Terapia neoadjuvante e cirurgia para câncer do reto. Estudo comparativo entre resposta patológica parcial e completa

Background - The approach of locally advanced extra-peritoneal rectal adenocarcinoma implies a treatment with neoadjuvant chemoradiotherapy associated with total mesorectal excision surgery. However, the tumors respond variably to this neoadjuvant therapy, and the mechanisms for response are not completely understood. Objective - Evaluate the variables related to the complete tumor response and the outcomes of patients who underwent surgery, comparing those with partial tumor regression and those with total remission of rectal lesion, at the pathological examination. Methods - Retrospective analysis of medical records of 212 patients operated between 2000 and 2010, in which 182 (85.9%) obtained partial remission at neoadjuvant therapy (Group 1) and 30 (14.1%), total remission (Group 2). Results - No difference was found between the groups in relation to gender, ethnicity, age, tumor distance from the anal verge, occurrence of metastases and synchronous lesions on preoperative staging, dose of radiotherapy and performed surgery. In Group 2, was verified high rate of complete remission when the time to surgery after neoadjuvant therapy was equal or less than 8 weeks (P=0.027), and a tendency of lower levels of pretreatment carcinoembryonic antigen (P=0.067). In pathological analysis, the Group 1 presented in relation to Group 2, more affected lymph nodes (average 1.9 and 0.5 respectively; P=0.003), more angiolymphatic (19.2% and 3.3%; P=0.032) and perineural involvement (15.4% and 0%; P=0.017) and greater number of lymph nodes examined (16.3 and 13.6; P=0.023). In the late follow-up, Group 1 also had lower overall survival than Group 2 (94.1 months and 136.4 months respectively; P=0.02) and disease-free survival (85.5 months and 134.6 months; P=0.004). There was no statistical difference between Group 2 and Group 1 in local recurrence (15% and 3.4%, respectively) and distant metastasis (28% and 13.8%, respectively). Conclusion - In this study, the only factor associated with complete remission of rectal adenocarcinoma was the time between neoadjuvant therapy and surgery. This group of patients had less affected lymph nodes, less angiolymphatic and perineural involvement, a longer overall and disease-free survival, but no significant statistical difference was observed in local recurrence and distant metastasis. Although the complete pathologic remission was associated with better prognosis, this not implied in the cure of the disease for all patients. © 2016, IBEPEGE - Inst. Bras. Estudos Pesquisas Gastroent. All rights reserved.The approach of locally advanced extra-peritoneal rectal adenocarcinoma implies a treatment with neoadjuvant chemoradiotherapy associated with total mesorectal excision surgery. However, the tumors respond variably to this neoadjuvant therapy, and the mechanisms for response are not completely understood. Objective - Evaluate the variables related to the complete tumor response and the outcomes of patients who underwent surgery, comparing those with partial tumor regression and those with total remission of rectal lesion, at the pathological examination. Methods - Retrospective analysis of medical records of 212 patients operated between 2000 and 2010, in which 182 (85.9%) obtained partial remission at neoadjuvant therapy (Group 1) and 30 (14.1%), total remission (Group 2). Results - No difference was found between the groups in relation to gender, ethnicity, age, tumor distance from the anal verge, occurrence of metastases and synchronous lesions on preoperative staging, dose of radiotherapy and performed surgery. In Group 2, was verified high rate of complete remission when the time to surgery after neoadjuvant therapy was equal or less than 8 weeks (P=0.027), and a tendency of lower levels of pretreatment carcinoembryonic antigen (P=0.067). In pathological analysis, the Group 1 presented in relation to Group 2, more affected lymph nodes (average 1.9 and 0.5 respectively; P=0.003), more angiolymphatic (19.2% and 3.3%; P=0.032) and perineural involvement (15.4% and 0%; P=0.017) and greater number of lymph nodes examined (16.3 and 13.6; P=0.023). In the late follow-up, Group 1 also had lower overall survival than Group 2 (94.1 months and 136.4 months respectively; P=0.02) and disease-free survival (85.5 months and 134.6 months; P=0.004). There was no statistical difference between Group 2 and Group 1 in local recurrence (15% and 3.4%, respectively) and distant metastasis (28% and 13.8%, respectively). Conclusion - In this study, the only factor associated with complete remission of rectal adenocarcinoma was the time between neoadjuvant therapy and surgery. This group of patients had less affected lymph nodes, less angiolymphatic and perineural involvement, a longer overall and disease-free survival, but no significant statistical difference was observed in local recurrence and distant metastasis. Although the complete pathologic remission was associated with better prognosis, this not implied in the cure of the disease for all patients533163168A abordagem do câncer retal extra-peritoneal localmente avançado implica em um tratamento com quimio e radioterapia neoadjuvante associada com a cirurgia de excisão total do mesorreto. Entretanto, os tumores respondem de maneiras variadas a esta terapia neoadjuvante, não se conhecendo completamente os mecanismos envolvidos nesta resposta. Objetivo - Avaliar os fatores relacionados à resposta tumoral completa e o seguimento de pacientes operados, comparando o grupo com regressão parcial com aqueles em que se evidenciou remissão total da lesão no reto, pelo estudo anatomopatológico. Métodos - Análise retrospectiva de prontuários médicos de 212 pacientes operados entre 2000 e 2010, sendo que 182 (85,9%) apresentaram remissão parcial a neoadjuvância (Grupo 1) e 30 (14,1%), remissão total (Grupo 2). Resultados - Não foi encontrada diferença entre os grupos em relação a gênero, etnia, idade, distância do tumor a margem anal, ocorrência de metástases e lesões sincrônicas no estadiamento pré-operatório, dose de radioterapia e tipo de cirurgia realizada. No Grupo 2, foi verificada alta taxa de remissão completa quando o paciente foi operado com intervalo menor ou igual a 8 semanas após a terapia neoadjuvante (P=0,027), e uma tendência a menor valor de antígeno carcinoembrionário pré-tratamento (P=0,067). Na análise patológica, o Grupo 1 apresentou em relação ao Grupo 2, mais linfonodos acometidos (média de 1,9 e 0,5 respectivamente; P=0,003), mais invasão angiolinfática (19,2% e 3,3%; P=0,032) e perineural (15,4% e 0%; P=0,017), e maior número de linfonodos examinados (16,3 e 13,6; P=0,023). No seguimento tardio, o Grupo 1 também apresentou menor sobrevida global do que o Grupo 2 (94,1 e 136,4 meses, respectivamente; P=0,02) e sobrevida livre de doença (85,5 e 134,6 meses; P=0,004). Não houve diferença estatística entre os Grupo 1 e Grupo 2 na ocorrência de recidiva local (3,4% e 15%, respectivamente; P=0,32) e metástases à distância (13,8 e 28%; P=0,26). Conclusão - Neste estudo, o único fator que foi associado à remissão completa do adenocarcimona retal, foi o tempo entre neoadjuvância e a cirurgia. Este grupo de pacientes apresentou menos linfonodos acometidos, menor invasão angiolinfática e perineural, maior sobrevida global e livre de doença, porém não apresentou diferença estatística significativa com relação à recorrência local e metástases à distância. Embora a remissão completa fosse associada com melhor prognóstico, não implicou na cura da doença em todos os paciente