A Randomized Phase III Trial of Complete Mesocolic Excision Compared with Conventional Surgery for Right Colon Cancer: Interim Analysis of a Nationwide Multicenter Study of the Italian Society of Surgical Oncology Colorectal Cancer Network (CoME-in trial).

BACKGROUND: Although complete mesocolic excision (CME) is supposed to be associated with a higher lymph node (LN) yield, decreased local recurrence, and survival improvement, its implementation currently is debated because the evidence level of these data is rather low and still not supported by randomized controlled trials. METHOD: This is a multicenter, randomized, superiority trial (NCT04871399). The 3-year disease-free survival (DFS) was the primary end point of the study. The secondary end points were safety (duration of operation, perioperative complications, hospital length of stay), oncologic outcomes (number of LNs retrieved, 3- and 5-year overall survival, 5-year DFS), and surgery quality (specimen length, area and integrity rate of mesentery, length of ileocolic and middle-colic vessels). The trial design required the LN yield to be higher in the CME group at interim analysis. RESULTS: Interim data analysis is presented in this report. The study enrolled 258 patients in nine referral centers. The number of LNs retrieved was significantly higher after CME (25 vs. 20; p = 0.012). No differences were observed with respect to intra- or post-operative complications, postoperative mortality, or duration of surgery. The hospital stay was even shorter after CME (p = 0.039). Quality of surgery indicators were higher in the CME arm of the study. Survival data still were not available. CONCLUSIONS: Interim data show that CME for right colon cancer in referral centers is safe and feasible and does not increase perioperative complications. The study documented with evidence that quality of surgery and LN yield are higher after CME, and this is essential for continuation of patient recruitment and implementation of an optimal comparison. Trial registration The trial was registered at ClinicalTrials.gov with the code NCT04871399 and with the acronym CoME-In trial.

Robotic versus laparoscopic right colectomy for nonmetastatic pT4 colon cancer: A European multicentre propensity score-matched analysis.

AIM: Minimally invasive surgery has been increasingly adopted for locally advanced colon cancer. However, evidence comparing robotic (RRC) versus laparoscopic right colectomy (LRC) for nonmetastatic pT4 cancers is lacking. METHODS: This was a multicentre propensity score-matched (PSM) study of a cohort of consecutive patients with pT4 right colon cancer treated with RRC or LRC. The two surgical approaches were compared in terms of R0, number of lymph nodes harvested, intra- and postoperative complication rates, overall (OS), and disease-free survival (DFS). RESULTS: Among a total of 200 patients, 39 RRC were compared with 78 PS-matched LRC patients. The R0 rate was similar between RRC and LRC (92.3% vs. 96.2%, respectively; p = 0.399), as was the odds of retrieving 12 or more lymph nodes (97.4% vs. 96.2%; p = 1). No significant difference was noted for the mean operating time (192.9 min vs. 198.3 min; p = 0.750). However, RRC was associated with fewer conversions to laparotomy (5.1% vs. 20.5%; p = 0.032), less blood loss (36.9 vs. 95.2 mL; p < 0.0001), fewer postoperative complications (17.9% vs. 41%; p = 0.013), a shorter time to flatus (2 vs. 2.8 days; p = 0.009), and a shorter hospital stay (6.4 vs. 9.5 days; p < 0.0001) compared with LRC. These results were confirmed even when converted procedures were excluded from the analysis. The 1-, 3- and 5-year OS (p = 0.757) and DFS (p = 0.321) did not significantly differ between RRC and LRC. CONCLUSION: Adequate oncological outcomes are observed for RRC and LRC performed for pT4 right colon cancer. However, RRC is associated with lower conversion rates and improved short-term postoperative outcomes.

Effect of complete mesocolic excision (cme) on long-term survival after right colectomy for cancer: multivariate meta-analysis and restricted mean survival time estimation.

INTRODUCTION: Debate exists concerning the impact of complete mesocolic excision (CME) on long-term oncological outcomes. The aim of this review was to condense the updated literature and assess the effect of CME on long-term survival after right colectomy for cancer. METHODS: PubMed, MEDLINE, Scopus, and Web of Science were searched through July 2023. The included studies evaluated the effect of CME on survival. The primary outcome was long-term overall survival. Restricted mean survival time difference (RMSTD), hazard ratio (HR), and 95% confidence intervals (CI) were used as pooled effect size measures. GRADE methodology was used to summarize the certainty of evidence. RESULTS: Ten studies (3665 patients) were included. Overall, 1443 (39.4%) underwent CME. The RMSTD analysis shows that at 60-month follow-up, stage I-III CME patients lived 2.5 months (95% CI 1.1-4.1) more on average compared with noCME patients. Similarly, stage III patients that underwent CME lived longer compared to noCME patients at 55-month follow-up (6.1 months; 95% CI 3.4-8.5). The time-dependent HRs analysis for CME vs. noCME (stage I-III disease) shows a higher mortality hazard in patients with noCME at 6 months (HR 0.46, 95% CI 0.29-0.71), 12 months (HR 0.57, 95% CI 0.43-0.73), and 24 months (HR 0.73, 95% CI 0.57-0.92) up to 27 months. CONCLUSIONS: This study suggests that CME is associated with unclear OS benefit in stage I-III disease. Caution is recommended to avoid overestimation of the effect of CME in stage III disease since the marginal benefit of a more extended resection may have been influenced by tumor biology/molecular profile and multimodal adjuvant treatments.

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

PURPOSE: To investigate oncologic outcomes including overall survival and disease-free survival depending on the extent of lymphadenectomy (D3 versus D2) by comparing D3 and D2 lymphadenectomy in patients with clinical stage 2/3 right colon cancer. METHODS: Consecutive series of patients who underwent radical resection for right colon cancer at our three hospitals between January 2015 and June 2018 were retrospectively analyzed. Study cohorts were divided into two groups: D3 group and D2 group. Oncologic, pathologic, and perioperative outcomes of the two groups were compared. RESULTS: A total of 295 patients (167 in the D2 group and 128 in the D3 group) were included in this study. Patients' characteristics showed no significant difference between the two groups. The median number of harvested lymph nodes was significantly higher in the D3 group than in the D2 group. The rate of complications was not significantly different between the two groups except for chyle leakage, which was more frequent in the D3 group. Five-year disease-free survival was 90.2% (95% CI: 84.8-95.9%) in the D3 group, which was significantly (p = 0.028) higher than that (80.5%, 95% CI: 74-87.5%) in the D2 group. There was no significant difference in overall survival between the two groups. CONCLUSION: Our results indicate that D3 lymphadenectomy is associated with more favorable 5-year disease-free survival than D2 lymphadenectomy for patients with stage 2/3 right-sided colon cancer. D3 lymphadenectomy might improve oncologic outcomes in consideration of the recurrence rate.

Natural orifice specimen extraction surgery versus small-incision assisted laparoscopic radical right hemicolectomy.

Conventional laparoscopic-assisted right hemicolectomy requires a small abdominal incision to extract the specimen, which becomes an important source of postoperative complications and impairs perioperative experience. Transvaginal natural orifice specimen extraction surgery (NOSES VIIIA) avoids this small incision by extracting the specimen through the vagina. Here we describe the design of a multicenter, open-label, parallel, noninferior, phase III randomized controlled trial (NCT05495048). The aim of this study is to confirm that the NOSES VIIIA procedure is not inferior to small-incision assisted right hemicolectomy in long-term oncological efficacy. A total of 352 female patients with right colon adenocarcinoma/high-grade intraepithelial neoplasia will be randomly assigned to the NOSES VIIIA arm and the small-incision arm in a 1:1 ratio. The primary end point of this trial is 3 year disease-free survival. Clinical Trial Registration: NCT05495048 (ClinicalTrials.gov).

A prediction nomogram for postoperative gastroparesis syndrome in right colon cancer: a retrospective study.

PURPOSE: To investigate the high-risk factors for postoperative gastroparesis syndrome (PGS) in right colon cancer and to build a prediction nomogram for personalized prediction of PGS. METHODS: Our study retrospectively analyzed 361 patients with right colon cancer who underwent right hemicolectomy at The First Hospital of Putian City in Fujian Province, China and who were hospitalized between January 2012 and July 2022. Multivariate logistic regression was used to determine the independent risk factors for PGS and to establish a nomogram model. Furthermore, discrimination, calibration, and clinical benefits were used to evaluate the model. RESULTS: The multivariate logistic regression revealed that dissection of the subpyloric lymph nodes (No. 206 lymph node) (OR 5.242, P = 0.005), preoperative fasting blood glucose level (OR 3.708, P = 0.024), preoperative albumin level (OR 3.503, P = 0.020), and total operative time (OR 4.648, P = 0.014) were independent risk factors for PGS. Based on the above four factors, the area under the ROC curve (AUC) and C-index of the nomogram were 0.831. The prediction nomogram's calibration curve was closer to the ideal diagonal, and the Hosmer‒Lemeshow test indicated that the nomogram fit well (P = 0.399). Moreover, the decision curve analysis revealed that the model can present better clinical benefits when the threshold probability was between 1 and 28%, and the internal validation verified the dependability of the model (C-index = 0.948). CONCLUSIONS: A risk prediction nomogram based on perioperative factors provided the physician with a simple, visual, and efficient tool for the prediction and management of PGS in right colon cancer.

Long-term oncological outcomes of robotic versus laparoscopic approaches for right colon cancer: a systematic review and meta-analysis.

PURPOSE: The short-term outcomes of robotic right hemicolectomy for right colon cancer have been extensively studied in comparison to conventional laparoscopic right hemicolectomy. However, the long-term oncological outcomes of the two approaches have not been investigated, except in single-center retrospective studies. Therefore, this meta-analysis aimed to investigate the long-term oncological outcomes of robotic right hemicolectomy compared with those of laparoscopic right hemicolectomy for right colon cancer. METHODS: We searched PubMed, EMBASE, and Cochrane Library for studies comparing robotic right hemicolectomy with conventional laparoscopic right hemicolectomy for right colon cancer from the date of database inception to August 2022. For survival data extraction, hazard ratios (HRs) with 95% confidence intervals (CI) were calculated using random- or fixed-effects models from the Kaplan-Meier survival curves in the included studies. All calculations and statistical tests were performed using Review Manager software, version 5.4. RESULTS: A total of 523 patients (robotic right hemicolectomy, 230; laparoscopic right hemicolectomy, 293) from five studies were included in this meta-analysis. There were no significant differences in patient characteristics between the two groups. In terms of pathological characteristics, TNM stage was not different and revealed no differences in the number of harvested lymph nodes even though a larger number of lymph nodes were harvested in the robotic group in one study. Pooled analyses demonstrated no significant difference in disease-free survival (HR 0.72, 95% CI 0.46-1.13, p = 0.15) and overall survival (HR 0.73, 95% CI 0.48-1.13, p = 0.16) between robotic and laparoscopic right hemicolectomy for right colon cancer. CONCLUSION: Robotic right hemicolectomy for right colon cancer is comparable with conventional laparoscopic right hemicolectomy in terms of long-term oncological survival. More prospective, multicenter, randomized trials are necessary to determine the oncologic safety of robotic right hemicolectomy.

Complete mesocolic excision in comparison with conventional surgery for right colon cancer: a nationwide multicenter study of the Italian Society of Surgical Oncology colorectal cancer network (CoME-in trial). Study protocol for a randomized controlled trial.

Complete mesocolic excision with central vascular ligation, or simply CME, includes the sharp dissection along the mesocolic visceral and parietal layers, with the ligation of the main vessels at their origins. To date, there is low evidence on its safety and efficacy. This is a study-protocol of a multicenter, randomized, superiority trial in patients with right-sided colon cancer. It aims to investigate whether the complete mesocolic excision improves the oncological outcomes as compared with conventional right hemicolectomy, without worsening early outcomes. Data on efficacy and safety of complete mesocolic excision are available only from a large trial recruiting eastern patients and from a low-volume single-center western study. No results on survival are still available. For this reason, complete mesocolic excision continues to be a controversial topic in daily practice, particularly in western world. This new nationwide multicenter large-volume trial aims to provide further data on western patients, concerning both postoperative and survival outcomes.

Multidimensional evaluation of the learning curve for laparoscopic complete mesocolic excision for right colon cancer: a risk-adjusted cumulative summation analysis.

AIM: Despite the suggested potential benefit of complete mesocolic excision (CME) for right-sided colon cancer (RCC) for patient survival, concerns about its safety and feasibility have contributed to delayed acceptance of the procedure, especially when performed by a minimally invasive approach. Thus, the aim of this work was to evaluate the actual learning curve (LC) of laparoscopic CME for experienced colorectal surgeons. METHOD: Prospectively collected data for consecutive patients undergoing laparoscopic CME for RCC between October 2015 and January 2021 at our institution, operated on by experienced surgeons, were analysed. A multidimensional assessment of the LC was performed through cumulative sum (CUSUM) and risk-adjusted (RA) CUSUM analysis. RESULTS: Two hundred and two patients operated by on by three surgeons were considered. The CUSUM graphs based on operating time showed one peak of the curve between 17 and 27 cases. The CUSUM graphs based on surgical failure showed one peak of the curve between 20 and 24 cases The RA-CUSUM curve also showed one preeminent peak at 24-33 cases. Based on the CUSUM and RA-CUSUM analyses all the surgeons reached proficiency in 24-33 cases. CONCLUSIONS: Our study showed that an experienced minimally invasive colorectal surgeon acquires proficiency in laparoscopic CME for RCC after performing 24-33 cases.

Mid-term oncological outcomes after complete versus conventional mesocolic excision for right-sided colon cancer: a propensity score matching analysis.

BACKGROUND: The correct extent of mesocolic dissection for right-sided colon cancer (RCC) is still under debate. Complete mesocolic excision (CME) has not gained wide diffusion, mainly due to its technical complexity and unclear oncological superiority. This study aims to evaluate oncological outcomes of CME compared with non-complete mesocolic excision (NCME) during resection for I-III stage RCC. METHOD: Prospectively collected data of patients who underwent surgery between 2010 and 2018 were retrospectively analysed. 1:1 Propensity score matching (PSM) was used to balance baseline characteristics of CME and NCME patients. The primary endpoint of the study was local recurrence-free survival (LRFS). The two groups were also compared in terms of short-term outcomes, distant recurrence-free survival, disease-free survival, and overall survival. RESULTS: Of the 444 patients included in the study, 292 were correctly matched after PSM, 146 in each group. The median follow-up was 45 months (IQR 33-63). Conversion rate, complications, and 90-day mortality were comparable in both groups. The median number of lymph nodes harvested was higher in CME patients (23 vs 19, p = 0.034). 3-year LRFS rates for CME patients was 100% and 95.6% for NCME (log-rank p = 0.028). At 3 years, there were no differences between the groups in terms of overall survival, distant recurrence-free survival, and disease-free survival. CONCLUSION: Our PSM cohort study shows that CME is safe, provides a higher number of lymph nodes harvested, and is associated with better local recurrence-free survival.

Consensus statements on complete mesocolic excision for right-sided colon cancer-technical steps and training implications.

BACKGROUND: CME is a radical resection for colon cancer, but the procedure is technically demanding with significant variation in its practice. A standardised approach to the optimal technique and training is, therefore, desirable to minimise technical hazards and facilitate safe dissemination. The aim is to develop an expert consensus on the optimal technique for Complete Mesocolic Excision (CME) for right-sided and transverse colon cancer to guide safe implementation and training pathways. METHODS: Guidance was developed following a modified Delphi process to draw consensus from 55 international experts in CME and surgical education representing 18 countries. Domain topics were formulated and subdivided into questions pertinent to different aspects of CME practice. A three-round Delphi voting on 25 statements based on the specific questions and 70% agreement was considered as consensus. RESULTS: Twenty-three recommendations for CME procedure were agreed on, describing the technique and optimal training pathway. CME is recommended as the standard of care resection for locally advanced colon cancer. The essential components are central vascular ligation, exposure of the superior mesenteric vein and excision of an intact mesocolon. Key anatomical landmarks to perform a safe CME dissection include identification of the ileocolic pedicle, superior mesenteric vein and root of the mesocolon. A proficiency-based multimodal training curriculum for CME was proposed including a formal proctorship programme. CONCLUSIONS: Consensus on standardisation of technique and training framework for complete mesocolic excision was agreed upon by a panel of experts to guide current practice and provide a quality control framework for future studies.

Comparison of short-term outcomes between totally laparoscopic right colectomy and laparoscopic-assisted right colectomy: a retrospective study in a single institution on 300 consecutive patients.

BACKGROUND: Laparoscopic surgery has become the standard surgical approach for the treatment of colon cancer. However, the surgical procedure for right colectomy is not standardized. Selection between laparoscopy-assisted right colectomy (LARC) with extracorporeal anastomosis and totally laparoscopic procedures with intracorporeal anastomosis is still a hot topic. The aim of this study was to compare the short-term outcomes of totally laparoscopic right colectomy (TLRC) and LARC in the treatment of right colon cancer. METHODS: This was a retrospective and single-center study conducted between January 2016 and December 2019 featuring 120 TLRC patients and 180 LARC patients following the principles of the CME. We then collated and analyzed the clinicopathological characteristics, operative characteristics, and short-term outcomes. RESULTS: The baseline characteristics were balanced between two groups. TLRC was associated with a significantly lower estimated blood loss (p < 0.01), a shorter incision length (p < 0.01). In terms of postoperative recovery, patients in TLRC group were better, as confirmed by less postoperative pain (p < 0.01), less rescue analgesic usage (p = 0.04), faster to flatus (p < 0.01), defecation (p < 0.01), oral intake (p < 0.01) and discharge (p < 0.01). Incidence of postoperative complications according to Clavien-Dindo classification system was also similar in both groups. CONCLUSIONS: Our data demonstrate that TLRC is technically safe and feasible. This technique could lead to a better cosmetic outcome, a less pain experience and a faster recovery of bowel function.

Risk factors of chylous ascites and its relationship with long-term prognosis in laparoscopic D3 lymphadenectomy for right colon cancer.

BACKGROUND: Chylous ascites (CA) after laparoscopic D3 lymphadenectomy for right colon cancer is not rare. However, the risk factors for CA have not been fully explored. Few studies have investigated the effect of CA on long-term prognosis. METHODS: The clinical data of patients with right colon cancer who underwent laparoscopic D3 lymphadenectomy in five centers from January 2013 to December 2018 were retrospectively collected. Univariate and multivariate analyses were performed to determine the clinicopathological factors associated with CA. Then, the long-term prognosis of patients with and without CA was compared by propensity score matching and Kaplan-Meier survival analysis. RESULTS: The incidence of CA was 4.4% (48/1090). Pathological T stage (p = 0.025), dissection along the left side of the superior mesenteric artery (p < 0.001) and the number of retrieved lymph nodes (p < 0.001) were independent risk factors for CA. After propensity score matching, 48 patients in the CA group and 353 patients in the non-CA group were enrolled. Kaplan-Meier survival analysis indicated that CA was not associated with overall survival (p = 0.454) and disease-free survival (p = 0.163). In patients with stage III right colon cancer, there were no significant differences in overall survival (p = 0.501) and disease-free survival (p = 0.254). CONCLUSIONS: Pathological T stage, number of retrieved lymph nodes, and left side dissection along the superior mesenteric artery were independent risk factors for CA after laparoscopic D3 lymphadenectomy. CA does not impair the oncological outcomes of patients.

Value of different anastomoses in laparoscopic radical right hemicolectomy for right-sided colon cancer: retrospective study and literature review.

BACKGROUND: This study aimed to analyze the safety of circular lateral anastomosis and cross-lateral anastomosis in laparoscopic radical resection of right-sided colon cancer. METHODS: From January 2018 to March 2021, 147 patients with right-sided colon cancer were admitted to the Department of General Surgery, Cancer Hospital, Zhengzhou University. The experimental group comprised patients with circular lateral anastomosis, whereas the control group comprised patients with cruciform lateral anastomosis. The general clinical data, intraoperative features, and postoperative results of the two groups were compared and analyzed. RESULTS: Both groups successfully underwent laparoscopic lateral ileocolic anastomosis, with significant differences in anastomotic leakage (χ2=4.520, P < 0.05). By contrast, body mass index (t = 1.568, P = 0.119), histological typing (χ2 = 2.067, P = 0.559), intraoperative bleeding (t = 0.418, P = 0.677), and intestinal obstruction (χ2 = 2.564, P = 0.109) were not significantly different between the groups (P > 0.05). CONCLUSIONS: In laparoscopic-assisted radical hemicolectomy for right-sided colon cancer, the incidence of postoperative anastomotic leakage was lower with circular lateral anastomosis than with cross-lateral anastomosis, and circular lateral anastomosis was superior to cross-lateral anastomosis in terms of reducing the length of hospital stay and improving patients' postoperative quality of life.

The impact of tumor location on long-term survival outcomes in patients with right-sided colon cancer.

BACKGROUND: The oncologic outcomes of right-sided cancers are generally grouped in studies. We hypothesized that tumor location (cecal vs. ascending vs. hepatic flexure) may influence cancer-specific outcomes. METHODS: The Surveillance, Epidemiology, and End Results (SEER) database was queried for patients over 18 with non-metastatic, invasive (American Joint Committee on Cancer stage I-III) right-sided adenocarcinoma of the colon from 1988 to 2014 who underwent partial colectomy. Patients were categorized into groups: (1) cecum (2) ascending colon (3) hepatic flexure. Demographic, clinical and pathologic factors were compared between groups. Disease-specific and overall survival were described using the Kaplan-Meier method and compared using the log-rank test. Multivariate Cox regression analysis determined the independent association of primary tumor location. RESULTS: We identified 167,450 patients. Mean age was 72.2 ± 12.3 years and 54.9% were female. Of these, 81,611, 66,857, and 18,982 had cecal, ascending colon, and hepatic flexure cancers, respectively. Cecal cancers were associated with a lower number of examined nodes but a higher likelihood of nodal positivity. Cecal cancer patients were significantly older, had larger tumors, and higher tumor stage. On univariate analysis, cecal cancers were associated with poorer disease-specific and overall survival (all p values < 0.001). On multivariate analysis controlling for sex, age, tumor size, number of examined nodes and stage, hepatic flexure cancers were associated with worse disease-specific (HR 1.05) and overall survival (HR 1.03). CONCLUSION: Hepatic flexure cancers are associated with worse survival compared to more proximal colon cancers. The cause is likely multifactorial, including biological and technical factors. More aggressive surgical and multimodal therapy may be considered for hepatic flexure colon cancers.

Risk Factors for Severe Postoperative Complications after Oncologic Right Colectomy: Unicenter Analysis.

Background and Objectives: This study aimed to investigate the potential risk factors for severe postoperative complications after oncologic right colectomy. Materials and Methods: All consecutive patients with right colon cancer who underwent right colectomy in our department between 2016 and 2021 were retrospectively included in this study. The Clavien-Dindo grading system was used to evaluate postoperative complications. Univariate and multivariate logistic regression analyses were used to investigate risk factors for postoperative severe complications. Results: Of the 144 patients, there were 69 males and 75 females, with a median age of 69 (IQR 60-78). Postoperative morbidity and mortality rates were 41.7% (60 patients) and 11.1% (16 patients), respectively. The anastomotic leak rate was 5.3% (7 patients). Severe postoperative complications (Clavien-Dindo grades III-V) were present in 20 patients (13.9%). Univariate analysis showed the following as risk factors for postoperative severe complications: Charlson score, lack of mechanical bowel preparation, level of preoperative proteins, blood transfusions, and degree of urgency (elective/emergency right colectomy). In the logistic binary regression, the Charlson score (OR = 1.931, 95% CI = 1.077-3.463, p = 0.025) and preoperative protein level (OR = 0.049, 95% CI = 0.006-0.433, p = 0.007) were found to be independent risk factors for postoperative severe complications. Conclusions: Severe complications after oncologic right colectomy are associated with a low preoperative protein level and a higher Charlson comorbidity index.

Laparoscopic surgery for right colon cancer with intestinal malrotation: A case report and review of the literature.

Intestinal malrotation (IM) results from abnormal midgut rotation during embryogenesis and usually presents in early infancy. IM in adults is often an incidental radiological diagnosis. Right colon cancer with IM has been sparingly reported in the world literature. Only 44.7% of these documented cases underwent successful laparoscopic resection, all of which were reported from Japan. The presence of aberrant anatomy and altered vascular orientation in IM presents challenges for laparoscopic resection with adequate nodal clearance. We present the case of a 72-year-old female diagnosed with carcinoma of the ascending colon, with IM incidentally detected on pre-operative cross-sectional imaging. She underwent laparoscopic right hemicolectomy. We also reviewed the documented cases of successful laparoscopic surgery for right colon cancers with IM. Aided by accurate delineation of vascular anatomy on pre-operative cross-sectional imaging, laparoscopic colectomy in the setting of IM is safe and feasible, and should be favourably considered.

Proper surgical extent for clinical Stage I right colon cancer.

PURPOSE: Pre-operative evaluation identifying clinical-stage affects the decision regarding the extent of surgical resection in right colon cancer. This study was designed to predict a proper surgical resection through the prognosis of clinical Stage I right colon cancer. PATIENTS AND METHODS: We included patients who were diagnosed with clinical and pathological Stage I right-sided colon cancer, including appendiceal, caecal, ascending, hepatic flexure and proximal transverse colon cancer, between August 2010 and December 2016 in two tertiary teaching hospitals. Patients who underwent open surgeries were excluded because laparoscopic surgery is the initial approach for colorectal cancer in our institutions. RESULTS: Eighty patients with clinical Stage I and 104 patients with pathological Stage I were included in the study. The biopsy reports showed that the tumour size was larger in the clinical Stage I group than in the pathological Stage I group (3.4 vs. 2.3 cm, P < 0.001). Further, the clinical Stage I group had some pathological Stage III cases (positive lymph nodes, P = 0.023). The clinical Stage I group had a higher rate of distant metastases (P = 0.046) and a lower rate of overall (P = 0.031) and cancer-specific survival (P = 0.021) than the pathological Stage I group. Compared to pathological Stage II included in the period, some of the survival curves were located below the pathological Stage II, but there was no statistical difference. CONCLUSION: The study results show that even clinical Stage I cases, radical resection should be considered in accordance with T3 and T4 tumours.

Examining More Lymph Nodes May Improve the Prognosis of Patients With Right Colon Cancer: Determining the Optimal Minimum Lymph Node Count.

OBJECTIVES: The objective is to determine the optimal minimum lymph node examination number for right colon cancer (RCC) patients. METHODS: We comprehensively analysed the Surveillance, Epidemiology and End Results database data from 2004 to 2016 to determine the 13-year trend in the number of lymph nodes examined among 108,703 left colon cancer and 165,937 RCC patients. 133,137 RCC patients eligible for inclusion were used to determine the optimal minimum for lymph node examination. We used restricted cubic splines to analyse the dose-response relationship between the number of lymph nodes examined and prognosis. X-tiles and decision trees were used to determine the optimal cutoff for the number of lymph nodes based on the survival outcomes of patients with RCC. The Kaplan-Meier method and COX model were used to estimate the overall survival and independent prognostic factors, and a prediction model was constructed. The C-index, calibration curve, net reclassification improvement and integrated discrimination improvement were used to determine the predictive performance of the model, and decision curve analysis was used to evaluate the benefits. RESULTS: Lymph node examinations were common among colon cancer patients over the 13-year study period. It is generally agreed that at least 12 lymph nodes must be examined to ensure proper dissection and accurate staging of RCC; however, the optimal number of lymph nodes to be examined is controversial. The dose-response relationship indicated that 12 was not the optimal minimum number of lymph nodes for RCC patients. X-tile and survival decision-tree analysis indicated that 20 nodes was the optimal number. Survival analysis indicated that <20 nodes examined was a risk factor for poor prognosis, and the classification performance was superior for 20 nodes compared to 12 nodes. CONCLUSION: Lymph node examination in RCC patients should be altered. Our research suggests that a 20-node measure may be more suitable for RCC patients.

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.