formally characterized in 2012. Therefore, this article mainly focuses on the anatomy development of the mesocolon and the achievement in this field. Meanwhile, we introduce the latest progress in laparoscopic surgery for colon cancer achieved by our team.

Enhanced Reality and Intraoperative Imaging in Colorectal Surgery

Colorectal surgery is one of the most common procedures performed around the world with more than 600,000 operations each year in the United States, and more than a million worldwide. In the past two decades, there has been a clear trend toward minimal access and surgeons have embraced this evolution. Widespread adoption of advanced minimally invasive procedures is often limited by procedural complexity and the need for specific technical skills. Furthermore, the loss of 3D vision, limited overview of the surgical field, and diminished tactile sensation make major colorectal procedures more challenging and have an impact on the surgeons' learning curves. New technologies are emerging that can compensate for some of the sensory losses associated with laparoscopy. High-definition picture acquisition, 3D camera systems, and the use of biomarkers will allow improved identification of the target structures and help differentiate them from surrounding tissues. In this article, we describe some of the new technologies available and, in particular, focus on the possible implications of biomarkers and fluorescent laparoscopic imaging.

Influence of extent of lymph node dissection on survival for patients with pT2 colon cancer

PURPOSE

The optimal extent of lymph node dissection for early-stage colon cancer (CC) remains undefined. This study assessed the influence of the extent of lymph node dissection on overall survival (OS) in patients with pT2 CC.

METHODS

We retrospectively examined data from the multi-institutional registry system of the Japanese Society for Cancer of the Colon and Rectum and used a propensity score matching method to balance potential confounders of lymph node dissection. We extracted 463 matched pairs from 1433 patients who underwent major resections for pT2 CC between 1995 and 2004.

RESULTS

Lymph node metastasis was found in 301 (21.0%) of 1433 patients with pT2 CC. In this cohort, significant independent risk factors for lymph node metastasis were lymphatic invasion and venous invasion. Patients who underwent D3 or D2 lymph node dissection did not significantly differ in OS, either among the propensity score-matched cohort (estimated hazard ratio [HR] 0.85, 95% confidence interval [CI] 0.536-1.346, P = 0.484) or in the cohort as a whole (HR 0.720, 95% CI 0.492-1.052, P = 0.089).

CONCLUSIONS

For patients with pT2 CC, D3 lymph node dissection did not add to OS. D2 lymph node dissection may be adequate for pT2 CC.

Extent of surgery in cancer of the colon: Is more better?

Since the introduction of total mesorectal excision as the standard approach in mid and low rectal cancer, the incidence of local recurrence has sharply declined. Similar attention to surgical technique in colon cancer (CC) has resulted in the concept of complete mesocolic excision (CME), which consists of complete removal of the intact mesentery and high ligation of the vascular supply at its origin. Although renewed attention to meticulous surgical technique certainly has its merits, routine implementation of CME is currently unfounded. Firstly, in contrast to rectal cancer, local recurrence originating from an incompletely removed mesentery is rare in CC and usually a manifestation of systemic disease. Secondly, although CME may increase nodal counts and therefore staging accuracy, this is unlikely to affect survival since the observed relationship between nodal counts and outcome in CC is most probably not causal but confounded by a range of clinical variables. Thirdly, several lines of evidence suggest that metastasis to locoregional nodes occurs early and is a stochastic rather than a stepwise phenomenon in CC, in essence reflecting the tumor-host-metastasis relationship. Unsurprisingly, therefore, comparative studies in CC as well as in other digestive cancers have failed to demonstrate any survival benefit associated with extensive, additional or extra-mesenteric lymphadenectomy. Finally, routine implementation of CME may cause patient harm by longer operating times, major vascular damage and autonomic nerve injury. Therefore, data from randomized trials reporting relevant endpoints are required before CME can be recommended as a standard approach in CC surgery.

Complete mesocolic excision in colorectal cancer: a systematic review

AIM

Several studies have suggested an increased lymph node yield, reduced locoregional recurrence and increased disease-free survival after complete mesocolic excision (CME) for colorectal cancer. This review was undertaken to assess the use of CME for colon cancer by evaluating the technique and its clinical outcome.

METHOD

A literature search of publications was performed using PubMed and Medline. Only studies published in English were included. Studies assessed for quality and data were extracted by two independent reviewers. End-points included number of lymph nodes per patient, quality of the plane of mesocolic excision, postoperative mortality and morbidity, 5-year locoregional recurrence and 5-year cancer-specific survival.

RESULTS

There were 34 articles comprising 12 retrospective studies, nine prospective studies and 13 original articles including case series, observational studies and editorials. Of the prospective studies, four reported an increased lymph node harvest and a survival benefit. The others reported an improvement in the quality of the specimen as assessed by histopathological examination. Laparoscopic CME has the same oncological outcome as open surgery but completeness of excision during laparoscopy may be compromised for tumours in the transverse colon.

CONCLUSION

Studies demonstrate that CME removes significantly more tissue around the tumour including maximal lymph node clearance. There is little information on serious adverse events after CME and a long-term survival benefit has not been proved.