Radiologic Factors and Areas of Local Recurrence in Locally Advanced Lower Rectal Cancer After Lateral Pelvic Lymph Node Dissection.

BACKGROUND Identifying preoperative risk factors of local recurrence and patterns of treatment failure resulting after rectal cancer management is important for planning treatment strategies and improving the results of multidisciplinary care. OBJECTIVE The purpose of this study was to analyze the associations between the preoperative factors and local recurrence and to investigate the local recurrence areas in patients with locally advanced lower rectal cancer who underwent lateral pelvic lymph node dissection. DESIGN The study used a retrospective cohort design. SETTINGS It was conducted at a single institution. PATIENTS Overall 469 patients with locally advanced lower rectal adenocarcinoma located below the peritoneal reflex who received curative resection with lateral pelvic lymph node dissection during 2010 to 2018 were included. MAIN OUTCOME MEASURES Independent risk factors for local recurrence were assessed using multivariate Cox regression. Local recurrence was classified into 3 areas using follow-up images. RESULTS A total of 286 patients underwent upfront surgery, 132 patients received neoadjuvant chemotherapy followed by surgery, and 51 patients received preoperative chemoradiotherapy followed by surgery. Eighty-six patients (18.3%) were extramural venous invasion positive, and 113 patients (24.1%) were circumferential resection margin positive. The median follow-up period was 46 months. Local recurrence showed significant association with extramural venous invasion positive (HR = 2.596 (95% CI, 1.321-5.102); p = 0.006) or circumferential resection margin positive (HR = 2.298 (95% CI, 1.158-4.560); p = 0.017). The incidence of local recurrence was observed in 51 patients (10.8%), with the pelvic plexus and internal iliac area being the most frequent (6.6%), followed by the central pelvis area (3.8%), and was markedly low in the obturator area (0.4%). LIMITATIONS This was a retrospective, single-institution design. CONCLUSIONS Extramural venous invasion status and circumferential resection margin status were associated with a high local recurrence rate in patients who underwent lateral pelvic lymph node dissection. In addition, local recurrence in the obturator area was low compared with that in other areas. See Video Abstract at http://links.lww.com/DCR/B683. FACTORES RADIOLGICOS Y REAS DE RECURRENCIA LOCAL EN EL CNCER DE RECTO INFERIOR LOCALMENTE AVANZADO DESPUS DE LA DISECCIN GANGLIONAR PLVICA LATERAL ANTECEDENTES:El identificar los factores de riesgo preoperatorios para recurrencia local y los patrones de fracaso del tratamiento que resultan del manejo del cancer de recto es importante para planificar las estrategias de tratamiento y mejorar los resultados de la atencion multidisciplinaria.OBJETIVO:Analizar las asociaciones entre los factores preoperatorios y la recidiva local, e investigar las areas de recidiva local en pacientes con cancer de recto inferior localmente avanzado que se sometieron a diseccion de ganglios linfaticos pelvicos laterales.DISENO:Un diseno de cohorte retrospectivo.ENTORNO CLINICO:Una sola institucion.PACIENTES:Un total de 469 pacientes con adenocarcinoma rectal inferior localmente avanzado ubicado debajo del reflejo peritoneal que recibieron reseccion curativa con diseccion de ganglios linfaticos pelvicos laterales durante 2010-2018.PRINCIPALES MEDIDAS DE RESULTADO:Los factores de riesgo independientes de recurrencia local se evaluaron mediante regresion de Cox multivariante. La recurrencia local se clasifico en 3 areas utilizando imagenes de seguimiento.RESULTADOS:Doscientos ochenta y seis pacientes se sometieron a cirugia inicial, 132 pacientes recibieron quimioterapia neoadyuvante seguida de cirugia y 51 pacientes recibieron quimiorradioterapia preoperatoria seguida de cirugia. Ochenta y seis pacientes (18,3%) fueron positivos para invasion venosa extramural y 113 pacientes (24,1%) fueron positivos para el margen de reseccion circunferencial. La mediana del periodo de seguimiento fue de 46 meses. La recidiva local mostro una asociacion significativa con la invasion venosa extramural positiva (cociente de riesgo: 2,596; intervalo de confianza del 95%: 1,321-5,102; p = 0,006) o el margen de reseccion circunferencial positivo (cociente de riesgo: 2,298; intervalo de confianza del 95%: 1,158-4,560; p = 0,017). La incidencia de recidiva local se observo en 51 pacientes (10,8%), siendo el plexo pelvico y el area iliaca interna los mas frecuentes (6,6%), seguidos del area pelvica central (3,8%), y fue marcadamente baja en el area del obtudador (0.4%).LIMITACIONES:Un diseno retrospectivo de una sola institucion.CONCLUSIONES:El estado de invasion venosa extramural o el estado del margen de reseccion circunferencial se asociaron con una alta tasa de recurrencia local en pacientes que se sometieron a diseccion de ganglios linfaticos pelvicos laterales. Ademas, la recurrencia local en el area del obturador fue baja en comparacion con la de otras areas. Consulte Video Resumen en http://links.lww.com/DCR/B683.