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

PURPOSE: Complete mesocolic excision (CME) has been associated with improved oncological outcomes in treatment of colon cancer. However, widespread adoption is limited partly because of the technical complexity and perceived risks of the approach. The aim of out study was to evaluate the safety of CME compared to standard resection and to compare robotic versus laparoscopic approaches. METHODS: Two parallel searches were undertaken in MEDLINE, Embase and Web of Science databases 12 December 2021. The first was to evaluate IDEAL stage 3 evidence to compare complication rates as a surrogate marker of perioperative safety between CME and standard resection. The second independent search compared lymph node yield and survival outcomes between minimally invasive approaches. RESULTS: There were four randomized control trials (n = 1422) comparing CME to standard resection, and three studies comparing laparoscopic (n = 164) to robotic (n = 161) approaches. Compared to standard resection, CME was associated with a reduction in Clavien-Dindo grade 3 or higher complication rates (3.56% vs. 7.24%, p = 0.002), reduced blood loss (113.1 ml vs. 137.6 ml, p < 0.0001) and greater mean lymph node harvest (25.6 vs. 20.9 nodes, p = 0.001). Between the robotic and laparoscopic groups, there were no significant differences in complication rates, blood loss, lymph node yield, 5-year disease-free survival (OR 1.05, p = 0.87) and overall survival (OR 0.83, p = 0.54). CONCLUSIONS: Our study demonstrated improved safety with CME. There was no difference in safety or survival outcomes between robotic and laparoscopic CME. The advantage of a robotic approach may lie in the reduced learning curve and an increased penetration of minimally invasive approach to CME. Further studies are required to explore this. PROSPERO ID: CRD42021287065.

Abdominoperineal excision in Australasia: clinical outcomes, predictive factors and recent trends of nonrestorative rectal cancer surgery.

AIM: The decision to perform an abdominoperineal excision (APR) rather than restorative bowel resection relies on a number of clinical factors. There remains great variability in APR rates internationally. The aim of this study was to demonstrate trends of APR surgery in low rectal cancer (< 6 cm from the anal verge) in Australasia and identify predictors of nonrestoration. METHOD: This study reviewed a prospectively maintained colorectal registry - the Binational Colorectal Cancer Audit (BCCA) - from general/colorectal surgical units across Australia and New Zealand. Data were analysed to determine factors predictive of nonrestorative resection. Patients were analysed based on the presence (control) or absence (comparison) of a primary anastomosis. RESULTS: Of 3628 patients with rectal cancer, 2096 were diagnosed with low rectal cancer between 2007 and 2017. The incidence of APR remained constant over the study period, with 58% of all resections of low rectal cancer being APR. The majority of resections were performed by consultants in urban hospitals (86% vs 14%). Tumours ≤ 3 cm from the anal verge, T4, M1 disease and neoadjuvant therapy were the greatest predictors of APR (P < 0.001). A significantly increased rate of restorative surgery was observed in public hospital settings (59% vs 41%, P < 0.05). The rate of positive circumferential resection margin (CRM) was 7.95%, with significantly increased rates in patients undergoing APR (12.2% vs 6.2%, P < 0.001). CRM positivity was increased in open approaches, T4, N2 and M1 staged disease and in an emergency/urgent setting (P < 0.001 and P < 0.045, respectively). Significantly increased wound and pulmonary complications were observed in the APR cohort (P < 0.01). CONCLUSION: The rates of APR in Australia and New Zealand remain high but are comparable to international figures, with one-third of rectal cancers being treated by APR. The main determinants of APR are tumour height, T stage and neoadjuvant therapy requirement. CRM positivity was higher in APR patients.

Robotic complete mesocolic excision using indocyanine fluorescence imaging in colorectal cancer: A case study and technical approach.

INTRODUCTION: Colorectal cancer is the second most common malignancy in developed countries and accurate staging is vital for determining the most appropriate management plan, in particular, whether adjuvant chemotherapy is recommended in addition to surgical resection. There is currently no consensus regarding standard practice for lymph node resection in colorectal cancer although there is increasing evidence to support the use of sentinel lymph node mapping to target lymph node sampling and facilitate ultra-staging of nodes. PRESENTATION OF CASE: We present the case of a 49 year old female who underwent a robotic right hemicolectomy and complete mesocolic excision for caecal adenocarcinoma using indocyanine fluorescence imaging (ICG FI) to guide nodal dissection. DISCUSSION: ICG FI may be useful for sentinel lymph node mapping in colorectal cancer. This technique can assist to identify the first draining lymph nodes and permit ultra-staging of lymph nodes. CONCLUSION: While there is still limited evidence to support ICG FI, the current body of literature suggests that it is likely to be a feasible and sensitive technique for guiding sentinel lymph node sampling in colorectal cancer.

Outcomes of extended radical resections for locally advanced and recurrent pelvic malignancy involving the aortoiliac axis.

AIM: Currently, there is no clear consensus on the role of extended pelvic resections for locally advanced or recurrent disease involving major vascular structures. The aims of this study were to report the outcomes of consecutive patients undergoing extended resections for pelvic malignancy involving the aortoiliac axis. METHODS: Prospective data were collected on patients having extended radical resections for locally advanced or recurrent pelvic malignancies, with aortoiliac axis involvement, requiring en bloc vascular resection and reconstruction, at a single institution between 2014 and 2018. RESULTS: Eleven patients were included (median age 60 years; range 31-69 years; seven women). The majority required resection of both arterial and venous systems (n = 8), and the technique for vascular reconstruction was either interposition grafts or femoral-femoral crossover grafts. The median operative time was 510 min (range 330-960 min). Clear resection margins (R0) were achieved in nine patients. The median length of stay was 25 days (range 7-83 days). Seven patients did not suffer an early complication. There was one serious complication (Clavien-Dindo ≥ 3), an arterial graft occlusion secondary to thrombus in the immediate postoperative period, requiring a return to theatre and thrombectomy. The median length of follow-up in this study was 22 months (range 4-58 months). CONCLUSION: This series demonstrates that en bloc major vascular resection and reconstruction can be performed safely and can achieve clear resection margins in selected patients with locally advanced or recurrent pelvic malignancy at specialist surgery centres.

Successful patient-oriented surgical outcomes in robotic vs laparoscopic right hemicolectomy for cancer - a systematic review.

AIM: Minimally invasive surgical approaches for cancer of the right colon have been well described with significant patient and equivalent oncological benefits. Robotic surgery has advanced in its ability to provide multi-quadrant abdominal access, leading the surgical community to widen its application outside of the pelvis to other abdominal compartments. Globally it is being realized that a patient's surgical episode of care is becoming the epicentre of cancer treatment. In order to establish the role of robotic surgery in a patient's episode of care, 'successful patient-oriented surgical' parameters in right hemicolectomy for malignancy were measured. The objective was to examine the rates of successful patient-oriented surgical outcomes in robotic right hemicolectomy (RRH) compared to laparoscopic right hemicolectomy (LRH) for cancer. METHODS: A systematic search of MEDLINE (Ovid: 1946-present), PubMed (NCBI), Embase (Ovid: 1966-present) and Cochrane Library was conducted using PRISMA for parameters of successful patient-oriented surgical outcomes in RRH and LRH for malignancy alone. The parameters measured included postoperative ileus, anastomotic complication, surgical wound infection, length of stay (LOS), incisional hernia rate, conversion to open, margin status, lymph node harvest and overall morbidity and mortality. RESULTS: There were 15 studies which included 831 RRH patients and 3241 LRH patients, with a median age of 62-74 years. No study analysed the concept of successful patient-oriented surgical outcomes. There was no significant difference in the incidence of postoperative ileus, with less time to first flatus in RRH (2.0-2.7 days, compared with 2.5-4.0 days, P < 0.05). Anastomotic leak rate in one study reported a significant increase in LRH compared to RRH (P < 0.05, 0% vs 8.3%). Significantly decreased LOS following RRH was outlined in six studies. One study reported a significantly higher rate of incisional hernias following LRH with extracorporeal anastomoses compared to RRH with intracorporeal anastomoses. Overall rates of conversion to open surgery were less with RRH (0%-3.9% vs 0%-18%, P < 0.001, 0.05). One study outlined significantly higher rates of incomplete resection with an open right hemicolectomy compared with minimally invasive laparoscopic and robotic resections, with positive margin rates of 2.3%, 0.9% and 0% respectively (P < 0.001). Two studies reported significantly higher lymph node harvest in RRH (P < 0.05). Overall morbidity and 30-day mortality were comparable in both approaches. CONCLUSION: Thirty-day morbidity and mortality were comparable between the two approaches, with patients undergoing RRH having lower anastomotic complications, increased lymph node harvest, and reduced LOS, conversion to open and incisional hernia rates in a number of studies. There are limited data on surgical approach and impact on quality of life and what patients deem successful surgical outcomes. There is a further need for a randomized controlled trial examining successful patient-oriented outcomes in right hemicolectomy for malignancy.

Surgical techniques in the management of rectal cancer: a modified Delphi method by colorectal surgeons in Australia and New Zealand.

BACKGROUND: Technological developments have allowed advances in minimally invasive techniques for total mesorectal excision such as laparoscopy, robotics, and transanal surgery. There remains an ongoing debate about the safety, benefits, and appropriate clinical scenarios for which each technique is employed. The aim of this study was to provide a panel of expert opinion on the role of each surgical technique currently available in the management of rectal cancer using a modified Delphi method. METHODS: Surveys were designed to explore the key patient- and tumor-related factors including clinical scenarios for determining a surgeon's choice of surgical technique. RESULTS: Open surgery was favoured in obese patients with an extra-peritoneal tumor and a positive circumferential resection margin (CRM) or T4 tumor when a restorative resection was planned. Laparoscopy was favoured in non-obese males and females, in both intra- and extra-peritoneal tumors with a clear CRM. Robotic surgery was most commonly offered to obese patients when the CRM was clear and if an abdominoperineal resection was planned. Transanal total mesorectal excision (taTME) was preferred in male patients with a mid or low rectal cancer, particularly when obese. Transanal endoscopic microsurgery/transanal minimally invasive surgery local excision was only offered to frail patients with small, early stage tumors. CONCLUSIONS: All surgical techniques for rectal cancer dissection have a role and may be considered appropriate. Some techniques have advantages over others in certain clinical situations, and the best outcomes may be achieved by considering all options before applying an individualised approach to each clinical situation.

Prognostic factors and patterns of failure after surgery for T4 rectal cancer in the beyond total mesorectal excision era.

BACKGROUND: Despite advances in the rates of total mesorectal excision (TME) for rectal cancer surgery, decreased local recurrence rates and increased 5-year survival, there still exists large variation in the quality of treatment received. Up to 30 per cent of rectal cancers are locally advanced at presentation and approximately 5-10 per cent still breach the mesorectal plane and invade adjacent structures despite neoadjuvant therapy. With the evolution of extended resections for rectal cancers beyond the TME plane, proponents advocate that these resections should be performed only in specialist centres. The aim was to assess the prognostic factors and patterns of failure after beyond TME surgery for T4 rectal cancers. METHODS: Data were collected from prospective databases at three high-volume institutions specializing in beyond TME surgery for T4 rectal cancers between 1990 and 2013. The primary outcome measures were overall survival, local recurrence and patterns of first failure. RESULTS: Three hundred and sixty patients were identified. The negative resection margin (R0) rate was 82·8 per cent (298 patients) and the local recurrence rate was 12·5 per cent (45 patients). The type of surgical procedure (Hartmann's: hazard ratio (HR) 4·49, 95 per cent c.i. 1·99 to 10·14; P = 0·002) and lymphovascular invasion (HR 2·02, 1·08 to 3·77; P = 0·032) were independent predictors of local recurrence. The 5-year overall survival rate for all patients was 61 (95 per cent c.i. 55 to 67) per cent. The 5-year cumulative incidence of first failure was 8 per cent for local recurrence, 6 per cent for local and distant disease, and 18 per cent for distant disease. CONCLUSION: This study has demonstrated that a coordinated approach in specialist centres for beyond TME surgery can offer good oncological and long-term survival in patients with T4 rectal cancers.

ANTECEDENTES: A pesar de las mejoras en los porcentajes de extirpación total del mesorrecto (total mesorectal excision, TME) en la cirugía de cáncer de recto, la disminución de los porcentajes de recidiva local y el aumento de la supervivencia a 5 años, todavía existe una gran variabilidad en la calidad del tratamiento recibido. Hasta el 30% de los cánceres de recto están localmente avanzados en el momento del diagnóstico y aproximadamente el 5-10% sobrepasarán el plano mesorrectal e invadirán las estructuras adyacentes a pesar del tratamiento neoadyuvante. Con la evolución de las resecciones ampliadas para los cánceres de recto que sobrepasan el plano de la TME, los defensores recomiendan que estas resecciones solo se realicen en centros especializados. El objetivo fue evaluar los factores pronósticos y los patrones de recidiva después de la cirugía ampliada más allá de la TME para los cánceres de recto T4. MÉTODOS: Los datos se recogieron a partir de bases de datos prospectivas de tres instituciones de alto volumen especializadas en resecciones ampliadas más allá de la TME para el cáncer de recto T4 entre 1990 y 2013. Los criterios de valoración principal fueron la supervivencia global, la recidiva local y los patrones de la primera recidiva. RESULTADOS: Se identificaron 360 pacientes. El margen de resección fue negativo (R0) en el 82,8% (n = 298) y el porcentaje de recidiva local fue de 12,5% (n = 45). El tipo de cirugía realizada (Hartmann: cociente de riesgos instantáneos, hazard ratio, HR 4,49; i.c. del 95%: 1,99-10,14; P = 0,002) y la invasión linfovascular (HR 2,02; i.c. del 95%: 1,08-3,77; P = 0,032) fueron factores predictivos independientes de recidiva local. La supervivencia global a 5 años para todos los pacientes fue del 61% (i.c. del 95%: 55-67). La incidencia acumulada a los 5 años de la primera recidiva fue de 8% para la recidiva local, 6% para la recidiva local y a distancia, y 18% para la recidiva a distancia. CONCLUSIÓN: Este estudio demuestra que un abordaje coordinado en centros especializados para cirugía más allá de la TME puede ofrecer una buena supervivencia oncológica y a largo plazo en pacientes con cáncer de recto T4.

The effect of increasing body mass index on laparoscopic surgery for colon and rectal cancer.

AIM: Obesity is common in Western countries and its prevalence is increasing. Colorectal cancer is common, and surgery for colorectal cancer is technically more challenging in obese patients. Laparoscopic surgery for colon cancer has been shown to be oncologically equivalent, with improved short- term outcomes. Laparoscopic surgery for rectal cancer has proven technically challenging, and recent results have raised concerns about oncological equivalence. Our aim was to evaluate the effect of body mass index (BMI) on the clinical and oncological outcomes of surgery for colorectal cancer, including the rate at which laparoscopic surgery is attempted and the rate at which laparoscopic surgery is converted to open surgery. METHOD: A retrospective analysis of prospectively collected data from two tertiary institutions was performed. Data were obtained from the Cabrini Monash University colorectal neoplasia database for patients having surgical resection for colon and rectal cancers between 1 January 2010 and 30 June 2015. Surgical and medical complications, tumour recurrence and overall survival and laparoscopic surgery and conversion rates were investigated. RESULTS: This large case series of 1464 patients undergoing elective surgery for colorectal cancer has demonstrated that an elevated BMI is associated with a lower likelihood of attempting laparoscopic surgery and a higher conversion rate to open surgery when laparoscopy is attempted. Conversion was 1.9 times more likely in obese patients with colon cancer and 4.1 times more likely in obese patients with rectal cancer. The critical BMI for colon cancer patients was > 35 kg/m2 , and for rectal cancer patients > 30 kg/m2 . Obesity is also associated with increased rates of surgical complications, including anastomotic leakage and wound complications. Pathological parameters, tumour recurrence and survival were not affected by elevated BMI. CONCLUSION: In the surgical management of colorectal cancer, obesity is associated with a lower likelihood of laparoscopic surgery being attempted, a higher likelihood of conversion to open surgery when laparoscopic surgery is attempted, and a higher rate of surgical complications.

Prognostic value of tumour regression grade in locally advanced rectal cancer: a systematic review and meta-analysis.

AIM: The current standard of care for locally advanced rectal cancer involves neoadjuvant chemoradiotherapy (CRT) followed by total mesorectal excision. There is a spectrum of response to neoadjuvant therapy; however, the prognostic value of tumour regression grade (TRG) in predicting disease-free survival (DFS) or overall survival (OS) is inconsistent in the literature. METHOD: This study was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic search was undertaken using Ovid MEDLINE, Embase and Google Scholar. Inclusion criteria were Stage II and III locally advanced rectal cancer treated with long-course CRT followed by radical surgery. The aim of the meta-analysis was to assess the prognostic implication of each TRG for rectal cancer following neoadjuvant CRT. Long-term prognosis was assessed. The main outcome measures were DFS and OS. A random effects model was performed to pool the hazard ratio (HR) from all included studies. RESULTS: There were 4875 patients from 17 studies, with 775 (15.9%) attaining a pathological complete response (pCR) and 719 (29.9%) with no response. A significant association with OS was identified from a pooled-estimated HR for pCR (HR = 0.47, P = 0.002) and nonresponding tumours (HR = 2.97; P < 0.001). Previously known tumour characteristics, such as ypN, lymphovascular invasion and perineural invasion, were also significantly associated with DFS and OS, with estimated pooled HRs of 2.2, 1.4 and 2.3, respectively. CONCLUSION: In conclusion, the degree of TRG was of prognostic value in predicting long-term outcomes. The current challenge is the development of a high-validity tests to predict pCR.

An assessment of an Australasian pathway for the introduction of transanal total mesorectal excision (taTME).

AIM: To evaluate the use of a pathway for the introduction of transanal total mesorectal excision (taTME) into Australia and New Zealand. METHOD: A pathway for surgeons with an appropriate level of specialist training and baseline skill set was initiated amongst colorectal surgeons; it includes an intensive course, a series of proctored cases and ongoing contribution to audit. Data were collected for patients who had taTME, for benign and malignant conditions, undertaken by the initial adopters of the technique. RESULTS: A total of 133 taTME procedures were performed following the introduction of a training pathway in March 2015. The indication was rectal cancer in 84% of cases. There was one technique-specific visceral injury, which occurred prior to that surgeon completing the pathway. There were no cases of postoperative mortality; morbidity occurred in 27.1%. The distal resection margin was clear in all cases of rectal cancer, and the circumferential resection margin was positive in two cases. An intact or nearly intact total mesorectal excision was obtained in more than 98% of cases. CONCLUSION: This study demonstrates the safe and controlled introduction of a new surgical technique in a defined surgeon population with the use of a pathway for training. The authors recommend a similar pathway to facilitate the introduction of taTME to colorectal surgical practice.

A case series of anal melanoma including the results of treatment with imatinib in selected patients.

AIM: Anal melanoma is a rare malignancy with a poor prognosis. METHOD: All patients with a diagnosis of anal melanoma treated at a single institution between 2000 and 2012 were identified and their treatment and outcome were evaluated. RESULTS: Sixteen patients had a median survival of 2.9 years. Fourteen had Stage I or II disease with a median survival of 4.0 years and progression-free survival of 1.5 years. When used for disease staging, whole body positron emission tomography/CT identified an additional three sites of metastasis in five patients compared with CT of the chest, abdomen and pelvis. Surgery involved wide local excision or abdominoperineal excision with respective local recurrence rates of 50% and 66%. Eleven patients underwent testing for c-Kit mutations, of whom five were positive. Four of these were treated with the tyrosine kinase inhibitor imatinib, and showed rapid response of metastases outside the central nervous system. CONCLUSION: The outcome of this malignancy remains poor. PET is the modality of choice for disease staging. Testing tumours for c-Kit mutations may allow selected patients to participate in trials of tyrosine kinase inhibitors.

Predicting pathological complete response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer: a systematic review.

AIM: Approximately 20% of patients treated with neoadjuvant chemoradiotherapy (nCRT) for locally advanced rectal cancer achieve a pathological complete response (pCR) while the remainder derive the benefit of improved local control and downstaging and a small proportion show a minimal response. The ability to predict which patients will benefit would allow for improved patient stratification directing therapy to those who are likely to achieve a good response, thereby avoiding ineffective treatment in those unlikely to benefit. METHOD: A systematic review of the English language literature was conducted to identify pathological factors, imaging modalities and molecular factors that predict pCR following chemoradiotherapy. PubMed, MEDLINE and Cochrane Database searches were conducted with the following keywords and MeSH search terms: 'rectal neoplasm', 'response', 'neoadjuvant', 'preoperative chemoradiation', 'tumor response'. After review of title and abstracts, 85 articles addressing the prediction of pCR were selected. RESULTS: Clear methods to predict pCR before chemoradiotherapy have not been defined. Clinical and radiological features of the primary cancer have limited ability to predict response. Molecular profiling holds the greatest potential to predict pCR but adoption of this technology will require greater concordance between cohorts for the biomarkers currently under investigation. CONCLUSION: At present no robust markers of the prediction of pCR have been identified and the topic remains an area for future research. This review critically evaluates existing literature providing an overview of the methods currently available to predict pCR to nCRT for locally advanced rectal cancer. The review also provides a comprehensive comparison of the accuracy of each modality.

Assessing pathological complete response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer: a systematic review.

AIM: Pathological complete response to neoadjuvant chemoradiotherapy is found in 20% of patients with rectal cancer undergoing long-course chemoradiotherapy. Some authors have suggested that these patients do not need to undergo surgery and can be managed with careful follow-up, with surgery only used in the event of clinical failure. Widespread adoption of this regimen is limited by the accuracy of methods to confirm a pathological complete response (pCR). METHOD: A systematic search of PubMed, Medline and Cochrane databases was conducted to identify clinical, histological and radiological features in those patients with rectal cancer who achieved a pCR following chemoradiotherapy. Searches were conducted with the following keywords and MeSH search terms: 'rectal neoplasm', 'response', 'neoadjuvant', 'preoperative chemoradiation' and 'tumour response'. After review of title and abstracts, 89 articles addressing the assessment of pCR were identified. RESULTS: Histology and clinical assessment are the most effective methods of assessment of pCR, with histology considered the gold standard. Clinical assessment is limited to low rectal tumours and is open to significant inter-rater variability, while histological examination requires a surgical specimen. Diffusion-weighted MRI and (18) F-fluorodeoxyglucose positron emission tomography/CT demonstrate the greatest potential for the assessment of pCR, but both modalities have limited accuracy. CONCLUSION: Determination of a pCR is crucial if a nonoperative approach is to be undertaken proactively. Various methods are available, but currently they lack sufficient sensitivity and specificity to define management. This is likely to be an area of further research in the future.