Prediction of Pathologic Complete Response for Rectal Cancer Based on Pretreatment Factors Using Machine Learning.

BACKGROUND: Pathologic complete response after neoadjuvant therapy is an important prognostic indicator for locally advanced rectal cancer and may give insights into which patients might be treated nonoperatively in the future. Existing models for predicting pathologic complete response in the pretreatment setting are limited by small data sets and low accuracy. OBJECTIVE: We sought to use machine learning to develop a more generalizable predictive model for pathologic complete response for locally advanced rectal cancer. DESIGN: Patients with locally advanced rectal cancer who underwent neoadjuvant therapy followed by surgical resection were identified in the National Cancer Database from years 2010 to 2019 and were split into training, validation, and test sets. Machine learning techniques included random forest, gradient boosting, and artificial neural network. A logistic regression model was also created. Model performance was assessed using an area under the receiver operating characteristic curve. SETTINGS: This study used a national, multicenter data set. PATIENTS: Patients with locally advanced rectal cancer who underwent neoadjuvant therapy and proctectomy. MAIN OUTCOME MEASURES: Pathologic complete response defined as T0/xN0/x. RESULTS: The data set included 53,684 patients. Pathologic complete response was experienced by 22.9% of patients. Gradient boosting showed the best performance with an area under the receiver operating characteristic curve of 0.777 (95% CI, 0.773-0.781), compared with 0.684 (95% CI, 0.68-0.688) for logistic regression. The strongest predictors of pathologic complete response were no lymphovascular invasion, no perineural invasion, lower CEA, smaller size of tumor, and microsatellite stability. A concise model including the top 5 variables showed preserved performance. LIMITATIONS: The models were not externally validated. CONCLUSIONS: Machine learning techniques can be used to accurately predict pathologic complete response for locally advanced rectal cancer in the pretreatment setting. After fine-tuning a data set including patients treated nonoperatively, these models could help clinicians identify the appropriate candidates for a watch-and-wait strategy. See Video Abstract . EL CNCER DE RECTO BASADA EN FACTORES PREVIOS AL TRATAMIENTO MEDIANTE EL APRENDIZAJE AUTOMTICO: ANTECEDENTES:La respuesta patológica completa después de la terapia neoadyuvante es un indicador pronóstico importante para el cáncer de recto localmente avanzado y puede dar información sobre qué pacientes podrían ser tratados de forma no quirúrgica en el futuro. Los modelos existentes para predecir la respuesta patológica completa en el entorno previo al tratamiento están limitados por conjuntos de datos pequeños y baja precisión.OBJETIVO:Intentamos utilizar el aprendizaje automático para desarrollar un modelo predictivo más generalizable para la respuesta patológica completa para el cáncer de recto localmente avanzado.DISEÑO:Los pacientes con cáncer de recto localmente avanzado que se sometieron a terapia neoadyuvante seguida de resección quirúrgica se identificaron en la Base de Datos Nacional del Cáncer de los años 2010 a 2019 y se dividieron en conjuntos de capacitación, validación y prueba. Las técnicas de aprendizaje automático incluyeron bosque aleatorio, aumento de gradiente y red neuronal artificial. También se creó un modelo de regresión logística. El rendimiento del modelo se evaluó utilizando el área bajo la curva característica operativa del receptor.ÁMBITO:Este estudio utilizó un conjunto de datos nacional multicéntrico.PACIENTES:Pacientes con cáncer de recto localmente avanzado sometidos a terapia neoadyuvante y proctectomía.PRINCIPALES MEDIDAS DE VALORACIÓN:Respuesta patológica completa definida como T0/xN0/x.RESULTADOS:El conjunto de datos incluyó 53.684 pacientes. El 22,9% de los pacientes experimentaron una respuesta patológica completa. El refuerzo de gradiente mostró el mejor rendimiento con un área bajo la curva característica operativa del receptor de 0,777 (IC del 95%: 0,773 - 0,781), en comparación con 0,684 (IC del 95%: 0,68 - 0,688) para la regresión logística. Los predictores más fuertes de respuesta patológica completa fueron la ausencia de invasión linfovascular, la ausencia de invasión perineural, un CEA más bajo, un tamaño más pequeño del tumor y la estabilidad de los microsatélites. Un modelo conciso que incluye las cinco variables principales mostró un rendimiento preservado.LIMITACIONES:Los modelos no fueron validados externamente.CONCLUSIONES:Las técnicas de aprendizaje automático se pueden utilizar para predecir con precisión la respuesta patológica completa para el cáncer de recto localmente avanzado en el entorno previo al tratamiento. Después de realizar ajustes en un conjunto de datos que incluye pacientes tratados de forma no quirúrgica, estos modelos podrían ayudar a los médicos a identificar a los candidatos adecuados para una estrategia de observar y esperar. (Traducción-Dr. Ingrid Melo ).

Factors Associated With Performing IPAA After Total Colectomy for Ulcerative Colitis.

BACKGROUND: IPAA is considered the procedure of choice for restorative surgery after total colectomy for ulcerative colitis. Previous studies have examined the rate of IPAA within individual states but not at the national level in the United States. OBJECTIVE: This study aimed to assess the rate of IPAA after total colectomy for ulcerative colitis in a national population and identify factors associated with IPAA. DESIGN: This was a retrospective cohort study. SETTINGS: This study was performed in the United States. PATIENTS: Patients who were aged 18 years or older and who underwent total colectomy between 2009 and 2019 for a diagnosis of ulcerative colitis were identified within a commercial database. This database excluded patients with public insurance, including all patients older than 65 years with Medicare. MAIN OUTCOME MEASURES: The primary outcome was IPAA. Multivariable logistic regression was used to assess the association between covariates and the likelihood of undergoing IPAA. RESULTS: In total, 2816 patients were included, of whom 1414 (50.2%) underwent IPAA, 928 (33.0%) underwent no further surgery, and 474 (16.8%) underwent proctectomy with end ileostomy. Younger age, lower comorbidities, elective case, and laparoscopic approach in the initial colectomy were significantly associated with IPAA but socioeconomic status was not. LIMITATIONS: This retrospective study included only patients with commercial insurance. CONCLUSIONS: A total of 50.2% of patients who had total colectomy for ulcerative colitis underwent IPAA, and younger age, lower comorbidities, and elective cases are associated with a higher rate of IPAA placement. This study emphasizes the importance of ensuring follow-up with colorectal surgeons to provide the option of restorative surgery, especially for patients undergoing urgent or emergent colectomies. See Video Abstract . FACTORES ASOCIADOS CON LA REALIZACIN DE ANASTOMOSIS ANALBOLSA ILEAL DESPUS DE UNA COLECTOMA TOTAL POR COLITIS ULCEROSA: ANTECEDENTES:La anastomosis ileo-anal se considera el procedimiento de elección para la cirugía reparadora tras la colectomía total por colitis ulcerosa. Estudios previos han examinado la tasa de anastomosis ileo-anal dentro de los estados individuales, pero no a nivel nacional en los Estados Unidos.OBJETIVO:Evaluar la tasa de anastomosis bolsa ileal-anal después de la colectomía total para la colitis ulcerosa en una población nacional e identificar los factores asociados con la anastomosis bolsa ileal-anal.DISEÑO:Se trata de un estudio de cohortes retrospectivo.LUGAR:Este estudio se realizó en los Estados Unidos.PACIENTES:Los pacientes que tenían ≥18 años de edad que se sometieron a colectomía total entre 2009 y 2019 para un diagnóstico de colitis ulcerosa fueron identificados dentro de una base de datos comercial. Esta base de datos excluyó a los pacientes con seguro público, incluidos todos los pacientes >65 años con Medicare.MEDIDAS DE RESULTADO PRINCIPALES:El resultado primario fue la anastomosis ileal bolsa-anal. Se utilizó una regresión logística multivariable para evaluar la asociación entre las covariables y la probabilidad de someterse a una anastomosis ileal.RESULTADOS:En total, se incluyeron 2.816 pacientes, de los cuales 1.414 (50,2%) se sometieron a anastomosis ileo-anal, 928 (33,0%) no se sometieron a ninguna otra intervención quirúrgica y 474 (16,8%) se sometieron a proctectomía con ileostomía terminal. La edad más joven, las comorbilidades más bajas, el caso electivo, y el abordaje laparoscópico en la colectomía inicial se asociaron significativamente con la anastomosis ileal bolsa-anal, pero no el estatus socioeconómico.LIMITACIONES:Este estudio retrospectivo incluyó sólo pacientes con seguro comercial.CONCLUSIONES:Un 50,2% de los pacientes se someten a anastomosis ileo-anal y la edad más joven, las comorbilidades más bajas y los casos electivos se asocian con una mayor tasa de colocación de anastomosis ileo-anal. Esto subraya la importancia de asegurar el seguimiento con cirujanos colorrectales para ofrecer la opción de cirugía reparadora, especialmente en pacientes sometidos a colectomías urgentes o emergentes. (Traducción-Dr. Yolanda Colorado ).

Delphi Initiative for Early-Onset Colorectal Cancer (DIRECt) International Management Guidelines.

BACKGROUND & AIMS: Patients with early-onset colorectal cancer (eoCRC) are managed according to guidelines that are not age-specific. A multidisciplinary international group (DIRECt), composed of 69 experts, was convened to develop the first evidence-based consensus recommendations for eoCRC. METHODS: After reviewing the published literature, a Delphi methodology was used to draft and respond to clinically relevant questions. Each statement underwent 3 rounds of voting and reached a consensus level of agreement of ≥80%. RESULTS: The DIRECt group produced 31 statements in 7 areas of interest: diagnosis, risk factors, genetics, pathology-oncology, endoscopy, therapy, and supportive care. There was strong consensus that all individuals younger than 50 should undergo CRC risk stratification and prompt symptom assessment. All newly diagnosed eoCRC patients should receive germline genetic testing, ideally before surgery. On the basis of current evidence, endoscopic, surgical, and oncologic treatment of eoCRC should not differ from later-onset CRC, except for individuals with pathogenic or likely pathogenic germline variants. The evidence on chemotherapy is not sufficient to recommend changes to established therapeutic protocols. Fertility preservation and sexual health are important to address in eoCRC survivors. The DIRECt group highlighted areas with knowledge gaps that should be prioritized in future research efforts, including age at first screening for the general population, use of fecal immunochemical tests, chemotherapy, endoscopic therapy, and post-treatment surveillance for eoCRC patients. CONCLUSIONS: The DIRECt group produced the first consensus recommendations on eoCRC. All statements should be considered together with the accompanying comments and literature reviews. We highlighted areas where research should be prioritized. These guidelines represent a useful tool for clinicians caring for patients with eoCRC.

Improved Prediction of Surgical-Site Infection After Colorectal Surgery Using Machine Learning.

BACKGROUND: Surgical-site infection is a source of significant morbidity after colorectal surgery. Previous efforts to develop models that predict surgical-site infection have had limited accuracy. Machine learning has shown promise in predicting postoperative outcomes by identifying nonlinear patterns within large data sets. OBJECTIVE: This study aimed to seek usage of machine learning to develop a more accurate predictive model for colorectal surgical-site infections. DESIGN: Patients who underwent colorectal surgery were identified in the American College of Surgeons National Quality Improvement Program database from years 2012 to 2019 and were split into training, validation, and test sets. Machine-learning techniques included random forest, gradient boosting, and artificial neural network. A logistic regression model was also created. Model performance was assessed using area under the receiver operating characteristic curve. SETTINGS: A national, multicenter data set. PATIENTS: Patients who underwent colorectal surgery. MAIN OUTCOME MEASURES: The primary outcome (surgical-site infection) included patients who experienced superficial, deep, or organ-space surgical-site infections. RESULTS: The data set included 275,152 patients after the application of exclusion criteria. Of all patients, 10.7% experienced a surgical-site infection. Artificial neural network showed the best performance with area under the receiver operating characteristic curve of 0.769 (95% CI, 0.762-0.777), compared with 0.766 (95% CI, 0.759-0.774) for gradient boosting, 0.764 (95% CI, 0.756-0.772) for random forest, and 0.677 (95% CI, 0.669-0.685) for logistic regression. For the artificial neural network model, the strongest predictors of surgical-site infection were organ-space surgical-site infection present at time of surgery, operative time, oral antibiotic bowel preparation, and surgical approach. LIMITATIONS: Local institutional validation was not performed. CONCLUSIONS: Machine-learning techniques predict colorectal surgical-site infections with higher accuracy than logistic regression. These techniques may be used to identify patients at increased risk and to target preventive interventions for surgical-site infection. See Video Abstract at http://links.lww.com/DCR/C88 . PREDICCIN MEJORADA DE LA INFECCIN DEL SITIO QUIRRGICO DESPUS DE LA CIRUGA COLORRECTAL MEDIANTE EL APRENDIZAJE AUTOMTICO: ANTECEDENTES:La infección del sitio quirúrgico es una fuente de morbilidad significativa después de la cirugía colorrectal. Los esfuerzos anteriores para desarrollar modelos que predijeran la infección del sitio quirúrgico han tenido una precisión limitada. El aprendizaje automático se ha mostrado prometedor en la predicción de los resultados posoperatorios mediante la identificación de patrones no lineales dentro de grandes conjuntos de datos.OBJETIVO:Intentamos utilizar el aprendizaje automático para desarrollar un modelo predictivo más preciso para las infecciones del sitio quirúrgico colorrectal.DISEÑO:Los pacientes que se sometieron a cirugía colorrectal se identificaron en la base de datos del Programa Nacional de Mejoramiento de la Calidad del Colegio Estadounidense de Cirujanos de los años 2012 a 2019 y se dividieron en conjuntos de capacitación, validación y prueba. Las técnicas de aprendizaje automático incluyeron conjunto aleatorio, aumento de gradiente y red neuronal artificial. También se creó un modelo de regresión logística. El rendimiento del modelo se evaluó utilizando el área bajo la curva característica operativa del receptor.CONFIGURACIÓN:Un conjunto de datos multicéntrico nacional.PACIENTES:Pacientes intervenidos de cirugía colorrectal.PRINCIPALES MEDIDAS DE RESULTADO:El resultado primario (infección del sitio quirúrgico) incluyó pacientes que experimentaron infecciones superficiales, profundas o del espacio de órganos del sitio quirúrgico.RESULTADOS:El conjunto de datos incluyó 275.152 pacientes después de la aplicación de los criterios de exclusión. El 10,7% de los pacientes presentó infección del sitio quirúrgico. La red neuronal artificial mostró el mejor rendimiento con el área bajo la curva característica operativa del receptor de 0,769 (IC del 95 %: 0,762 - 0,777), en comparación con 0,766 (IC del 95 %: 0,759 - 0,774) para el aumento de gradiente, 0,764 (IC del 95 %: 0,756 - 0,772) para conjunto aleatorio y 0,677 (IC 95% 0,669 - 0,685) para regresión logística. Para el modelo de red neuronal artificial, los predictores más fuertes de infección del sitio quirúrgico fueron la infección del sitio quirúrgico del espacio del órgano presente en el momento de la cirugía, el tiempo operatorio, la preparación intestinal con antibióticos orales y el abordaje quirúrgico.LIMITACIONES:No se realizó validación institucional local.CONCLUSIONES:Las técnicas de aprendizaje automático predicen infecciones del sitio quirúrgico colorrectal con mayor precisión que la regresión logística. Estas técnicas se pueden usar para identificar a los pacientes con mayor riesgo y para orientar las intervenciones preventivas para la infección del sitio quirúrgico. Consulte Video Resumen en http://links.lww.com/DCR/C88 . (Traducción-Dr Yolanda Colorado ).

Survival After Induction Chemotherapy and Chemoradiation Versus Chemoradiation and Adjuvant Chemotherapy for Locally Advanced Rectal Cancer.

BACKGROUND: Total neoadjuvant therapy (TNT) improves tumor response in locally advanced rectal cancer (LARC) patients compared to neoadjuvant chemoradiotherapy alone. The effect of TNT on patient survival has not been fully investigated. MATERIALS AND METHODS: This was a retrospective case series of patients with LARC at a comprehensive cancer center. Three hundred and eleven patients received chemoradiotherapy (chemoRT) as the sole neoadjuvant treatment and planned adjuvant chemotherapy, and 313 received TNT (induction fluorouracil and oxaliplatin-based chemotherapy followed by chemoradiotherapy in the neoadjuvant setting). These patients then underwent total mesorectal excision or were entered in a watch-and-wait protocol. The proportion of patients with complete response (CR) after neoadjuvant therapy (defined as pathological CR or clinical CR sustained for 2 years) was compared by the χ2 test. Disease-free survival (DFS), local recurrence-free survival, distant metastasis-free survival, and overall survival were assessed by Kaplan-Meier analysis and log-rank test. Cox regression models were used to further evaluate DFS. RESULTS: The rate of CR was 20% for chemoRT and 27% for TNT (P=.05). DFS, local recurrence-free survival, metastasis-free survival, and overall survival were no different. Disease-free survival was not associated with the type of neoadjuvant treatment (hazard ratio [HR] 1.3; 95% confidence interval [CI] 0.93-1.80; P = .12). CONCLUSIONS: Although TNT does not prolong survival than neoadjuvant chemoradiotherapy plus intended postoperative chemotherapy, the higher response rate associated with TNT may create opportunities to preserve the rectum in more patients with LARC.

Adoption of Organ Preservation and Surgeon Variability for Patients with Rectal Cancer Does Not Correlate with Worse Survival.

BACKGROUND AND OBJECTIVES: Watch-and-wait is variably adopted by surgeons and the impact of this on outcomes is unknown. We compared the disease-free survival and organ preservation rates of locally advanced rectal cancer patients treated by expert colorectal surgeons at a comprehensive cancer center. METHODS: This study included retrospective data on patients diagnosed with stage II/III rectal adenocarcinoma from January 2013 to June 2017 who initiated neoadjuvant therapy (either with chemoradiation, chemotherapy, or a combination of both) and were treated by an expert colorectal surgeon. RESULTS: Overall, 444 locally advanced rectal cancer patients managed by five surgeons were included. Tumor distance from the anal verge, type of neoadjuvant therapy, and organ preservation rates varied by treating surgeon. There was no difference in disease-free survival after stratifying by the treating surgeon (p = 0.2). On multivariable analysis, neither the type of neoadjuvant therapy nor the treating surgeon was associated with disease-free survival. CONCLUSIONS: While neoadjuvant therapy type and organ preservation rates varied among surgeons, there were no meaningful differences in disease-free survival. These data suggest that among expert colorectal surgeons, differing thresholds for selecting patients for watch-and-wait do not affect survival.

Predictors of operative difficulty in robotic low anterior resection for rectal cancer.

AIM: This study evaluates the relationship of tumour and anatomical features with operative difficulty in robotic low anterior resection performed by four experienced surgeons in a high-volume colorectal cancer practice. METHODS: Data from 382 patients who underwent robotic low anterior resection by four expert surgeons between January 2016 and June 2019 were included in the analysis. Operating time was used as a measure of operative difficulty. Univariate and multivariate mixed models were used to identify associations between baseline characteristics and operating time, with surgeon as a random effect, thereby controlling for variability in surgeon speed and proficiency. In an exploratory analysis, operative difficulty was defined as conversion to laparotomy, a positive margin or an incomplete mesorectum. RESULTS: Median operating time was 4.28 h (range 1.95-11.33 h) but varied by surgeon from 3.45 h (1.95-6.10 h) to 5.93 h (3.33-11.33 h) (P < 0.001). Predictors of longer operating time in multivariate analysis were male sex, higher body mass index, neoadjuvant radiotherapy, low tumour height, greater sacral height and larger mesorectal area at the S5 vertebral level. Conversion occurred in two cases (0.5%), and incomplete mesorectum and positive margins were found in nine (2.4%) and 19 (5.0%) patients, respectively. Neoadjuvant radiotherapy and larger pelvic outlet were the only characteristics associated with the exploratory measure of difficulty. CONCLUSION: Predicting operative difficulty based on easy to identify, preoperative radiological and clinical variables is feasible in robotic anterior resection.

Primary Tumor-Related Complications and Salvage Outcomes in Patients with Metastatic Rectal Cancer and an Untreated Primary Tumor.

BACKGROUND: For rectal cancer with unresectable metastases, current practice favors omitting interventions directed at the primary tumor in asymptomatic patients. OBJECTIVE: This study aimed to determine the proportion of patients with primary tumor-related complications, characterize salvage outcomes, and measure survival in patients with metastatic rectal cancer who did not undergo upfront intervention for their primary tumor. DESIGN: This is a retrospective analysis. SETTING: This study was conducted at a comprehensive cancer center. PATIENTS: Patients who presented between January 1, 2008, and December 31, 2015, with synchronous stage IV rectal cancer, an unresected primary tumor, and no prior primary tumor-directed intervention were selected. MAIN OUTCOME MEASURES: The main outcome measured was the rate of primary tumor-related complications in the cohort that did not receive any primary tumor-directed intervention. The Kaplan-Meier method and Cox regression analysis were used to determine whether complications are associated with survival. RESULTS: The cohort comprised 358 patients with a median age of 56 years (22-92). Median follow-up was 26 months (range, 1-93 months). Among the 168 patients (46.9%) who eventually underwent elective resection of the primary tumor, the surgery was performed with curative intent in 66 patients (18.4%) and preemptive intent in 102 patients (28.5%). Of the 190 patients who did not undergo an upfront or elective intervention for the primary tumor, 68 (35.8%) experienced complications. Nonsurgical intervention for complications was attempted in 34 patients with an overall success rate of 61.8% (21/34). Surgical intervention was performed in 47 patients (including 13 patients for whom nonsurgical intervention failed): diversion in 26 patients and resection in 21 patients. Of those 47 patients, 42 (89.4%) ended up with a colostomy or ileostomy. LIMITATIONS: This study was conducted at a single center. CONCLUSION: A significant proportion of patients with metastatic rectal cancer and untreated primary tumor experience primary tumor-related complications. These patients should be followed closely, and preemptive intervention (resection, diversion, or radiation) should be considered if the primary tumor progresses despite systemic therapy. See Video Abstract at http://links.lww.com/DCR/B400. COMPLICACIONES RELACIONADAS CON EL TUMOR PRIMARIO Y RESULTADOS DE RESCATE EN PACIENTES CON CÁNCER DE RECTO METASTÁSICO Y UN TUMOR PRIMARIO NO TRATADO: Para el cáncer de recto con metástasis no resecables, la práctica actual favorece la omisión de las intervenciones dirigidas al tumor primario en pacientes asintomáticos.Determinar la proporción de pacientes con complicaciones relacionadas con el tumor primario, caracterizar los resultados de rescate y medir la supervivencia en pacientes con cáncer rectal metastásico que no se sometieron a una intervención inicial para su tumor primario.Análisis retrospectivo.Centro oncológico integral.Pacientes que se presentaron entre el 1 de enero de 2008 y el 31 de diciembre de 2015 con cáncer de recto en estadio IV sincrónico, un tumor primario no resecado y sin intervención previa dirigida al tumor primario.Tasa de complicaciones relacionadas con el tumor primario en la cohorte que no recibió ninguna intervención dirigida al tumor primario. Se utilizó el método de Kaplan-Meier y el análisis de regresión de Cox para determinar si las complicaciones están asociadas con la supervivencia.La cohorte estuvo compuesta por 358 pacientes con una mediana de edad de 56 años (22-92). La mediana de seguimiento fue de 26 meses (rango, 1 a 93 meses). Entre los 168 pacientes (46,9%) que finalmente se sometieron a resección electiva del tumor primario, la cirugía se realizó con intención curativa en 66 pacientes (18,4%) y con intención preventiva en 102 pacientes (28,5%). De los 190 pacientes que no se sometieron a una intervención inicial o electiva para el tumor primario, 68 (35,8%) experimentaron complicaciones. Se intentó una intervención no quirúrgica para las complicaciones en 34 pacientes con una tasa de éxito global del 61,8% (21 de 34). La intervención quirúrgica se realizó en 47 pacientes (incluidos 13 pacientes en los que falló la intervención no quirúrgica): derivación en 26 pacientes y resección en 21 pacientes. De esos 47 pacientes, 42 (89,4%) terminaron con una colostomía o ileostomía.Único centro.Una proporción significativa de pacientes con cáncer de recto metastásico y primario no tratado experimentan complicaciones relacionadas con el tumor primario. Se debe hacer un seguimiento estrecho de estos pacientes y considerar la posibilidad de una intervención preventiva (resección, derivación o radiación) si el tumor primario progresa a pesar de la terapia sistémica. Consulte Video Resumen en http://links.lww.com/DCR/B400.

Type of recurrence is associated with disease-free survival after salvage surgery for locally recurrent rectal cancer.

PURPOSE: To compare the characteristics and outcomes of rectal cancer patients with local recurrence at a perianastomotic site (PA), a surgical field (SF) site, or in lateral lymph nodes (LLN). METHODS: A total of 114 consecutive patients who underwent surgery for recurrent, non-metastatic rectal cancer at a single comprehensive cancer center between 1997 and 2012 were grouped on the basis of radiographic assessment of type of recurrence: PA, 76 (67%) patients; SF, 25 (22%) patients; LLN, 13 (11%) patients. Demographic, clinical, and pathological features were compared between the three groups, as were disease-free survival (DFS) and overall survival (OS). RESULTS: Recurrence type was associated with positive circumferential margin in the primary resection (PA, 4 [6%]; SF, 4 [19%]; LLN, 3 [25%]; P = 0.027), prior neoadjuvant therapy for the primary tumor (PA, 57 [75%]; SF, 18 [72%]; LLN, 4 [31%]; P = 0.007), and location of the primary tumor in the upper rectum (PA, 33 [45%]; SF, 5 [23%]; LLN, 1 [8%]; P < 0.001). Patients with PA had longer median DFS (PA, 5.1 years; SF, 1.5 years; LLN, 1.2 years; P = 0.036). There was a non-significant trend toward longer OS and higher rates of R0 resection for PA. CONCLUSION: Type of recurrence after salvage surgery for locally recurrent rectal cancer is associated with longer DFS in patients with PA recurrence.

Patient-Reported Bowel Function in Patients With Rectal Cancer Managed by a Watch-and-Wait Strategy After Neoadjuvant Therapy: A Case-Control Study.

BACKGROUND: A watch-and-wait strategy is a nonoperative alternative to sphincter-preserving surgery for patients with locally advanced rectal cancer who achieve a clinical complete response after neoadjuvant therapy. There are limited data about bowel function for patients undergoing this organ-preservation approach. OBJECTIVE: The purpose of this study was to compare bowel function in patients with rectal cancer managed with a watch-and-wait approach with bowel function in patients who underwent sphincter-preserving surgery (total mesorectal excision). DESIGN: This was a retrospective case-control study using patient-reported outcomes. SETTINGS: The study was conducted at a comprehensive cancer center. PATIENTS: Twenty-one patients underwent a watch-and-wait approach and were matched 1:1 with 21 patients from a pool of 190 patients who underwent sphincter-preserving surgery, based on age, sex, and tumor distance from the anal verge. MAIN OUTCOME MEASURES: Bowel function was measured using the Memorial Sloan Kettering Cancer Center Bowel Function Instrument. RESULTS: Patients in the watch-and-wait arm had better bowel function on the overall scale (median total score, 76 vs 55; p < 0.001) and on all of the subscales, with the greatest difference on the urgency/soilage subscale (median score, 20 vs 12; p < 0.001). LIMITATIONS: The study was limited by its retrospective design, small sample size, and temporal variability between surgery and time of questionnaire completion. CONCLUSIONS: A watch-and-wait strategy correlated with overall better bowel function when compared with sphincter-preserving surgery using a comprehensive validated bowel dysfunction tool. See Video Abstract at http://links.lww.com/DCR/B218. FUNCIÓN EVACUATORIA INFORMADA POR PACIENTES EN CÁNCER RECTAL MANEJADO CON UNA ESTRATEGIA DE OBSERVAR Y ESPERAR DESPUÉS DE LA TERAPIA NEOADYUVANTE: UN ESTUDIO DE CASOS Y CONTROLES: Observar y esperar es una alternativa no operativa a la cirugía de preservación del esfínter para pacientes con cáncer rectal localmente avanzado que logran una respuesta clínica completa después de la terapia neoadyuvante. Hay datos limitados sobre la función evacuatoria en pacientes sometidos a este abordaje para preservación de órganos.Evaluar la función evacuatoria en pacientes con cáncer rectal manejados con observar y esperar comparado a pacientes sometidos a cirugía de preservación de esfínteres (escisión mesorrectal total).Estudio retrospectivo de casos y controles utilizando resultados reportados por pacientes.Centro especializado oncológico.21 pacientes se sometieron a observar y esperar y se compararon con 21 pacientes de un grupo de 190 pacientes que se sometieron a cirugía de preservación de esfínteres controlando por edad, sexo y la distancia del tumor al borde anal.Función evacuatoria utilizando un instrumento de valoración del Centro de Cáncer Memorial Sloan Kettering.Los pacientes de observar y esperar demostraron mejor función evacuatoria en la escala general (puntuación total media, 76 versus 55; p <0,001) y en todas las subescalas, con la mayor diferencia en la subescala de urgencia / ensuciamiento fecal (puntuación media, 20 versus 12; p <0,001).Diseño retrospectivo, numero de muestra pequeño y variabilidad temporal entre la cirugía y el tiempo de finalización del cuestionario.Observar y esperar se correlacionó con mejor función evacuatoria en general en comparación con la cirugía de preservación del esfínter utilizando una herramienta integral validada para la disfunción evacuatoria. Consulte Video Resumen en http://links.lww.com/DCR/B218. (Traducción-Dr. Adrián Ortega).

Assessment of the Value of Comorbidity Indices for Risk Adjustment in Colorectal Surgery Patients.

BACKGROUND AND PURPOSE: Comorbidity indices (CIs) are widely used in retrospective studies. We investigated the value of commonly used CIs in risk adjustment for postoperative complications after colorectal surgery. METHODS: Patients undergoing colectomy without stoma for colonic neoplasia at a single institution from 2009 to 2014 were included. Four CIs were calculated or obtained for each patient, using administrative data: Charlson-Deyo (CCI-D), Charlson-Romano (CCI-R), Elixhauser Comorbidity Score, and American Society of Anesthesiologists classification. Outcomes of interest in the 90-day postoperative period were any surgical complication, surgical site infection (SSI), Clavien-Dindo (CD) grade 3 or higher complication, anastomotic leak or abscess, and nonroutine discharge. Base models were created for each outcome based on significant bivariate associations. Logistic regression models were constructed for each outcome using base models alone, and each index as an additional covariate. Models were also compared using the DeLong and Clarke-Pearson method for receiver operating characteristic (ROC) curves, with the CCI-D as the reference. RESULTS: Overall, 1813 patients were included. Postoperative complications were reported in 756 (42%) patients. Only 9% of patients had a CD grade 3 or higher complication, and 22.8% of patients developed an SSI. Multivariable modeling showed equivalent performance of the base model and the base model augmented by the CIs for all outcomes. The ROC curves for the four indices were also similar. CONCLUSIONS: The inclusion of CIs added little to the base models, and all CIs performed similarly well. Our study suggests that CIs do not adequately risk-adjust for complications after colorectal surgery.

Role of the Interval from Completion of Neoadjuvant Therapy to Surgery in Postoperative Morbidity in Patients with Locally Advanced Rectal Cancer.

BACKGROUND: Increasing the interval from completion of neoadjuvant therapy to surgery beyond 8 weeks is associated with increased response of rectal cancer to neoadjuvant therapy. However, reports are conflicting on whether extending the time to surgery is associated with increased perioperative morbidity. METHODS: Patients who presented with a tumor within 15 cm of the anal verge in 2009-2015 were grouped according to the interval between completion of neoadjuvant therapy and surgery: < 8 weeks, 8-12 weeks, and 12-16 weeks. RESULTS: Among 607 patients, the surgery was performed at < 8 weeks in 317 patients, 8-12 weeks in 229 patients, and 12-16 weeks in 61 patients. Patients who underwent surgery at 8-12 weeks and patients who underwent surgery at < 8 weeks had comparable rates of complications (37% and 44%, respectively). Univariable analysis identified male sex, earlier date of diagnosis, tumor location within 5 cm of the anal verge, open operative approach, abdominoperineal resection, and use of neoadjuvant chemoradiotherapy alone to be associated with higher rates of complications. In multivariable analysis, male sex, tumor location within 5 cm of the anal verge, open operative approach, and neoadjuvant chemoradiotherapy administered alone were independently associated with the presence of a complication. The interval between neoadjuvant therapy and surgery was not an independent predictor of postoperative complications. CONCLUSIONS: Delaying surgery beyond 8 weeks from completion of neoadjuvant therapy does not appear to increase surgical morbidity in rectal cancer patients.

Use of the Xi robotic platform for total abdominal colectomy: a step forward in minimally invasive colorectal surgery.

BACKGROUND: The use of the da Vinci robotic platform for total colectomy has been limited by the need to reposition the patient-side surgical cart from one side of the patient to the other, which increases operative time. In this study, we examined the feasibility of robotic total colectomy using the da Vinci Xi model, which offers a rotating boom-mounted system and laser-targeted trocar positioning. METHODS: The study cohort consisted of 23 patients who underwent minimally invasive total colectomy for cancer or polyposis syndromes at a comprehensive cancer center between 2015 and 2017. Of the 23 colectomies, 15 were robotic and eight were laparoscopic. For the robotic colectomies, trocars were placed in the supraumbilical region and all four quadrants. The da Vinci Xi robot was placed between the patient's legs, and the boom was rotated from left to right and then to the middle in order to work sequentially on the right colon, the left colon, and the pelvis. Operating time and short-term outcomes were compared between the patients who underwent robotic surgery and the patients who underwent laparoscopic surgery. RESULTS: The two groups of patients were comparable in age, gender, BMI, physical status, and disease types. In the robotic group, median length of stay (4 vs. 6 days, p = 0.047) was significantly shorter and median operative time (243 vs. 263 min, p = 0.97) and median estimated blood loss (50 vs. 100 ml; p = 0.08) were similar between the groups. CONCLUSIONS: With the da Vinci Xi boom-mounted system, total abdominal colectomy can be performed without the need to move the patient-side surgical cart and is associated with shorter length of stay and similar operative time compared to the laparoscopic approach.

A perioperative multidisciplinary care bundle reduces surgical site infections in patients undergoing synchronous colorectal and liver resection.

BACKGROUND: Surgical site infections (SSIs) are a major cause of morbidity, mortality, and healthcare costs, and patients undergoing simultaneous colorectal/liver resections are at an especially high SSI risk. METHODS: Data were collected on all patients undergoing synchronous colorectal/liver resection from 2011 to 2016 (n = 424). The intervention, implemented in 2013, included 13 multidisciplinary perioperative components. The primary endpoints were superficial/deep and organ space SSIs. Secondary endpoints were hospital length of stay (LOS) and 30-day readmission rate. To control for changes in SSI rates independent of the intervention, interrupted time series analysis was conducted. RESULTS: Overall, superficial/deep, and organ space SSIs decreased by 60.5% (p < 0.001), 80.6% (p < 0.001), and 47.6% (p = 0.008), respectively. In the pre-intervention cohort (n = 231), there were 79 (34.2%), 31 (13.4%), and 48 (20.8%) total, superficial/deep, and organs space SSIs, respectively. In the post-intervention cohort (n = 193), there were 26 (13.5%), 5 (2.6%), and 21 (10.9%) total, superficial/deep, and organs space SSIs, respectively. Median LOS decreased from 9 to 8 days (p < 0.001). Readmission rates did not change (p = 0.6). Interrupted time series analysis found no significant trends in SSI rate within the pre-intervention (p = 0.35) and post-intervention (p = 0.55) periods. CONCLUSION: In combined colorectal/liver resection patients, implementation of a multidisciplinary care bundle was associated with a 61% reduction in SSIs, with the greatest impact on superficial/deep SSI, and modest reduction in LOS. The absence of trends within each time period indicated that the intervention was likely responsible for SSI reduction. Future efforts should target further reduction in organ space SSI.

Rectal Gastrointestinal Stromal Tumor (GIST) in the Era of Imatinib: Organ Preservation and Improved Oncologic Outcome.

BACKGROUND: Approximately 5% of gastrointestinal stromal tumors (GISTs) originate in the rectum, and historically, radical resection was commonly performed. Little is known about the outcome for rectal GIST in the era of imatinib. METHODS: Using a prospectively maintained database, this study retrospectively analyzed 47 localized primary rectal GISTs treated at our center from 1982 to 2016, stratified by when imatinib became available in 2000. Overall survival (OS), disease-specific survival (DSS), and recurrence-free survival (RFS) were analyzed by the Kaplan-Meier method. RESULTS: Rectal GISTs represented 7.1% of 663 primary GISTs. The findings showed 17 patients in the pre-imatinib era and 30 patients in the imatinib era. The two groups had similar follow-up evaluation, age, gender, Miettinen risk, and distance to the anal verge. In the imatinib era, tumors were smaller at diagnosis (median 4 vs. 5 cm; p = 0.029), and 24 of the 30 patients received perioperative imatinib. In the high-risk patients, organ preservation and negative margins were more common among the 13 patients treated with neoadjuvant imatinib than among the 21 patients treated directly with surgery. High-risk patients who received perioperative imatinib (n = 15) had greater (or nearly significantly greater) 5-year OS, DSS, local RFS, and distant RFS than those who did not (n = 19) (91, 100, 100, and 71% vs. 47, 65, 74, and 41%; p = 0.049, 0.052, 0.077, 0.051, respectively). In the imatinib era, no patient has had a local recurrence or death due to GIST. CONCLUSIONS: The use of imatinib is associated with organ preservation and improved oncologic outcome for patients with rectal GIST.

Developing a robotic colorectal cancer surgery program: understanding institutional and individual learning curves.

IMPORTANCE: Robotic colorectal resection continues to gain in popularity. However, limited data are available regarding how surgeons gain competency and institutions develop programs. OBJECTIVE: To determine the number of cases required for establishing a robotic colorectal cancer surgery program. DESIGN: Retrospective review. SETTING: Cancer center. PATIENTS: We reviewed 418 robotic-assisted resections for colorectal adenocarcinoma from January 1, 2009, to December 31, 2014, by surgeons at a single institution. The individual surgeon's and institutional learning curve were examined. The earliest adopter, Surgeon 1, had the highest volume. Surgeons 2-4 were later adopters. Surgeon 5 joined the group with robotic experience. INTERVENTIONS: A cumulative summation technique (CUSUM) was used to construct learning curves and define the number of cases required for the initial learning phase. Perioperative variables were analyzed across learning phases. MAIN OUTCOME MEASURE: Case numbers for each stage of the learning curve. RESULTS: The earliest adopter, Surgeon 1, performed 203 cases. CUSUM analysis of surgeons' experience defined three learning phases, the first requiring 74 cases. Later adopters required 23-30 cases for their initial learning phase. For Surgeon 1, operative time decreased from 250 to 213.6 min from phase 1-3 (P = 0.008), with no significant changes in intraoperative complication or leak rate. For Surgeons 2-4, operative time decreased from 418 to 361.9 min across the two phases (P = 0.004). Their intraoperative complication rate decreased from 7.8 to 0 % (P = 0.03); the leak rate was not significantly different (9.1 vs. 1.5 %, P = 0.07), though it may be underpowered given the small number of events. CONCLUSIONS: Our data suggest that establishing a robotic colorectal cancer surgery program requires approximately 75 cases. Once a program is well established, the learning curve is shorter and surgeons require fewer cases (25-30) to reach proficiency. These data suggest that the institutional learning curve extends beyond a single surgeon's learning experience.

Educational and Psychosocial Support Needs in Lynch Syndrome: Implementation and Assessment of an Educational Workshop and Support Group.

Few reports of educational and counseling support resources exist for Lynch syndrome (LS), a disorder requiring multi-organ cancer screening and specialized medical care throughout adult life. Here we describe the development and efficacy of two resources designed to address this need, the Memorial Sloan Kettering Cancer Center Clinical Genetics Service annual Lynch Syndrome Educational Workshop (LSEW), and a quarterly Lynch Syndrome Patient Advocacy Network (LSPAN) support group. The LSEW and LSPAN were implemented beginning in 2012. Participant survey data evaluating satisfaction, clarity, and unmet needs for each event were retrospectively analyzed and summarized using descriptive statistics. Annual LSEW attendance ranged from 53 to 75 total participants. LSEW year 1 participants indicated a need for a support group, and preferred in-person meetings at a frequency of every 3-6 months. For LSEW year 2-5 participants, >96 % reported satisfaction with the LSEW, and >82 % expressed interest in secure online support. Common themes for improvement included increased time for question and answer sessions and additional introductory genetics education. Responding LSPAN participants (n = 57 total survey responses in 11 meetings) found the meetings helpful (100 %), information clear (91 %), and presence of a genetic counselor useful (67 %). Desired discussion topics included coping with stress and anxiety, development of a support network, family communication about LS, genetic testing decisions, and bereavement. Following genetic counseling, a need exists for ongoing educational and emotional support in LS. Implementation of resources such as the LSEW and LSPAN is feasible and perceived as helpful by participants.

Lymph Node Metastasis Predicts Disease Recurrence in a Single-Center Experience of 70 Stages 1-3 Appendix Cancers: A Retrospective Review.

BACKGROUND: Previous reports on the surgical management of appendix cancer show high recurrence rates among patients initially presenting with localized disease. This study sought to characterize predictors of outcome among patients treated for stages 1-3 appendix cancer at the authors' institution. METHODS: Patients with nonmetastatic appendix cancer undergoing definitive surgery at a single cancer center from 1994 to 2013 were retrospectively reviewed. Patients with appendiceal adenomas, cystadenomas, or classical carcinoids were excluded from the study. The median follow-up period was 5.2 years (interquartile range 2.9-6.7 years). RESULTS: The study identified 70 patients, 49 % of whom were women. The median age was 52 years (range 20-84 years). All were explored by an expert surgeon who had treated at least 20 appendiceal cancers. The procedures were appendectomy (n = 2), right hemicolectomy (n = 66), and diagnostic laparoscopy and placement of an intraperitoneal port (n = 2). The final pathology showed that transmural (30 T4, 32 T3, 4 T2, 4 T1) and node-negative disease (80 %) were common. Goblet cell carcinoid (GCC) features were identified in 54 % of the tumors. These were smaller and more likely to present as acute appendicitis than appendiceal adenocarcinoma (AA), but were otherwise similar in clinical presentation and outcome. The presence of lymph node (LN) metastasis was associated with a higher risk of recurrence than of stage 2 appendix cancer (78 vs. 4 % at 5 years; p < 0.0001). A total of 12 patients experienced recurrence (5 GCC, 7 AA): 9 in the peritoneum, 2 in mesenteric LNs, and 1 in the surgical incision. CONCLUSION: Stages 1-3 invasive AA and GCC behave similarly in terms of clinical presentation and outcome. Perforated appendix and T4 tumor stage were common but not associated with recurrence. Although uncommon, LN metastasis strongly predicted recurrence.

Organ Preservation in Rectal Adenocarcinoma: a phase II randomized controlled trial evaluating 3-year disease-free survival in patients with locally advanced rectal cancer treated with chemoradiation plus induction or consolidation chemotherapy, and total mesorectal excision or nonoperative management.

BACKGROUND: Treatment of patients with non-metastatic, locally advanced rectal cancer (LARC) includes pre-operative chemoradiation, total mesorectal excision (TME) and post-operative adjuvant chemotherapy. This trimodality treatment provides local tumor control in most patients; but almost one-third ultimately die from distant metastasis. Most survivors experience significant impairment in quality of life (QoL), due primarily to removal of the rectum. A current challenge lies in identifying patients who could safely undergo rectal preservation without sacrificing survival benefit and QoL. METHODS/DESIGN: This multi-institutional, phase II study investigates the efficacy of total neoadjuvant therapy (TNT) and selective non-operative management (NOM) in LARC. Patients with MRI-staged Stage II or III rectal cancer amenable to TME will be randomized to receive FOLFOX/CAPEOX: a) before induction neoadjuvant chemotherapy (INCT); or b) after consolidation neoadjuvant chemotherapy (CNCT), with 5-FU or capecitabine-based chemoradiation. Patients in both arms will be re-staged after completing all neoadjuvant therapy. Those with residual tumor at the primary site will undergo TME. Patients with clinical complete response (cCR) will receive non-operative management (NOM). NOM patients will be followed every 3 months for 2 years, and every 6 months thereafter. TME patients will be followed according to NCCN guidelines. All will be followed for at least 5 years from the date of surgery or--in patients treated with NOM--the last day of treatment. DISCUSSION: The studies published thus far on the safety of NOM in LARC have compared survival between select groups of patients with a cCR after NOM, to patients with a pathologic complete response (pCR) after TME. The current study compares 3-year disease-free survival (DFS) in an entire population of patients with LARC, including those with cCR and those with pCR. We will compare the two arms of the study with respect to organ preservation at 3 years, treatment compliance, adverse events and surgical complications. We will measure QoL in both groups. We will analyze molecular indications that may lead to more individually tailored treatments in the future. This will be the first NOM trial utilizing a regression schema for response assessment in a prospective fashion. TRIAL REGISTRATION: NCT02008656.

Does endoscopic ultrasound improve detection of locally recurrent anal squamous-cell cancer?

BACKGROUND: Evaluating patients for recurrent anal cancer after primary treatment can be difficult owing to distorted anatomy and scarring. Many institutions incorporate endoscopic ultrasound to improve detection, but the effectiveness is unknown. OBJECTIVE: The aim of this study is to compare the effectiveness of digital rectal examination and endoscopic ultrasound in detecting locally recurrent disease during routine follow-up of patients with anal cancer. DESIGN: This study is a retrospective, single-institution review. SETTINGS: This study was conducted at an oncologic tertiary referral center. PATIENTS: Included were 175 patients with nonmetastatic anal squamous-cell cancer, without persistent disease after primary chemoradiotherapy, who had at least 1 posttreatment ultrasound and examination by a colorectal surgeon. MAIN OUTCOME MEASURES: The primary outcomes measured were the first modality to detect local recurrence, concordance, crude cancer detection rate, sensitivity, specificity, and predictive value. RESULTS: Eight hundred fifty-five endoscopic ultrasounds and 873 digital rectal examinations were performed during 35 months median follow-up. Overall, ultrasound detected 7 (0.8%) mesorectal and 32 (3.7%) anal canal abnormalities; digital examination detected 69 (7.9%) anal canal abnormalities. Locally recurrent disease was found on biopsy in 8 patients, all detected first or only with digital examination. Four patients did not have an ultrasound at the time of diagnosis of recurrence. The concordance of ultrasound and digital examination in detecting recurrent disease was fair at 0.37 (SE, 0.08; 95% CI, 0.21-0.54), and there was no difference in crude cancer detection rate, sensitivity, specificity, and negative or positive predictive values. LIMITATIONS: The heterogeneity of follow-up timing and examinations is not standardized in this study but is reflective of general practice. CONCLUSIONS: Endoscopic ultrasound did not provide any advantage over digital rectal examination in identifying locally recurrent anal cancer, and should not be recommended for routine surveillance.