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 ).

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.