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

Learning curve and safety of the implementation of laparoscopic complete mesocolic excision with intracorporeal anastomosis for right-sided colon cancer: results from a propensity score-matched study

BACKGROUND

Retrospective studies and randomized controlled trials support the safety of laparoscopic complete mesocolic excision (CME) for the treatment of right-sided colon cancer (RSCC). Few studies, however, examine the learning curve of this operation and its impact on safety during an implementation period. We aim to evaluate the learning curve and safety of the implementation of laparoscopic CME with intracorporeal anastomosis for RSCC.

METHODS

Consecutive patients undergoing a laparoscopic right colectomy with intracorporeal anastomosis for RSCC between January 2016 and June 2023 were included. Clinical, perioperative, and histopathological variables were collected. Correlation and cumulative sum (CUSUM) analyses between the operating time and case number were performed. Breakpoints of the learning curve were estimated using the broken-line model. CME and conventional laparoscopic right colectomy outcomes were compared after propensity score matching (PSM).

RESULTS

Two hundred and ninety patients underwent laparoscopic right colectomy during study period. One hundred and eight met inclusion criteria. After PSM, 56 non-CME and 28 CME patients were compared. CME group had a non-statistically significant tendency to a longer operating time (201 versus 195 min; p = 0.657) and a shorter hospital stay (3 versus 4 days; p = 0.279). No significant differences were found in total complication rates or their profile. Correlation analysis identified a significant trend toward operating time reduction with increasing case numbers (Pearson correlation coefficient =  - 0.624; p = 0.001). According to the CUSUM analysis, an institutional learning curve was deemed completed after 13 cases and the broken-line model identified three phases: learning (1-6 cases), consolidation (7-13 cases), and mastery (after 13 cases).

CONCLUSION

The learning curve of laparoscopic CME for RSCC can be achieved after 13 cases in centers with experience in advanced laparoscopic surgery and surgeons with familiarity with this technique. Its implementation within this setting seems to be as safe as performing a conventional right colectomy.

Proposal for standardization of laparoscopic D3 lymphadenectomy for right colon cancer

BACKGROUND

This study presents a laparoscopic surgical protocol for right hemicolectomy and D3 lymphadenectomy (R-D3L) in right colon cancer and reports the oncological outcomes based on a prospective series.

METHODS

The study comprises two phases. In the first phase, a dynamic demonstration of the R-D3L surgical protocol is provided through textual explanation, illustrations, and edited surgical videos. The protocol emphasizes technical steps such as dissection of the embryological plane of the right mesocolon, high tie of ileocolic vessels, surgical trunk of Gillot dissection, and high tie of superior right colic vein (SRCV). In the second phase, a prospective observational study was conducted involving patients undergoing R-D3L surgery with this protocol between July 2015 and July 2021. Demographic, perioperative, and postoperative variables are analyzed, along with anatomopathological variables and oncological outcomes.

RESULTS

A total of 33 patients were analyzed. Median operative time was 202 min. Perioperative bleeding occurred in 6%. Postoperative complications were mild (Clavien-Dindo III in 2%). Postoperative ileus was observed in 15%. No anastomotic dehiscence was reported. The median postoperative stay was 7 days. The median number of resected lymph nodes was 26, with 27% having positive nodes and 70% were classified as stage T3 or T4. After a median follow-up of 45 months, local recurrence, distant recurrence, and carcinomatosis rates were 0%. Mortality rate from other causes was 9%.

CONCLUSION

The surgical protocol shown in the present study could help in the implementation of this technique in those units that consider it appropriate.

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.

Inferior Mesenteric Artery Ligation Level in Rectal Cancer Surgery beyond Conventions: A Review

Within the intricate field of rectal cancer surgery, the contentious debate over the optimal level of ligation of the inferior mesenteric artery (IMA) persists as an ongoing discussion, influencing surgical approaches and patient outcomes. This narrative review incorporates historical perspectives, technical considerations, and functional as well as oncological outcomes, addressing key questions related to anastomotic leakage risks, genitourinary function, and oncological concerns, providing a more critical understanding of the well-known inconclusive evidence. Beyond the dichotomy of high versus low tie, it navigates the complexities of colorectal cancer surgery with a fresh perspective, posing a transformative question: "Is low tie ligation truly reproducible?" Considering a multidimensional approach that enhances patient outcomes by integrating the surgeon, patient, technique, and technology, instead of a rigid and categorical statement, we argued that a balanced response to this challenging question may require compromise.

Macroscopic Evaluation of Colon Cancer Resection Specimens

Colon cancer is a common disease internationally. Outcomes have not improved to the same degree as in rectal cancer, where the focus on total mesorectal excision and pathological feedback has significantly contributed to improved survival and reduced local recurrence. Colon cancer surgery shows significant variation around the world, with differences in mesocolic integrity, height of the vascular ligation and length of the bowel resected. This leads to variation in well-recognised quality measures like lymph node yield. Pathologists are able to assess all of these variables and are ideally placed to provide feedback to surgeons and the wider multidisciplinary team to improve surgical quality over time. With a move towards complete mesocolic excision with central vascular ligation to remove the primary tumour and all mechanisms of spread within an intact package, pathological feedback will be central to improving outcomes for patients with operable colon cancer. This review focusses on the key quality measures and the evidence that underpins them.

Extended Right-Sided Colon Resection Does Not Reduce the Risk of Colon Cancer Local-Regional Recurrence: Nationwide Population-Based Study From Danish Colorectal Cancer Group Database

BACKGROUND

It is controversial whether extensive resection of right-sided colon cancer confers oncological benefits.

OBJECTIVE

The aim of this study was to evaluate short- and long-term outcomes of extended surgical removal of the mesocolon compared to the conventional approach.

DESIGN

This was a retrospective population-based study.

SETTING

Study is based on a prospectively maintained Danish Colorectal Cancer Group database.

MAIN OUTCOME MEASURES

Primary outcome measures included local-regional recurrence in patients who underwent curative resection for right-sided colon cancer and 30-day postoperative complications. Distant metastasis, unplanned intraoperative adverse events, and 30- and 90-day postoperative mortality were also investigated. Patients who had palliative or compromised resection, emergency surgery, or neoadjuvant chemotherapy were excluded.

RESULTS

Of the 12,855 patients with resection of right-sided colon cancer retrieved, 1151 underwent extended right hemicolectomy. Patients who had extended right hemicolectomy were younger males with lower ASA scores, were operated on by colorectal surgeons using a laparoscopic approach, and had a significantly higher number of harvested lymph nodes. The rate of local-regional recurrence was 1.1% (136/12,855), with no difference between conventional right hemicolectomy and extended right hemicolectomy (OR, 1.7; 95% CI, 0.63-2.18). Postoperative medical complications were significantly higher in extended right hemicolectomy even after adjusting for age, comorbidity, access to the abdomen, and other covariates (OR, 1.26; 95% CI, 1.01-1.58). No significant difference was noticed between conventional right hemicolectomy and extended right hemicolectomy in the rates of distant metastasis, unplanned intraoperative adverse events, and mortality.

LIMITATIONS

Because it is a register-based study, underreporting cannot be excluded. Extended right hemicolectomy, as defined in this study, does not reflect the extent of lymphatic dissection performed during the surgery.

CONCLUSIONS

This large population-based register study showed no difference in local-regional recurrence of right-sided colon cancer between conventional and extended right hemicolectomy with mesenteric resection and ligation of the middle colic vessels. Extended resection was associated with higher rates of postoperative complications. See Video Abstract at http://links.lww.com/DCR/B907 .

LA RESECCIN AMPLIADA DEL COLON DERECHO NO REDUCE EL RIESGO DE RECURRENCIA LOCALREGIONAL DEL CNCER DE COLON ESTUDIO POBLACIONAL A NIVEL NACIONAL DE LA BASE DE DATOS DEL GRUPO DANS DE CNCER COLORRECTAL

ANTECEDENTES:Es aun un tema controversial si la resección ampliada del cáncer de colon del lado derecho confiere beneficios oncológicos.OBJETIVOS:El objetivo de este estudio fue examinar los resultados a corto y largo plazo de la resección quirúrgica ampliada del mesocolon en comparación con el enfoque convencional.DISEÑO:Este fue un estudio poblacional de tipo retrospectivo basado en una base de datos del Grupo Danés de Cáncer Colorrectal mantenida de manera prospectiva.AJUSTES:La medida de resultado primaria fue la recurrencia local-regional en pacientes sometidos a resección curativa por cáncer de colon del lado derecho y las medidas de resultado secundarias fueron las complicaciones posoperatorias a los 30 días. También fueron investigadas las metástasis a distancia, los eventos adversos intraoperatorios no planificados y la mortalidad posoperatoria a los 30 y 90 días. Se excluyeron los pacientes sometidos a resección paliativa o comprometida, cirugía de urgencia y quimioterapia neoadyuvante.RESULTADOS:De los 12.855 pacientes recuperados y sometidos a resección de cáncer de colon del lado derecho, 1151 fueron sometidos a hemicolectomía derecha ampliada. Los pacientes sometidos a hemicolectomía derecha ampliada fueron varones más jóvenes con puntuaciones ASA más bajas, operados por cirujanos colorrectales, utilizando la vía laparoscópica, y tuvieron un número significativamente mayor de ganglios linfáticos extraídos. La tasa de recidiva local-regional fue del 1,1% (136 / 12.855) sin diferencia entre la hemicolectomía derecha convencional y la hemicolectomía derecha ampliada (OR 1,7 IC 95% 0,63-2,18). Las complicaciones médicas post operatorias fueron significativamente mayores en la hemicolectomía derecha ampliada incluso después del ajuste por edad, comorbilidad, acceso al abdomen y otras covariables (OR 1,26; IC 95% 1,01-1,58). No se observaron diferencias significativas entre la hemicolectomía derecha convencional y la hemicolectomía derecha ampliada con respecto a las tasas de metástasis a distancia, eventos adversos intraoperatorios no planificados y mortalidad.LIMITACIONES:Es un estudio basado en registros, por lo tanto, no se puede excluir la sub notificación. La hemicolectomía derecha ampliada como se define en este estudio no refleja la extensión de la disección linfática realizada durante la cirugía.CONCLUSIONES:Este gran estudio basado en el registro poblacional no mostró diferencias en la recurrencia local-regional del cáncer de colon del lado derecho entre la hemicolectomía derecha convencional y ampliada con resección mesentérica y ligadura de los vasos cólicos medios. La resección ampliada se asoció con tasas más altas de complicaciones posoperatorias. Consulte Video Resumen en http://links.lww.com/DCR/B907 . (Traducción-Dr. Osvaldo Gauto ).

Impact on defecatory, urinary and sexual function after high-tie sigmoidectomy: a post-hoc analysis of a multicenter randomized controlled trial comparing extended versus standard complete mesocolon excision

OBJECTIVE

To assess the effect of high inferior mesenteric artery tie on defecatory, urinary, and sexual function after surgery for sigmoid colon cancer. Performing a sigmoidectomy poses a notable risk of causing injury to the preaortic sympathetic nerves during the high ligation of the inferior mesenteric artery, as well as to the superior hypogastric plexus during dissection at the level of the sacral promontory. Postoperative defecatory and genitourinary dysfunction after sigmoid colon resection are often underestimated and underreported.

METHODS

This study is a secondary research of a multicenter, single-blind, randomized clinical trial. The trial involved patients with sigmoid cancer who underwent either extended complete mesocolic excision (e-CME) or standard CME (s-CME). Patients completed questionnaires to assess defecatory, urinary, and sexual function before, 1 month after surgery, and 1 year after surgery. Multivariate analysis was conducted to identify factors associated with functional dysfunction.

RESULTS

Seventy-nine patients completed functional assessments before and 1 year after surgery. One year after sigmoidectomy with a high tie of the inferior mesenteric artery, 15.2% of patients had minor low anterior resection syndrome (LARS) and 12.7% had major LARS; 22.2% of males and 29.4% of females had urinary dysfunction; and 43.8% of males and 27.3% of females had sexual dysfunction. After multivariate analysis, no significant associations were found between clinical and surgical factors and gastrointestinal or urinary dysfunction after 1 year of surgery. Age was identified as the only factor linked to sexual dysfunction in both sexes (women, β =  - 0.54, p = 0.002; men β =  - 0.38, p = 0.010). Regarding recovery outcomes, diabetes mellitus was identified as a contributing factor to suboptimal gastrointestinal recovery (p = 0.033) and urinary recovery in women (p = 0.039). Furthermore, the treatment arm was found to be significantly associated with the recovery of erectile function after 1 year of surgery (p = 0.046).

CONCLUSIONS

A high tie of the inferior mesenteric artery during sigmoidectomy is associated with a high incidence of defecatory and genitourinary dysfunction. Age was identified as a significant factor associated with sexual dysfunction 1 year after sigmoid colon resection in both sexes.

TRIAL REGISTRATION

Clinical trials NCT03083951 HIGHLIGHTS: • One year after high-tie sigmoidectomy, 27.9% of patients had LARS; 22.2% of the men and 29.4% of the women had urinary dysfunction; and 43.8% of the men and 27.3% of the women had sexual dysfunction. • e-CME is associated with a high rate of urinary dysfunction in men 1 year after surgery. However, after multivariate analysis, no association was found between e-CME and urinary dysfunction in men. • Age was correlated with the recovery of sexual function in both sexes 1 year after surgery. Furthermore, diabetes mellitus was identified as the factor associated with poorer recovery of urinary function in females.

Surgical and oncological outcomes of laparoscopic right hemicolectomy (D3 + CME) for colon cancer: A prospective single-center cohort study

BACKGROUND

Complete mesocolic excision (CME) or D3 lymphadenectomy led to survival benefits for locally advanced right colon cancer, but with vague definitions in anatomy and debated surgical hazard in clinic. Aiming to achieve a precise definition of it in anatomy, we proposed laparoscopic right hemicolectomy (D3 + CME) as a novel procedure for colon cancer. However, the surgical and oncological results of this procedure in clinic were uncertain.

METHODS

We performed a cohort study involving prospective data collected from a single-center in China. Data from all patients who underwent right hemicolectomy between January 2014 and December 2018 were included. We compared the surgical and oncological outcomes between D3 + CME and conventional CME.

RESULTS

After implementation of exclusion criteria, a total of 442 patients were included. D3 + CME group performed better in lymph nodes harvested (25.0 [17.0, 33.8] vs. 18.0 [14.0, 25.0], P < 0.001) and the proportion of intraoperative blood loss ≥ 50 mL (31.7% vs. 51.8%, P < 0.001); no significant difference was observed in the complication rates between two groups. Kaplan-Meier analysis demonstrated that a better cumulative 5-year disease-free survival (91.3% vs. 82.2%, P = 0.026) and a better cumulative 5-year overall survival (95.2% vs. 86.1%, P = 0.012) were obtained in the D3 + CME group. Multivariate COX regression revealed that D3 + CME was an independent protective factor for disease-free survival (P = 0.026).

CONCLUSION

D3 + CME could improve surgical and oncological outcomes simultaneously for right colon cancer compared to conventional CME. Large-scale randomized controlled trials were further required to confirm this conclusion, if possible.

Young-onset colorectal cancer

In the past decades the incidence of colorectal cancer (CRC) in people under the age of 50 years has increased, which is referred to as early-onset CRC or young-onset CRC (YO-CRC). YO-CRC is expected to account for 11% of colon cancers and 23% of rectal cancers by 2030. This trend is observed in different parts of the world and in both men and women. In 20% of patients with YO-CRC, a hereditary cancer syndrome is found as the underlying cause; however, in the majority of patients no genetic predisposition is present. Beginning in the 1950s, major changes in lifestyle such as antibiotic use, low physical activity and obesity have affected the gut microbiome and may be an important factor in YO-CRC development. Owing to a lack of screening, patients with YO-CRC are often diagnosed with advanced-stage disease. Long-term treatment-related complications should be taken into account in these younger patients, making the more traditional sequential approaches of drug therapy not always the most appropriate option. To better understand the underlying mechanism and define relationships between environmental factors and YO-CRC development, long-term prospective studies are needed with lifestyle data collected from childhood.

Robot-assisted versus laparoscopic short- and long-term outcomes in complete mesocolic excision for right-sided colonic cancer: a systematic review and meta-analysis

BACKGROUND

Complete mesocolic excision (CME) surgery is increasingly implemented for the resection of right-sided colonic cancer, possibly resulting in improved 5-year overall and disease-free survival compared to non-CME surgery. However, it is not clear what surgical platform should be used. The aim of this study was to compare the following outcomes between robot-assisted and laparoscopic CME-surgery for right-sided colonic cancer: (i) short-term clinical outcomes, (ii) pathological specimen quality, and (iii) long-term oncological outcomes.

METHODS

Medline, Embase, and Cochrane Database of Systematic Reviews were searched from inception until August 2021. Pooled proportions were calculated by applying the inverse variance method. Heterogeneity was explored by I-square and supplemented by sensitivity- and meta-regression analyses. The risk of bias was evaluated by either MINORS or Cochrane's risk-of-bias tool (RoB 2).

RESULTS

Fifty-five studies with 5.357 patients (740 robot-assisted and 4617 laparoscopic) were included in the meta-analysis. Overall postoperative morbidity was 17% [95% CI (14-20%)] in the robot-assisted group and 13% [95%CI (12-13%)] in the laparoscopic group. Robot-assisted CME was associated with a shorter hospital stay, lower intraoperative blood loss, a higher amount of harvested lymph nodes, and better 3-year oerall and disease-free survival. MINORS and RoB2 indicated a serious risk of bias across studies included.

CONCLUSIONS

This review which includes predominantly non-randomized studies suggests a possible advantage of the robot-assisted CME compared with a laparoscopic technique for several short-term outcomes.

Definition and reporting of lymphadenectomy and complete mesocolic excision for radical right colectomy: a systematic review

BACKGROUND

Several procedures have been proposed to reduce the rates of recurrence in patients with right-sided colon cancer. Different procedures for a radical right colectomy (RRC), including extended D3 lymphadenectomy, complete mesocolic excision and central vascular ligation have been associated with survival benefits by some authors, but results are inconsistent. The aim of this study was to assess the variability in definition and reporting of RRC, which might be responsible for significant differences in outcome evaluation.

METHODS

PRISMA-compliant systematic literature review to identify the definitions of RRC. Primary aims were to identify surgical steps and different nomenclature for RRC. Secondary aims were description of heterogeneity and overlap among different RRC techniques.

RESULTS

Ninety-nine articles satisfied inclusion criteria. Eight surgical steps were identified and recorded as specific to RRC: Central arterial ligation was described in 100% of the included studies; preservation of mesocolic integrity in 73% and dissection along the SMV plane in 67%. Other surgical steps were inconstantly reported. Six differently named techniques for RRC have been identified. There were 35 definitions for the 6 techniques and 40% of these were used to identify more than one technique.

CONCLUSIONS

The only universally adopted surgical step for RRC is central arterial ligation. There is great heterogeneity and consistent overlap among definitions of all RRC techniques. This is likely to jeopardise the interpretation of the outcomes of studies on the topic. Consistent use of definitions and reporting of procedures are needed to obtain reliable conclusions in future trials. PROSPERO CRD42021241650.

The mesocolic apical fragment in complete mesocolic excision colectomies: Should it be analysed separately? A proof-of-concept study

AIM

The aim of this work is to describe a protocol and assess the feasibility of harvesting and analysing the mesocolic apical fragment (MAF) for the presence of central lymph node (LN) metastasis and extra lymphatic free tumour cells in a random subgroup extracted from a cohort of complete mesocolic excision colectomies with central vascular ligation.

METHOD

Forty-seven patients diagnosed with colorectal cancer were included. A 2/2 cm pyramid of tissue was cut around the central tie and sent for pathological examination. The MAF was sectioned into 16 slices. High-definition images were taken from the slices which were merged into a panoramic three-dimensional image of the MAF. The distribution of LNs in the MAF was quantified. Immunohistochemistry staining for cytokeratin 14 was used to identify isolated tumour cells and micrometastases in the extranodal tissue.

RESULTS

No tumoural cells migrating through the apical zone, outside of the LNs, were identified. Margins of resection, mesocolic tissue and LNs were all negative in the subgroup of ultrastaged MAFs. The number of examined central LNs varied between 0 and 24, with positive MAF LNs being identified only in pN2 stages. The rate of positive apical LNs in our cohort was 4.2% (n = 2).

CONCLUSIONS

The MAF can be easily extracted from standard specimens, allowing for accurate analysis of lymphatic and extra-nodal tumour cells on the central resection margins, in central LNs and in the apical mesocolic tissue. Future research on larger cohorts is required to establish if analysing the MAF has an impact on patient staging, prognosis and management.

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.

Vascular Anatomy and Variants: Knowledge during Laparoscopic Right Colectomy

From the review of the literature and clinical data, it is clear that the anatomy of the vessels of the right colon is remarkably variable, especially those of Henle branch. This justifies why the laparoscopic colectomy (LRC) plus complete mesocolon excision (CME) is often difficult to perform with the conversion rate due to the lesion of the vessels. The objective of this study was to retrospectively review the videos and literature of the right laparoscopic colectomy plus CME to highlight the greatest number of vascular variations of the right colon, to record them, and to highlight the methods by which cope with these variations during surgery.

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.

Circular RNA circ_0068464 combined with microRNA-383 regulates Wnt/β-catenin pathway to promote the progression of colorectal cancer

This study was to clarify the influence and mechanism of circular RNA hsa_circ_0068464 (circ_0068464) on the development of colorectal cancer (CRC). First, we combined bioinformatics analysis and the high-throughput sequencing to determine the expression profile of circRNAs in CRC dataset, and screened out the differentially expressed circ_0068464. Subsequently, qRT-PCR was utilized to measure circ_0068464 expression in CRC and normal cancer-adjacent tissues, CRC cell lines (SW480, SW620, HT29, LS174T and HCT116) and human fetal intestinal epithelial cell (FHC). The results revealed that circ_0068464 was abnormally up-regulated in CRC cells and tissues. Knockdown of circ_0068464 could inhibit CRC cell migration and proliferation and promoted apoptosis while suppressing the expression of Wnt/β-catenin pathway-related proteins (β-catenin, cyclin D1, C-myc and LEF-1). In addition, tumorigenic assays in nude mice confirmed that circ_0068464 downregulation significantly inhibited tumor growth and lung metastasis. Further, the binding interaction between circ_0068464 and microRNA-383 (miR-383) was verified by dual-luciferase assay and RNA immunoprecipitation assay. And miR-383 was significantly down-regulated in CRC tissues and cells. Interfering with miR-383 expression reversed the inhibitory effect of circ_0068464 knockdown on CRC cells. In conclusion, circ_0068464 targets miR-383 to regulate Wnt/β-catenin pathway activation, thereby promoting the development of CRC.

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

OBJECTIVE

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Postoperative Quality Assessment Score Can Select Patients with High Risk for Locoregional Recurrence in Colon Cancer

BACKGROUND

Monitoring surgical quality has been shown to reduce locoregional recurrence (LRR). We previously showed that the arterial stump length (ASL) after complete mesocolic excision (CME) is a reproducible quality instrument and correlates with the lymph-node (LN) yield. We hypothesized that generating an LRR prediction score by integrating the ASL would predict the risk of LRR after suboptimal surgery.

METHODS

502 patients with curative resections for stage I-III colon cancer were divided in two groups (CME vs. non-CME) and compared in terms of surgical data, ASL-derived parameters, pathological parameters, LRR and LRR-free survival. A prediction score was generated to stratify patients at high risk for LRR.

RESULTS

The ASL showed significantly higher values (50.77 mm ± 28.5 mm) with LRR vs. (45.59 mm ± 28.1 mm) without LRR (p < 0.001). Kaplan-Meier survival analysis showed a significant increase in LRR-free survival at 5.58 years when CME was performed (Group A: 81%), in contrast to non-CME surgery (Group B: 67.2%).

CONCLUSIONS

The prediction score placed 76.6% of patients with LRR in the high-risk category, with a strong predictive value. Patients with long vascular stumps and positive nodes could benefit from second surgery to complete the mesocolic excision.

A systematic review and meta-analysis of variants of the branches of the superior mesenteric artery: the Achilles heel of right hemicolectomy with complete mesocolic excision?

AIM

Dissection with subsequent ligation and resection of arteries at their origin (central vascular ligation) is essential for adequate oncological resection during right hemicolectomy with complete mesocolic excision. This technique is technically demanding due to the highly variable arterial pattern of the right colon. Therefore, this study aims to provide a comprehensive evidence-based assessment of the arterial vascular anatomy of the right colon.

METHODS

A thorough systematic literature search through September 2020 was conducted on the electronic databases PubMed, Scopus and Web of Science to identify studies eligible for inclusion. Data were extracted and pooled into a meta-analysis using MetaXl software.

RESULTS

A total of 41 studies (n = 4691 patients) were included. The ileocolic artery (ICA), right colic artery (RCA) and middle colic artery (MCA) were present in 99.7% (95% CI 99.4%-99.8%), 72.6% (95% CI 61.3%-82.5%) and 96.9% (95% CI 94.2%-98.8%) respectively of patients. Supernumerary RCA and MCA were observed in 3.2% and 11.4% respectively of all cases. The RCA shared a common trunk with the ICA and MCA in 13.2% and 17.7% respectively of patients. A retro-superior mesenteric vein course of the ICA and RCA was observed in 55.1% and 11.4% respectively of all cases.

CONCLUSION

The vascular anatomy of the right colon displays several notable variations, namely the absence of some branches (RCA absent in 27.4% of cases), supernumerary branches, common trunks, and retro-superior mesenteric vein courses. These variations should be taken into consideration during right hemicolectomy with complete mesocolic excision to ensure adequate oncological resection while minimizing intra-operative complications.

The Dual Role of Circular RNAs as miRNA Sponges in Breast Cancer and Colon Cancer

Breast cancer (BC) and colon cancer (CRC) are the two most deadly cancers in the world. These cancers partly share the same genetic background and are partially regulated by the same genes. The outcomes of traditional chemoradiotherapy and surgery remain suboptimal, with high postoperative recurrence and a low survival rate. It is, therefore, urgent to innovate and improve the existing treatment measures. Many studies primarily reported that the microRNA (miRNA) sponge functions of circular RNA (circRNA) in BC and CRC have an indirect relationship between the circRNA–miRNA axis and malignant behaviors. With a covalent ring structure, circRNAs can regulate the expression of target genes in multiple ways, especially by acting as miRNA sponges. Therefore, this review mainly focuses on the roles of circRNAs as miRNA sponges in BC and CRC based on studies over the last three years, thus providing a theoretical reference for finding new therapeutic targets in the future.

Laparoscopic complete mesocolic excision versus conventional resection for right-sided colon cancer: a propensity score matching analysis of short-term outcomes

BACKGROUND

Complete mesocolic excision (CME) for right-sided colon cancer (RCC) is a demanding operation, especially when performed laparoscopically. The potential impact of CME in increasing postoperative complications is still unclear. The aim of our study was to evaluate the safety and feasibility of laparoscopic CME compared with laparoscopic non-complete mesocolic excision (NCME) during colectomy for RCC.

METHODS

Data from a prospectively collected database of patients who underwent laparoscopic right and extended right colectomy at our institution between January 2008 and February 2020 were retrieved and analyzed. Short-term outcomes of patients undergoing CME and NCME were compared. A 1:1 propensity score matching (PSM) was used to balance baseline characteristics between groups.

RESULTS

A total of 663 consecutive patients underwent resection of RCC in the study period. Among these, 500 met the inclusion criteria and after PSM a total of 372 patients were correctly matched, 186 in each group. A similar rate of overall postoperative complications was found between the CME and NCME groups (21.5% and 18.3%, p = 0.436). No difference was found in terms of conversion rate, severe complications, reoperations, readmissions, and mortality. The median number of harvested lymph nodes was higher in the CME group (22 versus 19, p = 0.003), with a lower rate of inadequate sampling (7.0% and 15.1%, p = 0.013).

CONCLUSION

Laparoscopic CME for RCC is technically feasible and safe. It does not seem to be associated with a higher rate of complications or mortality compared with the "traditional" approach, but it allows better nodal sampling.

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

Purpose

Laparoscopic complete mesocolic excision (CME) right colectomy is a technically demanding procedure infrequently employed in Western centers. This retrospective cohort study aims to analyze the safety of laparoscopic CME colectomy compared to standard colectomy for right-sided colon cancer in a Western series.

Methods

Prospectively collected data from 60 patients who underwent laparoscopic CME right colectomy were compared to the ones of 55 patients who underwent laparoscopic standard right colectomy.

Results

No differences in clinical characteristics were observed between the CME and standard right colectomy groups. No differences were demonstrated in terms of blood loss (P = 0.060), intraoperative complications (P = 1), conversion rate (P = 0.102), and operative time (P = 0.473). No deaths were observed in either group, while complication rate was 40.0% in the CME and 49.1% in the standard group (P = 0.353). Severe complications occurred in 10.0% vs. 9.1% (P = 0.842), redo surgery in 5.0% vs. 7.3% (P = 0.708), and unplanned readmission in 5.0% vs. 5.5% (P = 1) after CME and standard colectomy, respectively. A significant difference in favor of CME was observed in the total length of specimen (P < 0.001), proximal (P = 0.018), and distal margins (P = 0.037). The number of lymph nodes harvested was significantly higher in the CME group (27 vs. 22, P = 0.037).

Conclusion

In Western series, where patients have less favorable clinical characteristics, laparoscopic CME allows to obtain better quality surgical specimens and comparable short-term outcomes compared to standard right colectomy.

D3-lymphadenectomy enhances oncological clearance in patients with right colon cancer. Results of a meta-analysis

BACKGROUND

D3-Lymphadenectomy, together with complete mesocolic excision (CME), were introduced to provide oncological results after right colon cancer. The aim of this systematic review with meta-analysis was to assess the short and long-term outcomes of right-sided hemicolectomy with CME + D3 as compared with classic right hemicolectomy. Secondary aims included the prevalence of D3-metastasis and skip metastasis when performing CME + D3.

MATERIAL AND METHODS

A systematic review with meta-analysis was conducted, according to PRISMA methodology.

RESULTS

29 studies were enrolled (2592 patients). No differences were accounted in morbidity variables associated with the measured techniques. CME + D3 was significantly associated with a greater distance between the tumour and the closest vascular tie, a longer colonic resection, a wider resection of mesentery and an increased number of harvested lymph nodes. Regarding to long-terms outcomes, we found a significant decrease in local recurrence in patients undergoing CME + D3 (HR:0.17) and a significant improvement in 3-year and 5-year overall survival rates (HR:0.53 vs. HR:0.57, respectively), as well as an improving survival in patients with stage II and III disease. Overall prevalence of patients with lymphatic metastases in D3-territory was of 8.6% and 2.2% of skip metastases.

CONCLUSIONS

CME + D3 is a feasible surgical procedure that allows to obtain specimens with higher quality oncological resection, without greater associated morbidity, thus improving survival in patients with stage II and III right colon cancer.

Complete mesocolic excision in minimally invasive surgery of colonic cancer: do we need the robot?

Background

Robotic surgery offers favorable prerequisites for complex minimally invasive surgeries which are delivered by higher degrees of freedom, improved instrument stability, and a perfect visualization in 3D which is fully surgeon controlled. In this article we aim to assess its impact on complete mesocolic excision (CME) in colon cancer and to answer the question of whether the current evidence expresses a need for robotic surgery for this indication.

Methods

Retrospective analysis and review of the current literature on complete mesocolic excision for colon cancer comparing the outcome after open, laparoscopic, and robotic approaches.

Results

Complete mesocolic excision results in improved disease-free survival and reduced local recurrence, but turns out to be complex and prone to complications. Introduced in open surgery, the transfer to minimally invasive surgery resulted in comparable results, however, with high conversion rates. In comparison, robotic surgery shows a reduced conversion rate and a tendency toward higher lymph node yield. Data, however, are insufficient and no high-quality studies have been published to date. Almost no oncologic follow-up data are available in the literature.

Conclusion

The current data do not allow for a reliable conclusion on the need of robotic surgery for CME, but show results which hypothesize an equivalence if not superiority to laparoscopy. Due to recently published technical improvements for robotic CME and supplementary features of this method, we suppose that this approach will gain in importance in the future.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Efficacy and Safety of Complete Mesocolic Excision in Patients With Colon Cancer: Three-year Results From a Prospective, Nonrandomized, Double-blind, Controlled Trial

OBJECTIVE

The aim of the study was to evaluate the oncological outcomes of complete mesocolic excision (CME) in colon cancer patients.

SUMMARY BACKGROUND DATA

CME is considered a standard procedure for colon cancer patients. However, previous evidence regarding the effect of CME on prognosis has fundamental limitations that prevent it from being fully accepted.

METHODS

Patients who underwent radical resection for colon cancer were enrolled between November 2012 and March 2016. According to the principles of CME, patients were stratified into 2 groups based on intraoperative surgical fields and specimen photographs. The primary outcome was local recurrence-free survival (LRFS). The clinicopathological data and follow-up information were collected and recorded. The final follow-up date was April 2016. The trial was registered in ClinicalTrials.gov (identifier: NCT01724775).

RESULTS

There were 220 patients in the CME group and 110 patients in the noncomplete mesocolic excision (NCME) group. Baseline characteristics were well balanced. Compared with NCME, CME was associated with a greater number of total lymph nodes (24 vs 20, P = 0.002). Postoperative complications did not differ between the 2 groups. CME had a positive effect on LRFS compared with NCME (100.0% vs 90.2%, log-rank P < 0.001). Mesocolic dissection (100.0% vs 87.9%, log-rank P < 0.001) and nontumor deposits (97.2% vs 91.6%, log-rank P < 0.022) were also associated with improved LRFS.

CONCLUSIONS

Our findings demonstrate that, compared with NCME, CME improves 3-year LRFS without increasing surgical risks.

A Proposal for Novel Standards of Histopathology Reporting for D3 Lymphadenectomy in Right Colon Cancer: The Mesocolic Sail and Superior Right Colic Vein Landmarks

BACKGROUND

Strong agreement exists concerning the standards of pathologic reporting for total mesorectal excision and complete mesocolic excision. It represents a quality standard that correlates with survival. However, no agreed standards of reporting are available to define D3 lymphadenectomy for right colectomy.

OBJECTIVE

The purpose of this study was to define anatomopathological standards of specimen quality obtained from the surgical specimen when an oncologic right hemicolectomy with D3 lymphadenectomy has been correctly performed.

DESIGN

This study was conducted in 2 different phases. The first part consisted of a cadaver-based study of right colon anatomy, and the second part consisted of a prospective assessment of a series of surgical specimens obtained after right hemicolectomy for cancer.

SETTINGS

The anatomic phase of the study was performed in collaboration with the University of Valencia Department of Anatomy and Embryology. The second part was performed at a colorectal unit of a tertiary hospital.

PATIENTS

Seventeen cadavers were used for the first phase, and 65 surgical specimens were examined for the second part of the study.

MAIN OUTCOME MEASURES

In each specimen, the pathologists looked for anatomic structures defined as markers of quality standards of the D3 lymphadenectomy during the first phase. Specimens were classified as complete, partial, and incomplete D3 lymphadenectomy.

RESULTS

Twenty percent of specimens were classified as incomplete D3 lymphadenectomy, 31% as partial, and 49% as complete. A median number of 14 (6-64), 22 (11-47), and 29 (14-55) lymph nodes were isolated (p = 0.01). Similarly, the median numbers of lymph nodes isolated in the area of D3 lymphadenectomy were 0 in incomplete, 1 (0-5) in Partial, and 3 (0-8) in Complete D3 lymphadenectomy specimens (p = 0.0001).

LIMITATIONS

A large multicenter study with adequate power is needed.

CONCLUSIONS

We propose the right mesocolic sail and trunk of superior right colic vein as new and reproducible anatomopathologic standards of D3 lymphadenectomy in oncologic right hemicolectomy. See Video Abstract at http://links.lww.com/DCR/B149. PROPUESTA PARA NUEVOS ESTÁNDARES HISTOPATOLÓGICOS EN LA LINFADENECTOMÍA D3 EN EL CÁNCER DE COLON DERECHO: LA VELA MESOCÓLICA Y LA VENA CÓLICA DERECHA SUPERIOR: Existe un claro acuerdo sobre los estándares de calidad patológicos para la escisión total del mesorrecto y la escisión completa del mesocolon. Son considerados "estándar de calidad" que se correlaciona con la supervivencia. Sin embargo, no se dispone de estándares de calidad para definir la linfadenectomía D3, en la colectomía derecha.Definir los estándares anatomopatológicos de calidad obtenidos de una muestra quirúrgica, cuando se ha realizado correctamente una hemicolectomía derecha oncológica, con linfadenectomía D3.Dos fases diferentes. La primera parte consistió en un estudio basado en la anatomía del colon derecho, realizado en cadáveres, y la segunda parte consistió en una evaluación prospectiva de una serie de muestras quirúrgicas obtenidas después de la hemicolectomía derecha para cáncer.La fase anatómica del estudio se realizó en colaboración con el Departamento de Anatomía y Embriología de la Universidad de Valencia. La segunda parte se realizó en la Unidad Colorrectal de un hospital terciario.Se utilizaron diecisiete cadáveres para la primera fase y se examinaron 65 muestras quirúrgicas para la segunda parte del estudio.En cada muestra, los patólogos buscaron estructuras anatómicas definidas, como marcadores de los estándares de calidad de la linfadenectomía D3, durante la primera fase. Las muestras se clasificaron como linfadenectomía D3 completa, parcial e incompleta.El veinte por ciento de las muestras se clasificaron como "Linfadenectomía D3 Incompleta", el 31% como "Parcial" y el 49% como "Completa." Se aisló una media de 14 (6-64), 22 (11-47) y 29 (14-55) ganglios linfáticos respectivamente (p = 0,01). Del mismo modo, el número medio de ganglios linfáticos aislados en el área de la linfadenectomía D3 fue 0 en "Incompleta", 1 (0-5) en "Parcial" y 3 (0-8) en muestras de "Linfadenectomía D3 Completa" (p = 0,0001).Se necesita un estudio multicéntrico con potencia adecuada.Proponemos la vela mesocólica derecha y el tronco de la vena cólica derecha superior, como estándares anatomopatológicos nuevos y reproducibles de linfadenectomía D3, en hemicolectomía derecha oncológica. Consulte Video Resumen en http://links.lww.com/DCR/B149.

Activation of PERK Contributes to Apoptosis and G2/M Arrest by Microtubule Disruptors in Human Colorectal Carcinoma Cells ‡

Microtubule-targeting agents (MTAs) are widely used in cancer chemotherapy, but the therapeutic responses significantly vary among different tumor types. Protein kinase RNA-like endoplasmic reticular (ER) kinase (PERK) is an ER stress kinase, and the role of PERK in the anticancer effects of MTAs is still undefined. In the present study, taxol (TAX) and nocodazole (NOC) significantly induced apoptosis with increased expression of phosphorylated PERK (pPERK; Tyr980) in four human colon cancer cell lines, including HCT-15, COLO205, HT-20, and LOVO cells. Induction of G₂/M arrest by TAX and NOC with increases in phosphorylated Cdc25C and cyclin B1 protein were observed in human colon cancer cells. Application of the c-Jun N-terminal kinase (JNK) inhibitors SP600125 (SP) and JNK inhibitor V (JNKI) significantly reduced TAX- and NOC-induced apoptosis and G₂/M arrest of human colon cancer cells. Interestingly, TAX- and NOC-induced pPERK (Tyr980) protein expression was inhibited by adding the JNK inhibitors, SP and JNKI, and application of the PERK inhibitor GSK2606414 (GSK) significantly reduced apoptosis and G₂/M arrest by TAX and NOC, with decreased pPERK (Tyr980) and pJNK, phosphorylated Cdc25C, and Cyc B1 protein expressions in human colon cancer cells. Decreased viability by TAX and NOC was inhibited by knockdown of PERK using PERK siRNA in COLO205 and HCT-15 cells. Disruption of the mitochondrial membrane potential and an increase in B-cell lymphoma-2 (Bcl-2) protein phosphorylation (pBcl-2; Ser70) by TAX and NOC were prevented by adding the PERK inhibitor GSK and JNK inhibitor SP and JNKI. A cross-activation of JNK and PERK by TAX and NOC leading to anti-CRC actions including apoptosis and G₂/M arrest was first demonstrated herein.

Right Colectomy with Extended D3 Mesenterectomy: Anterior and Posterior to the Mesenteric Vessels

BACKGROUND

In right colectomy for cancer, complete mesocolic excision and D3 lymphadenectomy each leave behind lymphatic tissue anterior and posterior to the superior mesenteric vein (SMV) and artery (SMA). In this article, we present D3 extended mesenterectomy: a surgical technique that excises the lymphatic tissue en bloc with the right colectomy specimen.

MATERIAL AND METHODS

A 3D map of the mesentery of the right colon was reconstructed from staging CT-angiogram scans. The surgical technique of right colectomy with D3 extended mesenterectomy consisted of eight steps: 1) reveal the SMV and SMA; 2) isolate the ileocolic artery; 3) isolate the middle colic artery; 4) resolve the anterior mesenteric flap; 5) specimen de-vascularization; 6) colectomy; 7) resolve the posterior mesenteric flap; and 8) anastomosis.

RESULTS

One-hundred-seventy-six patients (77 men) 66 years of age were operated upon from February 2011 to January 2017. There were 169 adenocarcinomas: 16.0% Stage I, 49.1% Stage II, 33.7% Stage III, 1.2% Stage IV. Tumor locations were 50.6% cecum, 41.5% ascending colon, 4.5% hepatic flexure, and 2.3% transverse colon. Mean operating time was 200 minutes, blood loss 273 ml, and length of stay 7.9 days. There were 9 anastomotic leakages and 15 reoperations. One patient underwent small bowel resection due to SMA tear. There was no postoperative mortality. The mean number of lymph nodes per specimen (40.9) was comprised of 27.1 in the D2 volume and 13.8 in the D3 volume. The mean number of metastatic lymph nodes was 1.2 in the D2 volume and 0.13 in D3. There were 7 patients with lymph node metastasis in D3, 2 of whom had node metastasis solely within D3.

CONCLUSION

This study shows that 1.2% of patients would have been incorrectly diagnosed as Stage II if extended D3 mesenterectomy had not been performed. Similarly, lymph node metastases would have been left behind in 4.1% of patients if extended D3 mesenterectomy had not been performed.

Complete mesocolic excision for colon cancer: is it worth it?

Total mesorectal excision (TME) has been the miracle surgical technique which has since allowed the outcomes of rectal cancer to surpass that of colon cancer. Complete mesocolic excision (CME) attempts to adopt the same principles as that of TME and apply it to colon cancer surgery. Initial retrospective case series and comparative studies have shown promising oncological outcomes. CME entails the en bloc removal of a sufficient length of colonic specimen within an intact peritoneal envelop with extended lymphadenectomy through a high central ligation of vessels. This technique, standardizing the method for resection of right sided colon cancer, has witness promising perioperative and oncological data for both open and laparoscopic methods. However, most data available are mostly retrospective with a glaring lack of level 1 evidence. Despite the technique showing similar outcomes to that of conventional colectomy, parts of the procedure put the patient (and surgeon) at risk of potentially catastrophic complications. As promising as the initial results of CME has been, more well-designed randomized control trials are necessary to justify the increased risks taken and effort to mount the learning curve for CME.

Colorectal cancer

Several decades ago, colorectal cancer was infrequently diagnosed. Nowadays, it is the world's fourth most deadly cancer with almost 900 000 deaths annually. Besides an ageing population and dietary habits of high-income countries, unfavourable risk factors such as obesity, lack of physical exercise, and smoking increase the risk of colorectal cancer. Advancements in pathophysiological understanding have increased the array of treatment options for local and advanced disease leading to individual treatment plans. Treatments include endoscopic and surgical local excision, downstaging preoperative radiotherapy and systemic therapy, extensive surgery for locoregional and metastatic disease, local ablative therapies for metastases, and palliative chemotherapy, targeted therapy, and immunotherapy. Although these new treatment options have doubled overall survival for advanced disease to 3 years, survival is still best for those with non-metastasised disease. As the disease only becomes symptomatic at an advanced stage, worldwide organised screening programmes are being implemented, which aim to increase early detection and reduce morbidity and mortality from colorectal cancer.

The fusion fascia of Fredet: an important embryological landmark for complete mesocolic excision and D3-lymphadenectomy in right colon cancer

BACKGROUND

The fusion fascia of Toldt is a well-known landmark used by colorectal surgeons. On the contrary, the fusion fascia of Fredet (the plane between the ascending mesocolon and the visceral duodenal-pancreatic peritoneum) still remains a neglected embryological structure. Aim of this study was to provide an anatomic description of this fascia and its application to minimally invasive D3-lymphadenectomy (D3-L) and complete mesocolic excision (CME) for right colon cancer.

METHODS

First phase: Cadaveric dissection and anatomic description of the fascia of Fredet. Second phase: prospective evaluation of its surgical application in a consecutive series of laparoscopic right hemicolectomies with CME and D3-L at a tertiary hospital.

RESULTS

The fascia of Fredet was identified and dissected in one fresh and two formalin-fixed cadavers. The trunk of Henle and the medial border of the superior mesenteric vein defined the medial limit of this embryologic plane. Seventeen patients were operated on. Laparoscopic dissection of the fascia of Fredet was possible in every patient. Median operative time was 210 (120-380) min. There were no major postoperative complications. All cases were adenocarcinomas, except one adenomatous polyp. T stage was Tis in three, T2 in two, T3 in seven, and T4 in five patients. Median number of harvested lymph nodes was 24 (9-39). Lymphatic invasion was found in six patients. All resections were classified as satisfactory mesocolic excision and R0. Median postoperative length of stay was 6 (4-20) days. Median follow-up time was 28 (16-41) months. Local and distal recurrence rate was 0.

CONCLUSION

The fusion fascia of Fredet is useful to achieve CME and D3-L in right colon cancers with reduced risk of intraoperative complications. This structure is particularly suitable for minimally invasive surgery; therefore, we encourage awareness of the fascia of Fredet by colorectal surgeons.

Prognostic significance of number versus location of positive mesenteric nodes in stage iii colon cancer

INTRODUCTION

Debate persists on the ideal extent of lymphadenectomy for colon cancer (CC). Specifically, it is unknown whether the anatomical location of positive lymph nodes (LN) has any independent prognostic significance. We assessed the prognostic value of positive LN location in stage III CC patients who underwent extensive (D3) lymphadenectomy.

METHODS

Patients from Kanagawa Cancer Center, Japan, who underwent D3 dissection for CC from 2000 to 16 were analyzed. Mesenteric LN were classified according to location as paracolic (L1), intermediate (L2), or central (L3). Recurrence-free survival (RFS) and the corresponding hazard function were evaluated with their trends over the L groups. Multivariate Cox models were used to evaluate the association of LN location with RFS.

RESULTS

Four hundred forty-six stage III patients were analyzed. The mean number of examined/positive nodes per patient was 42.5/2.6 in L1 (n = 310), 40.9/4.8 in L2 (n = 111), and 44.0/9.8 in L3 (n = 25). RFS was worse for L3 vs. L2 (HR: 2.00, 95%CI [1.05-3.75], p = 0.034) and for L3 vs. L1 (2.62 [1.45-4.71], p = 0.001), but not significantly different between L2 and L1 (1.32 [0.89-1.5], p = 0.17). In a multivariate model adjusting for age, tumor size, and number of lymph nodes harvested T-stage (p < 0.001), adjuvant therapy (p < 0.0038), lymphatic invasion (p = 0.023), and LNR (p = 0.038) were significantly associated with RFS, but not L level or tumor location.

CONCLUSION

The anatomical location of invaded LN does not significantly correlate with RFS in CC, after adjusting for potential confounders. Central LN are infrequently invaded and confer a worse RFS.

Encorafenib inhibits migration, induces cell cycle arrest and apoptosis in colorectal cancer cells

Encorafenib, a new-generation BRAF inhibitor, has been approved by FDA for the treatment of melanoma in combination with binimetinib. However, the mechanism of the drug works in colorectal cancer (CRC) is still unclear. In this study, the suppression of growth of CRC cells by encorafenib was investigated. The effects of treatment of encorafenib on pathways linked to cancer were studied, and the effective inhibition of cell proliferation was documented. Our findings showed that cell migration was inhibited by encorafenib through a likely involvement of MPP and TIMP modulation. Furthermore, encorafenib treatment also induced cell cycle arrest. In addition, induction of apoptosis in CRC cells by elevating levels of PUMA. These observations indicate the potential therapeutic efficacy of encorafenib on CRC.

D3 lymph node dissection reduces recurrence after primary resection for elderly patients with colon cancer

PURPOSE

The favorable oncological impact of D3 lymph node dissection after colon cancer surgery has been described previously. However, D3 lymph node dissection is potentially more invasive than conventional D2 lymph node dissection. The oncological merit of D3 lymph node dissection in elderly patients with colon cancer remains unclear. This study aimed to clarify the oncological outcome after D3 lymph node dissection in patients with colon cancer aged > 75 years.

METHODS

This is a retrospective cohort analysis using propensity matching method. The study was conducted at a university hospital and two community teaching hospitals in a large urban city. A total of 378 consecutive patients with pathological stage II and stage III colon cancer who underwent primary resection with either D2 or D3 lymph node dissection were retrospectively identified on a prospective database between 2000 and 2015. The primary and secondary outcomes of interests were recurrence-free survival and postoperative complication rate, respectively.

RESULTS

After propensity matching, 232 patients were analyzed. The long-term findings showed that the elderly who underwent D3 lymph node dissection had significantly better recurrence-free survival than those who underwent D2 lymph node dissection (p = 0.01). The incidence of postoperative complication was almost similar between the two groups.

CONCLUSIONS

D3 lymph node dissection provides better recurrence-free survival than D2 lymph node dissection after primary resection for elderly patients with pathological stage II and stage III colon cancer.

Minimally Invasive Colon Cancer Surgery

Colon cancer is the second leading cause of cancer death in the United States. Advances in surgical resection techniques, including minimally invasive colectomy, are becoming a standard of care. The oncologic principles of colectomy have included adequate lymphadenectomy, proximal ligation of primary vessels, and resection with adequate longitudinal margins. More recently, complete mesocolic excision has been advocated. Open and minimally invasive approaches must accomplish the same outcomes. This article focuses on the surgical principles of colon cancer, perioperative considerations, and technical aspects of minimally invasive colectomy. We review the current literature regarding oncologic and short-term outcomes of minimally invasive surgery.

Robotic right colectomy with complete mesocolic excision and indocyanine green guidance

BACKGROUND

Robotic complete mesocolic excision (CME) has recently emerged as promising technique to enhance oncologic results in hemicolectomy for cancer. The potential near-infrared (NIR) fluorescence with indocyanine-green (ICG) dye for lymphatic mapping is under investigation and few small case-series are reported.

METHODS

ICG solution was endoscopically injected the day before surgery in patients undergoing robotic right colectomy with CME using the Da Vinci Xi® system and the bottom to up technique. During surgery the ICG was excited by light in the near-infrared (NIR) spectrum of the Firefly™ system, of the Da Vinci Xi® system for image comparison in standard white light and NIR, and real-time visualization of the lymphatic drainage.

RESULTS

Twenty patients affected by right colon cancer underwent robotic right colectomy with the bottom to up technique. No cases converted to open surgery were observed. During surgery, a fluorescent mapping of draining lymph nodes, was visualized in all the 20 patients. In seven patients (35%), lymph nodes outside the standard lymphatic basin were identified and removed.

CONCLUSIONS

The association of robotic right colectomy with the bottom to up technique and ICG-guided lymphadenectomy is a feasible and safe procedure. ICG lymphatic mapping may help to perform a correct CME, although the independent impact of these procedures on oncologic outcome deserves further investigations.

Risk Factors for Peritoneal Recurrence in Stage II to III Colon Cancer

BACKGROUND

Most previous reports to analyze risk factors for peritoneal recurrence in patients with colon cancer have been observational studies of a population-based cohort.

OBJECTIVE

This study aimed to determine the risk factors for peritoneal recurrence in patients with stage II to III colon cancer who underwent curative resection.

DESIGN

This was a pooled analysis using a combined database obtained from 3 large phase III randomized trials (N = 3714).

SETTINGS

Individual patient data were collected from the Japanese Foundation for Multidisciplinary Treatment of Cancer clinical trials 7, 15, and 33, which evaluated the benefits of postoperative 5-fluorouracil-based adjuvant therapies in patients with locally advanced colorectal cancer.

PATIENTS

We included patients who had stage II to III colon cancer and underwent curative resection with over D2 lymph node dissection.

MAIN OUTCOME MEASURES

Main outcomes measured were risk factors for peritoneal recurrence without other organ metastasis after curative surgery.

RESULTS

Peritoneal recurrence occurred in 2.3% (86/3714) of all patients undergoing curative resection. Mean duration from operation to peritoneal recurrence was 17.0 ± 10.3 months. Of these patients with peritoneal recurrence, 29 patients (34%) had recurrence in ≥1 other organ. Multivariate analysis showed that age (≥60 y: HR = 0.531; p = 0.0182), pathological T4 (HR = 3.802; p < 0.0001), lymph node involvement (HR = 3.491; p = 0.0002), and lymphadenectomy (D2: HR = 1.801; p = 0.0356) were independent predictors of peritoneal recurrence. The overall survival was lower in patients who developed peritoneal recurrence than in those with other recurrence (HR = 1.594; p = 0.002).

LIMITATIONS

The regimens of adjuvant chemotherapy were limited to oral 5-fluorouracil.

CONCLUSIONS

Our findings clarified the risk factors for peritoneal recurrence in patients who underwent curative resection for colon cancer. See Video Abstract at http://links.lww.com/DCR/A609.

Feasibility of fluorescence lymph node imaging in colon cancer: FLICC

BACKGROUND

In colon cancer, appropriate tumour excision and associated lymphadenectomy directly impact recurrence and survival outcomes. Currently, there is no standard for mesenteric lymphadenectomy, with a lymph node yield of 12 acting as a surrogate quality marker. Our goal was to determine the safety and feasibility of indocyanine green (ICG) fluorescence imaging to demonstrate lymphatic drainage in colon cancer in a dose-escalation study.

METHODS

A prospective pilot study of colon cancer patients undergoing curative laparoscopic resection was performed. At surgery, peritumoural subserosal ICG injection was done to demonstrate lymphatic drainage of the tumour. A specialized fluorescence system excited the ICG and assessed lymphatics in real time. The primary outcome was the feasibility of ICG fluorescent lymphangiography for lymphatic drainage in colon cancer. Secondary outcomes were the optimal protocol for dose, injection site, and ICG lymphatic mapping timing.

RESULTS

Ten consecutive patients were evaluated (six males, mean age 69.5 years). In all, lymphatic channels were seen around the tumour to a varying extent. Eight (80%) had drainage to the sentinel node. In all cases where the lymphatic map was seen, there was no further spread 10 min after injection. In 2 patients (20%), additional lymph nodes located outside of the proposed resection margins were demonstrated. In both cases the resection was extended to include the nodes and in both patients these nodes were positive on histopathology. Factors contributing to reduced lymphatic visualization were inadequate ICG concentrations, excess India ink blocking drainage, and inflammation from tattoo placement.

CONCLUSIONS

ICG can be safely injected into the peritumoural subserosal and demonstrate lymphatic drainage in colon cancer. This proof of concept and proposed standards for the procedure can lead to future studies to optimize the application of image-guided precision surgery in colon cancer. Furthermore, this technique may be of value in indicating the need for more extended lymphadenectomy.

Right colic artery anatomy: a systematic review of cadaveric studies

Background

Complete mesocolic excision for right-sided colon cancer may offer an oncologically superior excision compared to traditional right hemicolectomy through high vascular tie and adherence to embryonic planes during dissection, supported by preoperative scanning to accurately define the tumour lymphovascular supply and drainage. The authors support and recommend precision oncosurgery based on these principles, with an emphasis on the importance of understanding the vascular anatomy. However, the anatomical variability of the right colic artery (RCA) has resulted in significant discord in the literature regarding its precise arrangement.

Methods

We systematically reviewed the literature on the incidence of the different origins of the RCA in cadaveric studies. An electronic search was conducted as per Preferred Reporting Items for Systematic Reviews and Meta-analyses recommendations up to October 2016 using the MESH terms ‘right colic artery’ and ‘anatomy’ (PROSPERO registration number CRD42016041578).

Results

Ten studies involving 1073 cadavers were identified as suitable for analysis from 211 articles retrieved. The weighted mean incidence with which the right colic artery arose from other parent vessels was calculated at 36.8% for the superior mesenteric artery, 31.9% for the ileocolic artery, 27.7% for the root of the middle colic artery and 2.5% for the right branch of the middle colic artery. In 1.1% of individuals the RCA shared a trunk with the middle colic and ileocolic arteries. The weighted mean incidence of 2 RCAs was 7.0%, and in 8.9% of cadavers the RCA was absent.

Conclusions

This anatomical information will add to the technical nuances of precision oncosurgery in right-sided colon resections.

Laparoscopic complete mesocolic excisions for colonic cancer in the last decade: Five-year survival in a single centre

AIM

To analyse clinical and long-term oncologic results after laparoscopic complete mesocolic excision (CME) for colonic cancer over a 10-year period.

METHODS

Consecutive patients who received laparoscopic CME at our hospital from 2007 to 2017 were prospectively registered and retrospectively analysed. In total, 341 patients were included with tumour-nodal-metastasis (TNM) stages 0-III.

RESULTS

The mean age of the patients was 71.9 years. The median length of stay was 5 d. The mean lymph node harvest was 17.8. The mortality rate was 1.2%. Fifteen patients were reoperated on for anastomotic leaks. The local recurrence rate was 2.3%. Five-year TTR and cancer-specific survival CSS were 83.1% and 90.3%. The location of the tumour was not a significant variable for survival in unadjusted and adjusted survival analysis. TNM stage and anastomotic leaks were significant variables with respect to survival.

CONCLUSION

Laparoscopic CME results in acceptable complication rates and long-term oncologic results. It is important to avoid anastomotic leaks because of their negative effect on survival.