Revista Brasileira de Coloproctologia
versão impressa ISSN 0101-9880
PRIOLLI, Denise Gonçalves et al. Metastatic lymph node ratio as an independent prognostic variable in colorectal cancer. Rev bras. colo-proctol. [online]. 2008, vol.28, n.4, pp. 431-442. ISSN 0101-9880. http://dx.doi.org/10.1590/S0101-98802008000400005.
In patients with colorectal cancer, the compromising of the lymph node is one of the most important prognostic factors. Aim: The aim of this study is to determine the prognostic independent value of relation between compromised and examined lymph nodes, (LNR) in patients with colorectal cancer. METHOD: One hundred and thirteen 113 patients (62 women) with colon ad upper rectum cancer were studied. Fifteen patients were staged to the stadium I of the TNM classification, 44 to II, 42 to III and 24 to the stadium IV. The lymph node ratio rate was determined by the relation between total number of compromised and examined lymph nodes. The patients were divided in three groups according to the proportion of compromised lymph nodes: LNR-0: when there was no lymph node involvement; LNR-1: when there was compromising of up to 20% of the examined lymph nodes and LNR-2: when there was compromising in 21% or more of the examined nodes. The relations between lymph node ratio, number of removed lymph nodes and number of compromising lymph nodes by cancer were determined. Patients younger than 18 years old who were submitted to neoadjuvant quimioradiation protocol were excluded as well as the ones who had less than 12 lymph nodes removed. The clinical and histopathological variables were analyzed through descriptive statistic. The correlation between the variables was valued by Spearman correlation test. The five years survival was determined by the tests of Kaplan-Meier, Log-rank and the multivariate analysis of the prognostic variables by the Cox model establishing level of significance of 5 % (p=0.05). RESULTS: There was significant difference in the five years overall survival in patients classified in the different groups of LNR (p=0.009). Patients of the group LNR-0 presented five years overall survival bigger than 80%, while in those classified to the groups LNR-1 and LNR-2, the five years overall survival was less than 60% and 40%, respectively. The number of compromising lymph nodes alone was correlated to the five years overall survival (p=0.03). The multivariate analysis demonstrated that the LNR is an independent prognosis variable of the five years overall survival (p=0.009). There was relation between the total number of compromised lymph nodes and the LNR (p=0.00001, with rs=0.977). CONCLUSION: The results of the present study showed that the LNR can be considered an independent prognostic variable of overall survival in patients with colorectal cancer.
Palavras-chave : Lymph Nodes; Lymph Node Excision; Prognosis; Colorectal Neoplasms; Survival Analysis; Survival Rate.