INTRODUÇÃO: A ressecção hepática é o único tratamento potencialmente curativo para as metástases hepáticas de câncer colorretal (MHCCR), porém com taxas de recidiva entre 60 e 70%. Desta forma, faz-se necessário um melhor entendimento das vias de disseminação e recidiva da doença. Os brotamentos tumorais (BT) e grupamentos pouco diferenciados (GPD), relacionados à transição epitélio-mesenquimal, são fatores prognósticos para o câncer colorretal; entretanto sua presença e importância nas MHCCR ainda não estão estabelecidas. Os objetivos deste trabalho foram avaliar a presença dos BT e GPD nas MHCCR, determinar sua importância prognóstica e sua relação com outros fatores patológicos conhecidos. MÉTODOS: Foram avaliados, retrospectivamente, 229 pacientes submetidos a ressecção de MHCCR com intuito curativo, entre janeiro de 2004 e junho de 2014. Nos espécimes cirúrgicos das MHCCR ressecadas, foi realizada análise anatomopatológica através de lâminas coradas em hematoxilina e eosina (HE), para avaliação dos BT, GPD, infiltrado inflamatório peritumoral, presença de pseudocápsula e tipo de borda; e por imuno-histoquímica, por meio de anticorpos anti-AE1/AE (BT e GPD), anti-D2-40 (invasão linfática) e anti-CD34 (invasão venosa portal). Também foram analisadas as variáveis clínicas relacionadas ao prognóstico. RESULTADOS: O seguimento médio após a hepatectomia foi de 43 meses. As taxas de sobrevida global e livre de doença em 1, 3 e 5 anos foram de, respectivamente, 94,1%, 66,7% e 45,5% e 53,6%, 31,5% e 29,6%. Os BT estiveram presentes em 61,1% dos pacientes na avaliação pelo AE1/AE3 e em 48,9% pelo HE, enquanto os GPD estiveram presentes em 42,8% dos pacientes na avaliação pelo AE1/AE3 e em 49,3% pelo HE. Na análise univariada, os BT e os GPD grau 3 ( > 9 GPD) mostraram significância prognóstica, tanto na avaliação pelo AE1/AE3 quanto pelo HE. Na análise múltipla, os fatores independentes para sobrevida global foram: a presença de GPD grau 3 (pelo HE), presença de pseudocápsula, invasão venosa portal e presença de 4 ou mais nódulos. Os fatores independentes para sobrevida livre de doença foram: GPD grau 3 (pelo HE), quimioterapia prévia, presença de 4 ou mais nódulos, infiltrado inflamatório peritumoral ausente ou leve, invasão venosa portal e borda infiltrativa. Os BT e GPD não estiveram associados à recidiva hepática. Os BT foram associados a: GPD, MHCCR sincrônicas, tumores de até 5 cm, ausência de pseudocápsula, borda infiltrativa, e presença de invasão venosa portal. Os GPD foram associados a: BT, infiltrado inflamatório peritumoral ausente ou leve, ausência de pseudocápsula e borda infiltrativa. CONCLUSÕES: Os BT e os GPD são frequentes nas MHCCR e ambos, na análise univariada, são fatores de pior prognóstico na sobrevida global e livre de doença, estando associados à recidiva extra-hepática. A presença de GPD grau 3 avaliada pelo HE é fator prognóstico independente na sobrevida global e livre de doença, sugerindo que este é um importante mecanismo de disseminação tumoral na MHCCR

INTRODUCTION: The only potentially curative treatment for colorectal liver metastases is surgical resection. However, about 60 to 70% of patients will recur, showing the necessity of a better knowledge regarding spread and disease recurrence pathways. Tumor budding and poorly differentiated clusters, markers related to epithelial-mesenchymal transition, are prognostic factors for colorectal cancer, but their presence and significance in colorectal liver metastases is not yet established. The aims of this study were to evaluate the presence of tumor budding and poorly differentiated clusters in colorectal liver metastases, to determine their prognostic value and to relate them to other known pathological factors. METHODS: A total of 229 patients that underwent hepatic resection for colorectal liver metastases between January 2004 and June 2014 were retrospectively evaluated. Resected specimens of colorectal liver metastases were submitted to pathological evaluation by hematoxilin and eosin staining, to analyze tumor budding, poorly differentiated clusters, peritumoral inflammatory infiltrate, presence of tumor pseudocapsule and tumor growth pattern; and by immunohistochemical staining with antibodies anti- AE1/AE3 (tumor budding and poorly differentiated clusters), anti-D2-40 (lymphatic invasion) and anti-CD-34 (portal vein invasion). Clinical variables related to prognosis were also evaluated. RESULTS: Mean follow up after hepatectomy was 43 months. Overall and disease-free survival rates at 1, 3 and 5 years were 94.1%, 66.7% and 45.5% and 53.6%, 31.5% and 29.6%, respectively. Tumor budding was present in 61.1% of patients in the evaluation by AE1/AE3 staining and in 48.9% by hematoxilin and eosin, while poorly differentiated clusters were present in 42.8% of patients by AE1/AE3 staining and 49.3% by hematoxilin and eosin. At univariate analysis, tumor budding and poorly differentiated clusters grade 3 ( > 9 poorly differentiated clusters) by AE1/AE3 and hematoxilin and eosin staining showed prognostic significance. On multiple analysis, independent factors for overall survival were: presence of poorly differentiated clusters grade 3 (by hematoxilin and eosin), presence of tumor pseudocapsule, portal vein invasion and presence of 4 or more nodules. Independent factors for disease-free survival were: poorly differentiated clusters grade 3 (by hematoxilin and eosin), preoperative chemotherapy, portal vein invasion, presence of 4 or more nodules, none/mild peritumoral inflammatory infiltrate and infiltrative tumor border. Tumor budding and poorly differentiated clusters were not related to hepatic recurrence. Tumor budding was associated with: presence of poorly differentiated clusters, synchronous colorectal liver metastases, tumor size up to 5 cm, absence of tumor pseudocapsule, infiltrative tumor border and presence of portal vein invasion. Poorly differentiated clusters were associated with: presence of tumor budding, none/mild peritumoral inflammatory infiltrate, absence of tumor pseudocapsule and infiltrative tumor border. CONCLUSIONS: Tumor budding and poorly differentiated clusters are frequent in colorectal liver metastases and, on univariate analysis, are prognostic factors for overall and disease-free survival, being associated to extrahepatic recurrence. Presence of poorly differentiated clusters grade 3 stained by hematoxilin and eosin is an independent prognostic factor for overall and disease-free survival, suggesting that it is an important spread pathway in colorectal liver metastases