Mishra, Nitin

BACKGROUND: Metachronous cancer risk varies by mismatch repair mutation in patients with hereditary nonpolyposis colorectal cancer. Total colectomy offers decreased risk of metachronous colorectal cancers but decreased quality of life compared with segmental colectomy. OBJECTIVE: Compare segmental versus total colectomy for colon cancer via a mutation-specific Markov decision model. DESIGN: Simulated survival and colorectal metachronous occurrence among patients with MLH1, MSH2 , or MSH6 mutations undergoing either segmental or total colectomy. SETTINGS: National databases, literature review. PATIENTS: Simulated patients with hereditary nonpolyposis colorectal cancer. MAIN OUTCOME MEASURES: Overall survival, quality-adjusted life years based on procedure-specific utility states (segmental colectomy 0.99, total colectomy 0.95). RESULTS: Among patients aged 25 years, total colectomy offered less than 1 year of increased mean survival compared with segmental resection across all mutations ( MLH1: 0.8 years, MSH2: 0.9, MSH6: 0.3). This difference in survival decreased with increasing age. Segmental resection offered a small increase in quality-adjusted life years compared with total colectomy across all ages. This difference was highest for MSH6 (0.9 years vs MLH1 : 0.6 and MSH2 : 0.4 at age 25), particularly at younger ages of diagnosis. In a sensitivity analysis, lower total colectomy utility states resulted in greater increases in quality-adjusted life years with segmental colectomy across all mutations. LIMITATIONS: Metachronous cancer risk data do not distinguish between colon and rectal cancers and is extrapolated beyond age 70 years. CONCLUSIONS: Segmental and total colectomy offer similar survival and quality-adjusted life year outcomes. With decreased risk of metachronous cancers, patients with MSH6 mutations across all ages may prefer segmental resection owing to higher quality-adjusted life years and lower survival benefits from total colectomy compared with MLH1 and MSH2 patients. Operative strategy in patients with hereditary nonpolyposis colorectal cancer should be individualized, and this study shows that mutation-specific differences in survival and quality-adjusted life years are small. See Video Abstract . MODELO DE DECISIÓN ESPECÍFICO PARA LA MUTACIÓN EN LA COLECTOMÍA ABDOMINAL SEGMENTARIA FRENTE A LA COLECTOMÍA ABDOMINAL TOTAL EN EL CÁNCER COLORRECTAL HEREDITARIO NO POLIPOSO ANTECEDENTES: El riesgo de cáncer metacrónico varía según la mutación de reparación de desajustes en pacientes con cáncer colorrectal hereditario no poliposo. La colectomía total ofrece un menor riesgo de cánceres colorrectales metacrónicos, pero una menor calidad de vida en comparación con la colectomía segmentaria. OBJETIVO: Comparar la colectomía segmentaria con la colectomía total para el cáncer de colon mediante un modelo de decisión de Markov específico para mutaciones. DISEÑO: Simulación de la supervivencia y la aparición metacrónica de cáncer colorrectal en pacientes con mutaciones MLH1, MSH2 o MSH6 sometidos a colectomía segmentaria o total. ENTORNO: Bases de datos nacionales, revisión de la literatura. PACIENTES: Pacientes simulados con cáncer colorrectal hereditario no poliposo. PRINCIPALES MEDIDAS DE RESULTADO: Supervivencia global, años de vida ajustados por calidad basados en estados de utilidad específicos del procedimiento (colectomía segmentaria 0,99, colectomía total 0,95). RESULTADOS: Entre los pacientes de 25 años, la colectomía total ofreció menos de un año de aumento de la supervivencia media en comparación con la resección segmentaria en todas las mutaciones ( MLH1: 0,8 años, MSH2: 0,9, MSH6: 0,3). Esta diferencia en la supervivencia disminuyó con el aumento de la edad. La resección segmentaria ofreció un pequeño aumento en los años de vida ajustados por calidad en comparación con la colectomía total en todas las edades. Esta diferencia fue mayor para MSH6 (0,9 años frente a MLH1 : 0,6 y MSH2 : 0,4 a los 25 años), especialmente en las edades más jóvenes de diagnóstico. En un análisis de sensibilidad, los estados de utilidad más bajos de la colectomía total dieron lugar a mayores aumentos en los años de vida ajustados por calidad con la colectomía segmentaria en todas las mutaciones. LIMITACIONES: Los datos sobre el riesgo de cáncer metacrónico no distinguen entre cánceres de colon y recto y se extrapolan más allá de los 70 años. CONCLUSIONES: La colectomía segmentaria y la colectomía total ofrecen resultados similares en cuanto a la supervivencia y los años de vida ajustados por calidad. Con la disminución del riesgo de cánceres metacrónicos, los pacientes con mutaciones MSH6 de todas las edades pueden preferir la resección segmentaria debido a los mayores años de vida ajustados por calidad y los menores beneficios de supervivencia de la colectomía total en comparación con los pacientes MLH1 y MSH2 . La estrategia quirúrgica en pacientes con cáncer colorrectal hereditario no poliposo debe individualizarse, y este estudio muestra que las diferencias específicas de la mutación en la supervivencia y los años de vida ajustados por calidad son pequeñas. ( AI-generated translation )

Abstract Introduction Ileal pouch–anal anastomosis (IPAA) is a common surgical procedure for patients with ulcerative colitis or familial adenomatous polyposis. This study compared the outcomes of robotic, laparoscopic, and open IPAA techniques, with a focus on surgical complications and pouch failure rates. Methods A retrospective study was conducted of patients who underwent IPAA at three Mayo Clinic locations between 2015 and 2020. Data on patient demographics, surgical details, and postoperative outcomes were collected and compared across the three surgical approaches. Pouch failure was defined as the need for pouch excision or a diverting loop ileostomy. Results In all, 401 patients underwent IPAA with either an open (149, 37.2%), robotic (145, 36.2%), or laparoscopic (107, 26.7%) technique. The overall rate of pouch failure was 6.5% and did not differ significantly between the three surgical approaches. Compared with laparoscopy, robotic IPAA was associated with a lower conversion rate to open surgery (1.4 versus 17.8%; P < 0.0001) and fewer 30-day readmissions (15.9% versus 28.0%; P = 0.02). However, robotic and laparoscopic IPAA approaches had higher rates of venous thromboembolism/pulmonary embolism and readmission than the open approach. Pouchitis was the most common cause of pouch failure across all surgical techniques. Conclusion Robotic IPAA had lower conversion and reduced 30-day admission rates compared with a laparoscopic approach. However, open surgery had lower rates of 30-day readmission and rates thromboembolism than robotic IPAA. The surgical approach itself does not appear to significantly impact long-term pouch failure rates.

BACKGROUND: Venous thromboembolism occurs in approximately 2% of patients undergoing abdominal and pelvic surgery for cancers of the colon, rectum, and anus and is considered preventable. The American Society of Colon and Rectal Surgeons recommends extended prophylaxis in high-risk patients, but there is low adherence to the guidelines. OBJECTIVE: This study aims to analyze the impact of venous thromboembolism risk-guided prophylaxis in patients undergoing elective abdominal and pelvic surgeries for colorectal and anal cancers from 2016 to 2021. DESIGN: This was a retrospective analysis. SETTING: The study was conducted at a multisite tertiary referral academic health care system. PATIENTS: Patients who underwent elective abdominal or pelvic surgery for colon, rectal, or anal cancer. MAIN OUTCOME MEASURES: Receipt of Caprini-guided venous thromboembolism prophylaxis, 90-day postoperative rate of deep vein thrombosis, pulmonary embolism, venous thromboembolism, and bleeding events. RESULTS: A total of 3504 patients underwent elective operations, of whom 2224 (63%) received appropriate thromboprophylaxis in the inpatient setting. In the postdischarged cohort of 2769 patients, only 2% received appropriate thromboprophylaxis and no thromboembolic events were observed. In the group receiving inappropriate thromboprophylaxis, at 90 days postdischarge, the deep vein thrombosis, pulmonary embolism, and venous thromboembolism rates were 0.60%, 0.40%, and 0.88%, respectively. Postoperative bleeding was not different between the 2 groups. LIMITATIONS: Limitations to our study include its retrospective nature, use of aggregated electronic medical records, and single health care system experience. CONCLUSION: Most patients in our health care system undergoing abdominal or pelvic surgery for cancers of the colon, rectum, and anus were discharged without appropriate Caprini-guided venous thromboembolism prophylaxis. Risk-guided prophylaxis was associated with decreased rates of inhospital and postdischarge venous thromboembolism without increased bleeding complications. See Video Abstract. MARGEN DE MEJORA: EL IMPACTO DE LA TROMBOPROFILAXIS RECOMENDADA POR LAS DIRECTRICES EN PACIENTES SOMETIDOS A CIRUGÍA ABDOMINAL POR CÁNCER COLORRECTAL Y ANAL EN UN CENTRO DE REFERENCIA TERCIARIO ANTECEDENTES: El tromboembolismo venoso ocurre en aproximadamente el 2% de los pacientes sometidos a cirugía abdominal y pélvica por cánceres de colon, recto y ano, y se considera prevenible. La Sociedad Estadounidense de Cirujanos de Colon y Recto recomienda una profilaxis prolongada en pacientes de alto riesgo, pero el cumplimiento de las directrices es bajo. OBJETIVO: Este estudio tiene como objetivo analizar el impacto de la profilaxis guiada por el riesgo de tromboembolismo venoso (TEV) en pacientes sometidos a cirugías abdominales y pélvicas electivas por cáncer colorrectal y anal entre 2016 y 2021. DISEÑO: Este fue un análisis retrospectivo. AJUSTE: El estudio se llevó a cabo en un sistema de salud académico de referencia terciaria de múltiples sitios. PACIENTES: Pacientes sometidos a cirugía abdominal o pélvica electiva por cáncer de colon, recto o ano. PRINCIPALES MEDIDAS DE RESULTADO: Recepción de profilaxis de tromboembolismo venoso guiada por Caprini, tasa postoperatoria de 90 días de trombosis venosa profunda, embolia pulmonar, tromboembolismo venoso y eventos de sangrado. RESULTADOS: Un total de 3.504 pacientes se sometieron a operaciones electivas, de los cuales 2.224 (63%) recibieron tromboprofilaxis adecuada en el ámbito hospitalario. En el cohorte de 2.769 pacientes después del alta, solo el 2% recibió tromboprofilaxis adecuada en la que no se observaron eventos tromboembólicos. En el grupo que recibió tromboprofilaxis inadecuada, a los 90 días después del alta, las tasas de trombosis venosa profunda, embolia pulmonar y tromboembolia venosa fueron del 0,60%, 0,40% y 0,88%, respectivamente. El sangrado posoperatorio no fue diferente entre los dos grupos. LIMITACIONES: Las limitaciones de nuestro estudio incluyen su naturaleza retrospectiva, el uso de registros médicos electrónicos agregados y la experiencia de un solo sistema de atención médica. CONCLUSIÓN: La mayoría de los pacientes en nuestro sistema de salud sometidos a cirugía abdominal o pélvica por cánceres de colon, recto y ano fueron dados de alta sin una profilaxis adecuada de TEV guiada por Caprini. La profilaxis guiada por el riesgo se asoció con menores tasas de tromboembolismo venoso hospitalario y dado de alta sin un aumento de las complicaciones de sangrado. (Traducción—Dr. Aurian Garcia Gonzalez)

Extrapulmonary involvement of coronavirus-19 disease (COVID-19) is being documented and studied at an increasing frequency. Specifically, gastrointestinal involvement is hypothesized to occur due to cellular entry via the ACE2 receptor found in gastrointestinal epithelial cells, causing inflammation and symptoms such as abdominal pain, nausea/vomiting, and diarrhea. We present the case of a 45-year-old female with recent severe COVID-19 infection and early gastrointestinal symptoms who later presented with worsening abdominal pain, nausea, vomiting, and constipation after initial discharge. She was diagnosed with a large bowel obstruction and underwent urgent exploratory laparotomy, which revealed a stricture of the distal transverse colon. Following segmental resection, the patient experienced resolution of symptoms. We hypothesize that this patient’s colonic stricture arose secondary to severe COVID-19-induced bowel inflammation.

BACKGROUND: Intraoperative frozen-section analysis provides real-time margin resection status that can guide intraoperative decisions made by the surgeon and radiation oncologist. For patients with locally recurrent rectal cancer undergoing surgery and intraoperative radiation therapy, intraoperative re-resection of positive margins to achieve negative margins is common practice. OBJECTIVE: This study aimed to assess whether re-resection of positive margins found on intraoperative frozen-section analysis improves oncologic outcomes. DESIGN: This is a retrospective cohort study. SETTINGS: This study was an analysis of a prospectively maintained multicenter database. PATIENTS: All patients who underwent surgical resection of locally recurrent rectal cancer with intraoperative radiation therapy between 2000 and 2015 were included and followed for 5 years. Three groups were compared: initial R0 resection, initial R1 converted to R0 after re-resection, and initial R1 that remained R1 after re-resection. Grossly positive margin resections (R2) were excluded. MAIN OUTCOME MEASURES: The primary outcome measures were 5-year overall survival, recurrence-free survival, and local re-recurrence. RESULTS: A total of 267 patients were analyzed (initial R0 resection, n = 94; initial R1 converted to R0 after re-resection, n = 95; initial R1 that remained R1 after re-resection, n = 78). Overall survival was 4.4 years for initial R0 resection, 2.7 years for initial R1 converted to R0 after re-resection, and 2.9 years for initial R1 that remained R1 after re-resection (p = 0.01). Recurrence-free survival was 3.0 years for initial R0 resection and 1.8 years for both initial R1 converted to R0 after re-resection and initial R1 that remained R1 after re-resection (p ≤ 0.01). Overall survival did not differ for patients with R1 and re-resection R1 or R0 (p = 0.62). Recurrence-free survival and freedom from local re-recurrence did not differ between groups. LIMITATIONS: This study was limited by the heterogeneous patient population restricted to those receiving intraoperative radiation therapy. CONCLUSIONS: Re-resection of microscopically positive margins to obtain R0 status does not appear to provide a significant survival advantage or prevent local re-recurrence in patients undergoing surgery and intraoperative radiation therapy for locally recurrent rectal cancer. See Video Abstract at http://links.lww.com/DCR/B886. LA RE-RESECCIÓN DE LOS MÁRGENES MICROSCÓPICAMENTE POSITIVOS ENCONTRADOS DE MANERA INTRAOPERATORIA MEDIANTE LA TÉCNICA DE CRIOSECCIÓN, NO DA COMO RESULTADO UN BENEFICIO DE SUPERVIVENCIA EN PACIENTES SOMETIDOS A CIRUGÍA Y RADIOTERAPIA INTRAOPERATORIA PARA EL CÁNCER RECTAL LOCALMENTE RECIDIVANTE ANTECEDENTES: El análisis de la ténica de criosección para los margenes positivos encontrados de manera intraoperatoria proporciona el estado de la resección del margen en tiempo real que puede guiar las decisiones intraoperatorias tomadas por el cirujano y el oncólogo radioterapeuta. Para los pacientes con cáncer de recto localmente recurrente que se someten a cirugía y radioterapia intraoperatoria, la re-resección intraoperatoria de los márgenes positivos para lograr márgenes negativos es una práctica común. OBJETIVO: Evaluar si la re-resección de los márgenes positivos encontrados en el análisis de la ténica por criosecciónde manera intraoperatorios mejora los resultados oncológicos. DISEÑO: Estudio de cohorte retrospectivo. AJUSTES: Análisis de una base de datos multicéntrica mantenida de forma prospectiva. POBLACIÓN: Todos los pacientes que se sometieron a resección quirúrgica de cáncer de recto localmente recurrente con radioterapia intraoperatoria entre 2000 y 2015 fueron incluidos y seguidos durante 5 años. Se compararon tres grupos: resección inicial R0, R1 inicial convertido en R0 después de la re-resección y R1 inicial que permaneció como R1 después de la re-resección. Se excluyeron las resecciones de márgenes macroscópicamente positivos (R2). PRINCIPALES MEDIDAS DE RESULTADO: Supervivencia global a cinco años, supervivencia sin recidiva y recidiva local. RESULTADOS: Se analizaron un total de 267 pacientes (resección inicial R0 n = 94, R1 inicial convertido en R0 después de la re-resección n = 95, R1 inicial que permaneció como R1 después de la re-resección n = 78). La supervivencia global fue de 4,4 años para la resección inicial R0, 2,7 años para la R1 inicial convertida en R0 después de la re-resección y 2,9 años para la R1 inicial que permaneció como R1 después de la re-resección (p = 0,01). La supervivencia libre de recurrencia fue de 3,0 años para la resección inicial R0 y de 1,8 años para el R1 inicial convertido en R0 después de la re-resección y el R1 inicial que permaneció como R1 después de la re-resección (p ≤ 0,01). La supervivencia global no difirió para los pacientes con R1 y re-resección R1 o R0 (p = 0,62). La supervivencia libre de recurrencia y la ausencia de recurrencia local no difirieron entre los grupos. LIMITACIONES: Población de pacientes heterogénea, restringida a aquellos que reciben radioterapia intraoperatoria. CONCLUSIONES: La re-resección de los márgenes microscópicamente positivos para obtener el estado R0 no parece proporcionar una ventaja de supervivencia significativa o prevenir la recurrencia local en pacientes sometidos a cirugía y radioterapia intraoperatoria para el cáncer de recto localmente recurrente. Consulte Video Resumen en http://links.lww.com/DCR/B886. (Traducción—Dr. Daniel Guerra)

Abstract Aim The aim of this study was to describe the surgical management, outcomes and risk of malignancy of presacral tailgut cysts. Method A retrospective analysis of all patients who underwent resection of tailgut cyst at Mayo Clinic in Arizona, Florida and Minnesota between 2008 and 2020 was performed. Demographics, presentation, evaluation, surgical approach, postoperative complications, pathology and recurrence rates were reviewed. Results Seventy‐three patients were identified (81% female) with a mean age of 45 years. Thirty‐nine patients (53%) were symptomatic, most commonly with pelvic pain (26 patients). Digital rectal examination identified a palpable mass in 68%. Mean tumour size was 6 cm. Resection was primarily performed through a posterior approach (77%, n = 56), followed by a transabdominal approach (18%, n = 13) and a combined approach (5%, n = 4). Six patients underwent a minimally invasive resection (laparoscopic/robotic). Coccygectomy or distal sacrectomy was performed in 41 patients (56%). Complete resection was achieved in 94% of patients. Thirty‐day morbidity occurred in 18% and was most commonly wound related; there was no mortality. Malignancy was identified in six patients (8%). For the 30 patients with follow‐up greater than 1 year, the median follow‐up was 39 months (range 1.0–11.1 years). Local recurrence was identified in three patients and distant metastatic disease in one patient. Conclusion The rate of malignancy in presacral tailgut cysts based on this current review was 8%. Overall recurrence was 5% at a median of 24 months.

AbstractBackgroundTo evaluate the economic burden of locally advanced rectal cancer (LARC) treatment from a society perspective through analysis of health insurance‐derived data of commercially insured and Medicare Advantage (MA) patients.MethodsRetrospective cost analysis of patients undergoing rectal resection within a multimodal (neoadjuvant chemoradiation + adjuvant chemotherapy) treatment strategy between January 1, 2010 and October 31, 2018, using the claims OptumLabs Data Warehouse database.ResultsIn total, 1738 (935 commercial and 803 MA) patients were included. Overall treatment costs totaled $230,881,746 (on average $183 653 ± 82 384 per commercially insured and $73 681 ± 32 917 per MA patient). Cost distribution according to category (commercially insured patients) was: 29.92% related to outpatient care (follow‐up visits/diagnostics), radiotherapy: 21.83%, index resection: 20.62%, chemotherapy: 17.44%, surgical inpatient: 6.32%, medical inpatient: 3.28%, emergency room: 0.58%. Relative cost distribution of the index resection itself differed marginally between the three approaches and was 21.49% for open, 19.30% for laparoscopic, and 20.93% for robotic surgery. Relative cost distributions of neoadjuvant, adjuvant, and outpatient treatments remained unchanged, independently of the surgical approach. This representation was similar in MA patients.ConclusionIndex‐surgery related costs were outweighed by costs related to oncological and outpatient workup/follow‐up treatments independently of both surgical approach and insurance type.

AbstractSigmoid diverticulitis represents a most common gastroenterological diagnosis in the western world. There has been a significant change in the management of recurrent uncomplicated diverticulitis in the last 10 to 15 years. The absolute number of previous episodes is not used as criteria to recommend surgery anymore. Young age is no longer considered to be an indication for more aggressive surgical treatment. It is accepted that subsequent episodes of diverticulitis are not significantly worse than the first episode. Laparoscopic surgery is now the standard of care for elective surgery for diverticulitis where expertise is available. There is a consensus that decision to perform sigmoid colectomy should be individualized, after careful risk benefit assessment.

INTRODUCTION: As multidisciplinary treatment modalities for rectal cancer continue to evolve, neoadjuvant chemoradiation then surgical resection is a common approach. Robotic-assisted abdominoperineal resection is becoming more prevalent in part because of better visualization and instrument mobility within the pelvis. After abdominoperineal resection, postoperative perineal wound complications remain a significant risk. Pelvic reconstruction lowers this risk, and a pedicled rectus abdominis muscle flap is frequently used to achieve this. Traditional flap harvest requires laparotomy, resulting in violation of both rectus sheaths and a large midline scar. Robotic harvest of the rectus abdominis muscle for pelvic reconstruction after abdominoperineal resection is a novel approach with foreseeable benefits. TECHNIQUE: After completion of abdominoperineal resection, 2 additional trocars are inserted in the lateral abdomen, and the robot is reoriented toward the posterior abdominal wall. The peritoneum and posterior rectus sheath are incised, and dissection is carried superiorly and inferiorly in a sagittal plane to reveal the rectus abdominis muscle. The muscle body is separated from the anterior rectus sheath. Once the inferior epigastric artery is identified, the superior pole of the muscle is transected. Continued lateral dissection ensures flap mobility for placement within the pelvis. After obtaining proper reach, the robot is undocked, and the flap is sutured in place through the perineal defect. RESULTS: After trocar placement and robot repositioning, both the colorectal and plastic surgeons trade places at the console. Robotic flap harvest precludes the need for laparotomy. The anterior rectus sheath remains unviolated and the patient avoids an additional midline scar. The aforementioned benefits of robot-assisted abdominoperineal resection, namely increased visualization and maneuverability, were also found applicable when robotically harvesting this flap. CONCLUSIONS: This technique exemplifies an additional minimally invasive technique for patients pursuing abdominoperineal resection. With knowledge of this novel approach, surgeons can better tailor their operations to benefit the patient.

BACKGROUND: Primary colorectal lymphoma is rare, representing 0.2% to 0.6% of all colorectal cancers. Because of its low incidence and histologic variety, no treatment guidelines exist. OBJECTIVE: The purpose was to report the experience of primary colorectal lymphoma in an institutional and a national cohort. DESIGN: This was a retrospective cohort study. SETTINGS: The study was conducted with institutional data composed of 3 tertiary referral centers and national data. PATIENTS: Patients with primary colorectal lymphoma were identified within the Mayo Clinic (1990–2016) and the Surveillance, Epidemiology, and End Results database (1990–2014). MAIN OUTCOME MEASURES: Primary outcomes were overall and 5-year survival. RESULTS: For the institutional cohort (N = 82), 5-year survival was 79.9%. Five-year survival was higher for rectal (88.4%) than for colon tumors (77.2%; p = 0.004). On multivariable analysis, age <50 years was associated with higher overall survival ( p = 0.04). Left-sided colon masses and aggressive histological subtypes were associated with worse survival (0.04 and 0.03). No effect of treatment modality on survival was noted. For the national cohort (N = 2942), 5-year survival was 58.4%. Five-year survival for rectal tumors was 61.0% and 57.8% for colon tumors. On multivariable analysis, factors associated with improved survival were age <70 y, ( p < 0.0001), female sex ( p = 0.005), right-sided masses ( p = 0.02), and diagnoses after 2000 compared with 1990–1999 ( p < 0.0001). Aggressive pathology ( p < 0.0001) and stage III or stage IV presentation compared with stage I ( p = 0.02 and p < 0.0001) were associated with worse survival. LIMITATIONS: The institutional cohort was limited by sample size to describe treatment effect on survival. A major limitation of the national cohort was the ability to describe treatment modalities other than surgery, including chemotherapy and/or no additional treatment. CONCLUSIONS: Poorer survival was noted in elderly patients and in those with aggressive pathology. An overall survival advantage was seen in women in the national cohort. Currently, optimal strategies should follow a patient-centered multidisciplinary approach. See Video Abstract at http://links.lww.com/DCR/A807. LINFOMA COLORECTAL PRIMARIO: EXPERIENCIA INSTITUCIONAL Y REVISIÓN DE UNA BASE DE DATOS NACIONAL ANTECEDENTES: El linfoma colorectal primario es poco frecuente, representando del 0.2% al 0.6% de todos los cánceres colorectales. Debido a su baja incidencia y variedad histológica, no existen guías de tratamiento. OBJETIVO: El propósito fue reportar la experiencia en linfoma colorectal primario en una cohorte institucional y una nacional. DISEÑO: Este fue un estudio de cohorte retrospectivo. ESCENARIO: El estudio se realizó con datos institucionales provenientes de 3 centros de referencia terciarios y datos nacionales. PACIENTES: Se identificaron pacientes con linfoma colorectal primario en la base de datos de la Clínica Mayo (1990–2016) y en la base de datos de vigilancia, epidemiología y resultados finales [Surveillance, Epidemiology, and End Results database (1990–2014)]. PRINCIPALES MEDIDAS DE RESULTADO: Los resultados primarios fueron la sobrevida general y a 5 años. RESULTADOS: Para la cohorte institucional (N = 82), la sobrevida a 5 años fue de 79.9%. La sobrevida a cinco años fue mayor en tumores rectales (88.4%) que en los de colon (77.2%; p = 0.004). En el análisis multivariable, la edad <50 años se asoció con una mayor sobrevida general (p = 0,04). Las masas de colon izquierdo y los subtipos histológicos agresivos se asociaron con una peor sobrevida (0.04 y 0.03). No se observó ningún efecto según la modalidad de tratamiento en la sobrevida. Para la cohorte nacional (N = 2942), la sobrevida a 5 años fue del 58.4%. La sobrevida a cinco años fue de 61.0% para los tumores rectales y 57.8% para los tumores de colon. En el análisis multivariable, los factores asociados con una mayor sobrevida fueron edad <70 años, (p <0.0001), sexo femenino (p = 0.005), masas derechas (p = 0.02) y los casos diagnósticados después del año 2000 comparados con los de 1990–1999 (p <0.0001). Histopatología agresiva (p <0.0001) y presentación en estadio III o estadio IV en comparación con estadio I (p = 0.02 y p <0.0001) se asociaron con una peor sobrevida. LIMITACIONES: La cohorte institucional estuvo limitada por el tamaño de la muestra para describir el efecto del tratamiento en la sobrevida. Una limitación mayor en la cohorte nacional fue la habilidad para describir modalidades de tratamiento distintas a la cirugía, incluyendo quimioterapia y/o ningún tratamiento adicional. CONCLUSIONES: Una menor sobrevida fue documentada en pacientes de edad avanzada y en aquellos con histopatología agresiva. Se observó ventaja en cuanto a sobrevida general en las mujeres de la cohorte nacional. Actualmente, las estrategias óptimas deben de seguir un abordaje multidisciplinario centrado en cada paciente. Vea el abstract en video en http://links.lww.com/DCR/A807.