Impacto pronóstico del diámetro tumoral en pacientes con cáncer renal estadío pT3a

espanolOBJETIVO: Determinar el impacto pronostico que tiene el tamano tumoral en pacientes con cancer renal estadio patologico pT3a. METODOS: Estudio retrospectivo, descriptivo donde se evaluaron 261 pacientes con diagnostico de cancer renal estadio patologico pT1-3aN0M0 entre 1995 y 2013. En cada grupo se evaluaron caracteristicas clinicas y patologicas. Para determinar el punto de corte optimo del tamano tumoral en relacion a la muerte por cancer se utilizo una curva ROC. La supervivencia libre de metastasis y la supervivencia cancer especifico, fueron evaluados por el metodo de Kaplan Meier y las diferencias entre los grupos fueron evaluadas por el Log Rank test. El analisis multivariado de regresion de Cox fue utilizado para evaluar la relacion del tamano tumoral en la supervivencia de estos pacientes. RESULTADOS: Se estudiaron 261 pacientes de los cuales 166 (63,6%) son estadio pT1a-b, 49 (18,8%) pT2 y 46 (17,6%) pT3a. Los pacientes con tumores pT3a presentaron mayor proporcion de tumores sintomaticos (56,5% vs 33,6%; p 0,003), diametro tumoral (7,1 cm vs 5,5 cm; p 0,0007), grado de Fuhrman 3-4 (52,2% vs 19,1%; p 0,0001), necrosis coagulativa (62,8% vs 28,8%; p 0,0001), metastasis a distancia (39,1% vs 14,9%; p 0,0001) y muerte por cancer (23,9% vs 8,9%; p 0,003) al ser comparados con tumores localizados (pT1-2). Por medio de una curva ROC evidenciamos que un punto de corte de 7cm es el tamano tumoral ideal para determinar mortalidad por cancer renal. La supervivencia libre de metastasis a los 5 anos fue 90% para tumores pT1a-b, 71% para pT2, 83% para pT3a 7cm, con diferencias estadisticamente significativas (Log rank test 7cm como el unico factor predictivo independiente de muerte por cancer renal. CONCLUSIONES: Aunque la invasion de la grasa perirrenal y la invasion de la vena renal (estadio pT3a) son factores pronosticos aceptados, discriminar esta categoria segun el tamano tumoral podria mejorar su calidad predictiva. Nuestros datos demuestran que el diametro tumoral (7cm) deberia ser aplicado a tumores pT3a con el fin de mejorar la exactitud del sistema TNM. EnglishOBJECTIVE: To determine the prognostic impact that tumor size has in patients with pathological renal cancer stage pT3a. METHODS: Retrospective, descriptive study evaluating 261 patients diagnosed with renal cancer pathological stage pT1-3aN0M0 between 1995 and 2013. Clinical and pathological characteristics were evaluated in each group. A ROC curve was used to determine the optimum cutting point of tumor size in relation to the death by cancer. Metastasis-free survival and cancer specific survival were evaluated by the Kaplan Meier method and the differences between the groups were evaluated by the Log Rank test. Multivariate Cox regression analysis was used to evaluate the relationship of tumor size and survival of these patients. RESULTS: 261 patients were studied, 166 of which (63.6%) were Stage pT1a-b, 49 (18.8%) pT2 and 46 (17.6%) pT3a. Patients with pT3a tumors had higher proportion of symptomatic tumors (56.5% vs 33.6%; p 0.003), tumor size (7.1 cm vs 5.5 cm; 0.0007), Fuhrman grade 3-4 (52.2% vs 19.1%; p 0.0001), coagulative necrosis (62.8% vs 28.8%; p 0,0001), distance metastasis (39.1% vs 14.9%; p 0.0001) and death by cancer (23.9% vs 8.9%; p 0.003) when compared with localized tumors (pT1-2). The ROC curve demonstrated that a cut-off point of 7cm is the ideal tumor size to determine renal cancer mortality. Metastasis-free survival at 5 year was 90% for tumors pT1a-b, 71% for pT2, 83% for pT3a 7cm, with significant statistical differences (Log-rank test 7cm stage was an independent predictor of death by renal cancer. CONCLUSIONS: Although perirenal fat invasion and renal vein invasion (pT3a stage) are accepted as prognostic factors, to differentiate this category by tumor size could improve its predictive quality. The tumor diameter (7cm) should be applied to pT3a tumors in order to improve the accuracy of TNM system.