Prognostic impact of the lymph node metastatic ratio on 5-year survival of patients with rectal cancer not submitted to preoperative chemoradiation

Lymph node metastases are a major prognostic factor in colorectal cancer. Inadequate lymph node resection is related to shorter survival. The lymph nodes ratio (LNR) has been used as a prognostic factor in patients with colon cancer. Few studies have evaluated the impact of LNR on the 5-year survival of patients with rectal cancer. OBJECTIVE: To evaluate the impact of LNR on the survival of patients with rectal cancer not submitted to preoperative chemoradiotherapy. METHODS: Ninety patients with rectal cancer excluding colon tumors, synchronous tumors, hereditary colorectal cancer and those undergoing preoperative chemoradiation. The patients were divided into three groups according t < 0.05). RESULTS: The 5-year survival was related to the Dukes classification, TNM, number of metastatic lymph nodes and LNR. A difference was observed in 5-year survival between the different classes of LNR. Patients classified as LNR-0 had a survival rate of 85%, while classes LNR-1 and LNR-2, 73 and 19%, respectively (p=0.0001). CONCLUSIONS: The results showed that the LNR has an impact on 5-year survival of patients with rectal cancer not submitted to neoadjuvant therapy.Metástases linfonodais representam um dos principais fatores prognósticos no câncer colorretal. A ressecção linfonodal inadequada relaciona-se à menor sobrevida. A proporção entre linfonodos metastáticos (PLM) vem sendo utilizada como fator prognóstico em doentes com câncer de cólon. Poucos estudos avaliaram o impacto da PLM na sobrevida de doentes com câncer retal. OBJETIVO: Avaliar o impacto da PLM na sobrevida de doentes com câncer de reto não submetidos à quimioradioterapia pré-operatória. MÉTODOS: Foram incluídos 90 doentes com adenocarcinoma retal excluindo-se tumores de cólon, tumores sincrônicos, câncer colorretal hereditário e aqueles submetidos a tratamento radioquimioterápico pré-operatório. Os doentes foram divididos em três grupos segundo a PLM: PLM-0, sem linfonodos comprometidos; PLM-1, 1 a 20% dos linfonodos comprometidos; e PLM-2, mais de 21% dos linfonodos comprometidos. A identificação do ponto de corte da amostra selecionada foi obtida a partir da curva de características de operação do receptor (curva ROC). A sobrevida foi avaliada pelo teste de Kaplan-Meier, a diferença entre os grupos pelo teste de Cox-Mantel e a correlação entre as variáveis pelo teste de Pearson, adotando-se um nível de significância de 5% (p