Association of Coloproctology of Great Britain & Ireland (ACPGBI): Guidelines for the Management of Cancer of the Colon, Rectum and Anus (2017) - Diagnosis, Investigations and Screening

Surgical and Oncological Outcome of Laparoscopic Resection of Colorectal Cancers: A Single-Center Experience

BACKGROUND

Laparoscopy is one of the major advances in surgery in the last 30 years and has many benefits. Although laparoscopy was initially used for resection of benign colon lesions, it is now widely used for colorectal cancer resections after strong evidence has confirmed its safety and efficacy. We aim to report both the surgical and oncological outcomes of our first series of laparoscopic colorectal cancer resections.

METHODS

In 2013, a laparoscopic colorectal resection service was established in northern Iraq at Zheen Hospital, Erbil. Data from all consecutive colorectal cancers were collected. Patients with locally advanced diseases and those who required emergency operations for bowel obstruction or perforation were excluded. We analyzed demographic, operative, postoperative, and histopathological data for all patients who were included in the study.

RESULTS

A total of 124 patients with colorectal cancers presented to our unit between January 2013 and January 2023. Only 112 patients fulfilled the inclusion criteria and underwent laparoscopic resections. The median age of the patients was 54.5 years. The majority of patients were men (n=62; 55.4%). In 39 patients (35%), the cancer was located in the sigmoid; in 33 patients (29.5%) the cancer was in the rectum. Laparoscopic anterior resection was the most common procedure (n=50; 45%), followed by right hemicolectomy in 17 cases (15.1%). The conversion rate to open surgery was 8% (nine cases). The most common causes of conversion to open surgery were dilated bowel loops and tumour adherence to other structures. The mean operative time was 190 minutes and the mean hospital stay was three days. No complications were reported in 94 patients (84%). Among the complications, wound infection was seen in seven patients (7.8%). There were six anastomotic leaks (6.7%). The mean number of lymph nodes harvested was 13. In 70 patients (62.5%), the lymph node count was ≥12 with a median of 13. The mean distal resection margin was 6 cm and 2.5 cm for colon and rectal resections, respectively.

CONCLUSION

This study reveals that laparoscopic resection for colorectal cancers is surgically practicable and safe with the benefits of a short hospital stay, adequate resection margins, and adequate lymph node yield.

Recommendations for Optimal Endoscopic Localization of Colorectal Neoplasms: A Delphi Consensus of National Experts

BACKGROUND

Colonoscopy is the standard of care for diagnosis and evaluation of colorectal cancers before surgery. However, varied practices and heterogenous documentation affects communication between endoscopists and operating surgeons, hampering surgical planning.

OBJECTIVE

This study aimed to develop recommendations for the use of standardized localization and reporting practices for colorectal lesions identified during lower GI endoscopy.

DESIGN

A systematic review of existing endoscopy guidelines and thorough narrative review of the overall endoscopy literature were performed to identify existing practices recommended globally.

SETTING

An online Delphi process was used to establish consensus recommendations based on a literature review.

PATIENTS

Colorectal surgeons and gastroenterologists from across Canada who had previously demonstrated leadership in endoscopy, managed large endoscopy programs, produced high-impact publications in the field of endoscopy, or participated in the development of endoscopy guidelines were selected to participate.

PRIMARY OUTCOME MEASURES

The primary outcomes measured were colorectal lesion localization and documentation practice recommendations important to planning surgical or advanced endoscopic excisions.

RESULTS

A total of 129 of 197 statements achieved consensus after 3 rounds of voting by 23 experts from across Canada. There was more than 90% participation in each round. Recommendations varied according to lesion location in the cecum, colon, or rectum and whether the referral was planned for surgical or advanced endoscopic resection. Recommendations were provided for appropriate documentation, indications, location, and method of tattoo placement, in addition to photograph and real-time 3-dimensional scope configuration device use.

LIMITATIONS

Because of a paucity of evidence, recommendations are based primarily on expert opinion. There may be bias, as all representatives were based in Canada.

CONCLUSIONS

Best practices to optimize endoscopic lesion localization and communication are not addressed in previous guidelines. This consensus involving national experts in colorectal surgery and gastroenterology provides a framework for efficient and effective colorectal lesion localization. See Video Abstract at http://links.lww.com/DCR/C71 .

RECOMENDACIONES PARA LA LOCALIZACIN ENDOSCPICA PTIMA DE LAS NEOPLASIAS COLORRECTALES UN CONSENSO DELPHI DE EXPERTOS NACIONALES

ANTECEDENTES:La colonoscopia es el estándar de atención para el diagnóstico y la evaluación de los cánceres colorrectales antes de la cirugía. Sin embargo, las prácticas variadas y la documentación heterogénea afectan la comunicación entre los endoscopistas y los cirujanos operadores, lo que dificulta la planificación quirúrgica.OBJETIVO:Este estudio tuvo como objetivo desarrollar recomendaciones para el uso de prácticas estandarizadas de localización y notificación de lesiones colorrectales identificadas en la endoscopia gastrointestinal inferior.DISEÑO:Se realizó una revisión sistemática de las pautas de endoscopia existentes y una revisión narrativa exhaustiva de la literatura general sobre endoscopia para identificar las prácticas existentes recomendadas a nivel mundial. Se utilizó un proceso Delphi en línea para establecer recomendaciones de consenso basadas en la revisión de la literatura.PARTICIPANTES:Se seleccionaron para participar cirujanos colorrectales y gastroenterólogos de todo Canadá que previamente habían demostrado liderazgo en endoscopia, manejado grandes programas de endoscopia, producido publicaciones de alto impacto en el campo de la endoscopia o que habían participado en el desarrollo de pautas de endoscopia.RESULTADOS:Localización de lesiones colorrectales y recomendaciones prácticas de documentación importantes para planificar escisiones quirúrgicas o endoscópicas avanzadas.RESULTADOS:129 de 197 declaraciones lograron consenso después de tres rondas de votación de 23 expertos de todo Canadá. Hubo >90% de participación en cada ronda. Las recomendaciones variaron según la ubicación de la lesión en el ciego, colon o recto, y si se planificó la derivación para resección quirúrgica o endoscópica avanzada. Se proporcionaron recomendaciones para la documentación adecuada, las indicaciones, la ubicación y el método de colocación del tatuaje, además de la fotografía y el uso del dispositivo de configuración del alcance 3D en tiempo real.LIMITACIONES:Debido a la escasez de evidencia, las recomendaciones se basan principalmente en la opinión de expertos. Puede haber sesgo, ya que los representantes tenían su sede en Canadá.CONCLUSIONES:Las mejores prácticas para optimizar la localización y comunicación de lesiones endoscópicas no se abordan en las guías anteriores. Este consenso que involucra a expertos nacionales en cirugía colorrectal y gastroenterología proporciona un marco para la localización eficiente y efectiva de lesiones colorrectales. Consulte Video Resumen en http://links.lww.com/DCR/C71 . (Traducción-Dr. Mauricio Santamaria ).

Surgeon preference for treatment allocation in older people facing major gastrointestinal surgery: an application of the discrete choice experiment methodology

AIM

Variation in major gastrointestinal surgery rates in the older population suggests heterogeneity in surgical management. A higher prevalence of comorbidities, frailty and cognitive impairments in the older population may account for some variation. The aim of this study was to determine surgeon preference for major surgery versus conservative management in hypothetical patient scenarios based on key attributes.

METHOD

A survey was designed according to the discrete choice methodology guided by a separate qualitative study. Questions were designed to test for associations between key attributes (age, comorbidity, urgency of presentation, pathology, functional and cognitive status) and treatment preference for major gastrointestinal surgery versus conservative management. The survey consisting of 18 hypothetical scenarios was disseminated electronically to UK gastrointestinal surgeons. Binomial logistic regression was used to identify associations between the attributes and treatment preference.

RESULTS

In total, 103 responses were received after 256 visits to the questionnaire site (response rate 40.2%). Participants answered 1847 out of the 1854 scenarios (99.6%). There was a preference for major surgery in 1112/1847 (60.2%) of all scenarios. Severe comorbidities (OR 0.001, 95% CI 0.000-0.030; P = 0.000), severe cognitive impairment (OR 0.001, 95% CI 0.000-0.033; P = 0.000) and age 85 years and above (OR 0.028, 95% CI 0.005-0.168; P = 0.000) were all significant in the decision not to offer major gastrointestinal surgery.

CONCLUSION

This study has demonstrated variation in surgical treatment preference according to key attributes in hypothetical scenarios. The development of fitness-stratified guidelines may help to reduce variation in surgical practice in the older population.

Clinical Effectiveness of Faecal Immunochemical Test in the Early Detection of Colorectal Cancer-An Umbrella Review

Introduction: The colorectal cancer prognosis depends on the stage of the neoplasm; therefore, its early detection plays an important role. The aim of the study is evaluation of the sensitivity, specificity, and clinical effectiveness of the faecal immunochemical test in the early colorectal cancer detection. Methods: The clinical analysis was based on the results of the studies included in a systematic review conducted in accordance with the Cochrane Collaboration guidelines. The following medical information sources were searched: Medline (via PubMed), Embase (via Ovid), The Cochrane Library. Results: From 241 citations, 13 studies were included in this review. All included studies had a low risk of bias. The faecal immunochemical test is highly specific in all analysed populations ranging from 85% to 97%. In most of the found studies, sensitivity is over 75%. The faecal immunochemical test screening also determines a reduction in death (10-59%) due to colorectal cancer. Conclusions: The faecal immunochemical test is an effective and cost-effective method of conducting population-wide colorectal cancer screening. It is an alternative or complementary to other screening tests, including colonoscopy.

Evaluation of cellular stress responses in magnetomotive ultrasound

Early and accurate diagnoses are important for successful cancer treatment. Lymph node involvement is often critical, and magnetomotive ultrasound (MMUS) has been proposed for its detection and characterization. MMUS relies on a magnetic contrast agent, for example, iron oxide nanoparticles, delivered to the tissue of interest, magnetically set in motion and detected using ultrasound. The magneto-mechanical interaction has not previously been evaluated on a cellular level. Here we demonstrate uptake and dose-dependent retention of magnetic nanoparticles in two human adenocarcinoma cell lines, with <10% cytotoxicity which did not increase following magnetic excitation. Further, the oxidative stress levels were not affected by magnetic particles or force. Thus, we found no evidence of adverse effects from the magneto-mechanical interactions under these conditions.

Contrast enhanced magneto-motive ultrasound in lymph nodes - modelling and pre-clinical imaging using magnetic microbubbles

Despite advances in MRI, the detection and characterisation of lymph nodes in rectal cancer remains complex, especially when assessing the response to neo-adjuvant treatment. An alternative approach is functional imaging, previously shown to aid characterization of cancer tissues. We report proof-of-concept of the novel technique Contrast-Enhanced Magneto-Motive Ultrasound (CE-MMUS) to recover information relating to local perfusion and lymphatic drainage, and interrogate tissue mechanical properties through magnetically induced tissue deformations. The feasibility of the proposed application was explored using a combination of pre-clinical ultrasound imaging and finite element analysis. First, contrast enhanced ultrasound imaging on one wild type mouse recorded lymphatic drainage of magnetic microbubbles after bolus injection. Second, preliminary CE-MMUS data were acquired as a proof of concept. Third, the magneto-mechanical interactions of a magnetic microbubble with an elastic solid were simulated using finite element software. Accumulation of magnetic microbubbles in the inguinal lymph node was verified using contrast enhanced ultrasound, with peak enhancement occurring 3.7 s post-injection. Preliminary CE-MMUS indicates the presence of magnetic contrast agent in the lymph node. The finite element analysis explores how the magnetic force is transferred to motion of the solid, which depends on elasticity and bubble radius, indicating an inverse relation with displacement. Combining magnetic microbubbles with MMUS could harness the advantages of both techniques, to provide perfusion information, robust lymph node delineation and characterisation based on mechanical properties. Clinical Relevance- Robust detection and characterisation of lymph nodes could be aided by visualising lymphatic drainage of magnetic microbubbles using contrast enhanced ultrasound imaging and magneto-motion, which is dependent on tissue mechanical properties.

Intraoperative Colonic Irrigation for Low Rectal Resections With Primary Anastomosis: A Fail-Safe Surgical Model

Aim

Regardless the technological developments in surgery, the anastomotic leakage (AL) rate of low rectal anastomosis remains high. Though various perioperative protocols have been tested to reduce the risk for AL, there is no standard peri-operative management approach in rectal surgery. We aim to assess the short-term outcome of a multidisciplinary approach to reduce the rates of ALs using a fail-safe-model using preoperative and intraoperative colonic irrigation in low rectal resections with primary anastomosis.

Methods

Between January 2015 and December 2020, 92 patients received low rectal resections for rectal cancer with primary anastomosis and diverting ileostomy. All these patients received pre-operative mechanical bowel preparation (MBP) without antibiotics as well as intraoperative colonic irrigation. The intraoperative colonic irrigation was performed via the efferent loop of the ileostomy. All data were analyzed by SPSS for descriptive and inferential analyses.

Results

In the study period, 1.987 colorectal surgical procedures were performed. This study reports AL in 3 (3.3%) of 92 recruited patients. Other postoperative complications (Dindo-Clavien I-IV) were reported in 25 patients (27.2%), which occurred mainly due to non-surgical reasons such as renal dysfunction and sepsis. According to the fail-safe model, AL was treated by endoscopic or re-do surgery. The median postoperative length of hospitalization was 8 days (4–45) days.

Conclusion

This study validates the effectiveness of a multi-disciplinary fail-safe model with a pre-operative MBP and an intraoperative colonic irrigation in reducing AL rates. Intraoperative colonic irrigation is a feasible approach that lowers the AL rates by reducing fecal load and by decontamination of the colon and anastomotic region. Our study does not recommend a pre-operative administration of oral antibiotics for colorectal decontamination.

Do clinical practice guidelines consider evidence about diagnostic test consequences on patient-relevant outcomes? A critical document analysis

RATIONALE, AIMS AND OBJECTIVES

Supporting evidence for diagnostic test recommendations in clinical practice guidelines (CPGs) should not only include diagnostic accuracy, but also downstream consequences of the test result on patient-relevant outcomes. The aim of this study is to assess the extent to which evidence-based CPGs about diagnostic tests cover all relevant test-treatment pathway components.

METHODS

We performed a systematic document analysis and quality assessment of publicly accessible CPGs about three common diagnostic tests: C-reactive protein, colonoscopy and fractional exhaled nitric oxide. Evaluation of the impact of the full test-treatment pathway (diagnostic accuracy, burden of the test, natural course of target condition, treatment effectiveness, and link between test result and administration of treatment) on patient relevant outcomes was considered best practice for developing medical test recommendations.

RESULTS

We retrieved 15 recommendations in 15 CPGs. The methodological quality of the CPGs varied from poor to excellent. Ten recommendations considered diagnostic accuracy. Four of these were funded on a systematic review and rating of the certainty in the evidence. None of the CPGs evaluated all steps of the test-treatment pathway. Burden of the test was considered in three CPGs, but without systematically reviewing the evidence. Natural course was considered in two CPGs, without a systematic review of the evidence. In three recommendations, treatment effectiveness was considered, supported with a systematic review and rating of the certainty in the evidence in one CPG. The link between test result and treatment administration was not considered in any CPG.

CONCLUSIONS

The included CPGs hardly seem to consider evidence about test consequences on patient-relevant outcomes. This might be explained by reporting issues and challenging methodology. Future research is needed to investigate how to facilitate guideline developers in explicit reliable consideration of all steps of a test-treatment pathway when developing diagnostic test recommendations.

Healthcare professional preferences in the health and fitness assessment and optimization of older patients facing colorectal cancer surgery

AIM

There are few age- and fitness-specific, evidence-based guidelines for colorectal cancer surgery. The uptake of different assessment and optimization strategies is variable. The aim of this study was to explore healthcare professional opinion about these issues using a mixed methods design.

METHODS

Semi-structured qualitative interviews were undertaken with healthcare professionals from a single UK region involved in the treatment, assessment and optimization of colorectal surgery patients. Interviews were analysed using the framework approach. An online questionnaire survey was subsequently designed and disseminated to UK surgeons to quantitatively assess the importance of interview themes. Descriptive statistics were used to analyse questionnaire data.

RESULTS

Thirty-seven healthcare professionals out of 42 approached (response rate 88%) were interviewed across five hospitals in the south Yorkshire region. Three broad themes were developed: attitudes towards treatment of the older patient, methods of assessment of suitability and optimization strategies. The questionnaire was completed by 103 out of an estimated 256 surgeons (estimated response rate 40.2%). There was a difference in opinion regarding the role of major surgery in older patients, particularly when there is coexisting dementia. Assessment was not standardized. Access to optimization strategies was limited, particularly in the emergency setting.

CONCLUSION

There is wide variation in the process of assessment and provision of optimization strategies in UK practice. Lack of evidence-based guidelines, cost and time constraints restrict the development of services and pathways. Differences in opinion between surgeons towards patients with frailty or dementia may account for some of the variation in colorectal cancer outcomes.

Does self-reported symptom questionnaire play a role in nonadherence to colonoscopy for risk-increased population in the Tianjin colorectal cancer screening programme?

BACKGROUND

A colorectal cancer screening programme (CCSP) was implemented from 2012 to 2017 in Tianjin, China. Residents with a positive faecal immunochemical test (FIT) or positive self-reported symptom questionnaire (SRSQ) were recommended to undergo colonoscopy. The objective was to investigate the potential factors associated with nonadherence to colonoscopy among a risk-increased population.

METHODS

Data were obtained from the CCSP database, and 199,522 residents with positive FIT or positive SRSQ during two screening rounds (2012-2017) were included in the analysis. Logistic regression analysis was performed to assess the association between nonadherence to colonoscopy and potential predictors.

RESULTS

A total of 152,870 (76.6%) individuals did not undergo colonoscopy after positive FIT or positive SRSQ. Residents with positive SRSQ but without positive FIT were more likely not to undergo colonoscopy (negative FIT: OR, 2.35; 95% CI, 2.29-2.41, no FIT: OR, 1.27; 95% CI, 1.24-1.31). Patients without a cancer history were less likely to undergo colonoscopy even if they received risk-increased reports based on the SRSQ.

CONCLUSION

In the CCSP, seventy-seven percent of the risk-increased population did not undergo colonoscopy. FIT should be recommended since positive FIT results are related to improved adherence to colonoscopy. Residents with negative FIT but positive SRSQ should be informed of the potential cancer risk to ensure adherence to colonoscopy.

The Association of Coloproctology of Great Britain and Ireland consensus guidelines in emergency colorectal surgery

AIM

There is a requirement for an expansive and up to date review of the management of emergency colorectal conditions seen in adults. The primary objective is to provide detailed evidence-based guidelines for the target audience of general and colorectal surgeons who are responsible for an adult population and who practise in Great Britain and Ireland.

METHODS

Surgeons who are elected members of the Association of Coloproctology of Great Britain and Ireland Emergency Surgery Subcommittee were invited to contribute various sections to the guidelines. They were directed to produce a pathology-based document using literature searches that were systematic, comprehensible, transparent and reproducible. Levels of evidence were graded. Each author was asked to provide a set of recommendations which were evidence-based and unambiguous. These recommendations were submitted to the whole guideline group and scored. They were then refined and submitted to a second vote. Only those that achieved >80% consensus at level 5 (strongly agree) or level 4 (agree) after two votes were included in the guidelines.

RESULTS

All aspects of care (excluding abdominal trauma) for emergency colorectal conditions have been included along with 122 recommendations for management.

CONCLUSION

These guidelines provide an up to date and evidence-based summary of the current surgical knowledge in the management of emergency colorectal conditions and should serve as practical text for clinicians managing colorectal conditions in the emergency setting.

Factors Contributing to Delay in Specialist Care After Colorectal Cancer Diagnosis in Kentucky

BACKGROUND

Abundant studies have associated colorectal cancer (CRC) treatment delay with advanced diagnosis and worse mortality. Delay in seeking specialist is a contributor to CRC treatment delay. The goal of this study is to investigate contributing factors to 14-d delay from diagnosis of CRC on colonoscopy to the first specialist visit in the state of Kentucky.

METHODS

The Kentucky Cancer Registry (KCR) database linked with health administrative claims data was queried to include adult patients diagnosed with stage I-IV CRC from January 2007 to December 2012. The dates of the last colonoscopy and the first specialist visit were identified through the claims. Bivariate and logistic regression analysis was performed to identify factors associated with delay to CRC specialist visit.

RESULTS

A total of 3927 patients from 100 hospitals in Kentucky were included. Approximately, 19% of patients with CRC visited a specialist more than 14 d after CRC detection on colonoscopy. Delay to specialist (DTS) was found more likely in patients with Medicaid insurance (OR 3.1, P < 0.0001), low and moderate education level (OR 1.4 and 1.3, respectively, P = 0.0127), and stage I CRC (OR 1.5, P < 0.0001). There was a higher percentage of delay to specialist among Medicaid patients (44.0%) than Medicare (18.0%) and privately insured patients (18.8%).

CONCLUSIONS

We identified Medicaid insurance, low education attainment, and early stage CRC diagnosis as independent risk factors associated with 14-d delay in seeking specialist care after CRC detection on colonoscopy.

Faecal immunochemical test to triage patients with abdominal symptoms for suspected colorectal cancer in primary care: review of international use and guidelines

BACKGROUND

Recently, faecal immunochemical tests (FITs) have been introduced for investigation of primary care patients with low-risk symptoms of colorectal cancer (CRC), but recommendations vary across the world. This systematic review of clinical practice guidelines aimed to determine how FITs are used in symptomatic primary care patients and the underpinning evidence for these guidelines.

METHODS

MEDLINE, Embase and TRIP databases were systematically searched, from 1 November 2008 to 1 November 2018 for guidelines on the assessment of patients with symptoms suggestive of CRC. Known guideline databases, websites and references of related literature were searched. The following questions were addressed: (i) which countries use FIT for symptomatic primary care patients; (ii) in which populations is FIT used; (iii) what is the cut-off level used for haemoglobin in the faeces (FIT) and (iv) on what evidence are FIT recommendations based.

RESULTS

The search yielded 2433 publications; 25 covered initial diagnostic assessment of patients with symptoms of CRC in 15 countries (Asia, n = 1; Europe, n = 13; Oceania, n = 4; North America, n = 5; and South America, n = 2). In three countries (Australia, Spain and the UK), FIT was recommended for patients with abdominal symptoms, unexplained weight loss, change in bowel habit or anaemia despite a low level of evidence in the symptomatic primary care patient population.

CONCLUSIONS

Few countries recommend FITs in symptomatic patients in primary care either because of limited evidence or because symptomatic patients are directly referred to secondary care without triage. These results demonstrate a clear need for research on FIT in the symptomatic primary care population.

Tumour growth rate of carcinoma of the colon and rectum: retrospective cohort study

BACKGROUND

The growth pattern of colorectal cancer is seldom investigated. This cohort study aimed to explore tumour growth rate in colorectal cancers managed non-surgically or deemed not resectable, and to determine its implication for prognosis.

METHODS

Consecutive patients with colonic or rectal adenocarcinoma were identified through the colorectal multidisciplinary team database at Leeds Teaching Hospitals NHS Trust over a 2-year interval. Patients who received no treatment (surgery, stenting, colonic defunctioning procedures, chemotherapy, radiotherapy) and who underwent CT twice more than 5 weeks apart were included. Multidetector CT/three-dimensional image analysis was performed independently by three experienced radiologists.

RESULTS

Of 804 patients reviewed, 43 colorectal cancers were included in the final analysis. Median age at first CT was 80 (73-85) years and the median interval between scans was 150 (i.q.r. 72-471) days. An increase in T category was demonstrated in 31 of 43 tumours, with a median doubling time of 211 (112-404) days. The median percentage increase in tumour volume was 34·1 (13·3-53·9) per cent per 62 days. The all-cause 3-year mortality rate was 81 per cent (35 of 43) with a median survival time of 1·1 (0·4-2·2) years after the initial diagnostic scan. In those obstructed, the relative risk of death from subsequent perforation was 1·26 (95 per cent c.i. 1·07 to 1·49; P = 0·005).

CONCLUSION

This study documented a median doubling time of 211 days, with a concerning suggestion of tumour progression, which has implications for the current management standard.

The utility of preoperative radiological evaluation of early rectal neoplasia: a systematic review and meta-analysis

AIM

The diagnostic role for preoperative imaging of clinically benign rectal adenomas is unclear. The objective of this systematic review and meta-analysis was to examine the diagnostic accuracy of preoperative imaging in distinguishing benign adenomas from rectal cancer.

METHOD

A systematic search was performed for all studies published that correlated staging of clinically benign rectal adenomas with endorectal ultrasound (ERUS) or MRI and histology. Imaging was compared with postoperative histology and data on the numbers of true positives, false positives, true negatives and false negatives were extracted. Summary estimates of sensitivity and specificity with 95% CIs were calculated using a bivariate random effects model. The QUADAS2 tool was used to determine the methodological quality of included studies.

RESULTS

Eleven studies describing 1511 patients were retrieved. A total of 1134 patients underwent local excision and 377 had a formal proctectomy. A benign rectal adenoma was diagnosed in 840 and 214 had a T1 rectal cancer. For confirming benign adenomas, the pooled sensitivity of ERUS was 0.81 (95% CI 0.69-0.89) and specificity was 0.85 (95% CI 0.68-0.93). For detecting occult T1 tumours, the pooled sensitivity of ERUS was 0.50 (95% CI 0.33-0.66) and specificity was 0.89 (95% CI 0.82-0.94). Quantitative analysis of MRI could not be performed due to insufficient studies.

CONCLUSION

This study demonstrates the limited accuracy of preoperative ERUS in distinguishing benign adenomas from T1 rectal cancer. Preoperative imaging must be interpreted with caution to prevent over-staging and unnecessary proctectomy. We propose that clinically benign lesions may undergo local excision, with subsequent management based on final histology.

CRC COVID: Colorectal cancer services during COVID-19 pandemic. Study protocol for service evaluation

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COVID-19 disrupted healthcare provision worldwide.

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This is a four-phase multi-centre service evaluation of colorectal cancer services.

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Conducted through a research collaborative in the UK, Ireland and the USA.

•

The aim is to evaluate the impact of the COVID-19 pandemic on service provision.

Introduction

COVID-19 has had an impact on the provision of colorectal cancer care. The aim of the CRC COVID study is to describe the changes in colorectal cancer services in the UK and USA in response to the pandemic and to understand the long-term impact.

Methods and analysis

This study comprises 4 phases. Phase 1 is a survey of colorectal units that aims to evaluate adherences and deviations from the best practice guidelines during the COVID-19 pandemic. Phase 2 is a monthly prospective data collection of service provision that aims to determine the impact of the service modifications on the long-term cancer specific outcomes compared to the national standards. Phase 3 aims to predict costs attributable to the modifications of the CRC services and additional resources required to treat patients whose treatment has been affected by the pandemic. Phase 4 aims to compare the impact of COVID-19 on the NHS and USA model of healthcare in terms of service provision and cost, and to propose a standardised model of delivering colorectal cancer services for future outbreaks.

Ethics and dissemination

This study is a service evaluation and does not require HRA Approval or Ethical Approval in the UK. Local service evaluation registration is required for each participating centre. In the USA, Ethical Approval was granted by the Research and Development Committee. The results of this study will be disseminated to stakeholders, submitted for peer review publications, conference presentations and circulated via social media.

Registration details

Nil.

Comparison of the sigmoid take-off with other definitions of the rectosigmoid junction: A retrospective comparative cohort analysis

BACKGROUND

The diversity in definitions for the rectosigmoid junction is becoming a major obstacle in standardizing optimal treatment of rectal cancers. The study aimed to determine the average distance of the sigmoid take-off from the anal verge and its association with individual factors.

MATERIALS AND METHODS

Patients diagnosed with rectal and sigmoid colon cancer in our centre from January 2010 to December 2018 were retrospectively enrolled in the cancer group. The results of 200 controls without colorectal disease were also reviewed (normal group). The distance of different landmarks and margins of cancer from the anal verge were retrieved from computed tomography (CT), magnetic resonance imaging (MRI), and endoscopy findings.

RESULTS

The cancer group comprised 635 patients (381 men, median age: 64 years). The average distances of the sigmoid take-off from the anal verge measured in CT and MRI were comparable (P = 0.483). On MRI, the average distance of the sigmoid take-off from the anal verge in the cancer group was comparable with that of the normal group (P = 0.070). Multivariate regression revealed that the distance of the sigmoid take-off from the anal verge was associated with the distances of the sacral promontory (P < 0.001) and peritoneal reflection (P < 0.001) from the anal verge.

CONCLUSION

The cancer distributions of patients varied widely with the application of different definitions. The point of sigmoid take-off is an intuitive landmark influenced by individual factors. The measurement of the sigmoid take-off by different researchers in both CT and MRI revealed good consistency. Further studies regarding the clinical significance of this definition are still needed.

Imaging of Colorectal Liver Metastases: New Developments and Pending Issues

Computed tomography (CT), magnetic resonance imaging (MRI), and 18-fluorideoxyglucose positron emission tomography (18FDG-PET) are historically the most accurate imaging techniques for diagnosing liver metastases. Recently, the combination of diffusion-weighted imaging and hepatospecific contrast media, such as gadoxetic acid in MRI, have been demonstrated to have the highest diagnostic accuracy, sensitivity, and specificity for detecting liver metastases. Various recent meta-analyses have confirmed the diagnostic superiority of this combination (diffusion-weighted imaging and gadoxetic acid-enhanced MRI), especially in terms of per lesion sensitivity, as compared with CT and 18FDG-PET, even for smaller lesions (≤1 cm). However, none of the oncological guidelines have suggested the use of MRI as a first-line technique for liver metastasis detection during the staging process of oncological patients. This review analyzes the history of the principal imaging techniques for the diagnosis of liver metastases, in particular of colorectal liver metastases, focusing on the most accurate method (diffusion-weighted imaging combined with gadoxetic acid-enhanced MRI), possible reasons for the lack of its diffusion in the guidelines, and possible future scenarios.