Local Regrowth and the Risk of Distant Metastases Among Patients Undergoing Watch-and-Wait for Rectal Cancer: What Is the Best Control Group? Multicenter Retrospective Study.

BACKGROUND: A proportion of rectal cancer patients who achieve a clinical complete response may develop local regrowth. Although salvage appears to provide appropriate local control, the risk of distant metastases is less known. OBJECTIVE: To compare the risk of distant metastases between patients who achieve a clinical complete response (watch-and-wait strategy) and subsequent local regrowth and patients managed by surgery after chemoradiation. DESIGN: Retrospective multicenter cohort study. SETTINGS: This study used data of patients from 3 institutions who were treated between 1993 and 2019. PATIENTS: Patients with initial clinical complete response (after neoadjuvant therapy) followed by local regrowth and patients with near-complete pathological response (≤10%) after straightforward surgery after chemoradiation were included. MAIN OUTCOME MEASURES: Univariate and multivariate analyses were performed to identify risk factors for distant metastases. Kaplan-Meier curves were created (log-rank test) to compare survival outcomes. Analyses were performed using time zero as last day of radiation therapy or as date of salvage resection in the local regrowth group. RESULTS: Twenty-one of 79 patients with local regrowth developed distant metastases, whereas only 10 of 74 after upfront total mesorectal excision following neoadjuvant chemoradiation therapy ( p = 0.04). Local regrowth and final pathology (ypT3-4) were the only independent risk factors associated with distant metastases. When using date of salvage resection as time zero, distant metastases-free survival rates were significantly inferior for patients with local regrowth (70% vs 86%; p = 0.01). LIMITATIONS: Small number of patients, many neoadjuvant therapies, and selection bias. CONCLUSIONS: Patients undergoing watch-and-wait strategy who develop local regrowth are at higher risk for development of distant metastases compared to patients with near-complete pathological response managed by upfront surgery after chemoradiation. See Video Abstract. NUEVO CRECIMIENTO LOCAL Y EL RIESGO DE METSTASIS A DISTANCIA ENTRE PACIENTES SOMETIDOS A OBSERVACIN Y ESPERA POR CNCER DE RECTO CUL ES EL MEJOR GRUPO DE CONTROL ESTUDIO RETROSPECTIVO MUTICNTRICO: ANTECEDENTES:Una proporción de pacientes que logran una respuesta clínica completa pueden desarrollar un nuevo crecimiento local. Si bien el rescate parece proporcionar un control local apropiado, el riesgo de metástasis a distancia es menos conocido.OBJETIVO:Comparar el riesgo de metástasis a distancia entre los pacientes que logran una respuesta clínica completa (estrategia de observación y espera) y el nuevo crecimiento local posterior con los pacientes tratados con cirugía después de la quimiorradiación.DISEÑO:Estudio de cohorte multicéntrico retrospectivo.CONFIGURACIÓN:Este estudio utilizó datos de pacientes de 3 instituciones que fueron tratados entre 1993 y 2019.PACIENTES:Pacientes con respuesta clínica completa inicial (después de la terapia neoadyuvante) seguida de crecimiento local nuevo y pacientes con respuesta patológica casi completa (≤10 %) después de cirugía directa después de quimiorradiación.PRINCIPALES MEDIDAS DE RESULTADO:Se realizó un análisis univariante/multivariante para identificar los factores de riesgo de metástasis a distancia. Se crearon curvas de Kaplan-Meier (prueba de rango logarítmico) para comparar los resultados de supervivencia. El análisis se realizó utilizando el tiempo cero como último día de radioterapia (1) o como fecha de resección de rescate (2) en el grupo de recrecimiento local.RESULTADOS:Veintiuno de 79 pacientes con recrecimiento local desarrollaron metástasis a distancia, mientras que solo 10 de 74 después de una cirugía sencilla (p = 0,04). El recrecimiento local y la patología final (ypT3-4) fueron los únicos factores de riesgo independientes asociados con las metástasis a distancia. Cuando se utilizó la fecha de la resección de rescate como tiempo cero, las tasas de supervivencia sin metástasis a distancia fueron significativamente inferiores para los pacientes con recrecimiento local (70 frente a 86 %; p = 0,01).LIMITACIONES:Pequeño número de pacientes, muchas terapias neoadyuvantes, sesgo de selección.CONCLUSIONES:Los pacientes sometidos a observación y espera que desarrollan un nuevo crecimiento local tienen un mayor riesgo de desarrollar metástasis a distancia en comparación con los pacientes con una respuesta patológica casi completa manejados con cirugía por adelantado después de la quimiorradiación. (Traducción-Dr. Xavier Delgadillo ).

Transanal minimally invasive surgery for benign and malignant rectal lesions: midterm outcomes from a tertiary center.

BACKGROUND: Although transanal minimally invasive surgery (TAMIS) for rectal neoplasia has gained wide acceptance, the mid-term and long-term outcomes are not widely reported in the literature. OBJECTIVE: Describe the mid-term outcomes of patients who underwent TAMIS for benign and malignant rectal lesions in a single center. DESIGN: Retrospective cohort study. SETTINGS: Tertiary referral center. PATIENTS AND METHODS: Demographic, clinical, and oncological outcomes of patients who underwent TAMIS between January 2015 and December 2022 were prospectively collected. The indication for TAMIS was based on the National Comprehensive Cancer Network guidelines. The follow up for the cancer patients included clinical examination, tumor markers every 6 months and MRI rectum at the end of one year. In addition, colonoscopy and CT scan at years one and three and a final CT scan and colonoscopy at year five. MAIN OUTCOME MEASURES: Mid-term oncological and clinical outcome. RESULTS: Thirty elective TAMIS procedures included adenocarcinoma for 33.3% (n=10) of the patients, 20% (n=6) neuroendocrine tumor and the 40% (n=12) were adenomatous lesions. Negative resection margins were achieved in all malignant lesions. Perioperative complications occurred in 2 patients (6.6%), one patient had breaching into the peritoneal cavity, and postoperative hypotension occurred in another patient. The median follow-up time was 23 months (range: 5-72 months). Two patients with adenoma and positive margins developed recurrent adenoma (6.6%) and one patient with initial polypectomy biopsy of adenocarcinoma, had TAMIS with histopathology of adenoma and distant metastasis had developed. CONCLUSIONS: TAMIS for local excision of rectal neoplasia is a valid option with favorable mid-term outcomes provided there is adherence to careful selection criteria. LIMITATIONS: Retrospective nature and small number of the patients.

Textbook Oncological Outcomes for Robotic Colorectal Cancer Resections: An Observational Study of Five Robotic Colorectal Units.

BACKGROUND: The quality of care of patients receiving colorectal resections has conventionally relied on individual metrics. When discussing with patients what these outcomes mean, they often find them confusing or overwhelming. Textbook oncological outcome (TOO) is a composite measure that summarises all the 'desirable' or 'ideal' postoperative clinical and oncological outcomes from both a patient's and doctor's point of view. This study aims to evaluate the incidence of TOO in patients receiving robotic colorectal cancer surgery in five robotic colorectal units and understand the risk factors associated with failure to achieve a TOO in these patients. METHODS: We present a retrospective, multicentric study with data from a prospectively collected database. All consecutive patients receiving robotic colorectal cancer resections from five centres between 2013 and 2022 were included. Patient characteristics and short-term clinical and oncological data were collected. A TOO was achieved when all components were realized-no conversion to open, no complication with a Clavien-Dindo (CD) ≥ 3, length of hospital stay ≤ 14, no 30-day readmission, no 30-day mortality, and R0 resection. The main outcome measure was a composite measure of "ideal" practice called textbook oncological outcomes. RESULTS: A total of 501 patients submitted to robotic colorectal cancer resection were included. Of the 501 patients included, 388 (77.4%) achieved a TOO. Four patients were converted to open (0.8%); 55 (11%) had LOS > 14 days; 46 (9.2%) had a CD ≥ 3 complication; 30-day readmission rate was 6% (30); 30-day mortality was 0.2% (1); and 480 (95.8%) had an R0 resection. Abdominoperineal resection was a risk factor for not achieving a TOO. CONCLUSIONS: Robotic colorectal cancer surgery in robotic centres achieves a high TOO rate. Abdominoperineal resection is a risk factor for failure to achieve a TOO. This measure may be used in future audits and to inform patients clearly on success of treatment.

Watch and Wait for rectal cancer in inflammatory bowel disease.

Colorectal cancer is currently the third most frequently diagnosed type of cancer and the second cause of cancer death in the western world. Inflammatory bowel disease patients are 2-6 times more likely to develop CRC than the general population. Patients with CRC arising through Inflammatory Bowel Disease have an indication for surgery. However, in patients without Inflammatory Bowel Disease, the use of organ (rectum) preservation strategies after neoadjuvant treatment is on the rise, which means that patients are able to keep the organ without the need for complete excision, either by treatment with radiotherapy and chemotherapy, or in combination with endoscopic or surgical techniques that allow local excision without the need for resection of the entire organ. The patient management approach known as the Watch and Wait programme was first introduced in 2004 by a team from São Paulo, Brazil. This approach suggested that patients who had an excellent or complete clinical response after neoadjuvant treatment could defer surgery and instead undergo Watch and Wait. This organ preservation technique became popular because it allowed patients to avoid the complications associated with major surgery while achieving similar oncological outcomes to those who underwent both neoadjuvant therapy and radical surgery. Following completion of neoadjuvant treatment, a decision to defer surgery is made based on whether a clinical Complete Response can be achieved, which means there is no evidence of tumour in clinical and radiological examination. The International Watch and Wait Database has published long-term oncological outcomes for patients treated with this strategy, and more patients are showing interest in this treatment option. However, it is important to note that up to 1/3 of patients selected for Watch and Wait may eventually require surgery for local regrowth (also known as 'deferred definitive surgery') at any time during follow-up after an initial 'apparent' clinical Complete Response. Compliance with a strict surveillance protocol ensures early detection of regrowth, which is usually amenable to R0 surgery and provides excellent long-term local disease control. Nonetheless, it is crucial to assess the perioperative consequences of having surgery for regrowth later and whether there are any negative effects from deferring surgery. Currently, the Watch and Wait strategy is recommended in the NCCN guidelines for clinical complete responders and only in specialised multidisciplinary centres.There is no case in the literature that portrays the use of the Watch and Wait programme for patients with inflammatory bowel disease and rectal cancer.The authors intend to present a case that demonstrates the difficulties in the assessment of patients with inflammatory bowel disease, the risks of using radiotherapy in this patients and the challenges of surveillance for patients with colorectal cancer and inflammatory bowel disease.

Short-term outcomes in robotic vs laparoscopic ileal pouch-anal anastomosis surgery: a propensity score match study.

PURPOSE: Laparoscopic ileal pouch-anal anastomosis (IPAA) surgery offers improved short-term outcomes over open surgery but can be technically challenging. Robotic surgery has been increasingly used for IPAA surgery, but there is limited evidence supporting its use. This study aims to compare the short-term outcomes of laparoscopic and robotic IPAA procedures. METHODS: All consecutive patients receiving laparoscopic and robotic IPAA surgery at 3 centres, from 3 countries, between 2008 and 2019 were identified from prospectively collated databases. Robotic surgery patients were propensity score matched with laparoscopic patients for gender, previous abdominal surgery, ASA grade (I, II vs III, IV) and procedure performed (proctocolectomy vs completion proctectomy). Their short-term outcomes were examined. RESULTS: A total of 89 patients were identified (73 laparoscopic, 16 robotic). The 16 patients that received robotic surgery were matched with 15 laparoscopic patients. Baseline characteristics were similar between the two groups. There were no statistically significant differences in any of the investigated short-term outcomes. Length of stay trend was higher for laparoscopic surgery (9 vs 7 days, p = 0.072) CONCLUSION: Robotic IPAA surgery is safe and feasible and offers similar short-term outcomes to laparoscopic surgery. Length of stay may be lower for robotic IPAA surgery, but further larger scale studies are required in order to demonstrate this.

Outcomes of Robot-Assisted Surgery in Rectal Cancer Compared with Open and Laparoscopic Surgery.

With increasing trends for the adoption of robotic surgery, many centers are considering changing their practices from open or laparoscopic to robot-assisted surgery for rectal cancer. We compared the outcomes of robot-assisted rectal resection with those of open and laparoscopic surgery. We searched Medline, Web of Science, and CENTRAL databases until October 2022. All randomized controlled trials (RCTs) and prospective studies comparing robotic surgery with open or laparoscopic rectal resection were included. Fifteen RCTs and 11 prospective studies involving 6922 patients were included. The meta-analysis revealed that robotic surgery has lower blood loss, less surgical site infection, shorter hospital stays, and higher negative resection margins than open resection. Robotic surgery also has lower conversion rates, lower blood loss, lower rates of reoperation, and higher negative circumferential margins than laparoscopic surgery. Robotic surgery had longer operation times and higher costs than open and laparoscopic surgery. There were no differences in other complications, mortality, and survival between robotic surgery and the open or laparoscopic approach. However, heterogeneity between studies was moderate to high in some analyses. The robotic approach can be the method of choice for centers planning to change from open to minimally invasive rectal surgery. The higher costs of robotic surgery should be considered as a substitute for laparoscopic surgery (PROSPERO: CRD42022381468).

Standardization of the Definition and Surgical Management of Splenic Flexure Carcinoma by an International Expert Consensus Using the Delphi Technique: Room for Improvement?

BACKGROUND: Surgical management of splenic flexure carcinoma remains controversial. OBJECTIVE: This study aimed to establish an expert international consensus on splenic flexure carcinoma management. DESIGN: A 3-round online-based Delphi study was conducted between September 2020 and April 2021. SETTING: The first round included 18 experts from 12 different countries. For the second and third rounds, each expert in the first round was asked to invite 2 more colorectal surgeons (n = 47). Out of 47 invited experts, 89% (n = 42) participated in the second and third rounds of the consensus. INTERVENTIONS: A total of 35 questions were created and sent via the online questionnaire tool. MAIN OUTCOME MEASURES: Levels of recommendation based on voting concordance were graded as follows: more than 75% agreement was defined as strong, between 50% and 75% as moderate, and below 50% as weak. RESULTS: There was moderate consensus on the definition of splenic flexure (55%) as 10 cm from either side where the distal transverse colon turns into the proximal descending colon. Also, experts recommended an abdominopelvic CT scan plus intraoperative exploration (moderate consensus, 72%) for tumor localization and cancer registry. Segmental colectomy was the preferred technique for the management of splenic flexure carcinoma in the elective setting (72%). Moderate consensus was achieved on the technique of complete mesocolic excision and central vascular ligation principles for splenic flexure carcinoma (74%). Only strong consensus was achieved on the surgical approach for minimally invasive surgery (88%). LIMITATIONS: Subjective decisions are based on individual expert clinical experience and not evidence based. CONCLUSIONS: This is the first internationally conducted Delphi consensus study regarding splenic flexure carcinoma. The definition of splenic flexure remains ambiguous. To more effectively compare oncologic outcomes among different cancer registries, guidelines need to be developed to standardize each domain and avoid arbitrary definitions. See Video Abstract at http://links.lww.com/DCR/C143 . ESTANDARIZACIN DE LA DEFINICIN Y MANEJO QUIRRGICO DEL CARCINOMA DE NGULO ESPLNICO ESTABLECIDO POR UN CONSENSO INTERNACIONAL DE EXPERTOS UTILIZANDO LA TCNICA DELPHI ESPACIO PARA MEJORAR: ANTECEDENTES:El tratamiento quirúrgico del cáncer de ángulo esplénico sigue siendo controvertido.OBJETIVO:Establecer un consenso internacional de expertos sobre el manejo del cáncer del ángulo esplénico.DISEÑO:Se condujo un estudio Delphi en línea de 3 rondas entre septiembre de 2020 y febrero de 2021.ESCENARIO:La primera ronda incluyó a 18 expertos de 12 países distintos. Para la segunda y tercera rondas, a cada experto de la primera ronda se le pidió que invitara a 2 cirujanos colorrectales más de su región (n = 47). De los 47 expertos invitados, el 89% (n = 42) participó en la segunda y tercera ronda del consenso.INTERVENCIONES:Se crearon y enviaron un total de 35 preguntas a través de la herramienta de cuestionario en línea.PRINCIPALES MEDIDAS DE RESULTADO:Los niveles de recomendación basados en la concordancia de votos fueron jerarquizados de la siguiente manera: más del 75% de acuerdo se definió como fuerte, entre 50 y 75% como moderado y por debajo del 50% como débil.RESULTADOS:Hubo un consenso moderado sobre la definición de ángulo esplénico (55%) como 10 cm desde cualquier lado donde el colon transverso distal se convierte en el colon descendente proximal. Así también, los expertos recomendaron la tomografía computarizada abdominopélvica más la exploración intraoperatoria (consenso moderado, 72%) para la localización del tumor y el registro del ángulo esplénico. La colectomía segmentaria fue la técnica preferida para el tratamiento del cáncer de ángulo esplénico en el caso de ser electivo (72%). Se logró un consenso moderado sobre la técnica de escisión completa del mesocolon y los principios de ligadura vascular a nivel central para el cáncer de ángulo esplénico (74%). Solo se logró un fuerte consenso sobre el abordaje quirúrgico para la cirugía mínimamente invasiva (88%).LIMITACIONES:Decisiones subjetivas basadas en la experiencia clínica de expertos individuales y no basadas en evidencia.CONCLUSIONES:Este es el primer estudio internacional de consenso Delphi realizado sobre el cáncer de ángulo esplénico. Si bien encontramos un consenso moderado sobre las modalidades de diagnóstico preoperatorio y el manejo quirúrgico, la definición de ángulo esplénico sigue siendo ambigua. Para comparar de manera más efectiva los resultados oncológicos entre diferentes registros de cáncer, se deben desarrollar pautas para estandarizar cada dominio y evitar definiciones arbitrarias. Consulte Video Resumen en http://links.lww.com/DCR/C143 . (Traducción-Dr. Osvaldo Gauto ).

Choice of specimen's extraction site affects wound morbidity in laparoscopic colorectal cancer surgery.

BACKGROUND: The choice for an ideal site of specimen extraction following laparoscopic colorectal surgery remains debatable. However, midline incision (MI) is usually employed for right and left-sided colonic resections while left iliac fossa or suprapubic transverse incision (STI) were reserved for sigmoid and rectal cancer resections. OBJECTIVE: To compare the incidence of surgical site infection (SSI) and incisional hernia (IH) in elective laparoscopic colorectal surgery for cancer and specimen extraction via MI or STI. METHOD: Prospectively collected data of elective laparoscopic colorectal cancer resections between January 2017 and December 2019 were retrospectively reviewed. MI was employed for right and left-sided colonic resections while STI was used for sigmoid and rectal resections. SSI is defined according to the US CDC criteria. IH was diagnosed clinically and confirmed by CT scan at 1 year. RESULTS: A total of 168 patients underwent elective laparoscopic colorectal resections. MI was used in 90 patients while 78 patients had STI as an extraction site. Demographic and preoperative data is similar for two groups. The rate of IH was 13.3% for MI and 0% in the STI (p = 0.001). SSI was seen in 16.7% of MI vs 11.5% of STI (p = 0.34). Univariate and multivariate analysis showed that the choice of extraction site is associated with statistically significant higher incisional hernia rate. CONCLUSION: MI for specimen extraction is associated with higher incidence of both SSI and IH. The choice of incision for extraction site is an independent predicative factor for significantly higher IH and increased SSI rates.

Zebrafish Avatars of rectal cancer patients validate the radiosensitive effect of metformin.

Neoadjuvant chemoradiation (nCRT) followed by surgery represents the standard of care in patients with locally advanced rectal cancer. Increasing radiotherapy (RT) doses and chemotherapy cycles with 5FU have been associated with increased rates of complete response, however these strategies imply significant toxicity. In the last years, epidemiologic findings have demonstrated that metformin is associated with significantly higher rates of pathological complete response to nCRT. Also, pre-clinical studies using cell lines provide evidence for the radiosensitive effect of metformin. However, no studies have been performed using rectal cancer patient samples to test this radiosensitive effect of metformin and compared it to the standard 5FU. Here, we designed an experimental study to compare both radiosensitizers in the zebrafish xenograft model (zAvatar), using rectal cancer surgical specimens and diagnostic biopsies. Patient zAvatars confirmed that metformin has indeed a powerful in vivo radiosensitizer effect, similar to 5FU. Our work confirms that metformin constitutes a promising less toxic alternative to the standard 5FU, which could be game changing in elderly/frail patients to optimize tumor regression.

Safety and Feasibility of a Discharge within 23 Hours after Colorectal Laparoscopic Surgery.

Background: Enhanced or accelerating recovery programs have significantly reduced hospital length stay after elective colorectal interventions. Our work aims at reporting an initial experience with ambulatory laparoscopic colectomy (ALC) to assess the criteria of discharge and outcomes. Methods: Between 2006 and 2016, data regarding patients having benefited from elective laparoscopic colorectal resections in two main centres in the United Kingdom have been analysed. Both benign and malignant pathologies were included. A standardised enhanced recovery program was performed for each patient, except epidural analgesia was replaced with single shot spinal infiltration. Patients were followed up through a telephone call system by a nurse. Short-term clinical outcomes were analysed. Results: A total of 833 patients were included and 51 (6.1%) were discharged within 24 h following surgery. Of these, 4 out of 51 (7.8%) patients came back hospital within 30 days of discharge; 2 (3.9%) required reoperation (Small bowel obstruction and wound abscess drainage). Conclusions: This study highlights that a 24-h discharge following elective laparoscopic colorectal interventions seems safe and feasible in selected patients. Although challenging to achieve, a standardised approach to laparoscopic surgery in combination with strict adherence to an enhanced recovery protocol are the fundamental elements of this path.

A Rare Case of COVID-19 Infection Leading to Colonic Stricture: Case Report and Review of Literature.

Coronavirus disease 2019 (COVID-19) predominantly targets the respiratory tract; despite gastrointestinal (GI) symptoms that may present in many patients, colonic strictures in coronavirus disease (COVID-19) patients are extremely rare and, to our knowledge, have never been reported. We, herein, present a case of a 59-year-old lady who developed intestinal obstruction due to colonic strictures shortly after recovering from complicated COVID-19 pneumonia. Ultimately, she underwent laparoscopic subtotal colectomy with ileorectal anastomosis. After a long recovery period, she was discharged in good status. It has been more than two years since COVID-19 was declared as a pandemic by the World Health Organization. Infected individuals have highly variable clinical manifestations, yet the pathogenesis, diagnosis and ideal management of each of these complications is not well described in literature.

Laparoscopic Complete Mesocolic Excision Without Routine Gastro-Pancreatico-Colic Trunk Dissection: Survival Outcomes and Morbidity for 567 Cases.

Purpose: It is unclear whether the principles of open complete mesocolic excision (CME) can be safely applied to laparoscopic surgery. Furthermore, definitions vary over how radical optimal CME surgery should be. We report morbidity and oncological outcomes for laparoscopic CME without routine gastro-pancreatico-colic trunk (GPCT) dissection. Materials and Methods: An observational study with consecutive data for patients with Union for International Cancer Control (UICC) stage I-III colon adenocarcinoma who underwent elective laparoscopic resection between 2006 and 2015. Data were retrieved for demographics, tumor characteristics, treatment, and histology from prospectively maintained databases. Standardized, routinely video recorded, laparoscopic resections were performed in two United Kingdom centers from The National Training Programme for Laparoscopic Colorectal Surgery. Overall survival and disease-free survival (DFS) were reported using Kaplan-Meier curves and Cox regression. Results: Laparoscopic CME was performed in 567 patients, 52.7% (288/546) women, median (interquartile range [IQR]) age 73 (65-80) years. Median (IQR) length of stay was 4 (3-5) days with 4.0 (2.2-5.7)-year follow-up. Significant DFS predictors (hazard ratio [HR]) by multivariable Cox regression were age >80 years (1.9), American Society of Anesthesiologists (ASA) 3 and 4 (HR = 1.1), right colon cancer (1.7), UICC stage III (3.4), and intramesocolic grade (2.2). Overall 4-year DFS (95% confidence interval) was 81.3% (77-85). Four-year DFS by UICC grades I, II, and III was 94.6% (89-99), 83.4% (77-88), and 72.2% (66-78), respectively (log-rank P = .001). Morbidity by Clavien-Dindo grade was III 18 (3.2%), IV 4 (0.7%) and V 7 (1.2%). Conclusion: This large series suggests standardized laparoscopic CME without routine GPCT dissection has a low morbidity and achieves equivalent outcomes to the most radical open CME techniques.

Supervised training of laparoscopic colorectal cancer resections does not adversely affect short- and long-term outcomes: a Propensity-score-matched cohort study.

BACKGROUND: Supervised training of laparoscopic colorectal cancer surgery to fellows and consultants (trainees) may raise doubts regarding safety and oncological adequacy. This study investigated these concerns by comparing the short- and long-term outcomes of matched supervised training cases to cases performed by the trainer himself. METHODS: A prospective database was analysed retrospectively. All elective laparoscopic colorectal cancer resections in curative intent of adult patients (≥ 18 years) which were performed (non-training cases) or supervised to trainees (training cases) by a single laparoscopic expert surgeon (trainer) were identified. All trainees were specialist surgeons in training for laparoscopic colorectal surgery. Supervised training was standardised. Training cases were 1:1 propensity-score matched to non-training cases using age, American Society of Anesthesiologists (ASA) grade, tumour site (rectum, left and right colon) and American Joint Committee on Cancer (AJCC) tumour stage. The resulting groups were analysed for both short- (operative, oncological, complications) and long-term (time to recurrence, overall and disease-free survival) outcomes. RESULTS: From 10/2006 to 2/2016, a total of 675 resections met the inclusion criteria, of which 95 were training cases. These resections were matched to 95 non-training cases. None of the matched covariates exhibited an imbalance greater than 0.25 (│d│>0.25). There were no significant differences in short- (length of procedure, conversion rate, blood loss, postoperative complications, R0 resections, lymph node harvest) and long-term outcomes. When comparing training cases to non-training cases, 5-year overall and disease-free survival rates were 71.6% (62.4-82.2) versus 81.9% (74.2-90.4) and 70.0% (60.8-80.6) versus 73.6% (64.9-83.3), respectively (not significant). The corresponding hazard ratios (95% confidence intervals, p) were 0.57 (0.32-1.02, p = 0.057) and 0.87 (0.51-1.48, p = 0.61), respectively (univariate Cox proportional hazard model). CONCLUSIONS: Standardised supervised training of laparoscopic colorectal cancer procedures to specialist surgeons may not adversely impact short- and long-term outcomes. This result may also apply to newer surgical techniques as long as standardised teaching methods are followed.